Distribution Of Predators Research Articles

Assessing small pelagic fish trends in space and time using piscivore stomach contents

Changing distribution and abundance of small pelagic fishes may drive changes in predator distributions, affecting predator availability to fisheries and surveys. However, small pelagics are difficult to survey directly, so we developed a novel method of assessing the aggregate abundance of 21 small pelagic forage taxa via predator stomach contents. We used stomach contents collected from 22 piscivore species captured by multiple bottom trawl surveys within a vector autoregressive spatio-temporal model to assess trends of small pelagics on the Northeast US shelf. The goal was to develop a spatial “forage index” to inform survey and (or) fishery availability in the western North Atlantic bluefish ( Pomatomus saltatrix) stock assessment. This spatially resolved index compared favorably with more traditional design-based survey biomass indices for forage species well sampled by surveys. However, our stomach content-based index better represented smaller unmanaged forage species that surveys are not designed to capture. The stomach-based forage index helped explain bluefish availability to the recreational fishery for stock assessment and provided insight into pelagic forage trends throughout the regional ecosystem.

Voices from the deep: Odontocete occurrence patterns relative to oceanographic conditions in the northern California Current System

Odontocetes play an important ecological role as apex predators in the northern California Current System (CCS), which is characterized by seasonal rises in primary productivity fueled by wind-driven upwelling of cold nutrient-rich water. This productivity sustains higher trophic-level prey optimal for deep-diving odontocetes including beaked and sperm whales. Due to the cryptic ecology of these whales, there are few systematic studies of their occurrence across seasons in northern CCS waters. The Holistic Assessment of Living marine resources off Oregon (HALO) Project—a collaboration between Oregon State University and Cornell University—addresses this gap via quarterly vessel-based visual surveys and year-round passive acoustic monitoring (PAM). Here, we detect and classify species-specific odontocete acoustic signals using long-term spectral averages, automated click detection, and unsupervised clustering of semi-continuous PAM data from 10/2021 to 12/2022. Site-specific occurrence of beaked and sperm whales is revealed on hourly to seasonal temporal scales at three recording sites along a depth gradient spanning the continental slope (300 and 630 m water depth) and abyssal plain (2860 m). By relating odontocete detections to dynamic oceanographic conditions from nearby profiling moorings, we identify likely drivers of prey availability influencing predator distribution. These results will inform conservation efforts of cryptic odontocetes in the face of rapid environmental change.

An effective Allee effect may induce the survival of low-density predator

Allee effect, as one of the research hotspots in ecology and conservation biology, extremely easily affects the distribution of population in space, especially for the low-density population. In the ecosystem, the spatial distribution of predator is more vulnerable to Allee effect since the density of predator is always smaller than that of prey, but the relevant attention paid to it is few. In this paper, we establish and analyze a spatial predator–prey system incorporating Allee effect on predator population. Theoretically, we use multi-scale analysis to derive the amplitude equation and obtain the different Turing patterns under different intensities of Allee effect. Numerically, we verify the theoretical results. We also find that the growth rate of predator is significantly inhibited and the time of reaching equilibrium tends to be slower with the increase of Allee effect intensity within certain limits. More interestingly, it is discovered that the predator under Allee effect in a certain extent is more stable although Allee effect on predator may lead to more complex dynamic behaviors. Our results help better understand species invasion and nature conservation in ecology.

Impacts of marine heatwaves on top predator distributions are variable but predictable

Marine heatwaves cause widespread environmental, biological, and socio-economic impacts, placing them at the forefront of 21st-century management challenges. However, heatwaves vary in intensity and evolution, and a paucity of information on how this variability impacts marine species limits our ability to proactively manage for these extreme events. Here, we model the effects of four recent heatwaves (2014, 2015, 2019, 2020) in the Northeastern Pacific on the distributions of 14 top predator species of ecological, cultural, and commercial importance. Predicted responses were highly variable across species and heatwaves, ranging from near total loss of habitat to a two-fold increase. Heatwaves rapidly altered political bio-geographies, with up to 10% of predicted habitat across all species shifting jurisdictions during individual heatwaves. The variability in predicted responses across species and heatwaves portends the need for novel management solutions that can rapidly respond to extreme climate events. As proof-of-concept, we developed an operational dynamic ocean management tool that predicts predator distributions and responses to extreme conditions in near real-time.

