Long term declines in the functional diversity of sharks in the coastal oceans of eastern Australia.

Human impacts lead to widespread changes in the abundance, diversity and traits of shark assemblages, altering the functioning of coastal ecosystems. The functional consequences of shark declines are often poorly understood due to the absence of empirical data describing long-term change. We use data from the Queensland Shark Control Program in eastern Australia, which has deployed mesh nets and baited hooks across 80 beaches using standardised methodologies since 1962. We illustrate consistent declines in shark functional richness quantified using both ecological (e.g., feeding, habitat and movement) and morphological (e.g., size, morphology) traits, and this corresponds with declining ecological functioning. We demonstrate a community shift from targeted apex sharks to a greater functional richness of non-target species. Declines in apex shark functional richness and corresponding changes in non-target species may lead to an anthropogenically induced trophic cascade. We suggest that repairing diminished shark populations is crucial for the stability of coastal ecosystems.

Dogs suppress a pivotal function in the food webs of sandy beaches.

Domestic dogs are the most abundant carnivore globally and have demonstrable negative impacts to wildlife; yet, little evidence regarding their functional roles in natural food webs exists. Adding dogs to food webs may result in a net loss (via suppression of naturally occurring species), net gain (via mesopredator release), or no change (via functional replacement) to ecosystem function. Scavenging is a pivotal function in ecosystems, particularly those that are energetically supported by carrion. Dogs also scavenge on animal carcasses, but whether scavenging by dogs influences the structural and functional properties of food webs remains unclear. Here we used camera traps baited with carrion to test the effect of dogs on the composition and diversity of the vertebrate scavenger guild, as well as carrion detection and consumption rates. We conducted this work in sandy beach ecosystems, which rely on the import of marine organic matter (i.e. stranding of dead marine animals). Diversity of the scavenger community was similar on beaches without dogs. Dogs increased the time it took for carcasses to be detected and decreased the proportion of carrion consumed. This 'dog suppression effect' on scavenging was stronger for nocturnal mammalian scavengers, presumably being driven by indirect trait-mediated effects, which raises further questions about the broader ecological consequences of domestic dogs in natural systems.

The role of inputs of marine wrack and carrion in sandy-beach ecosystems: a global review.

Sandy beaches are iconic interfaces that functionally link the ocean with the land via the flow of organic matter from the sea. These cross-ecosystem fluxes often comprise uprooted seagrass and dislodged macroalgae that can form substantial accumulations of detritus, termed 'wrack', on sandy beaches. In addition, the tissue of the carcasses of marine animals that regularly wash up on beaches form a rich food source ('carrion') for a diversity of scavenging animals. Here, we provide a global review of how wrack and carrion provide spatial subsidies that shape the structure and functioning of sandy-beach ecosystems (sandy beaches and adjacent surf zones), which typically have little in situ primary production. We also examine the spatial scaling of the influence of these processes across the broader land- and seascape, and identify key gaps in our knowledge to guide future research directions and priorities. Large quantities of detrital kelp and seagrass can flow into sandy-beach ecosystems, where microbial decomposers and animals process it. The rates of wrack supply and its retention are influenced by the oceanographic processes that transport it, the geomorphology and landscape context of the recipient beaches, and the condition, life history and morphological characteristics of the macrophyte taxa that are the ultimate source of wrack. When retained in beach ecosystems, wrack often creates hotspots of microbial metabolism, secondary productivity, biodiversity, and nutrient remineralization. Nutrients are produced during wrack breakdown, and these can return to coastal waters in surface flows (swash) and aquifers discharging into the subtidal surf. Beach-cast kelp often plays a key trophic role, being an abundant and preferred food source for mobile, semi-aquatic invertebrates that channel imported algal matter to predatory invertebrates, fish, and birds. The role of beach-cast marine carrion is likely to be underestimated, as it can be consumed rapidly by highly mobile scavengers (e.g. foxes, coyotes, raptors, vultures). These consumers become important vectors in transferring marine productivity inland, thereby linking marine and terrestrial ecosystems. Whilst deposits of organic matter on sandy-beach ecosystems underpin a range of ecosystem functions and services, they can be at variance with aesthetic perceptions resulting in widespread activities, such as 'beach cleaning and grooming'. This practice diminishes the energetic base of food webs, intertidal fauna, and biodiversity. Global declines in seagrass beds and kelp forests (linked to global warming) are predicted to cause substantial reductions in the amounts of marine organic matter reaching many beach ecosystems, likely causing flow-on effects for food webs and biodiversity. Similarly, future sea-level rise and increased storm frequency are likely to alter profoundly the physical attributes of beaches, which in turn can change the rates at which beaches retain and process the influxes of wrack and animal carcasses. Conservation of the multi-faceted ecosystem services that sandy beaches provide will increasingly need to encompass a greater societal appreciation and the safeguarding of ecological functions reliant on beach-cast organic matter on innumerable ocean shores worldwide.

