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Restoration projects are increasingly widespread and many promote habitat succession and the diversity and abundance of faunal communities. These positive effects on biodiversity and abundance may extend to enhancing the ecological functioning and resilience of previously degraded ecosystems, but this is rarely quantified. This study surveyed a 200‐ha restoring coastal wetland and three control wetlands in the Maroochy River, eastern Australia to compare the effects of wetland restoration on the consumption of carrion and the biodiversity, abundance, and functional diversity of functionally important fish and crustaceans. Carrion consumption by fish and crustaceans was measured every 6 months from spring 2017 until spring 2021 for nine events using a combination of baited cameras and scavenging assays. We found restoration improved rates of carrion consumption and the biodiversity, functional diversity, and abundance of scavenger species. Despite positive effects on the diversity of scavengers and carrion consumption, the abundance of two species, longfin eels (Anguilla reinhardtii) and mud crabs (Scylla serrata), was the most important predictors of carrion consumption rates. The spatial distribution of carrion consumption was concentrated in areas with high saltmarsh extent, moderate to high mangrove extent, and high salinity, which also resembled the distribution of both longfin eels and mud crabs. We show that restoration can promote the rates of key ecological functions but that increases to functions are likely to be characterized by low functional redundancy and greater complementarity. Therefore, maintaining or increasing the abundance of functionally important species should become a key objective in future restoration projects. [ABSTRACT FROM AUTHOR]

Early indicators of restoration success can inform adaptive management strategies and maintain community interest and financial investment. Coastal wetland restoration projects prioritize monitoring the succession of habitat forming communities. However, these communities often expand slowly. In contrast, fish and crustaceans can quickly occupy newly available habitats and therefore, may be early indicators of restoration success. Here, we compared the short‐term responses of fish and crustacean communities and landcover area to restoration actions at a restoring wetland and three reference wetlands in the Maroochy River in eastern Australia. Fish and crustacean communities and landcover area were surveyed every 6 months between Spring 2017 and Spring 2019 (n = 5), with two sampling events conducted before restoration actions commenced in May 2018 and three after. Fish and crustaceans were surveyed using baited underwater video stations and fyke nets. Landcover was remotely sensed using a combination of Worldview‐2 satellite imagery, object‐based image analysis, and random forest classification. Fish and crustaceans make viable indicators for early restoration success, as our findings show the composition, diversity, and abundance of species targeted in fisheries of these communities can resemble assemblages at reference sites within 1 year of restoration actions. The area of tidal inundation significantly increased overtime, but the recovery of mangroves and saltmarsh communities did not. These findings support the notion that coastal wetland restoration can promote immediate recruitment by fish and crustacean communities, thus making these taxa useful indicators for communicating early success of restoration projects. [ABSTRACT FROM AUTHOR]

The effects of urbanisation are increasingly pervasive across landscapes, and this has implications for animals and the ecological functions they support. Differences in ecological attributes and assemblages between ecosystems means we cannot assume that different ecosystems within the same landscapes are affected by urbanisation in the same trajectory or over the same spatial scales. We test whether and how ecosystem type can modify ecological responses to urbanisation, contrasting beaches, estuaries, rocky headlands and coastal lagoons impacted by a range of urbanisation intensities on the Sunshine Coast in eastern Australia. We sampled coastal vertebrates and measured carrion scavenging, a key ecological function in all ecosystems, using baited camera traps at 85 sites distributed among five beaches (25 sites at five sites per beach), three estuaries (15 sites at five sites per estuary), four coastal lagoons (20 sites at five sites per lagoon) and five headlands (25 sites at five sites per headland). Coastal vertebrate assemblages were best predicted by the additive effects of ecosystem type and the extent of urbanisation within 5 km of each site, and this was typically characterised by increases in synanthropic species abundance at sites with high to intermediate extents of urbanisation nearby. However, two key indicator species had opposing relationships with the extent of urbanisation, and four varied only between ecosystems and not with urbanisation. Urbanisation substantially depressed rates of carrion scavenging, with some variation in species‐specific consumption rates among ecosystems. While native crows, raptors and water rats accounted for 2/3 of carrion consumed, invasive black rats and free‐ranging domestic dogs were significant consumers of carrion. Our results not only stress the pervasive effects of urbanisation on species distributions and abundance across multiple ecosystems in landscapes, but highlight that pivotal ecological functions can be compromised across multiple ecosystems embedded within the same landscape. [ABSTRACT FROM AUTHOR]

Ecosystems are increasingly degraded, fragmented and lost because of human activities globally. These impacts cause changes in the distribution of biodiversity and key ecological functions, modifications to food webs and reductions in ecosystem condition and seascape connectivity. Understanding whether, and how, the spatial context (i.e. extent, position) and condition (i.e. structure and condition of patches, including habitat forming species) of ecosystems coalesce to support their function as animal habitats is critical for effective and cost efficient coastal management. These potential combined, or interactive, effects of spatial context and habitat condition on fish assemblages are, however, rarely quantified. We sampled fish assemblages from six different ecosystems (mangrove, seagrass, saltmarsh, log snag, rocky outcrop and unvegetated sediment) across 13 estuaries in eastern Australia and quantified the relative importance of spatial context and habitat condition variables for fish assemblage composition. Spatial context variables were consistently more important than habitat condition in structuring fish abundance and diversity. Sites that were closer to smaller vegetated habitats (i.e. mangrove and seagrass) and key seascape features (i.e. estuary mouth and intertidal flats) typically supported diverse fish assemblages in high abundance. While the composition of fish assemblages was primarily linked to spatial context variables, habitat condition variables that index food availability were also important for fish in mangroves, seagrass and rocky outcrops. Our results show that fish abundance and diversity are intimately linked to seascape connectivity and heterogeneity, and have important implications for conservation planning and fisheries management decisions in coastal ecosystems. We highlight the importance of quantifying the influence of the combined effects of habitat condition and spatial context for biodiversity across multiple ecosystems, and expect the outcomes to lead to more efficient and effective management planning. [ABSTRACT FROM AUTHOR]