The circumpolar impacts of climate change and anthropogenic stressors on Arctic cod (Boreogadus saida) and its ecosystem

Arctic cod (Boreogadus saida) is the most abundant forage fish in the Arctic Ocean. Here we review Arctic cod habitats, distribution, ecology, and physiology to assess how climate change and other anthropogenic stressors are affecting this key species. This review identifies vulnerabilities for different life stages across the entire distribution range of Arctic cod. We explore the impact of environmental (abiotic and biotic) and anthropogenic stressors on Arctic cod with a regional perspective in a scenario up to the year 2050 and identify knowledge gaps constraining predictions. Epipelagic eggs and larvae are more vulnerable to climate change and stressors than adults. Increased water temperatures, sea-ice decline, altered freshwater input, acidification, changing prey field, increased interspecific competition, new predators, and pollution are the principal stressors that will affect Arctic cod populations. Detrimental effects are likely to be greater in regions characterized by the advection of warmer Atlantic and Pacific waters. In contrast, Arctic cod may benefit from ocean warming in colder areas of the High Arctic. The risk from fisheries is moderate and primarily limited to bycatch. Overall, a decrease in suitable habitat and an associated decline in total Arctic cod biomass are predicted. In most Arctic seas, the relative abundance of Arctic cod within the fish community will likely fluctuate in accordance with cold and warm periods. A reduced abundance of Arctic cod will negatively affect the abundance, distribution, and physiological condition of certain predators, whereas some predators will successfully adapt to a more boreal diet. Regional management measures that recognize the critical role of Arctic cod are required to ensure that increased anthropogenic activities do not exacerbate the impacts of climate change on Arctic marine ecosystems. Ultimately, the mitigation of habitat loss for Arctic cod will only be achieved through a global reduction in carbon emissions.

Hedgerows interact with forests to shape the abundance of mesopredators and their predation rate on eggs in farmland landscapes

Nest predation is the main cause of reproductive failure, particularly in ground-nesting birds on farmlands. Understanding the links between nest predation and habitat change can help design effective management schemes to constrain the negative impact of predation pressure on birds. However, the mechanisms underlying the relationships between landscape attributes, predator distribution, and nest predation are still unclear. Here, we use an experimental approach to examine the effects of distance to the hedgerow as well as hedgerow and forest densities on the abundance of major mesopredators of ground nests of our study area (i.e., corvids) and on the predation rate of artificial ground nests (n = 2576). We found evidence that landscape configuration influenced predation patterns differently depending on the predator species. Nest predation by corvids was more likely in homogeneous and open agricultural landscapes with a low density of forest and hedgerows, whereas predation by other predators was more likely close to hedgerows. Nest predation by corvids and the abundance of corvids also tended to be lower in landscapes dominated by grasslands. Other variables such as road density and distance to human settlements had contrasted effects on the likelihood of a nest being depredated by corvids, i.e., no effect with proximity to human settlements and decreasing trend with road density. Altogether, our results suggest that landscape features interact with mesopredator distribution and their predation rates of ground nests. Therefore, from a conservation and management perspective, a heterogeneous agricultural landscape that includes a mixture of crops associated with patches of forests, hedgerows, and grasslands offering alternative food to generalist predators should contribute to reducing ground-nesting bird predation.

Quantifying inter-annual variability on the space-use of parental Northern Gannets (Morus bassanus) in pursuit of different prey types.

