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This special issue marks the 25th anniversary of Aquatic Conservation, and comprises papers written by groups of board members from both marine and freshwater backgrounds on some of the main topics covered by the journal., Over the last 25 years the number of submissions to the journal has grown and the geographical range of submissions has increased, with papers from almost 100 countries. Data for 2015 show that 42% were from Europe, 15% from North America, 15% from Asia, 12% from South and Central America, 9% from Australia and New Zealand, 5% from Africa, and 2% from elsewhere., AQC has published 154 issues, including 15 special issues and 10 supplements, and has grown from four issues and 360 pages per year in 1992 to six issues and 1210 pages in 2016. AQC received its first Impact Factor - 0.534 - in 1998, increasing to 2.415 in 2016., AQC publishes papers on a wide range of subjects, such as the theoretical principles underlying conservation, the status of endangered species and habitats, river basin management and habitat restoration. Areas of recent growth include climate change, the impact of invasive alien species on native species and habitats, ecosystem services and conservation genetics., Submissions to the journal suggest that marine conservation is a more clearly defined area of study than freshwater conservation. Factors that may be responsible include site designations exclusively for marine areas, the formation of groups and societies dedicated to conserving marine habitats and species, and the presence of large 'iconic species' (e.g. whales, sharks, dolphins) that are far more common in marine than freshwater habitats., The aim of this journal is to continue publishing high-quality work from all parts of the world, and to encourage scientists to recognize and promote the application of their research to practical conservation and management., Copyright © 2016 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

According to an International Union for Conservation of Nature (IUCN) Red List assessment (RLA), the American horseshoe crab (Limulus polyphemus), an iconic coastal species, is at risk of extirpation in some regions within its range where small and vulnerable populations occur. However, the RLA does not consider future status beyond viability and does not attempt to identify the conservation necessary to effectively mitigate threats and recover the species to full ecological functionality. To aid in conservation planning for vulnerable species, the IUCN developed the Green Status of Species assessment (GSA) process to complement the RLA.This paper describes the application of the GSA process to assess the recovery potential of the American horseshoe crab. First, specific Limulus populations within spatial units for conservation were delineated, and their statuses were defined based on viability and ecological functionality. Then conservation actions were identified that would promote recovery and affect their near‐ and long‐term population status under different conservation scenarios.Horseshoe crab conservation has relied on, and will continue to depend on, effective harvest regulation. However, as currently conceived, conservation is not expected to mitigate habitat loss at the scale required to restore range‐wide ecological functionality, primarily because habitat loss is widespread and affected by climate change. Thus, the GSA results, while indicating that there is potential for near‐term recovery gains, reveal that long‐term recovery is in doubt owing to expected loss of habitat.To conserve critical habitats for spawning and early life stages and achieve ecological functionality, it is imperative to identify and develop conservation plans at appropriate spatial scales. Unfortunately, such plans do not currently exist and need to be established. The GSA Green Score can then serve as a metric for monitoring recovery and gauging the effectiveness of conservation implementation. [ABSTRACT FROM AUTHOR]

Intraspecific genetic diversity provides the evolutionary potential to adapt to changing environments and 'hotspots' of high intraspecific diversity are recognized as key targets for conservation.In south‐western Australia, intraspecific genetic diversity for mesic taxa is not uniformly distributed. Many species comprise highly divergent lineages with unique haplotypes resulting from contraction to refugia during historical arid cycles. Sampling strategies in studies of the region's unique and ancient freshwater fauna have often focused on broad distributional range, making it difficult to determine boundaries between lineages and the location of genetic hotspots.This study explored the spatial distribution of intraspecific genetic diversity in the threatened freshwater mussel, Westralunio carteri. Mitochondrial DNA sequences for 164 specimens, sampled from all basins within the distribution of the species, were used to describe lineage boundaries and the location of hotspots, and to reconstruct historical demographics.There was strong evidence for three subregions of genetic diversity based on the largely non‐overlapping distributions of three evolutionarily significant units. Spatial and demographic analyses suggest that these evolutionarily significant units persisted through past arid cycles in separate refugia. The majority of haplotypes were unique to a single location, indicating limited connectivity among populations in recent times. Hotspots were identified throughout the region. Most notably, a significant hotspot in the south‐western corner probably arose through the overlap of lineages in historical refugia.Conservation assessments often focus on the species as a whole, even though sublineages, hotspots and the threats faced are not evenly distributed across the species range. This paper highlights that effective conservation of spatially structured taxa requires targeted management of multiple genetic units. Given the importance of formal taxonomic description for conservation listings, further investigation of the potential for species delimitation within W. carteri is required. [ABSTRACT FROM AUTHOR]

The short‐beaked common dolphin is one of the most numerous cetacean species in the North‐East Atlantic and plays a key functional role within the ecosystem as a top predator. However, in 2013, its conservation status for the European Marine Atlantic, under Article 17 of the Habitats Directive, was assessed as 'Unfavourable‐Inadequate'. Of key concern for this species is fishery bycatch, with pollution also being an issue. There are, however, major knowledge gaps concerning the extent of the effects of such pressures on the species.Implementation of national observer bycatch programmes and bycatch mitigation measures under EC Regulation 812/2004 has been important. The responsibility for this is currently being transferred to the EU fisheries Data Collection Framework and Technical Measures Framework, the potential advantages and disadvantages of which are discussed. Collection of data and samples through national stranding schemes in some countries has enabled assessments of life‐history parameters, dietary requirements, and the effects of stressors such as pollutants.Nevertheless, in order to improve the conservation status of the North‐East Atlantic population, a number of key actions are still required. These include the implementation of a species action plan, finalization of a management framework procedure for bycatch, and coordination between member states of monitoring programmes. It is important that there is monitoring of the state of the common dolphin population in the North‐East Atlantic management unit through regular surveys spanning the range of the management unit, as well as continued assessment of the independent and interactive effects of multiple stressors. Above all, conservation status would be improved through application and enforcement of existing legislation in European waters.This paper provides a summary of the current state of our knowledge of common dolphins in the North‐East Atlantic along with recommendations for conservation management that may also be relevant to the species in the Mediterranean Sea. [ABSTRACT FROM AUTHOR]

Oceans and coasts provide a wide array of services to humans, including climate regulation, food security, and livelihoods. Managing them well is vital to human well-being as well as the maintenance of marine biodiversity and ocean-dependent economies., Carbon sequestration and storage is increasingly recognized as a valuable service provided by coastal vegetation. Carbon sequestered and stored by mangrove forests, tidal marshes, and seagrass meadows is known as 'blue' carbon. These habitats capture and store carbon within the plants themselves and in the sediment below them. When the habitats are destroyed, much of their carbon is released back to the atmosphere and ocean contributing to global climate change., Therefore, blue carbon ecosystem protection is becoming a greater priority in marine management and is an area of interest to scientists, policy makers, coastal communities, and the private sector including those that contribute to ecosystem degradation but also those that are looking to reduce their carbon footprint. A range of policy and management responses aim to reduce coastal ecosystem loss, including the establishment of marine protected areas (MPAs)., This paper explores how MPA design, location, and management could be used to protect and increase carbon sequestration and ensure integrity of carbon storage through conservation and restoration activities. While additional research is necessary to validate the proposed recommendations, this paper describes much needed first steps and highlights the potential for blue carbon finance mechanisms to provide sustainable funding for MPAs. [ABSTRACT FROM AUTHOR]

Abstract: Native freshwater fish populations throughout South Africa's Cape Fold Ecoregion (CFE) are in decline as a result of human impacts on aquatic habitats, including the introduction of non‐native freshwater fishes. Climate change may be further accelerating declines of many species, although this has not yet been studied in the CFE. This situation presents a major conservation challenge that requires assigning management priorities through assessing species in terms of their vulnerability to climate change. One factor hindering reliable vulnerability assessments and the concurrent development of effective conservation strategies is limited knowledge of the biology and population status of many species. This paper reports on a study employing a rapid assessment method used in the USA, designed to capitalize on available expert knowledge to supplement existing empirical data, to determine the relative vulnerabilities of different species to climate change and other human impacts. Eight local freshwater fish experts conducted vulnerability assessments on 20 native and 17 non‐native freshwater fish species present in the CFE. Results show (1) that native species were generally classified as being more vulnerable to extinction than were non‐native species, (2) that the climate change impacts are expected to increase the vulnerability of most native, and some non‐native, species, (3) that vulnerability hotspots requiring urgent conservation attention occur in the Olifants‐Doring, upper Berg and upper Breede River catchments in the south west of the region, (4) that in addition to providing guidance for prioritizing management interventions, this study highlights the need for reliable data on the biology and distribution of many CFE freshwater fishes, and (5) that identification of priority areas for protection should be based on multiple sources of data. [ABSTRACT FROM AUTHOR]

