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. 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. 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. Three data storage tags revealed that resident individuals utilized most of the available depth habitat (6–205 m) in the area and occasionally visited deeper areas outside the immediate study area. 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.© 2014 Crown copyright. Aquatic Conservation: Marine and Freshwater Ecosystems © 2014 John Wiley & Sons, Ltd.

Seasonal and ontogenetic variations in depth use by benthic species are often concomitant with changes in their spatial distribution. This has implications for the efficacy of spatial conservation measures such as marine protected areas (MPAs). The critically endangered flapper skate (Dipturus intermedius) is the designation feature of an MPA in Scotland. This species is generally associated with deeper waters >100 m; however, little is known about its seasonal or ontogenetic variation in habitat use. This study used archival depth data from 25 immature and mature flapper skate tagged in the MPA over multiple years. Time series ranged from 3 to 772 (mean = 246) days. Generalised additive mixed models and highest density intervals were used to identify home (95%) and core (50%) highest density depth regions (HDDRs) to quantify depth use in relation to time of year and body size. Skate used a total depth range of 1–312 m, but home HDDRs typically occurred between 20 and 225 m. Core HDDRs displayed significant seasonal and ontogenetic variations. Summer core HDDRs (100–150 m) suggest high occupancy of the deep trenches in the region by skate of most size classes. There was an inverse relationship between body size and depth use and a seasonal trend of skate moving into shallow water over winter months. These results suggest that flapper skate are not solely associated with deep water, as skate, especially large females, are frequently found in shallow waters (25–75 m). The current management, which protects the entire depth range, is appropriate for the protection of flapper skate through much of its life history. This research demonstrates why collecting data across seasonal scales and multiple ontogenetic stages is needed to assess the effectiveness of spatial management.

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.

Aim Estimating environmental suitability from species distribution data is crucial in defining spatial conservation measures. To this end, species distribution models (SDMs) are commonly applied, but seldom validated by completely independent data. Here, we use data on individual tracks derived from electronic tags as an alternative means of validating SDM outputs.Location West coast of Scotland, NE Atlantic.Methods We used a binomial generalized additive model (GAM) to predict the environmental suitability for flapper skate (Dipturus cf. intermedia) in Scottish waters. The GAM modelled relative habitat usage as a function of environmental variables using presence-absence data obtained from scientific trawl surveys. Additional data obtained from electronic tags attached to six individual flapper skates were used to estimate individual tracks using a tidal-based geolocation model. Concordance between individual tracks and GAM-predicted maps of relative habitat usage (RHU) was tested by comparing predicted RHU between estimated tracks and randomly generated tracks.Results Environmental suitability for the flapper skate was driven by depth and distance from the coast in the SDM. We found high spatial concordance between the estimated tracks of the six tagged individuals and regions of high RHU predicted by the SDM.Main conclusions Integrating outputs from an independent data source allowed us to validate predictions from a species distribution model (SDM). The integration of individual-and population-level data sources increases confidence in the outputs being used to define spatial conservation measures. The information on flapper skate distribution provided by this study provides a useful framework for considering spatial conservation measures for this species.

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