The distribution, ecology and predicted habitat use of the Critically Endangered <scp>angelshark</scp> (<i>Squatina squatina</i>) in coastal waters of <scp>Wales</scp> and the central <scp>Irish Sea</scp>

Barker, Joanna; Davies, J.; Goralczyk, M; Patel, Surshti; O'Connor, J; Evans, Jason M.; Sharp, Rowland; Gollock, Matthew; Wood, Fenella R.; Rosindell, James; Bartlett, C; Garner, B; Jones, Daniel O. B.; Quigley, D. T. G.; Wray, Ben

doi:10.1111/jfb.15133

Cited by 7 publications

(1 citation statement)

References 53 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…An interesting finding from this study is that when variable importance was considered by IUCN status category, critically endangered species showed high proportions of SST and salinity drivers, further indicating increasing global warming and climate change is a specific threat to species already at extremely high risk of extinction. This pattern has been observed across marine predator taxa, with models identifying SST and salinity (alongside depth and chlorophyll a concentration) to be of importance in the critically endangered species: angel shark (Squatina squatina) in coastal waters of Wales and the central Irish Sea (Barker et al, 2022) and in the Canary Islands (Meyers et al, 2017), scalloped hammerhead (Sphyrna lewini) (Zhang, 2022), Balearic shearwaters Puffinus mauretanicus (Zhang, 2022).…”

Section: Environmental Drivers Of Species Richnessmentioning

confidence: 87%

Multi-species space use by marine predators: defining biodiversity ‘hotspots’ in the marine realm

Phillips

View full text Add to dashboard Cite

Anthropogenic change of ecosystems has led to wide-scale changes in biodiversity globally, with declines across terrestrial, freshwater and marine realms. Global concern about the increasing anthropogenic impact on biodiversity has driven intense research into the drivers and consequences of change, alongside rapidly moving international policy and conservation development. Quantifying critical marine habitats is vital for protecting remaining biodiversity, and understanding areas of increased coexistence or biodiversity hotspots is particularly important if management and conservation methods continue to focus on spatial approaches (such as marine protected areas). A key challenge in biogeography is to understand and predict the potential impacts of climate change on the distribution of biodiversity, therefore identifying the environmental drivers that may impact richness may provide insight into future species richness patterns. Studies have highlighted the difficulty in mapping biodiversity at a large scale due to patchy data coverage, and this is further intensified using a particularly cryptic set of species that inhabit and spend much of their life beneath the surface. Top marine predators have essential ecological roles as ecosystem engineers and amplify trophic information across multiple spatiotemporal scales and have been identified as sentinel species which can exhibit clear responses to environmental variability and ecosystem health. However quantitative maps of marine predator coexistence are lacking, with the collection of new standardised data expensive, time-consuming and often focused on small-scale local studies.This thesis utilises large available historical datasets to address this critical research gap in mapping the biodiversity of top marine predators across multiple taxa, around the UK. Chapter 2 summarises available data around the UK, which can be used to ascertain the status of the information available. This is useful for a wide range of stakeholders who are often under time pressure, under-resourced and trying to be proactive in a fast-paced legislative environment. It demonstrates available data exists to maximise temporal and spatial coverage of such a large-scale area, for large-scale research questions.However, it is well-known that databases have inherent biases due to heterogeneousdata sources and lack of standardisation. Chapter 3 adapts a well-recognised risk-assessment matrix approach to quantify biases within four example datasets. The study highlighted the level of risk in using heterogeneous datasets is lower for assessing patterns of association in marine predators, rather than counts or abundances. Therefore, research questions should be carefully considered when utilising datasets not designed for a specific research hypothesis. The matrix method presented has two important roles to advance this field of research: the first is to aid people to analyse existing datasets and provide a standardised approach to enumerating bias quantitatively as opposed to just describing bias assumptions. The second is to guide research to design better surveys by understanding which risk factors are most influential on their study.Critically, Chapter 4 provides maps of marine predator biodiversity hotspots around the UK, identifying areas of shared space use across taxa groups. It is the largest cross- taxa study of marine predator biodiversity around the UK to date. Sighting datasets were collated and species richness was determined across different spatial scales. Whilst species richness has been a keystone measure of biodiversity, it can be skewed by survey effort and therefore a new measure of ‘species richness per unit effort’ (SRPUE) was derived to identify relative areas of high and low richness. Patterns in species richness over time using seasonal-trend decomposition analysis revealed that the concept of carrying capacity becomes evident when survey effort is accounted for. This chapter demonstrates how the analysis of existing data can facilitate the mapping of the biodiversity of marine predators and allow areas of high shared space use to be prioritised in conservation and management.Simply quantifying biodiversity hotspots is not enough, with the potential drivers of species richness patterns identified as important in the literature, particularly with anthropogenic climate change causing shifts in species coexistence. Chapter 5 uses three modelling approaches to look at associations of high species richness with a suite of environmental variables. Macro-ecological models (MEMs) using generalised additive models (GAMs) and stacked species distribution models (SSDMs) were utilised to give maps of species richness. SRPUE is a useful method to factor in effort in richness mapping, but user interpretation is not as intuitive as the well-known species richness integer scale, and therefore an alternative approach was derived using effort as a predictor. All variables were significant predictors for biodiversity. The GAM using raw species richness and SSDM model demonstrated sea surfacetemperature has the highest relative contribution to richness hotspots and therefore is a concern in climate change with warming oceans.Overall, this thesis demonstrates how analysis of existing and diverse data can be utilised cost-effectively to map biodiversity. While some caution is needed when using historical datasets, these distribution maps are the first available output at this spatial scale and taxonomic coverage and have widespread and immediate applications in identifying important areas of protection and providing a focus for marine management strategies.