Human modifications to estuaries correlate with the morphology and functional roles of coastal fish.

Animals can respond to human impacts by favouring different morphological traits or by exploiting different food resources. We quantified the morphology and diet of four functionally different fish species (n = 543 fish) from 13 estuaries with varying degrees of human modification in Queensland, Australia. We found differences in the responses of trophic groups to the environmental conditions of estuaries; principally the extent of seagrass in the estuary, and the amount of shoreline and catchment urbanisation. Here, seagrass and urbanisation extent correlated with the diet and morphology of zooplanktivores and detritivores; thereby indicating that human modifications may modify these species functional roles. Conversely, environmental variables did not correlate with the diet or morphology of zoobenthivores or piscivores thereby indicating that human modifications may have less an effect on these species functional roles. Our findings demonstrate that anthropogenic impacts to coastal ecosystems might extend from the traditionally measured metrics of abundance and diversity.

Disturbance type determines how connectivity shapes ecosystem resilience.

Connectivity is fundamentally important for shaping the resilience of complex human and natural networks when systems are disturbed. Ecosystem resilience is, in part, shaped by the spatial arrangement of habitats, the permeability and fluxes between them, the stabilising functions performed by organisms, their dispersal traits, and the interactions between functions and stressor types. Controlled investigations of the relationships between these phenomena under multiple stressors are sparse, possibly due to logistic and ethical difficulties associated with applying and controlling stressors at landscape scales. Here we show that grazing performance, a key ecosystem function, is linked to connectivity by manipulating the spatial configuration of habitats in microcosms impacted by multiple stressors. Greater connectivity enhanced ecosystem function and reduced variability in grazing performance in unperturbed systems. Improved functional performance was observed in better connected systems stressed by harvesting pressure and temperature rise, but this effect was notably reversed by the spread of disease. Connectivity has complex effects on ecological functions and resilience, and the nuances should be recognised more fully in ecosystem conservation.

Diverse land uses and high coastal urbanisation do not always result in harmful environmental pollutants in fisheries species.

Human activities in coastal catchments can cause the accumulation of pollutants in seafood. We quantified the concentration of heavy metals, pesticides and PFASs in the flesh of the fisheries species yellowfin bream Acanthopagrus australis (n = 57) and mud crab Scylla serrata (n = 65) from 13 estuaries in southeast Queensland, Australia; a region with a variety of human land uses. Pollutants in yellowfin bream were best explained by the extent of intensive uses in the catchment. Pollutants in mud crabs were best explained by the extent of irrigated agriculture and water bodies. No samples contained detectable levels of pesticides, and only six samples contained low levels of PFASs. Metals were common in fish and crab flesh, but only mercury in yellowfin bream from the Mooloolah River breached Australian food safety standards. High pollutant presence and concentration is not the norm in seafood collected during routine surveys, even in estuaries with highly modified catchments.

Landscape context and nutrients modify the effects of coastal urbanisation.

Estuaries are focal points for coastal cities worldwide, their habitats frequently transformed into engineered shorelines abutting waters with elevated nutrients in an urbanised landscape. Here we test for relationships between shoreline armouring and nutrients on the diversity and trophic composition of fish assemblages across 22 estuaries in eastern Australia. Urbanisation was associated with fish diversity and abundance, but there were differences in the effects of shoreline armouring and nutrient level on the trophic composition of fish assemblages. Fish diversity and the abundance of most trophic groups, particularly omnivores, zoobenthivores and detritivores, was greatest in highly urban estuaries. We show that estuarine fish assemblages are associated with urbanisation in more nuanced ways than simple habitat transformation would suggest, but this depends on the broader environmental context. Our findings have wider implications for estuarine conservation and restoration, emphasizing that ecological benefits of habitat measures may depend on both landscape attributes and water quality in urban settings.

