Cockle

For wild cockles in fisheries independently certified by the MSC in the Thames estuary there is no concern for the biomass and no concern for catch levels.Route 2 (data limited) scoring has been applied to this rating owing to the lack of a reference point for biomass and fishing pressure. Cockle is considered to have low vulnerability to fishing (scoring 24 out of 100).Some cockle fisheries in the Thames estuary are independently certified to the Marine Stewardship Council (MSC) standard and are managed using stock assessments undertaken by the local Inshore Fisheries and Conservation Authorities (IFCAs) in England. The available stock assessments provide an indicator of local cockle stocks through population estimates, but do not include biological reference points to measure the overall stock sustainability against.In this fishery, independently certified by the MSC, the certification audits indicate relatively stable adult stocks with no concern under current fishing levels. Detailed assessment of the Thames certified fishery by the IFCA confirms the stocks surveyed and reported in 2021 (7052 million cockles) were below the 2016-2020 average (9034 million cockles) but within the abundance fluctuations of the period (lowest of 3597 in 2016 and highest of 13318 in 2019).Overstocking (rouching at surface) has been identified in the Thames estuary, where cockles are not able to bury themselves due to their density, risking die off in hot conditions. This rouching indicates locally high stock levels. Conversely, there are some indications of relatively low spat fall in the Thames fishery in the most recent assessment which could indicate low stocks in the future, however, the MSC certification assessment does not raise this as a concern for stock levels and biomass. Therefore, available evidence indicates no concern for the biomass for this MSC certified cockle fisheryIn the Thames fishery a total allowable catch limit (TAC) is set for the fishery, in response to stock assessment results, these are used to measure fishing pressure against in this rating. In the Thames fishery there are some inconsistencies between published data in MSC reports and data received directly from the IFCA. The data do however indicate that catches are either equal or below the set TAC. Therefore, available evidence indicates that this certified cockle fishery is not subject to overfishing.Additional cockles can be harvested by recreational fishers with an allocation of 5 kilograms daily for personal consumption, in fisheries that are not closed due to health risks or for stock recovery. There is no regulation or reporting of this harvesting. There are also several cases of harvesting in areas that are closed to fishing due to biosecurity risks or where collections for personal consumption were questionable. In the Thames fishery all cockles carried on board and landed must be in containers with appropriate labelling for permit holders to ensure permitted landings can be identified and to reduce the risk of illegal sales. The overall scale of recreational and illegal landings is not known or reported by authorities and so cannot be assessed in this rating. However, continuing unreported and illegal harvesting may affect cockle populations adversely.