Restored shellfish reefs provide valuable habitat for fish, but it is not clear how different approaches affect performance, and either promote the development of new fish populations (i.e. "production") or simply attract individuals from the broader seascape (i.e. "attraction"). We measured the effects of a 1.5 ha shellfish reef restoration site on fish assemblages in Pumicestone Passage in eastern Australia, which contains replicates of six different restoration units: shell patch reefs, crates of shells, and biodegradable matrix, and each had replicates with and without live oysters. Fish were surveyed before restoration and then every 6 months for 30 months with baited (at restoration and control sites) and unbaited (at 106 sites across the seascape to detect potential fish attraction, and at the different restoration units) underwater cameras. Shellfish reef restoration represents an addition to the carrying capacity of Pumicestone Passage for fish for two key reasons. First, restoration significantly enhanced the diversity and abundance of fish assemblages and the density of harvestable fish at the restoration site by 3.8, 10.7, and 16.4 times, respectively. Second, fish distributions across the broader seascape did not change in response to succession at the restoration site. Fish assemblages did not differ between restoration units or the presence or absence of oysters. These findings further support the notion that restored shellfish reefs significantly enhance fish abundance and diversity and that restored reefs can enhance the overall carrying capacity of seascapes for fish, rather than simply centralizing them at restoration sites. [ABSTRACT FROM AUTHOR]

Ecological restoration is increasingly being upscaled to larger spatial scales of tens to hundreds of kilometers. Yet the complex logistics and high costs of ecological restoration mean that actions must be placed strategically at local scales of tens of meters to maximize ecological benefits and reduce socioeconomic costs. Despite the purported use of systematic planning tools for allocating restoration effort, the uptake and implementation of data‐driven restoration planning and ecological goal setting remains poor in many restoration programs. Here we demonstrate how the sequential workflows of systematic conservation planning can be translated to restoration at two spatial scales to enhance estuarine fisheries in eastern Australia. We select estuaries where restoration is feasible and recommended based on quantitative regional ecological goals (i.e. regional‐scale prioritization), and then identify potential restoration sites at smaller spatial scales within estuaries based on the principles of spatial ecology to ensure that the success and benefits of restoration are maximized (i.e. local‐scale prioritization). At the regional scale, we identified four levels of restoration priorities (very high, high, intermediate, and low) using quantitative ecological goals and the current ecological understanding of each system. At the local scale, we used spatially explicit Bayesian belief networks to identify sites that maximize restoration outcomes based on the environmental niche of habitat‐forming species and the spatial configuration of habitats that maximizes their use by fish. We show that using systematic frameworks can become an essential tool to optimize restoration investments at multiple scales as efforts upscale globally. [ABSTRACT FROM AUTHOR]

The structure of seafloor terrain affects the distribution and diversity of animals in all seascapes. Effects of terrain on fish assemblages have been reported from most ecosystems, but it is unclear whether bathymetric effects vary among seascapes or change in response to seafloor modification by humans. We reviewed the global literature linking seafloor terrain to fish species and assemblages (96 studies) and determined that relief (e.g. depth), complexity (e.g. roughness), feature classes (e.g. substrate types) and morphology (e.g. curvature), have widespread effects on fish assemblages. Research on the ecological consequences of terrain have focused on coral reefs, rocky reefs, continental shelves and the deep sea (n ≥ 20 studies), but are rarely tested in estuaries (n = 7). Fish associate with a variety of terrain attributes, and assemblages change with variation in the depth and aspect of bathymetric features in reef and shelf seascapes, and in the deep sea. Fish from different seascapes also respond to distinct metrics, with fluctuations in slope of slope (coral reefs), rugosity (rocky reefs) and slope (continental shelves, deep sea) each linked to changes in assemblage composition. Terrain simplification from coastal urbanization (e.g. dredging) and resource extraction (e.g. trawling) can reduce fish diversity and abundance, but assemblages can also recover inside effective marine reserves. The consequences of these terrain changes for fish and fisheries are, however, rarely measured in most seascapes. The key challenge now is to examine how terrain modification and conservation combine to alter fish distributions and fisheries productivity across diverse coastal seascapes. [ABSTRACT FROM AUTHOR]

