The most frequently caught skate species around Jersey include blonde ray Raja brachyura, undulate ray Raja undulata, small-eyed ray Raja microocellata and thornback ray Raja clavata. Between September 2006 and December 2008, a total of 814 individuals were tagged and released, of which 64% were small-eyed ray, 22.6% blonde ray and 12.4% undulate ray. The size distribution, sex-ratio and maturity of these samples are summarized. There were 138 reported recaptures (return rate ¼ 17.1%), with most fish recaptured from the study area. Indeed, many of the tagged skates were recaptured within the same release area or within 20 km, indicating high site fidelity, with the longest distance travelled only 61 km. Thirteen fish were recaptured on multiple (2 -4) occasions. To date the longest time at liberty has been 754 days. These results are discussed in relation to our current knowledge of the stock structure and exploitation of skates in the western English Channel.

No abstract

We monitored the long-term residency of reef-associated ballan wrasse and sand-dwelling rays captured at the site of a potential future Marine Protected Area (MPA: Portelet Bay, Jersey) by implanting them with small transmitters and deploying underwater receivers inside the bay. Individual fish were detected at Portelet Bay for up to 618 days, but there were species-specific differences in residency and detection patterns. Ballan wrasse were year-round residents at the study site where they exhibited distinct, rhythmic, diel, tidal and seasonal patterns of behaviour, whereas rays were occasional visitors to Portelet Bay with no discernible pattern to their visits. Results indicate relatively small MPAs (<0.5 km2) that with suitable habitat could provide effective, long-term protection for ballan wrasse, but would likely be of little conservation benefit for rays. Our findings emphasize the importance of quantifying fish movements when planning MPAs which intend to protect multi-species assemblages of coastal fishes.

No abstract

No abstract