Low redundancy and complementarity shape ecosystem functioning in a low-diversity ecosystem.

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.

Effects of seascape connectivity on reserve performance along exposed coastlines.

Seascape connectivity (landscape connectivity in the sea) can modify reserve performance in low-energy marine ecosystems (e.g., coral reefs, mangroves, and seagrass), but it is not clear whether similar spatial linkages also shape reserve effectiveness on high-energy, exposed coastlines. We used the surf zones of ocean beaches in eastern Australia as a model system to test how seascape connectivity and reserve attributes combine to shape conservation outcomes. Spatial patterns in fish assemblages were measured using baited remote underwater video stations in 12 marine reserves and 15 fished beaches across 2000 km of exposed coastline. Reserve performance was shaped by both the characteristics of reserves and the spatial properties of the coastal seascapes in which reserves were embedded. Number of fish species and abundance of harvested fishes were highest in surf-zone reserves that encompassed >1.5 km of the surf zone; were located < 100 m to rocky headlands; and included pocket beaches in a heterogeneous seascape. Conservation outcomes for exposed coastlines may, therefore, be enhanced by prioritizing sufficiently large areas of seascapes that are strongly linked to abutting complementary habitats. Our findings have broader implications for coastal conservation planning. Empirical data to describe how the ecological features of high-energy shorelines influence conservation outcomes are lacking, and we suggest that seascape connectivity may have similar ecological effects on reserve performance on both sheltered and exposed coastlines.

Efectos de la Conectividad de Paisajes Marinos sobre el Desempeño de las Reservas a lo largo de Costas Expuestas Resumen La conectividad entre paisajes marinos puede modificar el desempeño de las reservas en los ecosistemas marinos de baja energía (p. ej.: arrecifes de coral, manglares, pastos marinos), pero no está claro si las conexiones espaciales similares también moldean la efectividad de las reservas en costas expuestas con alta energía. Usamos las zonas de rompimiento de las playas oceánicas en el este de Australia como sistema modelo para probar cómo la conectividad entre paisajes marinos y los atributos de la reserva se combinan para moldear los resultados de la conservación. Los patrones espaciales en los ensamblados de peces se midieron con estaciones remotas de video subacuático con carnada en doce reservas marinas y 15 playas a lo largo de 2000 km de costas expuestas. El desempeño de las reservas estuvo moldeado por las características de las reservas y las propiedades espaciales de los paisajes costeros en los cuales estaban insertadas las reservas. El número de especies de peces y la abundancia de peces recolectados fue mucho mayor en las reservas en las zonas de rompimiento que abarcaban >1.5 km de la zona de rompimiento; estaban localizadas a <100 m de cabos rocosos; e incluían playas pequeñas entre los cabos en un paisaje marino heterogéneo. Los resultados de conservación para las costas expuestas pueden, por lo tanto, mejorarse con la priorización suficiente de grandes áreas de paisajes marinos que están conectados fuertemente con hábitats complementarios colindantes. Nuestros hallazgos tienen consecuencias más generales para la planeación de la conservación costera. Los datos empíricos para describir cómo las características ecológicas de las costas con alta energía influyen sobre los resultados de conservación son muy pocos, y sugerimos que la conectividad entre paisajes marinos puede tener efectos ecológicos similares sobre el desempeño de las reservas en costas expuestas y resguardadas.

Optimizing conservation benefits for threatened beach fauna following severe natural disturbances.

Wildlife on sandy beaches is often constrained by transformation of natural areas for human use, and opportunities for acquiring or restoring new habitat are rare. Storms can often force changes in land use naturally by re-shaping coastal landforms, thereby creating high quality habitat; yet, wildlife requirements are seldom considered in post-storm recovery planning, and conservation practitioners lack suitable evidence to argue for the protection of habitats freshly formed by storms. Here we used a maximum-likelihood spatial modeling approach to quantify impacts of Hurricane Sandy (mid-Atlantic United States, October 2012) on nesting habitat of four bird species of conservation concern: American oystercatchers, black skimmers, least terns and piping plovers. We calculated the immediate storm-created changes (loss, persisting, gained) in nesting habitat under two levels of conservation protections: the current regulatory framework, and a scenario in which all potential habitats were under conservation protection. Hurricane Sandy resulted in apparent large gains for least terns (+181 ha) and piping plovers (+289 ha). However, actual gains were reduced to 16 ha for plovers and reversed for least terns (net loss of 6.4 ha) because newly formed habitat occurred outside existing reserve boundaries. Similarly, under the current management framework, black skimmer nesting habitat decreased by ~164 ha. We also tested whether birds benefited from newly created nesting habitat by identifying nest and colony locations for three years following Hurricane Sandy. All species overwhelmingly nested in habitat that existed prior the storm (76-98% of all nests/colonies); only a small percentage (≤17% for all species) occupied newly created habitat. We conclude that static spatial conservation efforts fail to capitalize on potentially large gains resulting from storms for several species and recommend flexible spatial conservation investments as a key input in post-storm recovery planning.