Ecosystem functioning is positively linked to biodiversity on land and in the sea. In high‐diversity systems (e.g. coral reefs), species coexist by sharing resources and providing similar functions at different temporal or spatial scales. How species combine to deliver the ecological function they provide is pivotal for maintaining the structure, functioning and resilience of some ecosystems, but the significance of this is rarely examined in low‐diversity systems such as estuaries.We tested whether an ecological function is shaped by biodiversity in a low‐diversity ecosystem by measuring the consumption of carrion by estuarine scavengers. Carrion (e.g. decaying animal flesh) is opportunistically fed on by a large number of species across numerous ecosystems. Estuaries were chosen as the model system because carrion consumption is a pivotal ecological function in coastal seascapes, and estuaries are thought to support diverse scavenger assemblages, which are modified by changes in water quality and the urbanization of estuarine shorelines.We used baited underwater video arrays to record scavengers and measure the rate at which carrion was consumed by fish in 39 estuaries across 1,000 km of coastline in eastern Australia.Carrion consumption was positively correlated with the abundance of only one species, yellowfin bream Acanthopagrus australis, which consumed 58% of all deployed carrion. The consumption of carrion by yellowfin bream was greatest in urban estuaries with moderately hardened shorelines (20%–60%) and relatively large subtidal rock bars (>0.1 km2).Our findings demonstrate that an ecological function can be maintained across estuarine seascapes despite both limited redundancy (i.e. dominated by one species) and complementarity (i.e. there is no spatial context where the function is delivered significantly when yellowfin bream are not present) in the functional traits of animal assemblages. The continued functioning of estuaries, and other low‐diversity ecosystems, might therefore not be tightly linked to biodiversity, and we suggest that the preservation of functionally dominant species that maintain functions in these systems could help to improve conservation outcomes for coastal seascapes. [ABSTRACT FROM AUTHOR]

Ecological restoration principally seeks to restore lost or degraded ecosystems. Restoration can, however, also deliver a suite of wider ecological, social, and economic benefits. To optimize performance it is, therefore, important to plan the design and placement of restoration initiatives with a view to maximizing joint effects on ecosystems, animal populations, ecological functions, and ecosystem services. We measured the effects of multiple (13) restored oyster reefs on a suite of restoration benefits (oyster settlement and growth, fish diversity and abundance, the ecological functions of scavenging and predation) in the Noosa River estuary, Australia, and used distribution models to identify potential restoration sites with the greatest overall benefits. Oysters recruited to reefs, and reefs enhanced the diversity and abundance of fishes and had higher rates of ecological functions than control sites. However, the growth of oyster reefs was most correlated with the proximity of restoration sites to urbanized shorelines and the estuary mouth, and the area of mangroves around the site. By contrast, fish diversity and abundance, and the rates of ecological functions, were typically negatively correlated with the proximity of reefs to both mangroves and seagrasses. This complex spatial mosaic resulted in distinct areas predicted to achieve all restoration benefits that were significantly smaller than the total area that could be restored. Applying a systematic and defensible method to identify potential restoration sites that maximize multiple benefits while lowering costs is a sensible social, economic, and ecological strategy. [ABSTRACT FROM AUTHOR]

The ecological impacts of landscape modification and urbanisation have transformed the composition of plant and animal assemblages, and altered the condition of ecosystems globally. Landscape transformation influences the spatial distribution of species and ecological functions by selecting for generalist species with wide ecological niches, which can adapt to opportunities in highly‐modified environments. These effects of landscape modification can shape functional diversity on land, but it is not clear whether they have similar functional consequences in the sea. We used estuaries as a model system to test how landscape transformation alters functional diversity in coastal seascapes, and measured how variation in level of urbanisation, catchment modification and habitat loss influenced fish diversity across thirty‐nine estuaries in eastern Australia. Fish were surveyed with baited remote underwater video stations and functional diversity was indexed with three metrics that describe variation in the functional traits and niche space of assemblages. The extent of landscape transformation in the catchment of each estuary was associated with variation in the functional diversity of estuarine fish assemblages. These effects were, however, not what we expected as functional diversity was highest in modified estuaries that supported a large area of both urban and grazing land in their catchments, were bordered by a small area of natural terrestrial vegetation and that contained a moderate area of mangroves. Zoobenthivores and omnivores dominated assemblages in highly‐modified estuaries, and piscivorous fishes were common in natural waterways. Our results demonstrate, that the modification and urbanisation of ecosystems on land can alter functional diversity in the sea. Intense landscape transformation appears to select for abundant generalists with wide trophic niches, and against species with specialised diets, and we suggest that these changes might have fundamental consequences for ecosystem functioning in estuaries, and other highly modified seascapes. [ABSTRACT FROM AUTHOR]

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Humans have urbanised and fragmented landscapes across the globe, with detrimental impacts to biodiversity, habitats and food webs in most biomes. Urbanisation might also modify the provision of ecological functions, but these putative effects of landscape transformation are rarely measured. Coastal cities are typically located near estuaries, and we tested for potential impacts of these on ecological functions. Our study used 22 estuaries in eastern Australia as model systems to examine how urbanisation shapes the consumption of carrion by fish, a pivotal ecological function in estuaries. Fish assemblages varied among estuaries according to the extent of shoreline hardening, and this was correlated with changes in the rate of carrion consumption. In estuaries with low levels of shoreline hardening and abundant remnant mangroves, most carrion was consumed by toadfishes (Tetraodontidae). By contrast, in moderately urban estuaries (i.e. where 20–60% of shorelines had been hardened with artificial structures) yellowfin bream (Sparidae) replaced toadfish and performed the bulk of the scavenging function. Bream are particularly effective scavengers that utilize artificial structures as habitat for both foraging and sheltering. We show that by augmenting habitat for an important species of scavenger, the moderate addition of urban structures to estuarine shorelines also helped to supplement a key ecological function in estuaries. Urbanisation impacts diversity in all ecosystems, but many opportunistic species flourish in urban habitats. Identifying and conserving taxa that perform important roles in urban environments is now a critical conservation challenge for maintaining ecological functions across disturbed landscapes. [ABSTRACT FROM AUTHOR]