Spatial planning for marine areas of multi-species conservation concern requires in-depth assessment of the distribution of predators and their prey. Northern Gannets Morus bassanus are generalist predators that predate several different forage fishes depending on their availability. In the western North Atlantic, gannets employ different dive tactics while in pursuit of different prey types, performing deep, prolonged U-shaped dives when foraging on capelin (Mallotus villosus), and rapid, shallow, V-shaped dives when foraging on larger pelagic fishes. Therefore, much can be inferred about the distribution and abundance of key forage fishes by assessing the foraging behaviour and space-use of gannets. In this study, we aimed to quantify space-use and to determine areas of suitable foraging habitat for gannets in pursuit of different prey types using habitat suitability models and kernel density utilization distributions. We deployed 25 GPS/Time-depth recorder devices on parental Northern Gannets at Cape St. Mary's, Newfoundland, Canada from 2019 to 2021. To assess the influence of environmental variables on gannets foraging for different prey types, we constructed three different habitat suitability models: a U-shaped dive model, and two V-shaped dive models (early and late chick-rearing). Suitable foraging habitat for capelin, deduced by the U-shaped dive model, was defined by coastal, shallow waters with flat relief and sea surface temperatures (SST) of 11-15° C. Suitable habitat for early V-shaped dives was defined by shallow and coastal waters with steep slope and SST of 12-15°C and ~18°C, likely reflecting the variability in environmental preferences of different prey species captured when performing V-shaped dives. Suitable habitat for late V-shaped dives was defined by shallow coastal waters (<100m depth), as well as waters deeper than 200 m, and by SST greater than 16°C. We show that space-use by gannets can vary both within and between years depending on environmental conditions and the prey they are searching for, with consequences for the extent of potential interaction with anthropogenic activities. Further, we suggest regions defined as suitable for U-shaped dives are likely to be critical habitat of multi-species conservation concern, as these regions are likely to represent consistent capelin spawning habitat.

Ensemble modelling the distribution and habitat suitability of wild goat Capra aegagrus in southwestern Iran

ABSTRACT Increasing anthropogenic pressures have caused drastic population decline of wild goats Capra aegagrus. The study aim was to determine habitat suitability and explore the factors influencing habitat selection and dispersal of wild goats in the Khaeiz and Sorkh protected area, southwestern Iran. We utilized ensemble modelling based on 25 replications of 10 species distribution models GLM (generalized linear model), GAM (generalized additive model), GBM (gradient boosting model), CTA (classification tree analysis), FDA (flexible discriminant analysis), ANN (artificial neural network), MARS (multivariate adaptive regression spline), RF (random forest), MaxEnt (maximum entropy), SRE (surface range envelope). Wild goat occurrence data were collected from 2019 to 2020 and related to five variables: predator distribution, slope, distance from road, distance from water resources, and normalized difference vegetation index (NDVI). We found that distribution of predators, slope, distance from water resources and distance from roads were the most important predictors of potential habitats for wild goats. The least important variable was NDVI. Probabilistic predictions suggest that only 5.89% of the area was highly suitable habitat, whereas 46.24% was unsuitable. Ensembling individually classified presence/absence maps further indicates that 79.72% of the study area was certainly unsuitable while only 8.06% was certainly suitable for wild goats. The results can help wildlife managers and policymakers work towards conservation and management goals and decreasing the conflicts between wildlife and humans.

The impact of anthropogenic pollutants on the distribution of a marine top predator within a coastal estuarine system.

Due to anthropogenic pressures, estuarine systems are among the most broadly impacted areas for marine top predator species. Given this, it is crucial to study the interaction between the vulnerable marine species that inhabit these regions with environmental and anthropogenic variables. This study aims to determine whether nutrient pollution is related to the presence of bottlenose dolphins in a coastal environment. Using a multi-year dataset and GAMs, we studied the relationship between marine pollutants and the presence of bottlenose dolphins in this highly impacted coastal marine environment. We observed that urban fertilizers were linked to the spatial distribution of bottlenose dolphins. There was a higher presence of bottlenose dolphins in areas with high levels of phosphoric acid. In contrast, at higher concentrations of nitrate, the presence of bottlenose dolphins decreased.

Tight spatial coupling of a marine predator with soniferous fishes: Using joint modelling to aid in ecosystem approaches to management