Managing birds of conservation concern on sandy shores: How much room for future conservation actions is there?

Resource limitations often prevent the active management required to maintain habitat quality in protected areas. Because restrictions in access or allowable public activities are the sole conservation measure in these locations, an important question to consider is whether species of conservation concern truly benefit from parcels that are shielded from human disturbance. Here, we assess the conservation benefit of protecting birds from human recreation on over 204 km of sandy beaches by (a) estimating the total area of beach-nesting bird habitat that has been created by conservation protections; (b) quantifying the change in nesting habitat extent should further conservation protections be implemented; and (c) providing data to inform future protected area expansion. We use a maximum entropy species distribution modeling approach to estimate the extent and quality of suitable habitat for four beach-nesting bird species of conservation concern under the existing management regime and compare it to scenarios in which the entire study area is either unprotected of fully protected from human disturbance. Managing humans has dramatic conservation returns for least terns and piping plovers, creating extensive nesting habitat that otherwise would not exist. There is considerable scope for conservation gains, potentially tripling the extent of nesting areas. Expanding conservation footprints for American oystercatchers and black skimmers is predicted to enhance the quality of existing nesting areas. The work demonstrates the utility of modeling changes in habitat suitability to inform protected area expansion on ocean beaches and coastal dunes.

Functional plasticity in vertebrate scavenger assemblages in the presence of introduced competitors.

Introduced species may suppress or enhance ecological functions, or they may have neutral effects in ecosystems where they replace or complement native species. Few studies, however, have explicitly tested for these trajectories, and for the effect these might have for native species. In this study, we experimentally test the trajectory and scale of change in the function of 'carrion removal' at different carrion loads along ocean beaches in Eastern Australia that have different numbers of introduced red foxes (Vulpes vulpes) and several species of native raptors. We hypothesized that the 'positive' effect of foxes on carrion removal would be greatest at high carrion loads, because competition for resources between native and introduced species is lower. Scavenger abundance, fox occurrences, and carrion consumption by these species differed widely between locations and times. Despite distinct spatial differences in the structure of vertebrate scavenger assemblages, total carrion consumption was not significantly different between locations at any carrion load. This lack of variation in functional rates indicates potential functional plasticity in the scavenger assemblage and possible functional accommodation of red foxes. Neutral fox effects on ecological functions or the ecosystem more broadly are, however, very unlikely to extend beyond carrion consumption.

Epitheliocystis in fish: An emerging aquaculture disease with a global impact.

Epitheliocystis is a skin and gill disease in fish caused by pathogenic intracellular bacteria. The disease has been reported in at least 90 species of marine and freshwater fish in both the southern and northern hemispheres. It affects a number of commercially important aquaculture species, including salmon, kingfish and bream. In infected fish, cysts typically develop in the gill epithelia, promoting the fusion of gill lamellae. Infections can lead to respiratory distress and death, particularly in cultured and juvenile fish with cases rarely reported in wild fish. Modern molecular techniques are challenging the conventional wisdoms regarding the epidemiology of epitheliocystis, showing now that a number of distinct bacterial pathogens from completely different phyla can cause this disease. Here, we review the state of knowledge, including updates on aetiology, host range, diagnosis and treatments. Traditionally, bacteria from the phylum Chlamydiae were the only known pathogenic agents of epitheliocystis, but aetiology is now recognized as being more complex, including a range of Proteobacteria. Notwithstanding recent advances in identifying the pathogens, the reservoirs and modes of transmission remain largely unknown. Recent genome sequencing of the growing number of epitheliocystis agents suggests that many bacteria causing this disease are unique to individual species of fish. Environmental conditions that approach or exceed animals' physiological tolerances (e.g. atypical temperature, salinity or pH levels) are thought to contribute to disease development and progression. Empirical data and evidence concerning epidemiology, aetiology and treatments are, however, in many cases limited, highlighting the need for more work to better characterize this disease across the different hosts and locales affected.

