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Unvegetated, open mudflat areas are a dominant feature of tropical coastlines, relatively productive and known to support high ichthyofaunal diversity. However, the mudflat's food web is poorly characterized, especially the primary production that supports it and the degree of dependence on adjacent mangroves. In this study, we investigated the trophodynamics of vagile fish fauna utilizing a large tropical intertidal mudflat area during high tide in Klang, Malaysia, using stomach content and stable isotope (carbon and nitrogen) approaches. Cluster analysis revealed that 53 major fish species using the mudflats, which comprised mainly of juveniles, can be grouped into eight dietary guilds implying a variable degree of food resource partitioning among species. The dominant guild of "shrimp feeders" and all other guilds prey on shrimps of the families Penaeidae and Sergestidae to varying degrees. These abundant crustaceans constitute the prevalent shared prey resource, ecologically important to the co-existence of many mudflat fishes. Stable isotope analysis revealed four to five trophic levels in a relatively complex food web fueled not only by microphytobenthos but also phytoplankton in highly turbid waters. Close pelagic–benthic coupling due to shallow waters and strong tidal mixing probably sustains the mudflat's primary production and relatively high number of trophic levels despite the transitory and highly dynamic environment. The mudflat's autochthonous production and diverse prey resources highlight the importance of this often overlooked coastal habitat especially in supporting the early life stage of diverse fish species and, thus, coastal fisheries. [ABSTRACT FROM AUTHOR]

In dynamic environments, resource availability may change by several orders of magnitude, over hours to months, but the duration of resource availability is not often included as a characteristic attribute of resources even though temporal resource dynamics might limit patterns of use. In our study of wading birds foraging in intertidal areas, tides cause large changes in the areal extent of shallow‐water foraging habitat (i.e., the resource), but tides also constrain the duration of availability, which is often overlooked. We hypothesized that temporal constraints on habitat availability from tides would be reflected in patterns of habitat use by foraging birds. We estimated the time‐integrated habitat availability and compared it to traditional habitat attributes (seagrass cover, substrate type, instantaneous water depth, and proximity to mangrove islands or deep water) that have strong evidential support for influencing patterns of use. To evaluate our hypotheses, we quantified habitat attributes at intertidal areas in the Florida Keys, USA, where wading birds were observed foraging (Little Blue Heron, Egretta caerulea: N = 183; Great White Heron, Ardea herodias occidentalis: N = 162). We tested for nonrandom use by sampling habitat attributes at two spatial scales around the observed feeding locations and we analyzed the data using a conditional logistic regression model. There was no evidence that seagrass cover or substrate explained patterns of use. The proximity of foraging locations relative to mangroves and to deep water were important at both spatial scales but had lower effect sizes (odds ratios) than time‐integrated habitat availability and water depth, and the latter may only serve as a physical constraint on access. We found support that time‐integrated habitat availability was a distinct resource attribute, had the greatest effect size (four‐ to eightfold change in relative probability of use), and best explained patterns of habitat use at the largest spatial scale. In studies of resource use where changes in resource availability are nonlinear or when strong constraints on access are imposed by behavior, incorporating time‐integrated estimates of resource availability into analyses can improve insights into spatiotemporal patterns of resource use. [ABSTRACT FROM AUTHOR]

One of the main limitations found in the numerical models available to simulate seagrass dynamics is the absence of processes that differentiate intertidal from subtidal seagrass meadows, namely the desiccation undergone by the leaves when emerged. The main objective of this work is therefore to contribute towards the mechanistic development and testing of a desiccation module to be later coupled with a numerical seagrass model, discussing its limitations and potential further improvements. The formulations proposed were established from both literature revision and data analysis from a field experiment performed in intertidal meadows of Zostera noltei in Ria de Aveiro lagoon (NW Portugal). The Relative Water Content ( RWC ), defined as a dynamic variable, depended on hydration and desiccation of seagrass leaves when exposed to air. The results showed that the module responded well to distinct tidal conditions (spring vs neap tides), different air temperature scenarios and sediment type based on grain size. Higher losses on RWC of seagrass leaves occur at spring tides, with higher air temperatures (over 38 °C), longer air-exposure periods, colonizing medium sized sand sediments. This work provides new tools for further improvements in the simulation of intertidal seagrass dynamics when subjected intermittently to air exposure periods and abnormally high air temperatures, contributing to advances of the already existent models in a context of global changing environment. [ABSTRACT FROM AUTHOR]

