Abstract
An overview of results from the Shetland Inshore Fish Survey (SIFS) conducted by UHI Shetland (formerly NAFC Marine Centre) from 2011 - 2024 in the coastal waters around Shetland is presented. The purpose of the survey is to provide independent information on the distribution, relative abundance, and population structure of fish species in local waters. Key results from the available data are reported here with a focus on commercially important species. This report is intended for a general audience with information presented in a concise and non-technical format.
The survey has been carried out annually using the 12 m MFV Atlantia II (LK 502) during August and September, using a standardised survey trawl fitted with a small-mesh (20 mm) cod-end. The original annual inshore fish survey involves hauls from 27 pre-defined locations within 12 nautical miles of Shetland. Since 2017, a concurrent shallow-water fish survey has been added, with up to 25 hauls targeting potential nursery grounds around the coast of Shetland. Catch rate results are used to investigate the relative abundance of commercial species by considering catch per unit effort (CPUE). Length data are used to further interpret variations in population structure and recruitment.
Results are presented with a focus on the most significant commercially important demersal fish species sampled throughout the surveys. Key findings from the 2024 surveys include:
• Haddock (Melanogrammus aeglefinus) continues to be the main component of catches, with the 2024 haddock data characterised by young age-classesthat have not yet reached marketable sizes and been recruited into the fishery.
• Average catch rates for several key commercial species were at the lower end of observed values, e.g. haddock, cod (Gadus morhua), whiting (Merlangius merlangus) and plaice (Pleuronectes platessa), while other species of less commercial significance were particularly widespread and/or abundant this year, e.g. spurdog (Squalus acanthias), horse mackerel (Trachurus trachurus), and John Dory (Zeus faber).
• Squid (Lologi spp.) catch rate on shallow grounds in 2024 remain high following the record levels observed in 2023 and were concentrated in specific nearshore areas.
• Two fish species were recorded in small numbers during the survey this year for the first time, scaldfish (Arnoglossus laterna) and imperial scaldfish (Arnoglossus imperialis), both small flatfish species typically distributed further south.
• The data from shallow hauls suggests that some nearshore grounds around the coastline of Shetland are nursery areas for a variety of commercial species including plaice, haddock, whiting, and cod; and contain important commercially exploitable abundances of other species such as thornback ray (Raja clavata).
The survey has been carried out annually using the 12 m MFV Atlantia II (LK 502) during August and September, using a standardised survey trawl fitted with a small-mesh (20 mm) cod-end. The original annual inshore fish survey involves hauls from 27 pre-defined locations within 12 nautical miles of Shetland. Since 2017, a concurrent shallow-water fish survey has been added, with up to 25 hauls targeting potential nursery grounds around the coast of Shetland. Catch rate results are used to investigate the relative abundance of commercial species by considering catch per unit effort (CPUE). Length data are used to further interpret variations in population structure and recruitment.
Results are presented with a focus on the most significant commercially important demersal fish species sampled throughout the surveys. Key findings from the 2024 surveys include:
• Haddock (Melanogrammus aeglefinus) continues to be the main component of catches, with the 2024 haddock data characterised by young age-classesthat have not yet reached marketable sizes and been recruited into the fishery.
• Average catch rates for several key commercial species were at the lower end of observed values, e.g. haddock, cod (Gadus morhua), whiting (Merlangius merlangus) and plaice (Pleuronectes platessa), while other species of less commercial significance were particularly widespread and/or abundant this year, e.g. spurdog (Squalus acanthias), horse mackerel (Trachurus trachurus), and John Dory (Zeus faber).
• Squid (Lologi spp.) catch rate on shallow grounds in 2024 remain high following the record levels observed in 2023 and were concentrated in specific nearshore areas.
• Two fish species were recorded in small numbers during the survey this year for the first time, scaldfish (Arnoglossus laterna) and imperial scaldfish (Arnoglossus imperialis), both small flatfish species typically distributed further south.
• The data from shallow hauls suggests that some nearshore grounds around the coastline of Shetland are nursery areas for a variety of commercial species including plaice, haddock, whiting, and cod; and contain important commercially exploitable abundances of other species such as thornback ray (Raja clavata).
Original language | English |
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Publisher | UHI Shetland |
Number of pages | 34 |
Publication status | Published - 30 Dec 2024 |