Functional changes in reef systems in warmer seas: Asymmetrical effects of altered grazing by a widespread crustacean mesograzer.

Grazing is a pivotal function in many marine systems, conferring resilience to coral reefs by limiting algal overgrowth, but triggering phase shifts on temperate reefs. Thus, changes to consumption rates of grazing species in response to higher future temperatures may have broad ecological consequences. We measured how the consumption rates of a widespread mesograzer (the hermit crab Clibanarius virescens) responded to changing temperatures in the laboratory and applied these findings to model the spatial footprint on grazing animals throughout the Indo-Pacific region under climate change scenarios. We show that mean grazing capacity may increase in shallow coastal areas in the second half of the century. The effects are, however, asymmetrical, with tropical reefs predicted to experience slightly diminished grazing whilst reefs at higher latitudes will be grazed substantially more. Our findings suggest that assessments of the effects of climate change on reef ecosystems should consider how warming affects grazing performance when predicting wider ecological impacts.

Species traits and connectivity constrain stochastic community re-assembly.

All communities may re-assemble after disturbance. Predictions for re-assembly outcomes are, however, rare. Here we model how fish communities in an extremely variable Australian desert river re-assemble following episodic floods and drying. We apply information entropy to quantify variability in re-assembly and the dichotomy between stochastic and deterministic community states. Species traits were the prime driver of community state: poor oxygen tolerance, low dispersal ability, and high fecundity constrain variation in re-assembly, shifting assemblages towards more stochastic states. In contrast, greater connectivity, while less influential than the measured traits, results in more deterministic states. Ecology has long recognised both the stochastic nature of some re-assembly trajectories and the role of evolutionary and bio-geographic processes. Our models explicitly test the addition of species traits and landscape linkages to improve predictions of community re-assembly, and will be useful in a range of different ecosystems.

Storm effects on intertidal invertebrates: increased beta diversity of few individuals and species.

Climate change is predicted to lead to more extreme weather events, including changes to storm frequency, intensity and location. Yet the ecological responses to storms are incompletely understood for sandy shorelines, the globe's longest land-ocean interface. Here we document how storms of different magnitude impacted the invertebrate assemblages on a tidal flat in Brazil. We specifically tested the relationships between wave energy and spatial heterogeneity, both for habitat properties (habitat heterogeneity) and fauna (ß-diversity), predicting that larger storms redistribute sediments and hence lead to spatially less variable faunal assemblages. The sediment matrix tended to become less heterogeneous across the flat after high-energy wave events, whereas ß-diversity increased after storms. This higher ß-diversity was primarily driven by species losses. Significantly fewer species at a significantly lower density occurred within days to weeks after storms. Negative density and biomass responses to storm events were most prominent in crustaceans. Invertebrate assemblages appeared to recover within a short time (weeks to months) after storms, highlighting that most species typical of sedimentary shorelines are, to some degree, resilient to short-term changes in wave energy. Given that storm frequency and intensity are predicted to change in the coming decades, identifying properties that determine resilience and recovery of ecosystems constitute a research priority for sedimentary shorelines and beyond.

Monitoring nitrogen pollution in seasonally-pulsed coastal waters requires judicious choice of indicator species.

We compared the sensitivity of algae and hermit crabs to seasonal shifts in the dominance of continuous sewage discharge vs. pulsed inputs of terrestrial material to a subtropical bay. During periods of low rainfall, when sewage was proportionately more important than diffuse loads from adjacent catchments, algae and crabs provided comparable information on the spatial distribution of N pollution. Conversely, during the wet season, when diffuse nitrogen loads from the catchment were of greater importance, the isotope signal of algae decoupled from that of crabs, indexing a greater magnitude of change and a more pronounced spatial gradient. Overall, algae better indexed the short-term impacts of anthropogenic nitrogen pollution whereas the signals provided by crabs provided a longer-term integrated measure of N inputs. Our results demonstrate the value of including multiple taxa with variable traits when monitoring the spatial and temporal extent of nitrogen inputs to coastal waters.

Marine turtles are not fussy nesters: a novel test of small-scale nest site selection using structure from motion beach terrain information.