On a global scale, most of the coastal zones in the world are undergoing rapid and accelerating changes. This coastal syndrome combines two major trends: one linked to the growth of coastal populations, habitat, transport and industrial infrastructures (assets); the other linked to the influence of climate change and its effects in terms of sea-level rise, increased frequency of extreme weather events, acidification and increase in ocean surface temperature, both affecting the health of coastal ecosystems. This situation is also reflected in the increase in coastal engineering solutions, which have significant impacts on coastal hydrodynamics and natural ecosystems., This extremely dynamic context calls for an evolution in conservation and spatial planning strategies in order to better anticipate changes that may affect not only the sustainability of both the distribution and health of natural ecosystems, but also the relevance of conservation efforts. Marine and coastal protected areas help preserve ecological services, and reduce the risks faced by coastal communities. Therefore, it can be argued that the effectiveness of these conservation units will depend on the ability, (i) to take into account their territorial context, and also (ii) to base the management decisions on a prospective and sufficiently anticipated (future-oriented) approach. MPA management must be proactive to cope with such rapid changes., The Nexus approach, promoted by the IUCN Commission on Ecosystem Management - coastal ecosystem group (CEM/CEG), places marine and coastal spatial planning as a key integrative element linking conservation, adaptation to climate change and coastal risk reduction, and as a part of no-regret adaptation strategies. This paper highlights the main factors that characterize current coastal dynamics, and then briefly presents three future-oriented pilot operations, implemented in Western Africa at different scales. These operations illustrate how MPAs must become structuring elements for the organization and development of coastal territories if they are to contribute to the resilience of coastal systems and to ensure their own long-term sustainability. [ABSTRACT FROM AUTHOR]

Recreational diving engages 20 million people worldwide. Most of the literature refers to tropical destinations but at least 1 million dives per year take place in Mediterranean marine protected areas (MPAs)., Divers may negatively affect underwater habitats. However, if effectively engaged, they can contribute to science, territorial management and more sustainable local economies., During 2006-2014, volunteers trained by the not-for-profit organization Reef Check Italia (RCI) completed 24 714 observations and 2417 dives in six Mediterranean countries, contributing to a dataset that supports scientific papers about climate change, rare and non-indigenous species (NIS), and informs MPA management decision-making., The wide range of opportunities offered by this dataset is illustrated with two examples relevant to marine conservation in the context of MPA management. They concern: (i) the spread of the NIS Caulerpa cylindracea along the Ligurian coasts, with a focus on Portofino MPA, and (ii) the distribution and abundance of protected species in the Portofino MPA., A diver-focused survey showed that RCI volunteers are highly committed, and that participation in RCI activities has led to a better understanding of, and a sense of stewardship towards, favoured dive sites and the marine world. Knowing who volunteers are, and why they volunteer in their favourite sector, is crucial to designing citizen-science based projects able to achieve their multiple goals., Copyright © 2016 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

The polar regions are undergoing vast changes in the land and seascape. They serve as major components of the Earth's climate system and are particularly vulnerable to climate change impacts. Warming temperatures, combined with increased human use and resource extraction, are putting increasing pressure on these vulnerable regions., While the Arctic and Antarctic are distinct from one another in their governance and human use, the 2014 World Parks Congress provided a platform for joint learning on progress and options for protecting marine areas in these unique regions. Though they remain among the remotest places on earth, their important role for global biodiversity, climate processes and economic activity have made them a focus for conservation efforts., Establishing a robust, integrated network of protected areas is one important tool for protecting ecosystem function and enhancing resilience as these regions face climate change impacts as well as increasing pressures for resource exploitation. This paper describes some major efforts to establish marine protected areas (MPAs) in the Arctic and Antarctic and analyses the similarities and differences in marine protection initiatives in the Earth's polar regions. As a basis for the analysis the authors focus on the following two themes: pressures - what are they and how fast are they growing; and governance - are there appropriate governance structures to establish and manage MPAs at appropriate geographic scales?, Copyright © 2016 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

ABSTRACT Migratory marine species (MMS) include many of the world's most charismatic organisms such as marine mammals, seabirds, turtles, sharks, and tuna. Many are now among the most threatened due to the diverse range of pressures they encounter during their extensive movements. This paper shows that 21% of MMS are classified as threatened (i.e. categorized as Critically Endangered, Endangered or Vulnerable). Sea turtles are the most threatened group (85%), followed by seabirds (27%), cartilaginous fish (26%), marine mammals (15%) and bony fish (11%). Taken together 48% of MMS are threatened, Near Threatened or Data Deficient., As well as being threatened they share in common being wide-ranging animals, travelling through the waters of multiple nations as well as in Areas Beyond National Jurisdiction (ABNJ) during different times of the year. This makes their conservation a challenge, requiring coordinated action by many nations, international organizations, Multilateral Environmental Agreements (MEAs) and other stakeholders if their populations are to recover to healthy levels and be safeguarded into the future., Even though they are wide-ranging, long-term studies reveal considerable site fidelity and well-defined habitats for many species and areas. These sites are prime candidates for enhanced management such as via Marine Protect Area (MPA) designations. However, existing management frameworks do not yet contribute sufficiently to MMS conservation, MPA networks need to be expanded to capture key areas, in many cases through the application of new dynamic management techniques such as time area closures., Data on the distribution, abundance, behaviours and threats faced by many MMS are now available. These data should be used to inform the design of effective management regimes, such as MPAs, both within and beyond national jurisdictions. MEAs should ensure a full complement of MMS are included within species listings, and encourage further action to safeguard their populations., Copyright © 2014 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

ABSTRACT Commercial fishing is an important socio-economic activity in coastal regions of the UK and Ireland. Ocean-atmospheric changes caused by greenhouse gas emissions are likely to affect future fish and shellfish production, and lead to increasing challenges in ensuring long-term sustainable fisheries management., The paper reviews existing knowledge and understanding of the exposure of marine ecosystems to ocean-atmospheric changes, the consequences of these changes for marine fisheries in the UK and Ireland, and the adaptability of the UK and Irish fisheries sector., Ocean warming is resulting in shifts in the distribution of exploited species and is affecting the productivity of fish stocks and underlying marine ecosystems. In addition, some studies suggest that ocean acidification may have large potential impacts on fisheries resources, in particular shell-forming invertebrates., These changes may lead to loss of productivity, but also the opening of new fishing opportunities, depending on the interactions between climate impacts, fishing grounds and fleet types. They will also affect fishing regulations, the price of fish products and operating costs, which in turn will affect the economic performance of the UK and Irish fleets., Key knowledge gaps exist in our understanding of the implications of climate and ocean chemistry changes for marine fisheries in the UK and Ireland, particularly on the social and economic responses of the fishing sectors to climate change. However, these gaps should not delay climate change mitigation and adaptation policy actions, particularly those measures that clearly have other 'co-benefits'. Copyright © 2012 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Stream habitat is distributed discontinuously, which restricts the dispersal of animals among streams. Freshwater decapod crustaceans have poor dispersal ability and thus may suffer high extinction risk in the face of habitat destruction and other forces. Here, the ecological characteristics of two freshwater decapods, the threatened crayfish Cambaroides japonicus (de Haan, 1841) and the widespread crab Geothelphusa dehaani (White, 1847), were compared. The objective of the study was to determine which characteristics are most likely to limit the distribution of C. japonicus.Environmental DNA sampling was conducted to detect C. japonicus and G. dehaani populations, and environmental characteristics were measured to identify suitable stream habitat. Phylogenetic divergence and genetic differentiation among populations were examined. Using species distribution modelling, the future distributions of both species under climate change were predicted.Stream habitats harbouring C. japonicus tended to be supplied with more beech leaves and fewer cedar leaves, whereas those of G. dehaani were relatively wide, indicating that C. japonicus favours upstream areas in natural broad‐leaved forest. The results also showed greater genetic divergence among populations of C. japonicus than those of G. dehaani. Modelling indicated that most areas within the current distribution of C. japonicus were predicted to be areas with low distribution probability under a future climate scenario.To protect C. japonicus, further loss of local populations should be prevented to allow for the maintenance of high genetic diversity among populations, which may provide the evolutionary capability of surviving under future climate conditions. To prevent further loss of C. japonicus populations, natural deciduous forests in mountainous areas need to be preserved. C. japonicus can be the indicator species within the freshwater environment in these forests. Conservation measures for C. japonicus should also be effective for the conservation of the other freshwater invertebrates in upstream areas. [ABSTRACT FROM AUTHOR]