AbstractAimUnderstanding the distribution of marine organisms is essential for effective management of highly mobile marine predators that face a variety of anthropogenic threats. Recent work has largely focused on modelling the distribution and abundance of marine mammals in relation to a suite of environmental variables. However, biotic interactions can largely drive distributions of these predators. We aim to identify how biotic and abiotic variables influence the distribution and abundance of a particular marine predator, the bottlenose dolphin (Tursiops truncatus), using multiple modelling approaches and conducting an extensive literature review.LocationWestern North Atlantic continental shelf.MethodsWe combined widespread marine mammal and fish and invertebrate surveys in an ensemble modelling approach to assess the relative importance and capacity of the environment and other marine species to predict the distribution of both coastal and offshore bottlenose dolphin ecotypes. We corroborate the modelled results with a systematic literature review on the prey of dolphins throughout the region to help explain patterns driven by prey availability, as well as reveal new ones that may not necessarily be a predator–prey relationship.ResultsWe find that coastal bottlenose dolphin distributions are associated with one family of fishes, the Sciaenidae, or drum family, and predictions slightly improve when using only fish versus only environmental variables. The literature review suggests that this tight coupling is likely a predator–prey relationship. Comparatively, offshore dolphin distributions are more strongly related to environmental variables, and predictions are better for environmental‐only models. As revealed by the literature review, this may be due to a mismatch between the animals caught in the fish and invertebrate surveys and the predominant prey of offshore dolphins, notably squid.Main ConclusionsIncorporating prey species into distribution models, especially for coastal bottlenose dolphins, can help inform ecological relationships and predict marine predator distributions.

Implications of tree expansion in shrubland ecosystems for two generalist avian predators.

Shrublands globally have undergone structural changes due to plant invasions, including the expansion of native trees. Removal of native conifer trees, especially juniper (Juniperus spp.), is occurring across the Great Basin of the western U.S. to support declining sagebrush (Artemisia spp.) habitats and associated wildlife species, such as greater sage-grouse (Centrocercus urophasianus). One justification for conifer removal is that it may improve survival of sagebrush-associated wildlife by reducing the abundance of avian predators. However, the relationship between conifer expansion and predator distributions has not been explicitly evaluated. Further, although structural characteristics of habitat are important for generalist predators, overall prey abundance may also affect habitat use by predators. We examined habitat use of common ravens (Corvus corax) and red-tailed hawks (Buteo jamaicensis), two generalist predators whose populations are increasing in western North America, to variation in structural characteristics and prey distributions in sagebrush habitat that has experienced conifer expansion. Structural characteristics of habitat were important predictors of habitat use for both ravens and red-tailed hawks, whereas measures of prey abundance were unimportant for both species likely because generalist predators can use a wide variety of food resources. Ravens, but not red-tailed hawks, responded positively to increasing cover of juniper and the probability of habitat use was highest (> 0.95) where juniper cover within 100 m was > 20%. Habitat use by red-tailed hawks, but not ravens, was greater near cliffs but was not associated with juniper cover. Our study suggests that the removal of conifer in similar environments may lower the probability of habitat use for ravens, a common predator with significant impacts on many prey species. Therefore, we suggest conifer removal may improve sage-grouse reproductive success and survival depending on responses to conifer removal from other predators. Our results may be reflective of similar changes in rangeland ecosystems around the world undergoing expansion of conifer and other woody vegetation. Though species identities differ from sagebrush habitats, generalist avian predators in other habitats may have similar relationships with structural resources.

Multiple antipredator behaviors in wild red-tailed monkey (Cercopithecus ascanius) groups reveal spatially distinct landscapes of fear

Abstract Foraging opportunity and predation risk act as opposing influences on an animal’s habitat use. “Landscapes of fear” (LOF), whereby one predicts the spatial distribution of predators or perceived predator presence using prey responses, are an important tool for modeling this conflict. LOF models examining perceived predation risk are often generated using a single behavioral metric, even though individuals can respond to predation pressure with multiple potential behaviors. Here, we expanded traditional LOF approaches by measuring three antipredator behaviors in wild red-tailed monkeys (Cercopithecus ascanius): aggregation, alarm calling, and vigilance. We predicted that each behavior would reveal spatially explicit regions of high risk, as each behavior may attend to different aspects of perceived predation risk. The use of different behaviors may depend upon factors such as vegetation type, age/sex class of an individual, and which other antipredator behaviors are being exhibited by group members. We collected data on two troops of monkeys in the Issa Valley, Tanzania for over 19 months and conducted 3189 group follows. We found that vegetation type varied in its effect on antipredator behavior. Monkeys conducted more antipredator behavior in more open vegetation types compared to more closed, riparian forests. The LOF models generated for each behavior mapped distinct and predominantly non-overlapping spatial regions of perceived predation risk, which was replicated across the two groups. This suggested that monkeys responded differently across their home range to specific perceived risks. Such spatially explicit behavior may indicate vegetation-specific predation risk or unique trade-offs in antipredator behavior throughout a heterogenous habitat.

