Common whelk

This stock is data limited. There is no concern for biomass but there is concern for fishing pressure.Route 2 (data limited) scoring has been applied to this rating owing to the lack of a reference point for biomass and fishing pressure.No independent assessment of species resilience or vulnerability is available. Common whelks mature between 6-9 years with a growth rate of k=0.2 and they are estimated to live around 10-12 years. Additionally, the species has sedentary life history characteristics. Therefore, MCS assesses the species to have low resilience.A stock assessment for common whelks in Shetland waters was undertaken in 2020, although this only uses commercial catch data to assess stocks. The landings per unit effort (LPUE) metric used is dependent on where and how fishing has taken place and is likely to be influenced by market access and value of targeted species. Therefore, LPUE can only be used as a crude indicator of stock biomass. Additionally, the stock assessment reports that due to whelks being very substrate dependent they can be vulnerable to localised overfishing, which could also skew LPUE data.Exact LPUE data is not detailed for the fishery, however, it appears to have been relatively stable at a relatively high level since 2015, around 2-2.5Kg/pot and 2.5Kg/pot in 2020. Prior to this LPUE had been lower between 2000-2014, ranging 1.5-2Kg/pot. As LPUE is stable at a relatively high level there is no concern for biomass.Exact landings data is not detailed for the fishery, however, the 2020 stock assessment for the fishery indicates that landings have been relatively high between 2016-2020 and the highest on record in 2020, ranging from approximately 200,000Kg to 450,000Kg. Whereas, between 2010-2015 landings were much lower ranging from approximately 20,000-100,000Kg. Due to the considerable increase in landings and the lack of reference points there is concern for fishing pressure.

Some appropriate management measures are in place in the Shetland whelk fishery. A minimum landing size is in place, the fishery is closed in the breeding season, licenses are required to fish for whelk commercially and effort is controlled through creel limits.Shetland shellfish fisheries are managed by the Shetland Shellfish Management Organisation (SSMO) through a regulation order, which awards the SSMO the legal right to manage shellfisheries, including whelks, between 0-6 nautical miles until 2028. The SSMO regulations go further than Scotland wide management. However, the lack of fisheries independent stock assessment and lack of appropriate catch controls means it is difficult to assess the appropriateness or effectiveness of management measures.The SSMO includes several regulations including:A size limit of 17 m for all boats (except scallop dredges).All buoys for static gear must be brightly coloured and clearly marked with vessel registration details.Confidential log sheets must be submitted monthly.The minimum landing size (MLS) for whelks is 75mm shell length – which is considerably larger than UK limits of 45mm shell length, however, this is lower than the reported size at which 50% of males (86mm) and females (101mm) mature around Shetland.The fishery is currently subject to closure from September to January during the breeding season.Whelk fisheries in Shetland are not limited by EU Total Allowable Catch (TAC) regulations or national regulations, and therefore are not limited in the number of whelks caught. However, creel limits of 600 per vessel are in place in Shetland.  All vessels registered in the UK must have a domestic fishing vessel license to fish within the UK EEZ that will be sold on. All commercial vessels under 10m, with a shellfish license, are required to complete a FISH1 form weekly and submit it to the registered Fishery Office. All vessels over 10m complete an EU logbook of catches. There are no whelk catch limits for hobby fishers. SSMO restrictions mean no new licenses or entitlements are being granted in Shetland however there is potential from increased activity if existing non-active license entitlements are used.The UK Fisheries Act came into force in January 2021 and requires the development of Fisheries Management Plans (FMPs). In the UK, it is too early to tell how effective management is, as the Fisheries Act only came into force in January 2021. The Act requires the development of Fisheries Management Plans (FMPs) (replacing EU Multi-Annual Plans). FMPs are currently in development, but the scope of them remains unclear. They have the potential to be very important tools for managing UK fisheries, although data limitations may delay them for some stocks. MCS is keen to see publicly available FMPs for all commercially exploited stocks, especially where stocks are depleted, that include:Targets for fishing pressure and biomass, and additional management when those targets are not being met, based on the best available scientific evidenceTimeframes for stock recoveryImproved data collection, transparency and accountability, supported by technologies such as Remote Electronic Monitoring (REM)Consideration of wider environmental impacts of the fishery

Potting or creeling is associated with negligible bycatch and habitat impacts, unless undertaken at high density or in sensitive environments. Potting may result in the entanglement of whales in this area.Whelks are mainly caught in customised baited plastic pots in Scottish waters.Bycatch species can both be caught during creel fishing and if pots are lost resulting in ghost fishing. Where studies have been undertaken small sharks, crustaceans, starfish and fish have been reported. A study has indicated that non-target species can usually escape creels after days or weeks especially if the pots include escape gaps for smaller animals.Discards are unknown and discard survival data are limited. However, invertebrates are understood to have high survival rates when discarded from pots or creels.In Scottish creel fisheries, there is potential for entanglement of endangered, threatened or protected (ETP) species from the ropes attached to the pots. The main species at risk are minke and humpback whales, basking sharks and leatherback turtles. Minke whales are the most common whale, however entanglement rates for humpback whales are relatively high given their low abundance in Scottish waters and may exceed sustainable levels for the species. A 2010 report found that Shetland has lower risk of entanglement than elsewhere in Scotland. Monitoring to date has been poor, with bycatch reporting requirements only in place since 2021 in the UK. Work is underway with fishers to investigate ways to reduce these risks, but no wide scale mitigation measures have so far been introduced.Habitat impacts from potting are low but can occur, impacting the benthic habitat through contact with the pot or end weight, or by scouring from ropes. Most damage occurs where traps are set in rocky habitats that are home to slow growing anchored species including soft corals, sponges and sea mats. These habitats and species provide nursery areas, refuges from predators and habitat for the settlement of invertebrate spat. Research that has taken place suggests that while some damage does occur, it is unlikely to be significant unless potting intensity is high (defined as approximately 30 pots per 500 square metres).Pot fishing is associated with negligible bycatch and habitat impacts. If undertaken at high intensity or in areas where entanglements are common there would be greater concern.To improve monitoring and reporting of fishing activity, MCS would like to see remote electronic monitoring (REM) with cameras implemented, used and enforced. To reduce the impacts of fishing on the marine environment we would like to see a just transition to the complete removal of bottom towed gear from offshore Marine Protected Areas designated to protect the seabed. We also want to see reduction and mitigation of environmental impacts including emissions and blue carbon habitat damage.