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This study provides the first report of an egg nursery for the Critically Endangered flapper skate Dipturus intermedius and a description of the habitat, thus contributing towards our understanding of essential habitats for the species.In total, 1,395 flapper skate egg cases were recorded (accounting for overlapping surveys) in two egg case collection dives (n = 67 egg cases), one photogrammetry dive (n = 10 egg cases), 509 drop‐down video (DDV) camera drifts (n = 510 egg cases) and 18 remote operated vehicle (ROV) flights (n = 1,031 egg cases), carried out in the Inner Sound on the west coast of Scotland from 2018 to 2021. All of the egg cases were found on a shallow bedrock plateau between the Isle of Scalpay and a deep (>100 m) water channel between the Isle of Longay and the Crowlin Islands. Egg cases were observed on a cobble/boulder reef between 25 and 58 m depth, with a modelled annual temperature range of 9–12 °C, modelled current speeds up to 0.2 m−1, a rugosity index of 1.7 and low levels of sedimentation.Flapper skate egg cases are large and the incubation period is protracted (18 months), making them potentially vulnerable to anthropogenic disturbance. A description of the habitat where egg cases were observed in this study will help inform the search for egg nurseries for this Critically Endangered species elsewhere. Targeted DDV, ROV and scuba diving surveys will support this search in areas where suitable bathymetric and hydrodynamic conditions are identified.Safeguarding egg nurseries is essential for successful conservation. Protection should involve the designation of egg nurseries as Marine Protected Areas where activities that are likely to damage or alter seabed habitats are managed. [ABSTRACT FROM AUTHOR]

Marine Protected Areas (MPAs) are widely used in marine management, but for mobile species understanding the spatio‐temporal scale of management measures that is required to deliver conservation benefits depends on a detailed knowledge of species' movements that is often lacking. This is especially the case for species of skate (Rajidae) for which relatively few movement studies have been conducted.In Scotland, the Loch Sunart to the Sound of Jura MPA covering 741 km2 has been designated for the conservation of the Critically Endangered flapper skate (Dipturus intermedius), but fine‐scale movements within this area remain poorly understood.A passive acoustic telemetry study which coupled acoustic tagging of 42 individuals and a static array of 58 receivers was conducted from March 2016 to June 2017. Using acoustic detection time series, angler capture–recapture data and depth time series from archival tags, fine‐scale movements of individuals were investigated.Overall, 33 of the 42 tagged individuals were detected. Residency, site fidelity and transiency were documented. Residency around receivers, lasting from 3 to more than 12 months, was documented in 16 acoustically detected individuals (48%) and all life‐history categories, but was most noticeable among females. Acoustic detections were associated with depth, salinity and season, but there was no evidence that individuals formed close‐knit groups in the areas in which they were detected.Taken together with historical occurrence records of flapper skate, the prevalence and scale of residency documented here suggest that the MPA is sufficiently large to benefit a notable percentage (38 [24–52]%) of skate found in the study area over monthly and seasonal timescales. This result strengthens the case for the use of MPAs to support the conservation of flapper skate and other skate species that display similar movement patterns in areas of high local abundance. [ABSTRACT FROM AUTHOR]

Flapper skates (Dipturus intermedius) were once widespread in European shelf waters but are currently classified as critically endangered by the International Union for Conservation of Nature due to historical overexploitation. Novel monitoring approaches are needed to assess the efficacy of management measures, such as dedicated marine protected areas, for the conservation of relict skate populations.Flapper skates possess distinctive dorsal spot patterns, which could potentially be used for individual recognition using photo‐identification (photo‐ID) approaches. This study assessed the potential of photo‐ID as a method for individual recognition of a relict population of skates within a dedicated marine protected area in western Scotland (UK), which has long been targeted by directed recreational angling. A collection of 486 photographs of 373 separate skate capture events from 2011 to 2016, taken with standard mobile phones and compact cameras, was studied using visual pairwise comparison methods to determine number of individuals and recapture rates.Results indicated that adult flapper skates were individually recognizable with a high degree of certainty through comparison of spot patterns, assuming appropriate lighting conditions. A total of 226 individuals were identified, of which 77 (34%) were recaptured at least once. The average recapture interval was 308 days (SE: 29.4 days), with the longest recapture interval to date being 4.4 years. Spot patterns among recaptured tagged or otherwise uniquely identifiable skates were found to remain stable over timescales of months to >1 year.Results indicate that photo‐ID, based on photographs sourced through citizen science approaches, can provide a low‐cost alternative means of monitoring flapper skate presence and distribution for the purposes of underpinning management decisions. [ABSTRACT FROM AUTHOR]

Micropopulation processes, such as gene flow, operating within geographic regions are often poorly understood, despite their potential to affect stock structure and sustainability. This is especially true for highly mobile species, such as elasmobranchs, where the potential for spatial overlap of regional populations is increased as a result of greater movement capabilities. A lack of information on these processes means that management plans rarely consider spatio‐temporal structure.Spurdog (Squalus acanthias) are globally distributed throughout temperate regions yet there is an apparent lack of gene flow between ocean basins. In the North‐east Atlantic there is little work on gene flow within the region, which is currently managed as a single stock that is estimated to be at 19% compared with 1905. Some evidence from this region suggests population processes that have the potential to cause structuring.The population structure of the North‐east Atlantic spurdog was investigated using an 828‐bp fragment of the mitochondrial DNA control region and seven focal polymorphic microsatellite markers. Samples from 295 individuals from eight locations throughout UK waters were used in this study.Overall, mitochondrial sequences suggest some regional differentiation. Genetic diversity was comparable with that reported in previous studies of spurdog. Haplotype diversity (0.782–1.000) is amongst the highest observed for an elasmobranch. Microsatellite markers suggest that a high level of relatedness was responsible for regional population structuring. There was no apparent spatial structure after removal of 'full sibling' relationships.Inter‐haul variation from Celtic Sea samples is suggestive of subpopulations and aggregation events, which may have important implications for fisheries conservation of this and other elasmobranch species. [ABSTRACT FROM AUTHOR]

1. In order to evaluate if marine protected areas (MPAs) can be expected to confer conservation benefits to large, mobile marine species it is important to assess their site fidelity and habitat ranging patterns. The flapper skate (Dipterus cf. intermedia) is a large, threatened elasmobranch for which MPAs are being considered on the west coast of Scotland. To inform MPA establishment, a multiannual mark-recapture programme, a year-long static array acoustic study and an archival tagging study of flapper skate were undertaken. 2. Capture-mark-recapture (CMR) modelling of 280 individuals indicated significant heterogeneity in the recapture rate suggesting the region contained a mixture of site-attached (resident) and vagrant (transient) individuals. The analysis estimated that 100-400 resident individuals were present in the study area. The number of transient individuals was estimated at around 25% of all those tagged. The average annual survival probability of resident individuals was estimated to be 0.64. 3. The acoustic study of 20 individuals demonstrated that over half were resident on a day-by-day basis for months at a time. Three individuals were detected over the entire year. Two individuals moved away immediately after tagging and over half moved out of the study area in the springtime. 4. Three data storage tags revealed that resident individuals utilizedmost of the available depth habitat (6-205m) in the area and occasionally visited deeper areas outside the immediate study area. 5. The results indicate that the establishment of a MPA would confer conservation benefits to flapper skate in the area. Management should consider all depths in the study area, areas beyond the study site, and alternative conservation measures such as technical gear measures for fisheries. This study has implications for the conservation and management of similar long-lived, mobile marine species. [ABSTRACT FROM AUTHOR]