Innovative financing, that is the development of new funding sources and mechanisms including from the private sector, can be used to deliver promising ocean conservation opportunities. Capital markets are increasingly accessible for sustainable development and climate finance, and are gaining traction for biodiversity conservation. Such financing concepts could also be applied in the High Seas. Drawing on natural capital economics as a way to ascribe economic value, specific marine investment opportunities can be identified and made accessible to new financiers and funding processes., International waters cover nearly half of the planet's surface, yet governance deficiencies have meant that marine habitats and ecosystems are rapidly deteriorating. Improved governance through the proposed Marine Biodiversity Implementing Agreement discussed under the 1982 UN Convention on the Law of the Sea and delivery of the Sustainable Development Goals, in particular ocean goal 14, will require additional financial support for High Seas solutions, including for the effective management of marine reserves., For projects to be attractive to funders they need to be clearly structured and deliver quantifiable benefits. A comprehensive ocean data infrastructure could be put in place to support large-scale marine conservation monitoring cost-effectively. This infrastructure could serve also other ocean users, thereby defraying the cost and could be delivered through public-private partnerships. Development finance and climate finance provide examples for relevant pathways for such integrated approaches., Existing efforts to find additional funding for ocean solutions can be enhanced through the range of specific innovative ocean finance mechanisms that are identified. These offer the prospect of long-term support., This review draws on progress made at the IUCN World Conservation Congress in Honolulu, Hawai'i in September 2016 and builds on the momentum created by the Paris Agreement and the Sustainable Development Goals. [ABSTRACT FROM AUTHOR]

Archived logbooks detailing landings at Scottish shore‐based whaling stations between 1903 and 1951 were used to map whale catch locations. Historical distribution and occurrence are inferred and summary statistics on total landings are updated for blue (Balaenoptera musculus), fin (Balaenoptera physalus), humpback (Megaptera novaeangliae), North Atlantic right (Eubalaena glacialis), sei (Balaenoptera borealis) and sperm (Physeter macrocephalus) whales: a total of 9,996 whales were caught during this period, which is 3.7% higher than previously reported and 25% higher for blue whales.The most frequently caught species were fin and sei whales. Whaling off Scotland in the 1920s contributed to the likely extinction of right whales in the eastern North Atlantic. Blue whales, once regularly hunted to the west of Scotland, are now rarely documented there and North‐east Atlantic whaling appears to have had a significant and lasting impact on sei whales.Analysis of whaling effort indicates that catch rates remained high despite the depletion of some species. This, may be a consequence of two features of Scottish shore‐based whaling: (1) the mixed species catch composition; and (2) the catching of whales as they migrated through Scottish waters.The findings of this study highlight the historical significance of the shelf‐seas around Scotland as a habitat for some species, which was not apparent from previous studies. These results can inform where there may be potential for the recovery of some species in the future.Current major threats in the North Atlantic include entanglement, ship strike and displacement owing to the effects of climate change. The baseline and historical information on distribution and seasonal occurrence examined here is important for informing spatial and temporal measures to reduce these threats. If populations are to recover post‐whaling there is an increasing need to reduce threats such as ship strikes and entanglement, whose magnitude is proportional to whale density. [ABSTRACT FROM AUTHOR]

Nest boxes and other human‐made constructions have been widely and successfully used as conservation tools to increase nest‐availability for hollow‐dependent fauna, especially birds and some small and medium mammals.This study applies, for the first time, this recovery technique to a large aquatic mammal, aiming to improve resting, birthing and nursing sites of endangered Saimaa ringed seals (Pusa hispida saimensis) by developing artificial nest boxes. This landlocked subspecies' breeding habitat is severely affected by climate change. Because of mild winters, sufficient ice and snow habitat for subnivean lairs is lacking.In this study, floating nest boxes were developed. It was found that free‐ranging ringed seals accept nest boxes as sites for resting, birthing and nursing. Thirty‐four boxes in total were offered during six successive breeding seasons. Almost half (47%) of the available boxes were used by seals, and two pups were born and reared in the boxes during the 6‐year study.Our study indicates that this innovative technique can be a valuable tool for the Saimaa ringed seal conservation in the changing climate. [ABSTRACT FROM AUTHOR]

Globally, freshwater systems are threatened by climate change, so projections under various climate change scenarios are needed to inform efforts to protect and conserve already vulnerable taxa.Here, the change in distribution of stream vertebrates was investigated under different greenhouse gas emission scenarios. Using occurrence data from multiple stream surveys in Washington State spanning 559 sites and 24 years, species distribution models for 23 aquatic vertebrate taxa (21 fish and two amphibians) were developed.Models projected changes in taxon distributions for 2070 under representative concentration pathways (RCPs) ranging from 2.6 to 8.5 W m−2. To assess potential biological impacts of these predictions, changes in taxon richness and beta diversity of stream vertebrates were also investigated. Moreover, predictor variables were examined to assess which ones were more important in determining taxon distributions.Substantial changes in the spatial distribution of stream vertebrates were projected for all RCP scenarios by 2070, but the greatest changes were expected to occur under RCP 6.0 and 8.5. The taxa evaluated were predicted to experience substantial increase, decrease, or shift in distribution.Taxon richness of stream vertebrates was forecasted to increase with RCP scenario relative to historical conditions, suggesting that distributional expansions outpaced distributional contractions. However, beta diversity was predicted to decrease considerably, suggesting increased biotic homogenization. Variables important for determining future distributions varied by taxa, with most species influenced by a combination of variables.These results indicate that failing to reduce greenhouse gas emissions will lead to dramatic impacts on stream vertebrates. The magnitude of predicted future impacts was dependent upon RCP scenario, so advancements in policy to reduce carbon emissions are necessary. We also recommend as potential conservation measures preserving cold‐water refugia and increasing efforts to lower stream water temperatures by, for example, expanding the riparian cover and/or linking surface water to groundwater. [ABSTRACT FROM AUTHOR]

Spring‐associated aquatic invertebrates tend to be narrow‐range endemics. Globally, they are threatened with extinction as a result of habitat loss caused by declining aquifers and by climate change.Extinction risks to narrow‐range endemics may be reduced by having multiple, separate populations, yet there have been few attempts to use conservation translocations to create new populations.Pyrgulopsis roswellensis (Roswell springsnail), Juturnia kosteri (Koster's springsnail) and Gammarus desperatus (Noel's amphipod) are range‐restricted, spring‐associated endangered species. Each species has lost one or more populations owing to habitat loss, and their distributions are now largely restricted to Bitter Lake National Wildlife Refuge, New Mexico.In 2014, Bitter Lake National Wildlife Refuge enhanced a series of springs by re‐routing a channelized section of river away from them. The goal was to create habitat suitable for establishing new populations of P. roswellensis and J. kosteri, and for expansion of G. desperatus. After assessing risks and benefits of translocations, approximately 6,177 P. roswellensis and 8,707 J. kosteri were introduced into the project area from 2015 to 2018.Efficacy was evaluated by comparing the abundance of invertebrates in the translocation site through time, and by comparing springsnail abundance with three reference spring systems. From 2014 to 2021, invertebrates were monitored twice annually in the translocation area. In reference spring systems, P. roswellensis and J. kosteri were monitored twice annually in 2020 and 2021.Counts of springsnails in the translocation area were comparable to one or more reference areas, which suggests that translocations were successful. In addition, the proportion of P. roswellensis, the less common springsnail, to J. kosteri was similar to references areas.G. desperatus did not increase, which may be because some measures of water quality have not stabilized.Globally, climate change and aquifer declines necessitate immediate consideration be given to conservation translocations as a means of keeping spring‐associated species from becoming extinct. [ABSTRACT FROM AUTHOR]

Diet is a key factor affecting seabird foraging behaviour, ultimately influencing survival, breeding success and long‐term population viability. The density and distribution of prey species in the marine environment are influenced by many factors including climate effects such as El Niño southern oscillation and climate change that alter water temperature.While poor quality diet has been implicated as a contributing factor in the decline of some mainland New Zealand yellow‐eyed penguin (Megadyptes antipodes) populations, little is known about their diet in the subantarctic where the majority of the species breeds.Blood and feather samples (n = 63) were collected for stable isotope analysis of diet from 25 individual birds breeding on subantarctic Enderby Island, Auckland Islands, New Zealand, from 2015 to 2018.Diet data were analysed by factors such as breeding year, sex and foraging behaviour. Stable isotope analysis demonstrated significant changes in diet during each year of the study, which included both El Niño and La Niña conditions.Diet during El Niño conditions comprised lower trophic level prey, which were more benthic, and found closer to shore than diet during La Niña.Coupled with the reported variable breeding success of yellow‐eyed penguins in the subantarctic, variable diet suggests prey availability is likely to be a limiting factor in some years. Prey availability is therefore expected to be a major influence on survival and breeding success of this endangered species in the future, particularly if the effects of climate change become more pronounced.This research highlights an urgent conservation need to identify prey species utilized by the southern population, along with their distribution in time and space, and therefore also the effect of diet on long‐term population stability. [ABSTRACT FROM AUTHOR]

Like other Mediterranean regions, south‐western Australia is predicted to experience an increase in temperature and drought conditions as a result of climate change, leading to altered species distributions. This study provides the first assessment of the effectiveness of the reserve system in Australia for conserving native freshwater fish by considering the congruence between protected areas and potential climate refugia in a global biodiversity hotspot.Using species distribution modelling, exposure to climate change was predicted for 13 native fish taxa, and priority areas (refugia) for fish conservation were identified by overlapping the present and future suitable climate envelopes of these taxa. Areas with climate refugia for >70% of the native freshwater fish fauna were recognized as 'coldspots'.Two taxa were predicted to lose all suitable climate in the region by 2080, and five other taxa were predicted to lose >80% of their area of suitable climate. A 'coldspot' was identified consisting of a core area where >80% of taxa were predicted to persist and a larger surrounding area where >70% of taxa were predicted to persist.Although 93% of the core area of the coldspot is at present contained within the established protected areas network, only 26% of the surrounding area is contained within reserve boundaries. Future conservation actions, including the design and implementation of the protected area network, should take this coldspot into consideration. [ABSTRACT FROM AUTHOR]