Abstract: Global declines in oyster reefs have resulted in reduced habitat heterogeneity, extent and quality for some coastal finfish, potentially reducing fish populations and catches. It is well established that habitat restoration results in higher finfish biomass and diversity where oyster reefs replace bare substrata. Therefore, restoring oyster reefs with a view to also improving fish stocks is often a key goal of oyster restoration. However, the principles of habitat quality, ecological connectivity and broader ecosystem management are poorly integrated within oyster reef restoration ecology, but such principles may be instructive in enhancing the benefits of projects on fish populations throughout estuarine seascapes. This manuscript presents a framework for projects seeking to restore both oyster reef habitat and finfish communities. Structurally and biologically complex oyster reefs, comprising both oysters and other invertebrates, are required to provide shelter, food and nursery services to fish. By carefully considering site selection at seascape scales (km to 10s of km), restoration can enhance the network of habitat available to fish and potentially increase the overall carrying capacity of the estuary. Managers of estuaries that now include restored oyster reefs should implement fisheries management plans and consider the effects of management actions broadly throughout catchments; failing to do so may jeopardize gains in fish yields. Management decisions must be adaptable, responding to key criteria in thorough monitoring programs. Integrating these ecological and coastal management concepts into oyster reef restoration will enhance outcomes for fishes and increase stakeholder engagement and cost‐effectiveness. [ABSTRACT FROM AUTHOR]

The surf zones of ocean beaches provide habitat for a diversity of fishes and are prime sites for recreational angling and commercial net fisheries. Here, we review the global literature (152 studies) on surf fish ecology to better inform fisheries management and coastal conservation planning. These studies suggest that surf zones support diverse fish assemblages, which are characterized by high numerical dominance (10 species typically comprise 95% of catches), but also show that few families are especially common. The composition of assemblages is highly variable, changing with fluctuations in water temperature, wave climate and the biomass of drifting algae or seagrass. Fish use surf zones as feeding habitats and transit routes, but these areas might not be widely used as spawning sites or juvenile nurseries. These systems are under escalating human pressures, most notably from coastal urbanization and recreational angling. Despite the recognized ecological and economic importance of surf-zone fishes, few studies have tested for impacts of urbanization or fishing. The benefits of marine reserves for fish in surf zones are also rarely measured. We suggest that progress will be made by moving from largely descriptive studies to hypothesis-driven research, which is guided by contemporary ecological theory and adapts modern techniques from research in other ecosystems. A key challenge is to obtain empirical data that are needed to improve the effectiveness of fisheries management and underpin conservation planning for coastal waters. [ABSTRACT FROM AUTHOR]

Connectivity is regarded globally as a guiding principle for conservation planning, but due to difficulties in quantifying connectivity, empirical data remain scarce. Lack of meaningful connectivity metrics is likely leading to inadequate representation of important biological connections in reserve networks. Identifying patterns in landscape connectivity can, theoretically, improve the design of conservation areas., We used a network model to estimate seascape connectivity for coral reef-associated fishes in a subtropical bay in Australia. The model accounted for two scales of connectivity: (i) within mosaics at a local scale and (ii) among these mosaics at a regional scale. Connections among mosaics were modelled using estimations of post-larval small and intermediate movement distances represented by home ranges of two fish species., Modelled connectivity patterns were assessed with existing data on fish diversity. For fishes with intermediate home ranges (0-6 km), connectivity [quantified by the index Probability of Connectivity ( dPC)] explained 51-60% of species diversity. At smaller home ranges (0-1 km), species diversity was associated closely with intramosaic connectivity quantified by the index dPCintra., Mosaics and their region-wide connections were ranked for their contribution to overall seascape connectivity and compared against current positions and boundaries of reserves. Our matching shows that only three of the 10 most important mosaics are at least partly encompassed within a reserve, and only a single important regional connection lies within a reserve., Synthesis and applications. Notwithstanding its formal recognition in reserve planning, connectivity is rarely accounted for in practice, mainly because suitable metrics of connectivity are not available in planning phases. Here, we show how a network analysis can be effectively used in conservation planning by identifying biological connectivity inside and outside present reserve networks. Our results demonstrate clearly that connectivity is insufficiently represented within a reserve network. We also provide evidence of key pathways in need of protection to avoid nullifying the benefits of protecting key reefs. The guiding principle of protecting connections among habitats can be achieved more effectively in future, by formally incorporating our findings into the decision framework. [ABSTRACT FROM AUTHOR]

