Shaun Fraser, Sarah Ayres, Martha Thomson, Angharad Powell, Chevonne Angus. 2023. UHI Shetland.

Executive summary

The first Fair Isle inshore fish survey was conducted during July 2022 in line with the objectives of the Fair Isle Demonstration and Research Marine Protected Area (DR MPA) Designation Order and recommendations from consultation with community members and wider stakeholder groups.

Data collection was conducted by Shetland UHI staff aboard the 12 m MFV Atlantia II (LK 502) using a standardised methodology and scientific trawl gear. The same method has been used since 2011 in inshore areas to the north of Fair Isle during the annual Shetland Inshore Fish Survey (SIFS) which provided opportunities for comparisons. Stomach samples were also taken, and diet analysed for the commercially important species cod (Gadus morhua), haddock (Melanogrammus aeglefinus), and whiting (Merlangius merlangus). Additional data were collected using baited remote underwater video (BRUV) landers that were constructed for this survey and deployed in nearshore areas unsuitable for trawling.

Catch data were collected from seven valid tows in areas east and west of Fair Isle which indicated an overall dominance of elasmobranchs, particularly spurdog (Squalus acanthias), in Fair Isle demersal fish communities during the study period. Average catch rates of spurdog, flapper skate (Dipturus intermedius), and lesser spotted dogfish (Scyliorhinus canicular) were shown to be substantially higher than corresponding data from SIFS. Of the commercial species, cod was the most significant overall in terms of weight; however, haddock was the highest in terms of number followed by cod and lemon sole (Microstomus kitt). Some notable species, for example sandeel (Ammodytes), were not observed. There was little evidence of significant juvenile populations of commercially important fish species.

Analysis from 110 stomach samples showed contributions from eight major prey groups. There was clear variability between species, with haddock data indicating a more generalist diet than cod or whiting. Overall, Norway pout (Trisopterus esmarkii) was by far the most important diet component.

Video footage from eight BRUV lander deployments showed that a variety of habitat types were sampled and least 17 mobile species were observed to be present, including some fish species not sampled by the trawl. Foraging seabirds were also observed in the footage.

These results are discussed in the context of other available information. Limitation of this study are identified and recommendations made including the repetition and expansion of the Fair Isle inshore fish survey in subsequent years which would further inform management of the Fair Isle DR MPA.