Taxonomic and functional trajectories of benthic assemblages were studied in shallow soft‐bottom sediments in the bay of Saint‐Brieuc (Western English Channel). Changes were assessed at different spatial and temporal scales using a macrobenthic dataset based on 38 stations sampled in 1987 and 2019, coupled with data from one station sampled annually between 2005 and 2019 as part of the European Water Framework Directive monitoring programme.Taxonomic trajectories indicated 1) changes in the structure and distribution of benthic assemblages, 2) an homogenization of the assemblages, and 3) significant functional shifts.Fishing activities and nutrient enrichment are probably strong drivers of the observed changes, as suggested by the higher mortality rate of fragile, flexible, tubiculous and burrowing species, and the increase in the abundance of opportunistic species in the assemblages. Certain populations of macroinvertebrates seem jointly controlled by climate change and by the aforementioned local factors of disturbance.The Community Trajectory Analysis framework appears as a new and interesting method to track ecological changes in marine ecosystems by measuring change with respect to a baseline state, to help define ecological recovery (station returning to the initial ecological state) and departure (station presenting increased changes over time), and to analyse trajectory similarity.According to the degradation of habitat over time, we identify the need for the implementation of knowledge‐based conservation strategies, especially within Natura 2000 sites. [ABSTRACT FROM AUTHOR]

Isoëtes sabatina is the rarest aquatic quillwort in Europe. Although recently found (2013) in Lake Bracciano (central Italy), the species is just one step away from extinction with an estimated population not exceeding 400 individuals and a spatial range of a few hundred square metres.Lake Bracciano is a deep, oligo‐mesotrophic Mediterranean volcanic lake that has been subjected to human activities. From January to October 2017, the lake experienced a dramatic water level decrease (up to −1.50 m), which significantly affected the littoral zone and the habitat of I. sabatina.To improve the chances of survival of I. sabatina, the first eco‐taxonomic investigation on this species was carried out to describe its genetic distinctness, physical and chemical requirements and companion species.The phylogenetic position of I. sabatina was investigated by applying standard DNA barcoding methods. Simultaneously, during summer 2019, the physical and chemical features of water and sediments of the I. sabatina population and five small Alpine lakes colonized by Isoëtes echinospora – a supposed close relative – were characterized. These data were then compared with the available data on the trophic requirements of the target obligate aquatic Isoëtes, together with Isoëtes lacustris and Isoëtes malinverniana.The present survey confirmed the taxonomic and ecological distinctness of I. sabatina – providing the first evidence of genetic differentiation from I. echinospora. Isoëtes sabatina grows in waters with temperature, conductivity and total alkalinity up to 30°C, 561 μS cm−1 and 3.45 meq L−1, respectively.The edaphic requirements of I. sabatina confirm its outstanding conservation value, and this study offers a basic understanding of how to prevent its extinction. Now, all possible actions must be taken immediately to save this species. [ABSTRACT FROM AUTHOR]

Climate change has emerged as an increasingly important threat to freshwater systems. To cope with rapidly changing thermal regimes, freshwater fishes must either relocate or adjust through genetic adaptation and/or phenotypic plasticity. Short‐term responses to elevated water temperature have been well studied in freshwater fishes; however, far less is understood about change induced by long‐term exposure. Furthermore, few studies have investigated the effects of temperature on already imperilled species, which may be more sensitive to environmental change.This study investigated the effects of rearing temperature on critical thermal maximum (CTmax), agitation temperature (Tag, temperature at which fish show behavioural signs of thermal stress) and gill size in pugnose shiner, Notropis anogenus, a threatened species in Canada. Juvenile pugnose shiner were reared for 4 months across five different ecologically relevant temperatures. CTmax and Tag were measured under normoxia and acute exposure to hypoxia to test for oxygen sensitivity of the upper thermal limits in this species.CTmax increased with elevated water temperature. Tag also increased with rearing temperature and occurred, on average, 4.3°C above acclimation temperatures. The CTmax and Tag were lower when fish were exposed acutely to hypoxia. Interestingly, gill size (e.g. total gill filament length) increased with rearing temperature, which may increase oxygen uptake capacity and support increased metabolic demands of warmer waters.Overall, pugnose shiner show plasticity in several traits in response to long‐term exposure to elevated water temperature that may facilitate persistence in warmer waters. However, acute hypoxia exposure reduced thermal tolerance, stressing the importance of evaluating interactive effects of multiple stressors.Identifying source populations of pugnose shiner with greater thermal tolerance or implementing captive breeding under higher temperature regimes may improve the success of re‐introduction efforts in the face of climate change, but the consequences to fitness of increased thermal tolerance should be examined. [ABSTRACT FROM AUTHOR]

Atlantic salmon populations have declined in recent decades. Many of the threats to the species during its freshwater and coastal residency periods are known, and management approaches are available to mitigate them. The global scale of climate change and altered ocean ecosystems make these threats more difficult to address.Managers need to be aware that promoting strong, healthy, and resilient wild populations migrating from rivers is the optimal approach currently to reduce the impacts of changing ecosystems and low marine survival. We argue that a fundamental strategy should be to ensure that the highest number of wild smolts in the best condition leave from rivers and coastal areas to the ocean. There is great scope for water quality, river regulation, migration barriers, and physical river habitat improvements.Maintenance of genetic integrity and diversity of wild populations by eliminating interbreeding with escaped farmed salmon, eliminating poorly planned stocking, and reducing impacts that reduce population sizes to dangerously low levels will support the ability of Atlantic salmon to adapt to changing environments. Reducing the impacts from aquaculture and other human activities in coastal areas can greatly increase marine survival in affected areas.As most of the threats to wild salmon are the result of human activities, a focus on human dimensions and improved communication, from scientific and management perspectives, needs to be increasingly emphasized. When political and social will are coupled with adequate resources, managers often have the tools to mitigate many of the threats to wild salmon. [ABSTRACT FROM AUTHOR]

Understanding the ecological and evolutionary processes that occur during range shift or (re‐)colonization is of critical importance for species whose ranges are changing due to human‐induced climate change or species such as New Zealand sea lions where their established colonies are significantly declining due to human impacts.The mechanisms underlying colonization are poorly understood. Observations are required to determine the processes that change individual's behaviour associated with colonization, but such observations are rare.Here, the establishment of a new breeding colony of New Zealand sea lions, Phocarctos hookeri, as they recolonized mainland New Zealand, an area from which they had been absent for ~200 years was investigated.There are differences in breeding location behaviour and population connectivity between established and establishing colonies of New Zealand sea lions. The recolonizing population is more dispersed with breeding locations that change annually and have more connections with other populations compared with established colonies and populations.The establishment of a new colony and the greater numbers of resightings between colonies means that for species' management, considerably more public education, habitat management, and protection is needed to ensure the safe return of New Zealand sea lions back on to mainland New Zealand. [ABSTRACT FROM AUTHOR]

In contrast to Antarctic krill Euphausia superba, Antarctic salps (Salpa thompsoni) respond positively to warmer water temperatures and have the ability to create massive blooms under favourable conditions. Therefore, they can compete with krill for primary production. Over the last three decades, significant variability in S. thompsoni occurrence has been observed as a response to the environmental fluctuations of the Southern Ocean ecosystem (e.g. changes in sea surface temperature and ice‐cover shrinkage around the cold Antarctic waters).This study presents historical abundance data of salps from the south‐west Atlantic Sector of the Southern Ocean, covering a time span of 26 years. These data allow tracking of fluctuations in Antarctic salp abundance and their distribution with bottom depth, temperature, and ice conditions, aiming to reveal salp hot spots and to predict the future range of S. thompsoni distribution with upcoming climate warming in the next 50 years.Results showed the highest salp density in shallow shelf waters with ice cover and low temperatures between 1 and −1°C. In the studied area, S. thompsoni hot spots were located mostly around Elephant Island, but also the islands around Brensfield and Gerlache Straits, as well as to the south near the Bellingshausen Sea. Inferences made of future salp distribution suggest that the range of S. thompsoni will move southwards, enlarging their habitat area by nearly 500,000 km2, which may have significant implications on the whole Antarctic food web. The information presented herein may be used for Antarctic ecosystem management, protection, and conservation. [ABSTRACT FROM AUTHOR]