Free-ranging livestock affected the spatiotemporal behavior of the endangered snow leopard (Panthera uncia).

Long recognized as a threat to wildlife, particularly for large carnivores, livestock grazing in protected areas can potentially undermine conservation objectives. The interspecific interactions among livestock, snow leopards (Panthera uncia), and their wild prey in fragile Asian highland ecosystems have been a subject of debate. We strategically deployed 164 camera traps in the Wolong National Nature Reserve to systematically investigate the activities of snow leopards, their primary wild ungulate prey species, and free-ranging livestock. We found that snow leopard habitat use was influenced by both wild prey and livestock. Blue sheep served as the main wild prey that spatially attracted snow leopards and coexisted with yaks while free-ranging yaks significantly restricted snow leopard habitat use both temporally and spatially. This study challenges the conventional understanding that livestock indirectly impacts large carnivores by competing with and displacing wild prey. Our findings highlight that free-ranging yaks within the alpine canyon terrain could directly limit snow leopard habitat use, suggesting a potential risk of grazing in reducing apex predator distribution and jeopardizing their populations. Consequently, managing their coexistence in shared habitats requires a more nuanced approach. Furthermore, our research underscores the importance of further research efforts aimed at enhancing our comprehension of the complex interplay within animal communities and ecosystems. This knowledge will contribute to the development of informed, evidence-based conservation strategies and policies.

Predator-prey collapses at the edge of predator distribution: the case of clupeids and common guillemots (Uria aalge) in NW Iberia

The spatial structuring of seabird populations makes individual colonies very dependent on regional factors. That is especially the case in small edge populations located far from large colonies. We analysed retrospectively the poorly known collapse, some 50 years ago (around 1962-1973), of a relatively small population of breeding common guillemots (Uria aalge) located at their southernmost limit of distribution in Europe (NW Iberia). We assumed that guillemots behaved locally as facultative specialists in small pelagic fish due to the occurrence of a strong clupeid fishery, and we studied the association between the guillemot collapse and annual regional landings of sardine (Sardina pilchardus) and anchovy (Engraulis encrasicolus), used as a proxy of total stock size. The overall relationship between ln-transformed guillemot counts (May-June) and ln-transformed sardine landings (May-October) was stronger than the fit on untransformed variables (r2 =0.52 vs. 0.27), indicating an exponential relationship between the non-transformed variables. This relationship was somewhat stronger and linear after the collapse, when only a few tens of guillemots remaining (r2 =0.60). A strong regime shift in sardine landings was detected in 1968 and also in anchovy landings in 1969. The overall relationship between guillemot numbers and anchovy landings was linear and strong (r2 =0.72) but completely dependent on the large 1960s estimate of guillemots. However, no relationship was found between guillemot numbers and anchovy landings (April-June) after the guillemot collapse. The most likely period for the guillemot collapse was therefore 1968-1970, as seabird colonies are known to collapse immediately after their staple prey crashes. Local guillemot colonies were not subsequently rescued by immigration and have remained empty or almost empty until present, showing the high sensitivity of edge populations to environmental variability at the regional scale.

Long-term stability in the circumpolar foraging range of a Southern Ocean predator between the eras of whaling and rapid climate change

Assessing environmental changes in Southern Ocean ecosystems is difficult due to its remoteness and data sparsity. Monitoring marine predators that respond rapidly to environmental variation may enable us to track anthropogenic effects on ecosystems. Yet, many long-term datasets of marine predators are incomplete because they are spatially constrained and/or track ecosystems already modified by industrial fishing and whaling in the latter half of the 20th century. Here, we assess the contemporary offshore distribution of a wide-ranging marine predator, the southern right whale (SRW, Eubalaena australis), that forages on copepods and krill from ~30°S to the Antarctic ice edge (>60°S). We analyzed carbon and nitrogen isotope values of 1,002 skin samples from six genetically distinct SRW populations using a customized assignment approach that accounts for temporal and spatial variation in the Southern Ocean phytoplankton isoscape. Over the past three decades, SRWs increased their use of mid-latitude foraging grounds in the south Atlantic and southwest (SW) Indian oceans in the late austral summer and autumn and slightly increased their use of high-latitude (>60°S) foraging grounds in the SW Pacific, coincident with observed changes in prey distribution and abundance on a circumpolar scale. Comparing foraging assignments with whaling records since the 18th century showed remarkable stability in use of mid-latitude foraging areas. We attribute this consistency across four centuries to the physical stability of ocean fronts and resulting productivity in mid-latitude ecosystems of the Southern Ocean compared with polar regions that may be more influenced by recent climate change.

