Solent Dredge Fisheries

Dredge fisheries in the Solent have historically supported a number of fishers from ports including Lymington, Warsash, Portsmouth, Langstone, Chichester, Cowes, Bembridge and Yarmouth. Target species have varied throughout the years, and the fleet has adapted to new and emerging opportunities based on the available fisheries. This has included native oysters ( Ostrea edulis ), Pacific oysters ( Magallana Gigas ), Manila clams ( Tapes phillipinarum ), American hard-shell clams ( Mercenaria mercenaria ), native paulourde clam ( Ruditapes decassatus ), cockles ( Cerastoderma edule ) and king scallops ( Pecten maximum ).

From the 1970s up until around the mid 2000’s the main target species supporting much of the fleet was the native oyster. During this period the Solent was considered one of the largest self-sustaining oyster fisheries in Europe employing at its peak, 700 individuals. The fishery has historically been a winter fishery and was spread across much of the subtidal sediments of the Solent including Southampton Water, Portsmouth, Langstone and Chichester. Since 2014 Southern IFCA has deemed parts or all of the native oyster fishery to be severely depleted.

Clams species have been the focus of various targeted fisheries. These have included the native pallourde, but more recently have focused on two non-native species. The American hard-shell clam was first targeted commercially in the 1970s and the fishery has been subject to various peaks and troughs throughout the years. They are fished in their own right but also are currently collected as a bycatch of the manila clam fishery. The manila clam is another non-native species which has spread into the Solent. First spreading to the area around 2006, naturalised populations have been the subject to fisheries since then. Both species of clams typically populate the intertidal areas, making the Solent an ideal area for them to proliferate.

More recently, from around 2012 onwards a scallop fishery has developed in the Solent. Particularly focused around the north-east side of the Isle of Wight, occupying the shallow subtidal sediments near the forts of the eastern Solent and into Osbourne bay. Previously targeted by a few vessels in each year, this fishery has expanded supporting a number of vessels at key times of year, predominantly the winter months.

All of the above species are typically based around mechanised dredges. The designs vary based on the species, habitat and are influenced by a variety of regulations designed to mitigate impact to the environment, standardise gear or influence efficiency.

Fishery Monitoring and Stock Assessments

Stock surveys are undertaken covering a variety of bivalve species in the Solent.

The Solent native oyster stock survey is undertaken annually since 2014. It involves officers working with a local fishing vessel to fish historic sites across the Solent to identify current stock levels and influence management of the species. The data is analysed to detect changes in catch per unit effort over the extent of the time series. You can find the assessments here:

Oyster Survey 2017

Oyster Survey 2018

Oyster Survey 2019

The Solent Bivalve populations have been surveyed since 2016, following the introduction of the Solent Dredge Fishing Byelaw. The survey work takes place aboard local fishing vessels from Southampton Water, Portsmouth and Langstone. These are sampled using a dredge and the results analysed to monitor trends in catch per unit effort at various stations across the areas. The reports for these assessments are found here:

Bivalve Survey 2017

Bivalve Survey 2018

Bivalve Survey 2019

The Solent Scallop populations have not currently been subject to the stock survey or assessment. It is currently proposed to be initially surveyed in 2021, to provide more detail on the emerging fishery. The survey would aim to use similar techniques as the native oyster stock survey and the bivalve survey, however will be developed to be compatible with COVID19 restrictions.

Marine Protected Area Assessments

Under the Marine and Coastal Access Act, Southern IFCA has a duty to further the conservation objectives of Marine Protected Areas (MPA). For each MPA, Southern IFCA must carry out an assessment of fishing activities within the site, to determine if the activities will hinder the conservation objectives. If this document finds that the activity could hinder the site objectives, Southern IFCA must create appropriate management measure to mitigate the risks.

Below are the assessments of bottom towed fishing gear activities in the Solent European Marine Sites. Following initial Habitats Regulation Assessments in 2016, it was determined that in order to protect sensitive habitats across the Solent from potential damaging activities the Solent Dredge Byelaw be implemented (link to byelaw), managing effort across Southampton Water, Portsmouth and Langstone Harbours, through a curfew and closed season. This was introduced in conjunction with the Bottom Towed Fishing Gear byelaw 2016, which protects key habitats from all forms of bottom towed fishing gear including shellfish dredges.

Following designation of two tranche 3 MCZs bottom towed fishing gear, including shellfish dredges, has been assessed in Yarmouth to Cowes MCZ and Bembridge MCZ. The findings of these assessments will feed into the MPA spatial management review being undertaken in 2021.

Further requirements for adaptive management have also led to the development of the Solent Dredge Permit Byelaw. This byelaw is due to be implemented in November 2021 and will incorporate many of the protections afforded by the Solent Dredge Byelaw, whilst allowing for adaptive management of the fishery through permit conditions and involving stakeholders in those decisions through community forums. Use of this byelaw will continue to manage the clam and oyster fisheries in the Solent, whilst allowing for potential management of emerging or developing fisheries. Outcomes of the ongoing Solent Scallop Review will feed into use of the Solent Dredge Permit Byelaw and has the potential to influence permit conditions in the future.