The ocean is the linchpin supporting life on Earth, but it is in declining health due to an increasing footprint of human use and climate change. Despite notable successes in helping to protect the ocean, the scale of actions is simply not now meeting the overriding scale and nature of the ocean's problems that confront us.Moving into a post‐COVID‐19 world, new policy decisions will need to be made. Some, especially those developed prior to the pandemic, will require changes to their trajectories; others will emerge as a response to this global event. Reconnecting with nature, and specifically with the ocean, will take more than good intent and wishful thinking. Words, and how we express our connection to the ocean, clearly matter now more than ever before.The evolution of the ocean narrative, aimed at preserving and expanding options and opportunities for future generations and a healthier planet, is articulated around six themes: (1) all life is dependent on the ocean; (2) by harming the ocean, we harm ourselves; (3) by protecting the ocean, we protect ourselves; (4) humans, the ocean, biodiversity, and climate are inextricably linked; (5) ocean and climate action must be undertaken together; and (6) reversing ocean change needs action now.This narrative adopts a 'One Health' approach to protecting the ocean, addressing the whole Earth ocean system for better and more equitable social, cultural, economic, and environmental outcomes at its core. Speaking with one voice through a narrative that captures the latest science, concerns, and linkages to humanity is a precondition to action, by elevating humankind's understanding of our relationship with 'planet Ocean' and why it needs to become a central theme to everyone's lives. We have only one ocean, we must protect it, now. There is no 'Ocean B'. [ABSTRACT FROM AUTHOR]

Ecological stability based on statistical variability was contrasted with the asymptotical local stability of transient states during successional changes in community structure in kelp forests and barren grounds.Simplified semi‐quantitative ecological models with different levels of complexity were constructed to represent transient successional states in kelp and barrens, and Routh–Hurwitz's criteria and Levins' criterion of local stability were also estimated.The results suggest that ecological stability based on statistical variation does not match local (mathematical) stability, since although successional changes in kelp exhibited less variability (measured as percentage coefficient of variation), barren beds were more locally stable. The local stability criteria used in the current work could be a suitable technique for evaluating the likelihood of transient ecological states to resist or change, since it considers states at equilibrium to maintain their properties only against small disturbances.These outcomes are relevant because the natural alternation between kelp and barrens could be disrupted by the intensive harvest of kelp species carried out over the last 10 years on the central‐north Chilean coast and in other temperate ecosystems.Additionally, the negative effects of harvesting kelp species could have a synergetic relationship with other drivers such as climate change and coastal pollution. Thus, strict policy managements to limit the kelp harvest are deeply encouraged. A monitoring programme for assessing the current conditions of benthic–pelagic ecosystems along the Chilean coast is also required. [ABSTRACT FROM AUTHOR]

The Amazon basin has been subjected to extreme climatic events and according to climate change projections this hydrosystem could face changes in the natural dynamic of flood cycles that support the feeding and reproduction of many fish species, threatening aquatic biodiversity.Protected areas (PAs) are the main tools used to safeguard the biodiversity in the long term; however, they are fixed areas that could be subject to climate change, questioning their future efficiency in protecting biodiversity.The Amazon basin currently benefits from a relatively high level of protection as 52% of its catchment area is under the form of true PAs or indigenous lands. However, the capacity of these PAs to protect freshwater biodiversity remains unclear as they have generally been assessed with little regard to freshwater ecosystems and their hydrological connectivity. Here, the aim was to evaluate the effectiveness of PAs in representing the Amazon fish fauna under current and future climatic conditions.A macroecological approach was used to estimate the minimum size of the geographical range needed by each species to achieve long‐term persistence, by a combined function of range size and body size, two ecological traits known to influence species extinction risk.In future the Amazon basin could risk losing 2% of its freshwater fish fauna owing to unsuitable climatic conditions, with a further 34% adversely affected. The present Amazon network of PAs will cover the minimum required range for species persistence for more than 60% of the freshwater fish species analysed under the future climate scenario. However, more than 25% of the future susceptible species are currently concentrated in large tributaries and in the central‐lower Amazon floodplain where few PAs occur, highlighting the lack of appropriate conservation actions for these specific water bodies. [ABSTRACT FROM AUTHOR]

In the current context of climate change, benthic cnidarians of the genus Palythoa have been suggested to be resistant owing to their intrinsic biological characteristics. In tropical regions, some species are currently proliferating in areas where environmental conditions are less suitable for other organisms, even replacing hard coral ecosystems.Considering their tropical affinities, phase‐shifts towards Palythoa‐dominated areas could become more frequent in future climate change scenarios, leading to changes in ecosystem organization. The aim of this study was to evaluate the effect of climate change stressors in two common Palythoa spp. with different habitat affinities within a subtropical region, and the effect upon their predator–prey interactions.The results of this experimental study demonstrated that colonies of P. aff. clavata and P. caribaeorum were significantly affected by exposure to temperature and pH conditions predicted for 2100 in the Canary Islands, during 62 days.Despite zoantharians' lack of carbonate in their body wall, Palythoa spp. were most affected in their growth rates by lowered pH, and colonies significantly decreased in weight and size. Although all colonies exhibited symptoms of bleaching at high temperature, a reduction in chlorophyll content was also observed at low pH.Predation by Platypodiella picta crabs decreased on P. aff. clavata exposed to acidic conditions, which may compensate for the lowered ecological performance of the species in these climate change conditions. In contrast, P. picta was able to actively feed on P. caribaeorum colonies regardless of the experimental conditions.Despite being suggested as winner species in a climate change scenario, our study demonstrated that low pH negatively impacted Palythoa spp. survival. If the species are not able to acclimatize to the new conditions, changes in their populations may be expected, although their magnitude could be ameliorated by means of a decrease in predation rates. [ABSTRACT FROM AUTHOR]

The five global Mediterranean‐climate regions are experiencing alarming rates of freshwater biodiversity loss. Although freshwater mussels are recognized as important functional components in aquatic ecosystems, and are among the most threatened faunal groups globally, there has been no synthesis of the plight of this group within these regions.Data from the International Union for Conservation of Nature (IUCN) Red List were reviewed to compare the conservation status, threats, and conservation actions needed for freshwater mussel species occurring in Mediterranean‐climate regions (med‐mussels) with those of other freshwater mussel species globally. The first comprehensive catalogue of med‐mussel species was compiled using existing taxonomic literature.There are 41 med‐mussel species, 30 of which occur in the Mediterranean basin. Many regions have just a single species, and regions where multiple species occur generally only have between one and four species per river basin. Med‐mussel species are almost twice as likely to be 'Imperilled', are affected by 2.4 times more threats, and require 3.5 times more conservation actions than non‐med mussels. In many cases, the exact threats have not been identified.In combination with low species richness, this level of imperilment means that Mediterranean‐climate regions are at risk of losing the benefits that mussels provide to broader ecosystem functioning. The conservation of med‐mussels can be improved by increasing our knowledge of species distributions, including the identification of cryptic species and significant management units, through population genetic work. In addition, recognizing the potential of 'novel' habitats and refuge areas could augment the management of this important functional group. [ABSTRACT FROM AUTHOR]

The conservation of aquatic species with complex life histories requires the protection of habitat for each life stage. Coastal cutthroat trout (Oncorhynchus clarkii clarkii) exhibit both mobile and sessile stages and are of conservation concern in north‐western North America. Models that predict how habitat changes with flow can inform water management for the species but rely on habitat descriptors that change with flow and are not suited to sessile life stages.Spawning and incubation habitat availability and use for coastal cutthroat trout were assessed in mesohabitats and microhabitats. Primary channel units were tallied, dimensions were measured, redds were counted, and redd locations within channel units were measured.Primary channel units were subdivided based on relative residual depth (RRD, bed elevation in relation to maximum pool depth) and hydraulic control (HC, the lowest point on the highest ridge across the riffle that controls the water surface elevation in the upstream pool). Habitat suitability was calculated for depth (D), velocity (V), Froude number (Fr), substrate (S), RRD, and channel units.Redds in riffles and pools were close to hydraulic controls; suitability decreased upstream in pools and downstream in riffles. Maximum suitability values were: 21–24 cm for D, 0.05–0.10 for RRD, 61–64 cm s−1 for V, >0.80 for Fr, and 1.3 to <3.8 cm for S. Channel units, RRDs, and microhabitat better identified spawning habitat than microhabitat alone.The results suggest that RRD and stage of zero flow are good indicators of habitat suitability for spawning through fry emergence and could be adapted for use with other species. This work generates criteria for delineating flow‐independent channel units that can be used to set more protective instream flows, prioritize the acquisition of instream water or conservation easements to protect critical habitat, and inform restoration projects to optimize habitat availability. [ABSTRACT FROM AUTHOR]