Light adaptive strategies were studied in a comparative analysis of the congeneric seagrass species Zostera muelleri and Zostera marina at two case study areas in New Zealand and Germany. Surveys in intertidal seagrass meadows were conducted from pre-dawn until sunset on days when either low or high tide coincided with noon. The results show marked fluctuations of photophysiology (optimum and effective quantum yield, non-photochemical quenching, cycling of xanthophyll cycle (XC) pigments) over daily and tidal cycles. At both locations, we observed a near complete conversion (de-epoxidation) of violaxanthin to zeaxanthin at times with high irradiance and a rapid and complete re-epoxidation under subsequent lower light conditions. At the New Zealand site we also observed significantly larger XC-pigment pool sizes in seagrass leaves sampled in a week when low tide coincided with noon (larger daily fluence and higher maximum irradiance), compared with leaves sampled in a week when high tide was at noon. This dynamic adjustment of xanthophyll pool size has not been previously reported for intertidal seagrasses. It adds to our understanding of an important adaptive feature in a highly dynamic light environment and to the general ecology and adaptability of seagrasses. [ABSTRACT FROM PUBLISHER]

The mangrove killifish Kryptolebias hermaphroditus is reported to the southeast and northeast regions of Brazil. Recently, a specimen of K. hermaphroditus was collected in a shallow running seawater stream at Ajuruteua beach, Pará state, northern Brazil. This new record is ca. 1,350 km from the nearest previously known occurrence in Rio Grande do Norte state, Brazil. Morphological, molecular, and ecological aspects of this species are described. [ABSTRACT FROM AUTHOR]

This study aimed to evaluate the effects of protection from extractive activities on the population structure of two limpets of commercial interest, Patella ulyssiponensis and Patella candei crenata. We evaluated the status of these populations in La Palma Marine Protected Area (MPA), Canary Islands, and in comparable unprotected areas in the lower intertidal zone of the same island. We showed that the density of P. ulyssiponensis depended greatly on the level of protection, whereas the effects of protection on the density of P. candei crenata were less clear and only differences between sites were found. These results are probably linked to the different habitat affinities of the two species studied and demonstrate the need to tailor conservation strategies in MPAs to individual species for appropriate management of local shellfish resources.

Mangrove forest rehabilitation should begin much sooner than at the point of catastrophic loss. We describe the need for “mangrove forest heart attack prevention”, and how that might be accomplished in a general sense by embedding plot and remote sensing monitoring within coastal management plans. The major cause of mangrove stress at many sites globally is often linked to reduced tidal flows and exchanges. Blocked water flows can reduce flushing not only from the seaward side, but also result in higher salinity and reduced sediments when flows are blocked landward. Long-term degradation of function leads to acute mortality prompted by acute events, but created by a systematic propensity for long-term neglect of mangroves. Often, mangroves are lost within a few years; however, vulnerability is re-set decades earlier when seemingly innocuous hydrological modifications are made (e.g., road construction, blocked tidal channels), but which remain undetected without reasonable large-scale monitoring. [ABSTRACT FROM AUTHOR]

The Delta Works, a series of dams and barriers constructed in the 1960's–1980's changed the estuarine landscape of the Rhine-Meuse-Scheldt delta (SW Netherlands) into more stagnant and disengaged freshwater, brackish water or saltwater lakes. The remaining tidal systems were adapted by building a storm surge barrier in the Oosterschelde and dike reinforcement works along the Westerschelde. The Delta Works brought protection against flooding, but at the same time resulted in environmental and socio-economic problems, such as degradation of ecological quality and ecosystem functioning, disruption of fish migration routes, water and sediment quality problems. In this study we explore in an integrated, quantitative way the consequences of a number of management options for the Southwest Delta and their implications for the occurrence and distribution of aquatic and estuarine habitats, considering the mutual coherence between the water basins. Five scenarios were evaluated using a 1D hydraulic, water quality and primary production numerical model and GIS habitat mapping. Scenarios vary from small-scale interventions, such as changes in day-to-day management of hydraulic infrastructures or creation of small inlets in dams, feasible in the short term, to restoration of an open delta by removing dams and barriers, as a long term potential. We evaluate the outcomes in relation to the restoration of estuarine dynamics, as this is in policy plans proposed as a generic solution for the current ecological and environmental problems. Net water flow rates show more complex patterns when connectivity between water basins is increased and when sluice management is less strict. Estuarine transition zones and fish migration routes are partly restored, but only fully develop when basins are in open connection with each other. Area of intertidal habitats, tidal flats and tidal marshes, increases in each scenario, ranging between 7 and 83%, 1–56%, and 8–100% respectively, depending on scenario. Large scale infrastructural adaptations are needed to restore estuarine dynamics at large scale. The use of a 1D numerical model allowed to quantify the effect of different management measures for all water basins simultaneously, but also has its limitations. The model does not resolve more complex processes such as vertical mixing and morphodynamic changes. This requires expert judgment and more detailed 3D modelling. [ABSTRACT FROM AUTHOR]