Prey resources are equally important as climatic conditions for predicting the distribution of a broad‐ranged apex predator

AbstractAimA current biogeographic paradigm states that climate regulates species distributions at continental scales and that biotic interactions are undetectable at coarse‐grain extents. However, advances in spatial modelling show that incorporating food resource distributions are important for improving model predictions at large distribution scales. This is particularly relevant to understand the factors limiting the distribution of widespread apex predators whose diets are likely to vary across their range.LocationNeotropical Central and South America.MethodsThe harpy eagle (Harpia harpyja) is a large raptor, whose diet is largely comprised of arboreal mammals, all with broad distributions across Neotropical lowland forest. Here, we used a hierarchical modelling approach to determine the relative importance of abiotic factors and prey resource distribution on harpy eagle range limits. Our hierarchical approach consisted of the following modelling sequence of explanatory variables: (a) abiotic covariates, (b) prey resource distributions predicted by an equivalent modelling for each prey, (c) the combination of (a) and (b), and (d) as in (c) but with prey resources considered as a single prediction equivalent to prey species richness.ResultsIncorporating prey distributions improved model predictions but using solely biotic covariates still resulted in a high‐performing model. In the Abiotic model, Climatic Moisture Index (CMI) was the most important predictor, contributing 76% to model prediction. Three‐toed sloth (Bradypus spp.) was the most important prey resource, contributing 64% in a combined Abiotic‐Biotic model, followed by CMI contributing 30%. Harpy eagle distribution had high environmental overlap across all individual prey distributions, with highest coincidence through Central America, eastern Colombia, and across the Guiana Shield into northern Amazonia.Main ConclusionsWith strong reliance on prey distributions across its range, harpy eagle conservation programmes must therefore consider its most important food resources as a key element in the protection of this threatened raptor.

Predator dispersal influences predator distribution but not prey diversity in pitcher plant microbial metacommunities.

The spatial distribution of predators can affect both the distribution and diversity of their prey. Therefore, differences in predator dispersal ability that affect their spatial distribution, could also affect prey communities. Here, we use the microbial communities within pitcher plant leaves as a model system to test the relationship between predator (protozoa) dispersal ability and distribution, and its consequences for prey (bacteria) diversity and composition. We hypothesized that limited predator dispersal results in clustered distributions and heterogeneous patches for prey species, whereas wide predator dispersal and distribution could homogenize prey metacommunities. We analyzed the distribution of two prominent bacterivore protozoans from a 2-year survey of an intact field of Sarracenia purpurea pitcher plants, and found a clustered distribution of Tetrahymena and homogeneous distribution of Poterioochromonas. We manipulated the sources of protozoan colonists and recorded protozoan recruitment and bacterial diversity in target leaves in a field experiment. We found the large ciliate, Tetrahymena, was dispersal limited and occupied few leaves, whereas the small flagellate Poterioochromonas was widely dispersed. However, the bacterial communities these protozoans feed on was unaffected by clustering of Tetrahymena, but likely influenced by Poterioochromonas and other bacterivores dispersing in the field. We propose that bacterial communities in this system are structured by a combination of well dispersed bacterivores, bacterial dispersal, and bottom-up mechanisms. Clustered predators could become strong drivers of prey communities if they were specialists or keystone predators, or if they exerted a dominant influence on other predators in top-down controlled systems. Linking dispersal ability within trophic levels and its consequences for trophic dynamics can lead to a more robust perspective on trophic metacommunities.