Aim Disturbance and connectivity shape the structure and spatial distribution of animal populations in all ecosystems, but the combined effects of these factors are rarely measured in coastal seascapes. We used surf zones of exposed sandy beaches in eastern Australia as a model seascape to test for combined effects of coastal urbanization and seascape connectivity (i.e. spatial links between surf zones, estuaries and rocky headlands) on fish assemblages. Location Four hundred kilometres of exposed surf beaches along the eastern coastline of Australia. Methods Fish assemblages were surveyed from surf zones of 14 ocean-exposed sandy beaches using purpose-built surf baited remote underwater video stations. Results The degree of coastal urbanization and connectivity were strongly correlated with the spatial distribution of fish species richness and abundance and were of greater importance to surf fishes than local surf conditions. Urbanization was associated with reductions in the abundance of harvested piscivores and fish species richness. Piscivore abundance and species richness were lowest on highly urbanized coastlines, and adjacent to beaches in wilderness areas where recreational fishing is intense. By contrast, seascape connectivity was correlated with the spatial distribution of omnivore and planktivore abundance. Spatial linkages between surf zones and estuaries were also important to two globally threatened guitarfish that are of international conservation significance. Main conclusions We show for the first time how vulnerable and iconic fish species in surf zones are affected by the presence of coastal cities and the attributes of seascapes in which these cities are embedded. It is possible that greater connectivity may lessen 'urbanization' impacts for species with broad diets and strong ecological links to other ecosystems - this offers new perspectives in coastal conservation, for fishes and beyond. [ABSTRACT FROM AUTHOR]

The composition of species pools can vary in space and time. While many studies are focused on understanding which factors influence the make-up of species pools, the question to which degree biogeographic variation in species composition propagates to biogeographic variation in ecological function is rarely examined. If different local species assemblages operate in ways that maintain specific ecological processes across continents, they can be regarded as functionally equivalent. Alternatively, variation in species assemblages might result in the loss of ecological function if different species fulfil different functions, and thereby fail to maintain the ecological process., Here, we test whether ecological function is affected by differences in the composition of species pools across a continental scale, comparing a tropical with a temperate pool. The model systems are assemblages of vertebrates foraging on ocean beaches, and the ecological function of interest is the consumption of wave-cast carrion, a pivotal process in sandy shore ecosystems., We placed fish carcasses ( n = 179) at the beach-dune interface, monitored by motion-triggered cameras to record scavengers and quantify the detection and removal of carrion. Scavenging function was measured on sandy beaches in two distinct biogeographic regions of Australia: tropical north Queensland and temperate Victoria., The composition of scavenging assemblages on sandy beaches varied significantly across the study domain. Raptors dominated in the tropics, while invasive red foxes were prominent in temperate assemblages. Notwithstanding the significant biogeographic change in species composition, ecological function - as indexed by carcass detection and removal - was maintained, suggesting strong functional replacement at the continental scale., Species pools of vertebrate scavengers that are assembled from taxonomically distinct groups (birds vs. mammals) and located in distinct climatic regions (temperate vs. tropical) can maintain an ecological process via replacement of species with comparable functional traits. [ABSTRACT FROM AUTHOR]

Connectivity is a pivotal feature of landscapes that affects the structure of populations and the functioning of ecosystems. It is also a key consideration in conservation planning. But the potential functional effects of landscape connectivity are rarely evaluated in a conservation context., The removal of algae by herbivorous fish is a key ecological function on coral reefs that promotes coral growth and recruitment. Many reef herbivores are harvested and some use other habitats (like mangroves) as nurseries or feeding areas. Thus, the effects of habitat connectivity and marine reserves can jointly promote herbivore populations on coral reefs, thereby influencing reef health., We used a coral reef seascape in eastern Australia to test whether seascape connectivity and reserves influence herbivory. We measured herbivore abundance and rates of herbivory (on turf algae and macroalgae) on reefs that differed in both their level of connectivity to adjacent mangrove habitats and their level of protection from fishing., Reserves enhanced the biomass of herbivorous fish on coral reefs in all seascape settings and promoted consumption of turf algae. Consumption of turf algae was correlated with the biomass of surgeonfish that are exploited outside reserves. By contrast, both reserve status and connectivity influenced herbivory on macroalgae. Consumption of macroalgae was greatest on fished reefs that were far from mangroves and was not strongly correlated with any fish species., Our findings demonstrate that landscape connectivity and reserve status can jointly affect the functioning of ecosystems. Moreover, we show that reserve and connectivity effects can differ markedly depending on resource type (in this case turf algae vs. macroalgae). The effectiveness of conservation initiatives will therefore depend on our ability to understand how these multiple interactive effects structure the distribution of ecological functions. These findings have wider implications for the spatial conservation of heterogeneous environments and strengthen the case that the impact of conservation on ecosystem functioning is contingent on how reserves are positioned in landscapes. [ABSTRACT FROM AUTHOR]

1. Analyses of the distributions of northern Melanesia's avifauna have helped researchers formulate major theories of evolution, speciation, and biogeography. In comparison, the region's mammalian fauna has been the subject of few empirical analyses of biogeography. Knowledge of mammalian biogeography is needed to formulate sound conservation strategies for mammals in the region and will help further advance these theories. 2. We aim to assess the relative importance of biogeographic variables to mammalian zoogeography in northern Melanesia and empirically describe patterns of species richness. 3. Using published literature, museum data bases and our own surveys, we compiled mammal inventories for 75 islands found within northern Melanesia (comprising the Admiralty, Bismarck, D'Entrecasteaux, Louisiade, Solomon, and Trobriand Archipelagos).We used direct comparisons of family compositions and Ochiai and endemism indices to compare mammal assemblages between island groups and a defined New Guinea source pool region. Generalised linear models and non-parametric multivariate analyses were used to identify, and rank, the importance of local and regional scale abiotic variables for mammalian species richness. 4. Northern Melanesia's islands are depauperate in marsupials and have a moderate diversity of insectivorous bats and a diversity of pteropodid bats that exceeds that known to occur in the adjacent northeastern area of New Guinea. The Solomon Islands are conspicuous for their outstandingly high mammalian endemism. 5. The mammalian fauna of northern Melanesia's islands was related primarily to island size and secondarily to isolation. Island size best explained inter-island variation in total mammal species richness and bat species richness. The linear distance to New Guinea best explained the species richness of non-volant mammals. Our results reveal islands that are in need of survey focus because their mammal inventories are lower than expected for their size, and we highlight areas of endemism where conservation actions might be prioritised to prevent species extinctions. [ABSTRACT FROM AUTHOR]