BACKGROUND: Nest selection is widely regarded as a key process determining the fitness of individuals and viability of animal populations. For marine turtles that nest on beaches, this is particularly pivotal as the nesting environment can significantly control reproductive success.The aim of this study was to identify the environmental attributes of beaches (i.e., morphology, vegetation, urbanisation) that may be associated with successful oviposition in green and loggerhead turtle nests. METHODS: We quantified the proximity of turtle nests (and surrounding beach locations) to urban areas, measured their exposure to artificial light, and used ultra-high resolution (cm-scale) digital surface models derived from Structure-from-Motion (SfM) algorithms, to characterise geomorphic and vegetation features of beaches on the Sunshine Coast, eastern Australia. RESULTS: At small spatial scales (i.e., <100 m), we found no evidence that turtles selected nest sites based on a particular suite of environmental attributes (i.e., the attributes of nest sites were not consistently different from those of surrounding beach locations). Nest sites were, however, typically characterised by occurring close to vegetation, on parts of the shore where the beach- and dune-face was concave and not highly rugged, and in areas with moderate exposure to artificial light. CONCLUSION: This study used a novel empirical approach to identify the attributes of turtle nest sites from a broader 'envelope' of environmental nest traits, and is the first step towards optimizing conservation actions to mitigate, at the local scale, present and emerging human impacts on turtle nesting beaches.

Optimising Land-Sea Management for Inshore Coral Reefs.

Management authorities seldom have the capacity to comprehensively address the full suite of anthropogenic stressors, particularly in the coastal zone where numerous threats can act simultaneously to impact reefs and other ecosystems. This situation requires tools to prioritise management interventions that result in optimum ecological outcomes under a set of constraints. Here we develop one such tool, introducing a Bayesian Belief Network to model the ecological condition of inshore coral reefs in Moreton Bay (Australia) under a range of management actions. Empirical field data was used to model a suite of possible ecological responses of coral reef assemblages to five key management actions both in the sea (e.g. expansion of reserves, mangrove & seagrass restoration, fishing restrictions) and on land (e.g. lower inputs of sediment and sewage from treatment plants). Models show that expanding marine reserves (a 'marine action') and reducing sediment inputs from the catchments (a 'land action') were the most effective investments to achieve a better status of reefs in the Bay, with both having been included in >58% of scenarios with positive outcomes, and >98% of the most effective (5th percentile) scenarios. Heightened fishing restrictions, restoring habitats, and reducing nutrient discharges from wastewater treatment plants have additional, albeit smaller effects. There was no evidence that combining individual management actions would consistently produce sizeable synergistic until after maximum investment on both marine reserves (i.e. increasing reserve extent from 31 to 62% of reefs) and sediments (i.e. rehabilitating 6350 km of waterways within catchments to reduce sediment loads by 50%) were implemented. The method presented here provides a useful tool to prioritize environmental actions in situations where multiple competing management interventions exist for coral reefs and in other systems subjected to multiple stressor from the land and the sea.

Regional drivers of clutch loss reveal important trade-offs for beach-nesting birds.

Coastal birds are critical ecosystem constituents on sandy shores, yet are threatened by depressed reproductive success resulting from direct and indirect anthropogenic and natural pressures. Few studies examine clutch fate across the wide range of environments experienced by birds; instead, most focus at the small site scale. We examine survival of model shorebird clutches as an index of true clutch survival at a regional scale (∼200 km), encompassing a variety of geomorphologies, predator communities, and human use regimes in southeast Queensland, Australia. Of the 132 model nests deployed and monitored with cameras, 45 (34%) survived the experimental exposure period. Thirty-five (27%) were lost to flooding, 32 (24%) were depredated, nine (7%) buried by sand, seven (5%) destroyed by people, three (2%) failed by unknown causes, and one (1%) was destroyed by a dog. Clutch fate differed substantially among regions, particularly with respect to losses from flooding and predation. 'Topographic' exposure was the main driver of mortality of nests placed close to the drift line near the base of dunes, which were lost to waves (particularly during storms) and to a lesser extent depredation. Predators determined the fate of clutches not lost to waves, with the depredation probability largely influenced by region. Depredation probability declined as nests were backed by higher dunes and were placed closer to vegetation. This study emphasizes the scale at which clutch fate and survival varies within a regional context, the prominence of corvids as egg predators, the significant role of flooding as a source of nest loss, and the multiple trade-offs faced by beach-nesting birds and those that manage them.