Pacific islands are particularly vulnerable to the effects of invasive species. After habitat destruction or modification, invasive species are responsible for more biological extinctions than any other cause. Further, the rate of extinction of native species has been higher on islands than anywhere else in the world. Invasive species have also degraded native ecosystems. In order to detect exotic intertidal mollusk species, an extensive sampling around Moorea Island, a more or less unspoiled island surrounded by a rich coral reef habitat, has been developed considering that sampled points have different characteristics in wave exposure, algae coverage, type of substrate, distance to ports, distance to freshwater, distance sewage and boat traffic. Samples were DNA barcoded for unequivocal species assignation. The presence of five NIS among 26 species seems an important signal of introduction of alien biota in Moorea Island coast. However they were represented by a total of 38 individuals among 1487 mollusks (2.55%). While the distance to relatively big ports influenced directly species richness, the intensity of maritime traffic measured as boat density near sampling points was significantly associated with the frequency of exotic species. Other environmental factors did not show significant correlation with the frequency of exotics, suggesting that in an environment without big discontinuities, with little habitat modification, local boat traffic is the most influential factor in the spread of exotic species. This could be mitigated relatively easily by reducing boat density in local zones of ecological interest. [ABSTRACT FROM AUTHOR]

Shellfish aquaculture is a widely practiced way of producing food for human consumption in coastal areas. When farming intertidal clams, farmers commonly protect young seedling clams from predatory losses by covering farmed plots with netting or screening. Recent discussion of the effectiveness of protective nets or screens and their environmental effects has raised questions concerning the utility of the practice. We provide data based on a review of more than 35 peer-reviewed articles, as well as our own research that demonstrates the efficacy of predator protection for clam farms in various habitats around the world. In addition, we evaluate the effects of screening on temperature, and comment on ancient practices of clam gardening as conducted in the Pacific Northwest. [ABSTRACT FROM AUTHOR]

An overview of the efficacy of anti-predator netting (APN) used by the shellfish industry is presented. There is little support that the currently favored APN effectively protects farmed clams from predators. Evidence does suggest that APN leads to impacts and pollution. APN is an attractant for predators, e.g., crabs, by providing a refuge within Ulva sp. which attaches onto the surface of APN. APN entrains silt and organic matter and increases sediment temperatures degrading habitat underneath the APN. APN present hazards to fish and wildlife and is a source of plastics to the marine environment. The continued use of ineffective APN does not serve either the environment or industry well, and many of these issues could be addressed through the alternate use of “ancient” technology used by aboriginal people to maintain clam gardens; building of rock walls optimizing the amount of clam habitat thereby increasing numbers without the use of APN. [ABSTRACT FROM AUTHOR]

The article discusses a research paper on genome evolution in mangroves, which references a study by Lyu et al., published within the issue of "New Phytologist". It tackles two non-exclusive possibilities on how mangrove genomes have become small, the growth of mangroves and the adaptive benefit of genome size reduction in mangroves.

Highlights: [•] We conducted a survey at different sites with contrasting sediment conditions. [•] Seagrass metrics and pigment composition varied strongly with site. [•] Possible interactions with environmental conditions are discussed. [•] Pigment compositions reflected site characteristics. [•] Zostera muelleri is well adapted to intertidal habitat through high pigment plasticity. [Copyright &y& Elsevier]

Highlights: [•] The phylogenetic relationships of combtooth blennies are resolved using four nuclear loci. [•] The taxonomy of combtooth blennies is redefined to maintain consistency with phylogeny. [•] The ancestral habitat of blennies is likely subtidal. [•] Four independent invasions of intertidal habitats were identified. [Copyright &y& Elsevier]