Aim Connectivity structures populations, communities and ecosystems in the sea. The extent of connectivity is, therefore, predicted to also influence the outcomes of conservation initiatives, such as marine reserves. Here we review the published evidence about how important seascape connectivity (i.e. landscape connectivity in the sea) is for marine conservation outcomes. Location Global. Methods We analysed the global literature on the effects of seascape connectivity on reserve performance. Results In the majority of cases, greater seascape connectivity inside reserves translates into better conservation outcomes (i.e. enhanced productivity and diversity). Research on reserve performance is, however, most often conducted separately from research on connectivity, resulting in few studies (< 5% of all studies of seascape connectivity) that have quantified how connectivity modifies reserve effects on populations, assemblages or ecosystem functioning in seascapes. Nevertheless, evidence for positive effects of connectivity on reserve performance is geographically widespread, encompassing studies in the Caribbean Sea, Florida Keys and western Pacific Ocean. Main conclusions Given that research rarely connects the effects of connectivity and reserves, our thesis is that stronger linkages between landscape ecology and marine spatial planning are likely to improve conservation outcomes in the sea. The key science challenge is to identify the full range of ecological functions that are modulated by connectivity and the spatial scale over which these functions enhance conservation outcomes. [ABSTRACT FROM AUTHOR]

Species composition is expected to alter ecological function in assemblages if species traits differ strongly. Such effects are often large and persistent for nonnative carnivores invading islands. Alternatively, high similarity in traits within assemblages creates a degree of functional redundancy in ecosystems. Here we tested whether species turnover results in functional ecological equivalence or complementarity, and whether invasive carnivores on islands significantly alter such ecological function. The model system consisted of vertebrate scavengers (dominated by raptors) foraging on animal carcasses on ocean beaches on two Australian islands, one with and one without invasive red foxes (Vulpes vulpes). Partitioning of scavenging events among species, carcass removal rates, and detection speeds were quantified using camera traps baited with fish carcasses at the dune-beach interface. Complete segregation of temporal foraging niches between mammals (nocturnal) and birds (diurnal) reflects complementarity in carrion utilization. Conversely, functional redundancy exists within the bird guild where several species of raptors dominate carrion removal in a broadly similar way. As predicted, effects of red foxes were large. They substantially changed the nature and rate of the scavenging process in the system: (1) foxes consumed over half (55%) of all carrion available at night, compared with negligible mammalian foraging at night on the fox-free island, and (2) significant shifts in the composition of the scavenger assemblages consuming beach-cast carrion are the consequence of fox invasion at one island. Arguably, in the absence of other mammalian apex predators, the addition of red foxes creates a new dimension of functional complementarity in beach food webs. However, this functional complementarity added by foxes is neither benign nor neutral, as marine carrion subsidies to coastal red fox populations are likely to facilitate their persistence as exotic carnivores. [ABSTRACT FROM AUTHOR]

Recent assessments of marine reserves have emphasized the importance of socio-economic factors in reserve performance. Debates continue, however, about whether we should avoid or promote the placement of reserves near potentially detrimental forces, including coastal cities or rivers. We performed a global meta-analysis to test whether proximity to major coastal influences affected the ability of marine reserves to enhance the abundance of organisms relative to surrounding areas. A strong effect of reserve performance was evident for a range of trophic groups. Positive effects of reserves were undiminished by proximity to coastal cities or river discharges for the majority of taxonomic groups under conservation. We conclude that reserves placed in coastal areas are likely to protect marine populations to a similar extent as reserves in remote or less-developed locations. Marine reserves in coastal settings can be an important tool to protect species and ecosystems in places threatened by human activities. [ABSTRACT FROM AUTHOR]