The largest changes in the circulation of the South‐eastern Pacific resulting from global warming are associated with the southward shift and intensification of the anticyclone and with coastal surface warming. Coastal upwelling is projected to be increase off central Chile, due to an increase in equatorward winds, although increased oceanic stratification and associated enhanced nearshore turbulence will yield an onshore deepening/flattening of the thermocline.The overall increase in south‐easterly trade winds of the South‐eastern Pacific in a warmer climate are likely to increase the connectivity pattern between Juan Fernandez and Desventuradas islands, and along the Sala y Gomez ridge, through increasing wind‐driven mean ocean currents.Deoxygenation associated with the warmer temperatures and changes in ventilation are likely to modify marine habitat and the respiratory barriers of species in the seamounts located in the vicinity of the limits of the minimum oxygen zone.In the South‐eastern Pacific, the prevailing 2D understanding of the responses of marine life to climate change needs to be expanded to 3D approaches, integrating the vertical habitat compression of marine organisms as a result of ocean warming and deoxygenation, as climate velocities for temperature and oxygen have contrasting vertical and horizontal patterns.There is a need for regional biogeochemical‐coupled modelling studies dedicated to the Chilean islands in order to provide an integrated view of the impact of anthropogenic stressors (e.g. deoxygenation, increased stratification, and climate shift) at the scale required for addressing socio‐ecological interactions.A refined understanding of the large‐scale biogeography and spatial dynamics of marine populations through experimentation with high‐resolution regional ocean models is a prerequisite for scaling‐up regional management planning and optimizing the conservation of interconnected marine ecosystems across large scales. [ABSTRACT FROM AUTHOR]

To facilitate conservation planning, there is a need for improved confidence in forecasts of climate change impacts on species distributions. Towards that end, there have been calls for the development of process‐based models to test hypotheses concerning the mechanisms by which temperature shapes distribution and to corroborate forecasts of correlative models.Models of temperature‐dependent growth (TDG) were developed for two Australian riverine blackfishes with disjunct longitudinal distributions: Gadopsis marmoratus (occupies lower, warmer elevations) and Gadopsis bispinosus (occupies higher, cooler elevations). The models were used to (a) predict blackfish monthly and annual growth dynamics under current and future climate scenarios within different elevation bands of their current distribution, and (b) test the hypothesis that, under the current climate, the distributions of each species would be positively correlated with predicted TDG.Increases in mean annual growth were forecast for both species under all warming scenarios, across all elevation bands. Both species currently occupy annual habitat temperatures below those optimal for growth. Under certain warming scenarios, the predicted increases in annual growth belie forecasts of within‐year dynamics that may interact with the phenology of blackfish to impair recruitment.There was not a significant positive linear relationship between predicted TDG and observed abundance among river segments for either species. Both species were strongly under‐represented where annual growth rates were forecast to be optimal and over‐represented where growth rates were forecast to be intermediate.Confidence in forecasts of climate change impacts based on correlative models will increase when those forecasts are consistent with a mechanistic understanding of how specific drivers (e.g. water temperature) affect processes (e.g. growth). This process‐based study revealed surprises concerning how future climates may affect fish growth dynamics, showing that although the blackfish distributions are correlated with temperature the temperature‐dependent mechanisms underpinning that correlation require further investigation. [ABSTRACT FROM AUTHOR]

Globally, momentum to restore damaged habitats has been increasing. For example, the number of European shellfish restoration projects has quadrupled in the past 3 years. In line with the increasing focus on both restoration and climate change mitigation efforts, this study highlights how these two practices can complement each other.This experimental study quantifies the active and passive sediment deposition associated with the European flat oyster (Ostrea edulis) and the organic and inorganic carbon fractions of the deposits. Treatments included 'dead', 'live', and control to account for (i) passive deposition, (ii) biodeposition and passive deposition, and (iii) background deposition respectively. By utilizing these data, the expected carbon deposition associated with a restored flat oyster bed was investigated.The experiment was conducted ex situ, with natural seawater input. Covariate data on temperature, suspended particulate influx, salinity, and oxygen availability were recorded. Enhanced sedimentation (2.9 times) and organic carbon deposition (three times) were observed in the presence of living oysters, compared with the control. The shell structure of the oysters had no influence on passive sedimentation in this study.By developing a full understanding of the ecosystem services (functioning, supporting, regulating, and cultural) provided by a habitat, it becomes possible to quantify overall ecosystem function. This evidence is key in advising policymakers, restoration funders, and marine spatial planners on the connection between keystone species restoration, ecosystem service restoration, and conservation management.The enhancement of benthopelagic coupling by the European flat oyster, evidenced here for the first time, is contextualized from the perspective of quantification of ecosystem service provision for both restoration practices and blue carbon store management. The data produced in this study are discussed comparatively with work that has focused on other species from both Europe and the USA. [ABSTRACT FROM AUTHOR]

Changes in migration timing, resulting from the alteration in river continuity or the effect of climate change, can have major consequences on the population dynamics of diadromous fish. Forecasting the phenology of fish migration is thus critically important to implement management actions aimed at protecting fish during their migration.In this study, an 11‐year monitoring survey of Atlantic salmon smolts (Salmo salar) from the Ourthe River, Belgium, was analysed within a European Special Area of Conservation to improve the understanding of environment‐induced spring migration. A logistic model was fitted to forecast smolt migration and to calculate phenological indicators for management, i.e. the onset, end, and duration of migration, while accounting for the influence of photoperiod, water temperature, and hydrological conditions.The results indicated that the photo‐thermal units accumulated by smolts above a 7°C temperature threshold was a relevant proxy to reflect the synergistic effect between temperature and photoperiod on smolt migration. After integrating the effect of river flow pulses, the model accurately explained the inter‐annual changes in migration timing (R2 = 0.95). The model predictions provide decisive management information to identify sensitive periods during which mitigation measures (e.g. hydropower turbine shutdown, river discharge management) should be conducted to promote smolt survival.The model was used to predict phenological characteristics under future scenarios of climate change. The results suggest a joint effect of hydrological alterations and water warming. Temperature increases of 1–4°C were associated with earlier initiation of migration, 6–51 days earlier, and spring flood events greatly influenced the duration of the migration period. Accordingly, the combined effects of human‐induced modifications of the hydrological regimes and increasing temperatures could result in a mismatch between the smolt and favourable survival conditions in the marine environment. [ABSTRACT FROM AUTHOR]

Reef manta rays (Mobula alfredi) are one of the ocean's largest and most charismatic species. Pressure from targeted and bycatch fisheries coupled with their conservative life‐history traits including slow growth, late maturity, and low fecundity has led to catastrophic declines of the global population. The species is now listed as Vulnerable to Extinction on IUCN Red List of Threatened Species.The global M. alfredi population is widely distributed in highly fragmented subpopulations. The Maldives supports the world's largest known subpopulation that undergoes seasonal migrations which are thought to be linked to peaks in ocean productivity induced by the South Asian Monsoon. Although the species is protected from targeted fisheries in the region, increasing pressures from habitat degradation and unsustainable tourism activities mean their effective conservation relies upon knowledge of the species' habitat use, seasonal distribution, and the environmental influences on such movements.Photo‐ID sighting records collected between 2005 and 2017 were used to identify key aggregation sites throughout the archipelago, and multiple linear regression and prediction analysis identified the environmental variables affecting variations in the intra‐annual sighting frequency of M. alfredi.Mobula alfredi were recorded at 273 different sites, 48 of which, with >100 sightings at each, were classified as key areas of habitat use. South‐west monsoon winds and chlorophyll‐a concentration predominantly affected the monthly percentage of M. alfredi sighted on the down‐current side of the atolls.In a country where climate change and touristic pressure are increasingly threatening this species and its habitat, the identification of key areas of habitat use and temporal changes in the use of these sites highlight the areas that should be prioritized for protection enabling more effective conservation management. [ABSTRACT FROM AUTHOR]

Motivated by recent global initiatives for biodiversity conservation and restoration, this article reviews the gaps in our understanding of, and the challenges facing, freshwater macroinvertebrate biodiversity and conservation in tropical regions.This study revealed a lack of adequate taxonomic, phylogenetic, and ecological information for most macroinvertebrate groups, and consequently there are large‐scale knowledge gaps regarding the response of macroinvertebrate diversity to potential climate change and other human impacts in tropical regions.We propose ideas to reduce the impact of key drivers of declines in macroinvertebrate biodiversity, including habitat degradation and loss, hydrological alteration, overexploitation, invasive species, pollution, and the multiple impacts of climate change.The review also provides recommendations to enhance conservation planning in these systems (as well as providing clear management plans at local, regional, and national levels), integrated catchment management, the formulation of regulatory measures, the understanding of the determinants of macroinvertebrate diversity across multiple scales and taxonomic groups, and the collaboration between researchers and conservation professionals.It is suggested that the integrated use of macroinvertebrate biodiversity information in biomonitoring can improve ecosystem management. This goal can be facilitated in part by conservation psychology, marketing, and the use of the media and the Internet. [ABSTRACT FROM AUTHOR]

