The Solent Forum

Working in parnership for the future

Solent Oyster Group Initiative (SOGI)

The Solent Forum's Water Quality Group launched a Solent Oyster Group Initiative whose aim is to contribute towards developing an evidence base to support the sustainable management of the native oysters Ostrea edulis in the Solent. The objectives of the group were to:

This page outlines possible activities that could be undertaken over time by the SOGI, reflecting discussions at the Solent Forum native oyster meeting in 2012. Using a three phase approach, the intention is that the work programme should guide the actions of SOGI over the next 3 to 4 years in both collating data and applying for funding.

Phase I – Review and collate existing information: 12 months

Aim 1: Understand the existing status of the Solent oyster (Ostrea edulis) population and the various factors that may influence its survival/redevelopment by bringing what we already know together, probably in a GIS format.

Activity: Collation and evaluation of data and information (peer reviewed and other) relating to the Solent (and other O. edulis populations where relevant) together with environmental factors that may influence the oysters from as wide a variety of sources as possible. Factors to be considered would cover biological, chemical, physical and human impact aspects, including:

  1. History of the O. edulis population within the Solent.
  2. Human influences (dredging, effluent release, fishing activity, etc).
  3. Biological knowledge of O. edulis life cycle – reproductive ecology, parasites, disease, reaction to physico-chemical stressors, habitat/settlement requirements, known predators, known habitat competitors – needs to encompass early work (1920s and ‘30s) as well as recent data.
  4. Solent water chemistry, especially at sediment water interface.
  5. Habitat/seabed maps of the Solent system.
  6. Hydrography (especially changes in channels and water movement over time) and existing models.
  7. Environmental knowledge; investigate potential relationships of fundamental environmental factors e.g. water temperature (and salinity, chlorophyll etc if such data exists) and stock (using fisheries landing data and cefas stock assessment data with appropriate time lags)
  8. Investigate the relationship between Cefas stock assessment data and the fisheries landings statistics. Are historic stock assessments of the fishery at pre-defined sites representative of the commercial landings from the Solent region?

Resources required: This work would commence with all SOGI members (and any other stakeholders we can think of such as colleagues in CEFAS) contributing to a metadatabase of information sources. Once this was complete a short term (at least 4 month) research assistant would be need to be appointed to conduct the review of existing knowledge compare information from different sites and identify gaps for future work. This would require funding, for example, to support a summer intern/studentship based at NOCS (Southampton) or IMS (Portsmouth).

Deliverable: Oyster (Ostrea edulis) metadatabase (with a strong Solent bias and applicability) and review report containing comparisons with other O. edulis populations and recommendations for future research.

Notes: SOGI are aware of MAFF/CEFAS reports, the Southern/Sussex Sea Fisheries Committee/IFCA minutes, DEFRA landing data and sources of environmental data linked to monitoring work by the EA and NE, Port Health water quality monitoring data, student projects from Portsmouth and Southampton universities and the Stanswood data collection (Gillian Mills). Some examples of these are given at the end of this document. All additional suggestions are welcome. 

Phase II – filling gaps in existing knowledge: 12 – 36 months

Aim 2: Identify and fill critical knowledge gaps, including collecting O. edulis and environmental samples in selected locations to build a foundation of scientific knowledge by analysing these samples when possible and affordable to do so.

Activity: in the assumed absence of focused funding this phase will look to develop the knowledge base, concentrating on aspects identified by Phase I activities. This could include identifying the economic and social importance of the O. edulis fishery over the last two or three decades, habitat mapping (both possible student projects) as well as developing a proactive sampling plan utilising ‘vessels of convenience’ run by Southern IFCA, Sussex IFCA, the EA, Portsmouth and Southampton universities (and the like) that will allow for ‘free sampling’ and subsequent storage (which may not be totally free) of samples taken in areas of the Solent that are not sampled by anyone else (or develop existing sampling activities to provide samples for a broader scope of analysis). Analysis of water, sediment and tissue samples will be on an ‘as and when funding is available’ basis and may range from inclusion in student projects as well as paying labs to analyse samples. Many sample types can be stored in a -20 degree freezer or in alcohol or formalin as appropriate. The types of samples and analysis envisaged are:

  1. Oyster tissue samples to monitor sex ratio, reproductive condition, bioaccumulation of priority chemicals (e.g. TBT). Some of this may need an organised programme rather than just opportunistic sampling.
  2. Water and sediment samples (with geographic and spatial variations) for specific chemical parameters (eg trace metals, organic chemical contaminants, etc.).

Resources required: good-will from collaborating organisations, willingness of SOGI members to write grant applications and develop student (and other) projects that will facilitate the aims of phase II. Good communication between SOGI members (essential) is needed to make sure that sampling is systematic and methodical. Some analytical and consumables costs will be needed to supply buckets and vials, freezers and preservatives, as well as keeping some analyses (the long term seasonal samples for example) on-going.

Deliverable: Increase in geospatially variable data relating to the Solent oyster entered into the GIS developed in Phase I.

Phase III – asking the bigger questions: 12 months +

Aim 3: Develop grant proposals to deliver research that will focus on the key factors (biological, chemical, physical or human) suspected of impacting oyster stocks and seek to deliver on the research questions from phase I.

Activities: Collaboration between SOGI members and associated stakeholders to develop grant applications over a period of time, from any source that seems feasible to address the relevant research questions left outstanding by phase I. These may include:

  1. Are ‘emerging new’ chemicals that may be released (through effluent or sediment plumes) into the Solent particularly hazardous to O. edulis or other marine bivalve molluscs and/or do existing chemicals identified as being toxic (such as TBT) have as yet undiscovered sublethal impacts (eg immunosuppression) in O. edulis or other bivalve molluscs?
  2. What is the biochemistry and physiology that underlies the sex change in O. edulis and is it vulnerable to disruption with plausible population consequences?
  3. How does the slipper limpet (Crepidula fornicata) compete with O .edulis, is there a physico-chemical component to this competition as well as a food and habitat element?
  4. What responses would O. edulis have to predicted climate changes factors such as raised water temperature, reduced saturation by O2, and decrease in pH as well as the possibility of an alteration in the species of plankton available for food, an increase in plankton bloom frequency (and so release of biotoxins and bacterial numbers as blooms die back)?
  5. Explore opportunities and establish a scheme to gather catch and landings data from the commercial fishing sector both past; access to fishers old log books and future; establish a voluntary log book scheme

Resources required: Essential for SOGI members to write high quality multidisciplinary proposals and a favourable funding climate.

Deliverables: Greater understanding of factors influencing the Solent oyster and an improvement in restoration project planning and enactment. Aiming for a ‘win-win local –national’ approach in terms of peer reviewed research papers providing scientific evidence for restoration initiatives throughout the UK, as well as in the Solent.