The relationship between ecological impact and ecosystem structure is often strongly nonlinear, so that small increases in impact levels can cause a disproportionately large response in ecosystem structure. Nonlinear ecosystem responses can be difficult to predict because locally relevant data sets can be difficult or impossible to obtain. Bayesian networks (BN) are an emerging tool that can help managers to define ecosystem relationships using a range of data types from comprehensive quantitative data sets to expert opinion. We show how a simple BN can reveal nonlinear dynamics in seagrass ecosystems using ecological relationships sourced from the literature. We first developed a conceptual diagram by cataloguing the ecological responses of seagrasses to a range of drivers and impacts. We used the conceptual diagram to develop a BN populated with values sourced from published studies. We then applied the BN to show that the amount of initial seagrass biomass has a mitigating effect on the level of impact a meadow can withstand without loss, and that meadow recovery can often require disproportionately large improvements in impact levels. This mitigating effect resulted in the middle ranges of impact levels having a wide likelihood of seagrass presence, a situation known as bistability. Finally, we applied the model in a case study to identify the risk of loss and the likelihood of recovery for the conservation and management of seagrass meadows in Moreton Bay, Queensland, Australia. We used the model to predict the likelihood of bistability in 23 locations in the Bay. The model predicted bistability in seven locations, most of which have experienced seagrass loss at some stage in the past 25 years providing essential information for potential future restoration efforts. Our results demonstrate the capacity of simple, flexible modeling tools to facilitate collation and synthesis of disparate information. This approach can be adopted in the initial stages of conservation programs as a low-cost and relatively straightforward way to provide preliminary assessments of nonlinear dynamics in ecosystems. [ABSTRACT FROM AUTHOR]

Aim Globally, urbanization is one of the most widespread, intense and ecologically destructive forms of landscape transformation, and it is often concentrated in coastal areas. Theoretically, species losses attributable to urbanization are predicted not to alter overall ecosystem function if functional redundancy (i.e. replacement of function by alternative species) compensates for such losses. Here, we test this expectation by measuring how coastal urbanization affects scavenger guilds on sandy beaches and whether changes in guild composition result either in an overall loss of scavenging efficiency, or in functional compensation under alternative guild structures, maintaining net ecosystem functioning. Location Fourteen beaches along the east coast of Australia with variable levels of urbanization. Methods Scavenging communities and rates of carrion removal were determined using motion-triggered cameras at the beach-dune interface. Results A substantial shift in the community structure of vertebrate scavengers was associated with gradients in urbanization. Iconic and functionally important raptors declined precipitously in abundance on urban beaches. Importantly, other vertebrates usually associated with urban settings (e.g. dogs, foxes, corvids) did not functionally replace raptors. In areas where < 15% of the abutting land had been developed into urban areas, carcass removal by scavengers was often complete, but always > 70%. Conversely, on beaches bordering coastal cities with < 40% of natural vegetation remaining, two-thirds of fish carcasses remained uneaten by scavengers. Raptors removed 70-100% of all deployed fish carcasses from beaches with < 8% urban land cover, but this number dropped significantly with greater levels of urbanization and was not compensated by other scavenger species in urban settings. Main conclusions There is limited functional redundancy in vertebrate scavenger communities of sandy beach ecosystems, which impacts the system's capacity to mitigate the ecological consequences of detrimental landscape transformations. [ABSTRACT FROM AUTHOR]

Natural ecosystems have experienced widespread degradation due to human activities. Consequently, enhancing resilience has become a primary objective for conservation. Nature reserves are a favored management tool, but we need clearer empirical tests of whether they can impart resilience. Catastrophic flooding in early 2011 impacted coastal ecosystems across eastern Australia. We demonstrate that marine reserves enhanced the capacity of coral reefs to withstand flood impacts. Reserve reefs resisted the impact of perturbation, whilst fished reefs did not. Changes on fished reefs were correlated with the magnitude of flood impact, whereas variation on reserve reefs was related to ecological variables. Herbivory and coral recruitment are critical ecological processes that underpin reef resilience, and were greater in reserves and further enhanced on reserve reefs near mangroves. The capacity of reserves to mitigate external disturbances and promote ecological resilience will be critical to resisting an increased frequency of climate-related disturbance. [ABSTRACT FROM AUTHOR]

Conservation focuses on maintaining biodiversity and ecosystem functioning, but gaps in our knowledge of species biology and ecological processes often impede progress. For this reason, focal species and habitats are used as surrogates for multispecies conservation, but species-based approaches are not widely adopted in marine ecosystems. Reserves in the Solomon Islands were designed on the basis of local ecological knowledge to conserve bumphead parrotfish ( Bolbometopon muricatum) and to protect food security and ecosystem functioning. Bumphead parrotfish are an iconic threatened species and may be a useful surrogate for multispecies conservation. They move across tropical seascapes throughout their life history, in a pattern of habitat use that is shared with many other species. We examined their value as a conservation surrogate and assessed the importance of seascape connectivity (i.e., the physical connectedness of patches in the seascape) among reefs, mangroves, and seagrass to marine reserve performance. Reserves were designed for bumphead parrotfish, but also enhanced the abundance of other species. Integration of local ecological knowledge and seascape connectivity enhanced the abundance of 17 other harvested fish species in local reserves. This result has important implications for ecosystem functioning and local villagers because many of these species perform important ecological processes and provide the foundation for extensive subsistence fisheries. Our findings suggest greater success in maintaining and restoring marine ecosystems may be achieved when they are managed to conserve surrogate species and preserve functional seascape connections. Incorporación de Especies Sustitutas y de Conectividad Marina para Mejorar los Resultados de Conservación [ABSTRACT FROM AUTHOR]