Intertidal habitat maps are needed at both fine and coarse scales to monitor change and inform conservation and management, but current methods of field survey and expert interpretation of aerial imagery can be time‐consuming and subjective. Object‐based image analysis (OBIA) of remote sensing data is increasingly employed for producing habitat or land cover maps. Users create automated workflows to segment imagery, creating ecologically meaningful objects, which are then classified based on their spectral or geometric properties, relationships to other objects and contextual data.This study evaluates the change‐detection capability of OBIA in the intertidal environment by developing and comparing two OBIA methods for quantifying change in extent and distribution of habitats from freely available multi‐temporal aerial imagery and LiDAR data. Despite considerable variability in the data, pre‐ and post‐classification change detection methods had sufficient accuracy (mean overall accuracy from 70.5 to 82.6%) to monitor deviation from a background level of natural environmental fluctuation.This insight into spatial and temporal patterns of natural cyclical change and their detectability by OBIA could inform use of remote sensing for regular, rapid coastal assessment, providing an alert system to direct survey resources to areas of ecologically relevant change. [ABSTRACT FROM AUTHOR]

Mahseer (Tor) fish species are critical components of locally adapted freshwater food webs across the Indian Himalayan biodiversity hotspot; however, multiple human stressors compounded by climate change have significantly depleted their populations over recent decades.Mahseer species are now considered locally vulnerable or endangered in many regions. Hydropower projects in particular have fragmented populations, impairing genetic exchange, obstructing migratory paths, and changing the structure and functioning of riverine habitats, especially of formerly fast‐flowing rivers.Worryingly, a literature survey and group discussions reveal that the increasing spread of non‐native fish species further compounds threats to mahseer and overall freshwater ecology. A better understanding of the current distribution, habitat requirement, and dispersal of non‐native fish is therefore essential to manage the growing threats to mahseer in the Indian Himalayan region. [ABSTRACT FROM AUTHOR]

The ocean crisis is urgent and central to human wellbeing and life on Earth; past and current activities are damaging the planet's main life support system for future generations. We are witnessing an increase in ocean heat, disturbance, acidification, bio‐invasions and nutrients, and reducing oxygen levels. Several of these act like ratchets: once detrimental or negative changes have occurred, they may lock in place and may not be reversible, especially at gross ecological and ocean process scales.Each change may represent a loss to humanity of resources, ecosystem function, oxygen production and species. The longer we pursue unsuitable actions, the more we close the path to recovery and better ocean health and greater benefits for humanity in the future.We stand at a critical juncture and have identified eight priority issues that need to be addressed in unison to help avert a potential ecological disaster in the global ocean. They form a purposely ambitious agenda for global governance and are aimed at informing decision‐makers at a high level. They should also be of interest to the general public.Of all the themes, the highest priority is to rigorously address global warming and limit surface temperature rise to 1.5°C by 2100, as warming is the pre‐eminent factor driving change in the ocean. The other themes are establishing a robust and comprehensive High Seas Treaty, enforcing existing standards for Marine Protected Areas and expanding their coverage, especially in terms of high levels of protection, adopting a precautionary pause on deep‐sea mining, ending overfishing and destructive fishing practices, radically reducing marine pollution, putting in place a financing mechanism for ocean management and protection, and lastly, scaling up science/data gathering and facilitating data sharing.By implementing all eight measures in unison, as a coordinated strategy, we can build resilience to climate change, help sustain fisheries productivity, particularly for low‐income countries dependent on fisheries, protect coasts (e.g. via soft‐engineering/habitat‐based approaches), promote mitigation (e.g. carbon storage) and enable improved adaptation to rapid global change. [ABSTRACT FROM AUTHOR]

In the last two decades, Brazil has advanced significantly with the expansion and improvement of its national system of protected areas. Until recently most of the expansion was concentrated in the Amazon region (with useful lessons). It also had an uneven ecological representation of coastal and marine ecosystems, concentrated in coastal waters. Despite significant advances, the levels of funding, staff and stakeholders' engagement remain relatively low for such a vast system.Within the past few years, key elements of a new strategy for protection of coastal and marine areas have started to emerge, combined with some participatory processes and a focus on expansion of the total area protected (from <1.5% protection of the country's marine area). These included: a renewed focus on priority areas for conservation; attention to national and international commitments and targets; clarity about the need for partnerships and funding; better engagement of Brazilian society and stakeholders; new, and more collaborative, models of protected areas management and conservation; and openness in the relationships with wider society.Significant results of this effort have started to appear: new large mosaics of oceanic protected areas were created; Amazon mangroves were recognized by the Ramsar Convention; new mangrove protected areas were created, besides other ones proposed; project proposals are under development with partners for better funding and sharing of responsibility; and there is a better engagement with stakeholders. The building of the Brazilian Blue Initiative is underway.The implementation of the proposed 15‐year marine strategy is at its onset: partnerships need to be strengthened and substantial funding is required. It will only be possible to manage the larger system of protected areas if there are more collaborative and innovative models for protected areas and conservation management. These should include partnerships with civil society, local and traditional communities and the private sector, as well as greater engagement of scientists and research institutions, stronger and more qualified tourism, volunteer work, etc. Further innovative funding mechanisms will also be needed along the way. [ABSTRACT FROM AUTHOR]

Important marine mammal areas (IMMAs) are discrete portions of habitat, important to marine mammal species, that have the potential to be delineated and managed for conservation. Although IMMAs are not a blueprint for marine protected areas or other conservation designations, they are useful for providing a foundation for marine spatial planning and systematic conservation planning that can then lead to protected areas or special spatial regulations. To be most useful for supporting management and conservation, however, the information coming out of IMMAs needs to reflect current conditions.An 'early warning system' is proposed with a generic set of indicators to flag when marine mammal species in IMMAs require management interventions due to changing distributions or decreasing populations. Rather than signifying that quantitative thresholds have been reached, these indicators comprise alerting information derived from visual or acoustic census, satellite imagery analysis, whale‐watching logs, or increases in mortality reported by stranding networks that can trigger additional targeted research.Although it is possible that in some regions data will be sufficient to provide quantifiable indicators, the system is meant to rely on existing data sources, and be adaptable to the circumstances of each region.Regional expert groups can utilize early warning system information and feed it into IMMA‐related spatial planning in two ways: by nominating additional areas of interest, and by providing a scientific rationale for revising IMMA boundaries, to be considered at the next decadal IMMA regional expert workshop.IMMA‐driven consolidation of information that is as current as possible will prove valuable for enhancing regional cooperation to conserve marine mammals, and will be useful as countries implement new protected areas to conserve marine mammals and other marine biodiversity. [ABSTRACT FROM AUTHOR]

Diver‐held video transect surveys at a subtropical reef complex in eastern Australia documented a significant difference in the fish assemblages eight years after the area was closed to fishing.Average sea temperatures at depth were 1–3°C warmer during the second survey period, and autumn averaged 5–6°C warmer than spring.Large differences in fish assemblages between the seasons in 2006 were not observed in subsequent 2014 surveys. Rather than any general shift towards greater topicalisation of the assemblage in warmer conditions, the difference between the assemblage sampled in the coldest sample period and the three warmer periods was a lower frequency of occurrence of both tropical and non-tropical species and decreased asymptotic species richness.Species that were otherwise rare, which consisted of a higher proportion of tropical species, were more likely to be absent in colder conditions. This was particularly so at the deepest and coldest location.Therefore, in this region warmer waters tend to increase the richness and abundance of most fish, but particularly rare tropical species.Protection from fishing since 2005 also contributed to the inter‐year differences with increased abundance of most fishery‐targeted species regardless of climatic affinities in 2014. [ABSTRACT FROM AUTHOR]

As top predators, it has been suggested that southern elephant seals serve as sentinels of ecosystem status to inform management and conservation.This is because southern elephant seals annually undertake two large‐scale foraging migrations for 2–3 and 7–8 months to replenish resources after fasting during breeding and moulting and often rely on dynamic macroscale latitudinal fronts to provide favourable foraging through aggregating prey.Yet it is largely unknown whether southern elephant seals respond to changes in frontal systems over the years, whether their foraging success is associated with specific frontal systems shifts, and how flexible southern elephant seals populations are in behaviourally adapting to changes in frontal systems.This study examines the relationship between frontal systems and the resource acquisition of 64 southern elephant seals during four post‐moult and three post‐breeding migrations between 2005 and 2010.Satellite‐relay‐data‐loggers provided in situ measurements concurrent with >27,500 dive profiles to define fronts and interfrontal zones between the Subtropical Frontal Zone and the Southern Boundary of the Antarctic Circumpolar Current. For >430,000 in situ measurements water mass properties could be identified.Generally, southern elephant seals associate more frequently with more southerly, higher‐latitude fronts/zones. Body condition improvements related to a given frontal system or water mass vary strongly according to year, season, month and sex.The variability in body condition improvements is higher in some frontal systems than in others, probably owing to shifts in the Subantarctic and Polar Front.During a migration, some individuals stay within ≤3 frontal systems, whilst others change between several frontal systems and primarily improve their body condition in upper ocean waters.Southern elephant seals do not trace particular water masses across frontal systems, and both surface and deep foraging strategies are used.This suggests that southern elephant seals do not target particular water masses but adjust foraging and movement strategies to exploit boundary areas at which mixing and prey aggregation is high.The large behavioural plasticity towards the spatio‐temporal variability in the different oceanographic regions they encounter could indicate resilience against environmental changes. [ABSTRACT FROM AUTHOR]