The Thames cockle fishery is compliant with certification by the Marine Stewardship Council (MSC). In this MSC certified cockle fishery there are a range of management measures that are appropriate for the local stocks. These are guided by regular stock assessments. The fishery needs to meet some conditions to maintain certification.  Landing limits are set through total allowable catches (TAC) using a proportion of total adult biomass (33%) in the Thames fishery, based on IFCA survey data. The Thames TAC also incorporates a deduction for overwintering birds as part of an agreed Habitat Regulation Assessment. Available data indicates that Thames fishery landings have been on or under the TAC in recent years based on available data.  The fisheries employ a range of methods to control effort including through: Licences and permit allocation.Landing size limits is 16mm in the Thames estuary. Although not detailed for this fishery or the species more widely this is larger than the reported size at maturity of 14mm in other fisheries.   Gear restrictions.Limiting landings per trip and trips per week. Ability to adjust landing limits depending on stock levels and minimum harvesting rates. Spatial controls have also been used in the Thames fishery to direct effort to overpopulated areas where cockles are ‘rouched’ on the surface and risk mortality as they can’t bury themselves in warm weather.  All area has periods closed to fishing from 31st December and opening depends on stock levels. Areas are also reactively closed during the season to alleviate fishing pressure. The Thames fishery requires daily reporting of catches and catch locations.  Monitoring of fishers is undertaken using vessel monitoring systems (VMS) and targeted sea and shore patrols. The independent MSC audit process has identified issues with non-compliance including fishing too early in the day, overloading bags and not notifying the IFCA of landings. MSC report significant improvements in compliance. MSC also raise a concern about the stock assessment approach in the Thames fishery, suggesting that independent peer review is needed.In this certified fishery management measures are effective at maintaining stock levels and managing fishing pressure on cockles, with appropriate use of enforcement where non-compliance is reported in fisheries.  There may be other cockle fisheries in the area of this assessment that are not directly managed by the inshore management authority, as in some areas private fishing and management rights can be granted. Stock and management data is not readily available for these fisheries so these areas cannot be assessed. In several areas, including the Thames, information to assess cockle biomass and fishing pressure is captured in independent MSC certification assessments but the source data is not all publicly available. Greater consistency, completeness and transparency of reporting would help to ensure timely and independent oversight of these fisheries. Additionally, there are non-MSC certified fisheries in other parts of the Thames estuary. There are concerns for the stocks outside of the certified area and the fishery is currently closed. Further accessible information is needed to assess the relationship between these two separate, but geographically close, fishing areas. Additional cockles can be harvested by recreational fishers with an allocation of 5 kilograms daily for personal consumption, in fisheries that are not closed due to health risks or for stock recovery. There is no regulation or reporting of this harvesting. There are also several cases of harvesting in areas that are closed to fishing due to biosecurity risks or where collections for personal consumption were questionable. In the Thames fishery all cockles carried on board and landed must be in containers with appropriate labelling for permit holders to ensure permitted landings can be identified and to reduce the risk of illegal sales. The overall scale of recreational and illegal landings is not known or reported by authorities and so cannot be assessed in this rating. However, continuing unreported and illegal harvesting may affect cockle populations adversely. 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 evidence  Timeframes for stock recovery  Improved data collection, transparency and accountability, supported by technologies such as Remote Electronic Monitoring (REM) Consideration of wider environmental impacts of the fishery

The cockles in the Thames MSC certified fishery are harvested using hydraulic dredges. Fishing for cockles using dredge methods are likely to cause some or moderate habitat impacts as they disturb sediments and benthic species.Management measures are in place for these fisheries as they occur in protected environments. Measures include allocating shellfish to wading birds when setting catch limits, and closed areas where the most vulnerable habitats, like salt marsh and seagrass, are found.The Thames fishery uses hydraulic suction cockle dredges. There is limited evidence about the specific impacts of cockle dredges on the seabed. A short-term study in Poole Harbour identified changes to benthic community structure following cockle dredging activities but no long-term assessment has been undertaken. Wider studies indicate that some bivalve shellfish may not recover quickly from disturbance. And a global review noted that hydraulic dredges cause the biggest depletion of biota and penetrate the seabed deepest of all bottom towed gear. However, the slow speed and narrow aperture width of the hydraulic dredge used are reported to only affect the top few cms of the mixed mud, gravel and sand sediment in the Thames certified fishery. The dredge impacts are shown to persist for less than two months in this fishery. Additionally, there are closed areas such as eelgrass beds, to protect vulnerable habitats in the area. Ultimately, the overall impacts of all dredge fisheries depend on the total hours, gear size, recurrence and spatial extent of all vessels in the fishery.This Thames fishery occurs in an area with special protection for habitats and birds including oyster catchers, marshes and estuary areas. The Special Protection Areas (SPA) and Special Areas of Conservation (SAC) require a Habitats Regulation Assessment (HRA) to assess whether the fishery will cause any adverse impact (alone or in combination with other activities) to the features of interest. Fisheries can only be opened if the HRA confirms that the fishery will not cause adverse impacts on habitats.The Thames fishery deducts a share of total cockle biomass from TACs to ensure that adequate food is available to wading birds like oystercatchers.Non-target and endangered, threatened and protected (ETP) species are rarely reported or expected in these dredge or rake fisheries. In the Thames fishery one reported smooth hound (Mustelus mustelus) was considered very unusual in cockle dredge gear, other species in the area including eel and dogfish are not considered at appreciable risk. Whilst stocks of the managed fish species caught (whiting, Dover sole and flounder) had relatively healthy stocks. Invertebrates are caught including manila clams (a non-native species). There are protected features including mixed sediments and native oyster beds that should not be disturbed.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.