Severe events such as floods or cyclones can have large ecological effects on the structure and functioning of ecosystems. The capacity of an ecosystem to adapt to, or absorb, the effects of a severe event depends on the severity and longevity of the event and the tolerance of the species present., Seagrasses exhibit phenotypic plasticity at the plant to meadow scale through a variety of physiological and morphological acclimations to light stress to enhance photosynthetic capacity. These acclimations provide early warning of the possible risk of larger scale seagrass loss and can therefore be used in predicting how ecosystems might respond to severe events., The physiological and morphological responses of 12 seagrass ( Zostera muelleri) meadows to a severe flood were examined to test two main hypotheses: (i) that the physiological and morphological characteristics of seagrass would differ between meadows along the established chronic water quality gradient, in a pattern consistent with prior acclimations which have been shown to enhance photosynthetic capacity and (ii) that physiological and morphological responses to the flood would differ between meadows in a manner consistent with their position along the water quality gradient., Meadows had different physiological and morphological characteristics across the water quality gradient, with meadows subject to chronically poorer water quality exhibiting characteristics consistent with those that maximize photosynthetic capacity. Despite a large discrepancy in impact among meadows, all meadows sampled responded consistently to the flood, exhibiting only physiological changes with no significant reduction in biomass. This suggests that photoacclimation to chronically poor conditions can enable seagrasses to withstand the effects of severe events, such as floods., Synthesis. Phenotypic plasticity in habitat-forming species can result in a large variation in their responses to severe events, such as floods or cyclones. Acclimation to prior poor environmental conditions can promote persistence in habitat-forming species, such as seagrasses, following severe events. The measurement of phenotypic characteristics along an impact gradient can therefore provide an indication of the response of habitat-forming species to severe events. [ABSTRACT FROM AUTHOR]

Aim To evaluate the potential of habitat connectivity to promote the effectiveness of marine reserves. We used heterogeneous reef seascapes as a model system to examine the potential interaction of reserves and mangrove-reef connectivity and compared the magnitude of these effects across the western Pacific Ocean. Location The tropical and subtropical western Pacific, including the Solomon Islands, Great Barrier Reef and Moreton Bay, Australia. Methods We quantified fish densities on coral reefs (38 sites) and in mangrove forests (19 sites) across seven marine reserves and twelve unprotected control locations. Fish assemblages were in seascapes supporting either adjacent reefs and mangroves or isolated reefs. For each reserve-control comparison, we evaluated the potential interactive effects of habitat connectivity on species richness and densities of harvested species, functional groups, families and individual species. We then examined the influence of spatial variation in reserve attributes, seascape heterogeneity and latitude on the magnitude of reserve-connectivity effects. Results Snappers ( Lutjanidae) and rabbitfish ( Siganidae) were more abundant on reserve reefs close to mangroves in all regions. These interactive effects also enhanced the abundance of sweetlip ( Haemulidae), bream ( Sparidae), harvested fish, herbivores and piscivores and species richness in two of the three regions examined. Spatial variation in the magnitude of reserve-connectivity effects was explained by differences among reserves in seascape variables (i.e. area of mangroves and reef, duration of mangrove inundation and distance to rivers) but not by reserve attributes (i.e. age, size, poaching) or latitude. Main conclusions Habitat connectivity improved the effectiveness of reserves across the western Pacific Ocean. We recommend that heterogeneous landscapes with high-habitat connectivity should be viewed as high priorities for conservation. By improving our understanding of connectivity, and through its explicit incorporation into conservation, we may have greater success in restoring biodiversity and functioning of ecosystems. [ABSTRACT FROM AUTHOR]

In light of the global extent and cascading effect of our impact on the environment, we design and manage reserves to restore biodiversity and the functioning of ecosystems. Mobile organisms link important processes across ecosystems, however, their roles in providing these services are often overlooked and we need to know how they influence ecosystem functions in reserves. Herbivorous fish play a key role in coral reef seascapes. By removing algae, they promote coral growth and recruitment, and help to increase resilience., We examined how connectivity with mangroves affected herbivore populations and benthic succession on reefs in eastern Australia. We surveyed fish assemblages, examined reef composition and characterised benthic recruitment on reefs at multiple levels of connectivity with mangroves, in a no-take reserve and areas open to fishing., Our results show that connectivity enhanced herbivore biomass and richness in reserves, and that these connectivity and reserve effects interacted to promote herbivory on protected reefs near mangroves., Connectivity and reserve protection combined to double the biomass of roving herbivorous fish on protected reefs near mangroves. The increase in grazing intensity drove a trophic cascade that reduced algal cover and enhanced coral recruitment and reef resilience., Synthesis and applications. Our findings demonstrate that ecosystem resilience can be improved by managing both reefs and adjacent habitats together as functional seascape units. By understanding how landscapes influence resilience, and explicitly incorporating these effects into conservation decision-making, we may have greater success with environmental restoration and preservation actions. [ABSTRACT FROM AUTHOR]

Connectivity is now a common consideration in conservation planning, but we need further empirical evidence for the role of connectivity in catalyzing reserve function. We examined whether connectivity improved reserve performance by investigating how isolation between coral reefs and mangroves influenced fish assemblages inside and outside a reserve in Moreton Bay, Australia. Connectivity greatly enhanced reserve performance, with close reserve habitats supporting more harvested fish, and a greater abundance of both piscivores and herbivores than similar nonreserve locations. Close reserve habitats also contained fewer prey fish than nonreserve locations. In contrast, fish abundance in isolated reserve habitats did not differ from similar nonreserve locations. We demonstrate that connectivity can improve the performance of a reserve in promoting fish abundance. We highlight its importance for maintaining ecological processes in reserves and advocate the prioritization of areas of similarly connected habitat for conservation. [ABSTRACT FROM AUTHOR]