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.

The scale of population structuring in cod Gadus morhua from the west of Scotland (ICES stock area VIa) and northern North Sea was investigated using a combination of non-genetic methods. Site fidelity of spawning aggregations was examined using historic tag-recapture experiments and individual geolocation estimates from data storage tagged fish. The extent of movements from spawning areas indicated by these two tagging approaches was broadly similar. Between 67 and 97% of adult cod remained within 100 km of spawning areas throughout the year, suggesting resident spawning groups. A small proportion of cod, however, did appear to stray between spawning areas. A comparison of the elemental signature of the otoliths of 0 year-group and the 0 year-group component from the same year-class at age 2 years indicated that most adults originate from local nursery areas. Moreover, there did not appear to be detectable exchange between spawning areas >200 km apart, such as the Clyde and Minch or Shetland and the Inner Hebrides. As such, population processes may operate at a smaller spatial scale than the stock level, with spawning aggregations functioning as local populations within a metapopulation. The relevance of this scale of dynamics is discussed in relation to recently imposed closed areas in the region. # 2006 Crown copyright

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Summary1. Birth date can be important to lifetime reproductive success. However, selection for birth date has rarely been addressed in fish, despite the opportunity provided by otolith microstructure. 2. This study examined the relationship between maternal age, spawning time and early survivorship in the North Sea haddock stock. Temporal changes in egg production were compared with the birth date distribution of progeny surviving to the demersal phase in 1994, 1996 and 1999, when the age structure of the spawning stock differed. 3. Estimates of intra-annual variation in stock egg production indicated that first-time spawning 2-year-olds began spawning much later than older age-classes. 4. The form and magnitude of selection on birth date varied between years, indicating that the production of multiple batches of eggs over an extended period has some adaptive significance to progeny survival. 5. Survivorship was consistently poor from the late spawning period when age 2 females contributed most to stock egg production. This persistent selection against late hatched offspring could reflect either low parental investment, as age 2 females produce smaller eggs, or the short length of the growing season prior to settlement. 6. Variability in birth date selection, particularly with respect to first vs. subsequent years of spawning, implies a strong selection pressure for a long reproductive lifespan. As such, reproductive potential in this and other exploited fish species with a similar reproductive trait may have been affected adversely by the general decline in repeat spawning females in recent years.

2006. Combined methods of otolith shape analysis improve identification of spawning areas of Atlantic cod. e ICES Journal of Marine Science, 63: 1710e1717.The effectiveness of otolith shape for identifying Atlantic cod (Gadus morhua) spawning populations in the northern North Sea and west coast of Scotland was investigated. Otolith shape was described using Cartesian Fourier analysis of the otolith outline and morphometric variable rectangularity. Pairwise randomization analysis of Fourier descriptors, and discriminant analysis of rectangularity and Fourier descriptors were used to identify differences between spawning stocks. Significant differences and a high classification success (>70%) in otolith shape indicated that spawning groups from Viking Bank and Moray Firth had different shapes from those of cod in other spawning areas. Significant differences in otolith shape of age 2 cod suggested that otoliths from the South Minch and Irish Sea were different from those from the Moray Firth and the Clyde. These results appear consistent with genetic evidence for a low gene flow, and tag-recapture evidence of resident populations. The results of pairwise randomization analysis and discriminant analysis differed slightly, indicating that use of a combination of methods increases the potential to identify spawning groups on the basis of otolith shape.