Island nations such as New Zealand provide valuable insights into conservation challenges posed by strongly connected and recently developed or exploited freshwater and marine ecosystems.The narrow land mass, high rainfall, and steep terrain of New Zealand, like many other island nations, mean that land‐based stressors are rapidly transferred to freshwater habitats and propagated downstream to coastal environments via short, fast‐flowing river systems.Freshwater and marine environments are linked through faunal life histories; for example, diadromous fishes, many of which are considered threatened or at risk of extinction, and require cross‐ecosystem conservation to ensure survival of critical life stages and persistence of source populations.Recent invasions of marine and freshwater environments by non‐indigenous species reveal rapid impacts on a naïve biota and highlight conservation conundrums caused by management aimed at enhancing native biodiversity by improving habitat connectivity.Understanding and managing interconnected freshwater and marine ecosystems is a key concept for local indigenous communities, and highlights socio‐cultural connectivity and sustainable local harvesting of traditional resources as key elements of contemporary marine and freshwater conservation planning in New Zealand. [ABSTRACT FROM AUTHOR]

This study assesses the evolution of major anthropogenic drivers of environmental impacts on Neotropical mangroves, the changes in the environmental pressures acting upon them, and the respective societal responses during the past 40 years. It reviews the impacts of new drivers, in particular those resulting from global climate change and the expansion in aquaculture and the effectiveness of local societal responses aimed at addressing them.Adaptation and mitigation actions are proposed to cope with the impacts and their socio‐economic consequences for Latin America and Caribbean mangroves. By comparing the situation in Latin America and the Caribbean with other regions, the knowledge gaps and priority research needs are discussed to support delineating a preliminary unifying framework to address the environmental pressures affecting mangroves.This scenario necessarily includes the interaction of climate change with human interventions and their effects on ecosystem goods and services, as well as their respective adaptation and management options. Results show that drivers of environmental impacts have changed in the past 40 years, reducing the effectiveness of some important societal responses towards conservation and sustainable management with a great potential to increase rates of mangrove deforestation and conversion to human uses.Although efforts in conservation and restoration have contributed to decreasing pressure on these ecosystems, the coupling of old drivers, such as damming, with climate change, and the appearance of new drivers in the region, such as shrimp aquaculture, may eclipse the gains made through these conservation efforts. Despite the negative trend, we discuss some successful efforts to curb negative impacts of human activities on mangroves.We also recommend regional assessments based on primary sources in the representative mangrove‐bearing countries throughout the continent to allow the upscaling of their experiences towards a regional response to the challenges facing Neotropical mangrove conservation and sustainable use. [ABSTRACT FROM AUTHOR]

Effective conservation of saltmarshes involves detailed and accurate mapping of their range, area of occupancy and plant community composition as part of region‐wide inventories. There is also a need to identify the major mesoscale influences on the distributions of types of saltmarsh, obligate saltmarsh plants and salt pans, and evaluate possible responses to macroclimatic changes.Tidal saltmarshes of Tasmania and its offshore islands (coastline of 4,882 km, spanning latitudes 39°40′ to 43°40′S), off south‐eastern Australia, were mapped at a high spatial resolution of 1 : 500–1 : 3,000. The distributions of types of saltmarsh, obligate plant taxa and salt pans were related to climatic, geomorphic and land‐use variation. The future distribution of climatically controlled species and communities was determined for two climate change scenarios.There was 58.6 km2 of tidal saltmarsh in Tasmania in 61 mesoscale complexes. The complexes were classified into three broad saltmarsh groups, which together offer a more ecologically relevant planning unit for saltmarsh conservation than macroscale bioregions. The small median patch size of 0.2 ha demonstrates the effectiveness of the manual interpretation and mapping with extensive field checking. Mapping of these smaller saltmarshes provides them recognition within the land use planning and approvals process.Climatic, but not geomorphic and land‐use, factors have strong effects on the distribution of saltmarsh plant communities, species and salt pans in Tasmania. Mean annual rainfall was most significant in predicting saltmarsh extent, range, plant community composition, salt pans and the three saltmarsh groups. Mean annual daily minimum temperature and saltmarsh area best predicted obligate plant distributions.Projected wetter and drier climatic change by 2100 is not expected to substantially alter macroscale plant community patterns but may reduce the range of the rare herb Wilsonia humilis R.Br. However, stochastic disturbances may continue to play an important role at local scales. [ABSTRACT FROM AUTHOR]

The distributions and conservation status of the six native amphibian species in Scotland are reviewed. Issues of under‐recording and false recording are noted, and steps to remedy these problems are described.Threats to amphibians in Scotland include diseases (a minor impact so far), road deaths, habitat loss, and climate change (to which populations may be resilient). Exploitation, competition, and pollution do not appear to be significant threats to amphibians in Scotland.Legal protection is currently strongest for the great crested newts (Triturus cristatus) and natterjack toads (Epidalea calamita), but the natterjack toads have only a small localized Scottish population. The ponds at Gartcosh hold the largest great crested newt population in Scotland. Translocation to a specially created reserve appears to have been successful but a new road across the site is an additional hazard, for which monitoring is in progress.Amphibian habitat enhancement in Scotland includes pond‐creation programmes, which have successfully increased the diversity of plants and invertebrates as well as amphibians. The value of Sustainable Drainage Systems (SuDS) for amphibians and other wildlife is reviewed. The Eurasian beaver reintroduction programme may benefit amphibians in the longer term, but research is currently lacking. Road tunnels combined with fences are a vital mitigation for road‐traffic impacts on amphibians and have been monitored at one Scottish site. Amphibian ladders in road drains are another potentially helpful mitigation.The amphibians of Scotland need more long‐term monitoring. A national strategy is imminent and should stimulate the required research and action. [ABSTRACT FROM AUTHOR]

In the Mediterranean Sea, dense populations of the gorgonian Paramuricea clavata shape marine animal forests, characterizing the seascapes of coralligenous habitats. Despite concerns for its health, with several anthropogenic threats and recent mass mortality events, mainly triggered by thermal anomalies, the understorey of its forests and the ecological processes that they promote are still little known. Here, the abundance and composition of epibenthic assemblages inside and outside P. clavata forests were investigated across the central and western Mediterranean Sea, by applying a multifactorial sampling design.In spite of the large variability in the structures of epibenthic assemblages at local and regional scales, the gorgonian understoreys share some common features, such as higher abundances of calcareous builder organisms and reduced invasion by the non‐indigenous alga Caulerpa cylindracea, compared with the adjacent unforested rocky bottoms. Paramuricea clavata showed non‐linear density‐dependent relationships with algal turfs and non‐encrusting algae belonging to the genus Peyssonnelia. Moreover, by entrapping benthic mucilaginous aggregates with their branches, these gorgonians risk topical necrotic lesions, but may reduce the suffocation risks for understorey organisms.Overall, P. clavata forests may enhance bioconstruction processes and increase resistance and resilience of the benthic assemblages in the Mediterranean coralligenous habitats. This species and its forests, together with their understoreys, should be considered as essential elements of the ecology of the Mediterranean Sea, and therefore worthy of specific and effective protection measures.Conservation strategies should reduce the risk of mechanical damage by regulating fishing activities, anchorages, and scuba diving where gorgonian forests are present. Moreover, when evident alterations are documented, restoration actions should be implemented to recover the integrity of gorgonian forests. [ABSTRACT FROM AUTHOR]

Abstract: In marine spatial planning, conserving adequate habitats and the food webs they support requires delineating habitats and projecting future trends. For bottom‐feeding marine birds and mammals, repeated benthic sampling over large areas to document changes and to develop predictive models of prey dispersion is quite costly. More easily monitored variables that relate strongly to the biomass and structure of benthic assemblages, and are more readily predicted from physical models of climate change, would facilitate planning efforts. The organic carbon (OC) content of sediments integrates diverse physical and biotic processes, and can be less variable over time than primary production, salinity, temperature, or position of water masses. Sediment OC further subsumes inputs at the base of food webs that can limit carbon flows to higher taxa. For the northern Bering Sea, this study explored the utility of sediment OC as a predictor of benthic assemblage types. Cluster analysis and multi‐dimensional scaling distinguished three main types along a gradient of sediment OC. The assemblage for highest sediment OC had a much greater biomass of brittlestars, diverse marine worms, and two mid‐sized, thinner‐shelled bivalves selected as prey by diving sea ducks. The assemblage for lowest sediment OC lacked brittlestars, had a much greater biomass of amphipods sought by gray whales (Eschrichtius robustus), and had a much higher biomass of two often larger or thicker‐shelled bivalves commonly targeted by walruses (Odobenus rosmarus). Areas of exceptionally low sediment OC tended towards dominance by sand dollars with low foraging value. Our study shows that sediment OC has promise as a proxy for monitoring and predicting changes in important prey assemblages in a given region. Models that link predicted hydrographic patterns to lateral advection of phytodetritus, and the resulting sediment OC, may further allow the use of physical climate models to project the future dispersion of benthic habitats for endothermic predators. [ABSTRACT FROM AUTHOR]