Modelling seabirds biodiversity through Bayesian Spatial Beta regression models: A proxy to inform marine protected areas in the Mediterranean Sea

Seabirds are bioindicators of marine ecosystems health and one of the world's most endangered avian groups. The creation of marine protected areas plays an important role in the conservation of marine environment and its biodiversity. The distributions of top predators, as seabirds, have been commonly used for the management and creation of these figures of protection.The main objective of this study is to investigate seabirds biodiversity distribution in the Mediterranean Sea through the use of Bayesian spatial Beta regression models. We used an extensive historical database of at-sea locations of 19 different seabird species as well as geophysical, climatology variables and cumulative anthropogenic threats to model species biodiversity. We found negative associations between seabirds biodiversity and distance to the coast as well as concavity of the seabed, and positive with chlorophyll and slope. Further, a positive association was found between seabirds biodiversity and coastal impact.In this study we define as hot spot of seabird biodiversity those areas with a posterior predictive mean over 0.50. We found potential hot spots in the Mediterranean Sea which do not overlap with the existing MPASs and marine IBAs. Specifically, our hot spots areas do not overlap with the 52.04% and 16.87% of the current MPAs and marine IBAs, respectively. Overall, our study highlights the need for the extension of spatial prioritization of conservation areas to seabirds biodiversity, addressing the challenges of establishing transboundary governance.

Insights obtained from a multidecadal citizen science scheme: grey seal (Halichoerus grypus) strandings in Cornwall and Isles of Scilly (2000–2020)

Abstract Changes in abundance and distribution of marine top predators can indicate environmental change or anthropogenic pressure requiring management response. Here, we used an extensive dataset (21 years) to conduct a spatial and temporal analysis of grey seal strandings in Cornwall and the Isles of Scilly, close to the southern edge of the breeding range of the species. A total of 2007 strandings were reported from 2000 to 2020, increasing by 474% from 35 to 201 individuals per year during this period. The continued rise in strandings was consistent across all life stages and timeframes (5, 10 and 20 years), underpinning the suggestion of increasing abundance in the region. The observed seasonality differed by life stage, coinciding with the increased presence of animals near the coast for key life phases such as breeding, moulting and pupping. Strandings are widely distributed across the coast of Cornwall and the Isles of Scilly; however, most strandings were recorded on the north coast of Cornwall (70%) where major pupping and haul out sites are found. Despite hosting several pupping and haul out sites, a small proportion was recorded on the Isles of Scilly (5%) where it is thought that strandings are particularly underreported. Describing baselines in magnitude of strandings and life-stage compositions across space and time allows future deviations in frequency, demographic composition or spatial distribution to be detected and investigated. We demonstrate the utility of long-term citizen science data to provide valuable and cost-effective information on the distribution and abundance of a highly mobile marine mammal.

Composition and location of trophic groupings of zoobenthos in the Arctic Ocean

This study is devoted to the distribution of trophic groups of zoobenthos in the Arctic Ocean. The patterns of distribution of detritus feeders, seston feeders, and predators along the bottom of the Arctic polar basin are analyzed. The object of the study is the geoecology of the distribution of food groups of benthic animals in the polar regions. The subject of the study is the methods used in assessing the distribution of zoobenthos with different types of nutrition in the polar regions. The results of the work are based on the analysis of the vertical and horizontal structures of the distribution of benthic fauna, reflected in the map of the distribution of trophic groups of zoobenthos and systematized in the distribution table of the leading species of zoobenthos in the Arctic Ocean. To assess the patterns of geoecological distribution of zoobenthos according to the method of feeding, the following were used: actual and cartographic scientific data on the relief, soils, waters, ice cover, maps on the distribution of plankton and the content of organic matter in bottom sediments, as well as data on the trophic characteristics of the benthic fauna of the polar regions, leading biocenoses of the polar regions and geoecological conditions for the existence of benthic fauna in the polar regions. This article presents a map of the distribution of zoobenthos in the Arctic Ocean (according to literary sources), developed by the author, and a table of distribution of guide species of zoobenthos trophic groups in various areas of the Arctic Ocean, compiled by the author based on literary sources. The obtained results of the distribution of food groups of zoobenthos can be used in further detailed assessment of food reserves of bioresources in the polar regions of the World Ocean and their consumption; when designing the economic development of the polar regions; during landscape monitoring.