show abstract

Section: Environmental Drivers Of Species Richnessmentioning

confidence: 87%

Multi-species space use by marine predators: defining biodiversity ‘hotspots’ in the marine realm

Phillips

View full text Add to dashboard Cite

show abstract

Distinct management units for the Critically Endangered angelshark (Squatina squatina) revealed in the Canary Islands

Meyers,

Faure,

Jiménez-Alvarado

et al. 2024

Conserv Genet

View full text Add to dashboard Cite

The angelshark, Squatina squatina, is listed as Critically Endangered on the IUCN Red List of Threatened Species, and remaining populations are highly fragmented throughout its historical distribution. The Canary Islands archipelago in the North East Atlantic has been identified as a uniquely large stronghold for the species. In the present study, we compared the population genetic structure of S. squatina across different islands of the Canary Island archipelago using both microsatellite and single nucleotide polymorphism (SNP) markers. Both markers revealed significant differentiation of angelsharks between islands in the archipelago, with three main genetic units at: (1) Tenerife, (2) Gran Canaria and (3) the island group consisting of La Graciosa, Lanzarote and Fuerteventura. Our results imply a connectivity barrier between some adjacent islands, most likely driven by abyssal depths, and varying geological history and formation of each island and oceanographic patterns (i.e. seasonal coastal upwellings off the African coast). Therefore, we suggest that in the Canary Islands, S. squatina populations should be managed locally, with conservation and research priorities designed and implemented specifically for each of the three genetic units.

show abstract

Century‐scale loss and change in the fishes and fisheries of a temperate marine ecosystem revealed by qualitative historical sources

Moore,

Brander,

Evans

et al. 2024

Fish and Fisheries

View full text Add to dashboard Cite

Policies aiming to restore ecosystems, achieve thriving fisheries and reverse biodiversity loss require knowledge of their former status and long‐term variation. As quantitative fish data is typically only available for recent decades long after changes may have occurred, a greater use of qualitative sources has been encouraged in marine historical ecology. We examined diverse historical information (including maritime history, fisheries reports, naturalists' accounts, recipes, nautical charts and newspapers) across a multi‐century time span (13th–20th century) for a wide range of species to document their long‐term trajectories in an understudied Northeast Atlantic ecosystem (Irish Sea coast of Wales). We find strong evidence of the loss of both a pelagic fishery for herring, which was of fundamental socio‐ecological importance since at least the 13th century, and the loss of significant multi‐species demersal and intertidal fisheries. Local, commercial and/or functional extinction has occurred for taxa spanning a wide range of diversity (crustacean, elasmobranchs, sturgeon, and teleosts), body size and ecological role, suggesting far‐reaching changes to food webs. This raises fundamental questions about the present‐day health and integrity of this coastal ecosystem and the long‐term viability of current fisheries which depend on a few shellfish species. Our century‐scale synthesis of qualitative data for multiple taxa allows the collective breadth of losses to be fully appreciated and may reduce the risk of ‘shifting baselines’. Restoration to historical baselines may not be achievable, but our findings provide evidence of long‐term change relevant to policies for recovery, and prevention of further decline of fishes, fisheries and ecosystems.

show abstract

The distribution, ecology and predicted habitat use of the Critically Endangered angelshark (Squatina squatina) in coastal waters of Wales and the central Irish Sea

Cited by 7 publications

References 53 publications

Multi-species space use by marine predators: defining biodiversity ‘hotspots’ in the marine realm

Multi-species space use by marine predators: defining biodiversity ‘hotspots’ in the marine realm

Distinct management units for the Critically Endangered angelshark (Squatina squatina) revealed in the Canary Islands

Century‐scale loss and change in the fishes and fisheries of a temperate marine ecosystem revealed by qualitative historical sources

Contact Info

Product

Resources

About