Qualitative rapid assessments and taxonomic surveys of decapod crustaceans were carried out along the entire coastline of Qeshm Island in the Persian Gulf. Shore morphology and habitat distribution were examined. Simultaneously, decapod samples were collected from 40 selected sites. In total, 131 species from five different infraorders were identified, of which 61 were recorded for the first time from Qeshm Island and 18 species were new records for the Persian Gulf. The Brachyura possessed the highest species richness (73 species, 56 %) within the different infraorders. Among the surveyed habitats, the combined habitat 'rocky/cobble', occurring mainly along the south coast, had the highest species diversity. Rocky shores were dominated by Grapsus albolineatus, Metopograpsus messor, and Eriphia smithii. Cobble beaches were dominated by Leptodius exaratus, Epixanthus frontalis, Clibanarius signatus, Nanosesarma sarii, Petrolisthes spp. and Alpheus lobidens. Mudflats and mangrove forests, typical habitats of the north coast of Qeshm Island, were bordered along their landward fringe with Nasima dotilliformis and Uca sindensis, which were accompanied by Uca iranica in some places with coarser sediments. On muddy substrate and among mangroves, Metopograpsus messor, Parasesarma persicum, Eurycarcinus orientalis, Macrophthalmus depressus, Metaplax indica, Ilyoplax stevensi, Manningis arabicum, Opusia indica and Alpheus lobidens were the most common species. Exposed sandy beaches, mainly found on the south coast, were inhabited by Ocypode rotundata and Coenobita scaevola in high-intertidal and supralittoral zones, respectively. Emerita holthuisi occurred slightly lower in the mid-intertidal zone of relatively steep beaches where Diogenes avarus and Ryphila cancellus were found whenever the sandy beach was relatively flat. Intertidal habitats of the island are generally in relatively good condition compared with the other Persian Gulf states. [ABSTRACT FROM AUTHOR]

Spartina alterniflora Loisel., widely recognised as an aggressive invader of estuaries and salt marshes around the world, was discovered growing in the temporarily open/closed Great Brak Estuary on the southern Cape coast of South Africa in 2004. This is the first record of this invasive plant in Africa as well as its first occurrence in an estuary that closes to the sea. Plant traits and sediment characteristics were measured in 2009 and 2011 and found to be comparable to those reported elsewhere. Prior to the 2011 sampling, S. alterniflora stands had been flooded for almost eight months. As a result, sediment redox potential (−268 + 4 mV) was significantly lower in 2011. Sediments were mostly clay in 2009 (71 ± 0.01%) compared to a predominance of sand in 2011 (40 ± 0.02%). These differences were related to the artificial breaching of the estuary one month prior to sampling in March 2011. The grass currently occupies 1.1 ha in the salt marsh, sandflat and mudflat habitats of the estuary where its cover is expanding at a rate of 0.162 ha y−1. Individual stands numbered about 12 in 2006, but have increased to 24 in 2011. These stands are expanding laterally at 0.9 m y−1 although the long period of inundation during 2010 reduced this to 0.6 m y−1. Expansion is due to vegetative spread as an analysis of the sediment seed bank showed no S. alterniflora seeds and very few salt marsh seeds (1 132 seeds m−2). If left unchecked, S. alterniflora has the potential to replace 42.9 ha or 41% of the total estuary habitat in the Great Brak Estuary, but also has the potential to invade other estuaries in South Africa, especially those with extensive intertidal habitat and containing S. maritima (19 estuaries in total). This study illustrates the adaptive potential of this invasive marsh plant and indicates the possibility of invasion in seasonally closed estuaries in other locations around the world. [ABSTRACT FROM AUTHOR]

It is often presumed that salt marshes provide a predation refuge for small fishes, but predation risks have rarely been compared in intertidal and subtidal habitats, making the importance of salt marshes as a predation refuge speculative. We measured relative survival of tethered mummichog ( Fundulus heteroclitus) in four habitats in a salt marsh-tidal creek system: unvegetated and vegetated intertidal areas and the subtidal creek at high and low tide. At high tide, mummichog in the intertidal zone had significantly higher survival than in the subtidal creek in June through August. Survival rates in unvegetated and vegetated intertidal habitats were not significantly different, suggesting that higher intertidal survival was due to less abundant predators compared with the creek, rather than predators being less effective in vegetation. The lower predation risk experienced by mummichog in the intertidal marsh suggests that access to intertidal habitats will be important for production of small estuarine fishes. [ABSTRACT FROM AUTHOR]

Bembidion (Lymnaeum) nigropiceum (Marsham) (=puritanum Hayward), a European species introduced into Massachusetts but presumed not to have become established, has been rediscovered during the Boston Harbor Islands All Taxa Biodiversity Inventory undertaken by the Museum of Comparative Zoology and the National Park Service. A summary is presented of treatment of this species in North America. Data on specimens collected are presented, along with observations on habitat and biology. Some speculations are presented about its highly specialized habitat in the gravel pushed up by high tide, which may act as a food-trapping sieve. A few words are included about future actions needed to resolve questions of distribution and behavior. [ABSTRACT FROM AUTHOR]

Abstract: We used an established seagrass monitoring programme to examine the short and longer-term impacts of an oil spill event on intertidal seagrass meadows. Results for potentially impacted seagrass areas were compared with existing monitoring data and with control seagrass meadows located outside of the oil spill area. Seagrass meadows were not significantly affected by the oil spill. Declines in seagrass biomass and area 1month post-spill were consistent between control and impact meadows. Eight months post-spill, seagrass density and area increased to be within historical ranges. The declines in seagrass meadows were likely attributable to natural seasonal variation and a combination of climatic and anthropogenic impacts. The lack of impact from the oil spill was due to several mitigating factors rather than a lack of toxic effects to seagrasses. The study demonstrates the value of long-term monitoring of critical habitats in high risk areas to effectively assess impacts. [Copyright &y& Elsevier]

Temperature and salinity were logged every 35 min during 52 days in April and May at a well-known spawning beach for capelin (Mallotus villosus) in Balsfjord, northern Norway. Two loggers were located either on or within the gravel of the spawning ground, whereas a reference logger was deployed 1 m below the lowest astronomical tide (LAT). The temperature on the gravel ranged from -5.3 to 26.7°C with an overall mean of 6.2±3.6°C. The diurnal temperature fluctuations (i.e. the difference between the daily maximum and minimum temperature, ▵T) varied between 3.9 and 20.8°C. Sub-zero temperatures were registered neither within the gravel nor at the reference site and the overall temperature for these loggers fluctuated considerably less than on the gravel. The salinity on the surface of the gravel fluctuated markedly (5.2-28.6 psu) and contrasted the salinities registered within the gravel (1.8-6.3 psu) and below LAT (14.0-30.0 psu). The results suggest that beach-spawned capelin eggs have evolved an array of biological adaptations to survive the unpredictable physical conditions of an intertidal habitat. [ABSTRACT FROM AUTHOR]

Distribution and structure of intertidal macrobenthic communities in the Zwin nature reserve, a lagoonal inlet consisting of marsh and tidal flat habitats, was investigated using univariate and multivariate analyses. Macrobenthos community structure was related to environmental characteristics and discussed in the framework of the implemented extension of the nature reserve.Based on explorative multivariate techniques, five different sample groups (SGs) were distinguished, which were, in general, located in different habitats of the Zwin nature reserve. The ecologically most important SGs consisted of the highest macrobenthic density, diversity and highest densities of Nereis diversicolor and Scrobicularia plana; these important prey species for wading birds and fish occurred in the deep tidal inlet channels. This habitat was characterized by fine to medium sand sediment and strong tidal currents, guaranteeing water renewal at each high tide. Other SGs were found in less and erratically submersed and thus stressed areas (i.e. tidal pond, salt pans and shallow flats). These assemblages were characterized by typical r-strategists (i.e. Capitella capitata and Polydora cornuta) and typical supralittoral, mobile species (i.e. Orchestia gammarellus and Collembola spp.). Being ecologically most important, the extension of wide, tidal creeks should be a prime target within the future development and management of the nature reserve. [ABSTRACT FROM PUBLISHER]

Managed realignment has aroused increasing interest over the past decade, reflecting a growing awareness of the high cost of holding the line, the widespread trend of coastal squeeze, and the potentially adverse effects of accelerated sea level rise. This comparative study of England's and Germany's approaches to managed realignment sought to explore similarities and differences and hence provide insights on its future use. Although consideration of managed realignment is widely perceived as a positive development, important and sometimes surprising differences were found concerning its application. This reflects various factors ranging from the physical landscape and the state of coastal defences to cultural factors. Existing schemes are mostly concentrated on the coasts of eastern England and the German federal states of Lower Saxony and Mecklenburg-Western Pomerania. Managed realignment in England, and to some extent on Germany's Baltic Sea coast, seems driven by longer term factors, such as the desire to create more sustainable flood defences and to provide new intertidal habitats, although these are often combined with the more immediate need to upgrade defences. On Germany's well-defended North Sea coast, managed realignment has only been undertaken for specific compensation reasons, although broader conservation concerns might become an important future driver for managed realignment in summer polders. Thus managed realignment is now firmly on the agenda in both countries, reflecting a radical departure from the recent past, in which protection was the only possible response. However, application is likely to differ significantly both between and within these countries. [ABSTRACT FROM AUTHOR]

Intertidal and shallow subtidal boulder fields are relatively uncommon along the coast of New South Wales, Australia. Nevertheless, they provide habitat for a diverse suite of species, many of which are seldom found in other habitats. The types and abundances of animals found on or under boulders can be influenced by features of the boulders themselves, or by features of the substratum on which a boulder lies. Boulders can be colonized by larvae, or by adult or juvenile animals drifting in the water column or crawling up from the substratum. This experiment investigated the effect of an algal or sandy substratum on early stages of colonization of new boulders in two boulder fields by a suite of invertebrates, including gastropods, bivalves, chitons, polychaetes and insect larvae. Replicate times of three different periods (5, 18 and 38 days) tested for consistency of patterns of colonization at different times. Although the experiment was completed in a single season (within 2 months), there was considerable variation in patterns of abundances and diversity between replicate times. Thus, for each time in each period of a particular length, a different assemblage developed on the algal or sandy substratum in each boulder field. Despite this temporal variation, a few taxa showed some consistency of colonization among habitats, although most showed unpredictable patterns. The implications of these patterns of colonization for the creation or restoration of new intertidal and shallow subtidal boulder fields are discussed. [Copyright &y& Elsevier]

Leptodius exaratus has been used traditionally as a bait for recreational fishing in Kuwait, however little known about the effect of this practice. The present study is the first step towards understanding the recreational fisheries in Kuwait and the indirect impact of this fishery on the intertidal rocky shore habitats through bait collection, using field and questionnaire survey approaches. Anglers catch 46 different fish species, with seven of them making up more than 70% of the reported catches. L. exaratus is considered very selective for sea breams and it represented 21.4% of intertidal gleaning catches, with an average harvesting rate of 191 crabs/collector/tide. Crab gleaners reported declines in crab abundance over time and impacts on some rocky shore habitats. Direct fishing mortality was relatively low, but habitat damage caused by gleaning high, in sites with low crab abundance and fragile rock substrate, where 80% of the rocks were turned over and more than half were broken. This indicates that development of unregulated gleaning on Kuwait shores may cause irreversible ecological impacts to sensitive intertidal habitats before legislation and effective enforcement can be put in place. Partial restriction of gleaning effort and/or catches is unlikely to be effective, so that a spatial management approach identifying habitats requiring a high level of protection is needed. The latter requires information on distribution of rocky shore habitat types, refining existing intertidal habitat classifications to inform development of a sensitivity matrix approach on sufficiently fine scale to resolve variation in sensitivity of different rocky shore types to physical disturbance. • Anglers in Kuwait catch 46 fish species, seven of which make up over 70% of catches. • The rocky shore crab Leptodius exaratus is selectively used as bait for sea bream species. • Fishing mortality from gleaning for L. exaratus is low relative to natural mortality. • Damage to fragile biogenic rock habitat is the main impact of intertidal gleaning for bait crabs. • There is an urgent need to enforce control of gleaning practices in Kuwait to protect sensitive habitats. [ABSTRACT FROM AUTHOR]

Mangrove forest rehabilitation should begin much sooner than at the point of catastrophic loss. We describe the need for "mangrove forest heart attack prevention", and how that might be accomplished in a general sense by embedding plot and remote sensing monitoring within coastal management plans. The major cause of mangrove stress at many sites globally is often linked to reduced tidal flows and exchanges. Blocked water flows can reduce flushing not only from the seaward side, but also result in higher salinity and reduced sediments when flows are blocked landward. Long-term degradation of function leads to acute mortality prompted by acute events, but created by a systematic propensity for long-term neglect of mangroves. Often, mangroves are lost within a few years; however, vulnerability is re-set decades earlier when seemingly innocuous hydrological modifications are made (e.g., road construction, blocked tidal channels), but which remain undetected without reasonable large-scale monitoring., (Copyright © 2016 Elsevier Ltd. All rights reserved.)