Quantifying the status and success on restored native oyster Ostrea edulis beds in the Solent

Dr Chris Hauton, Dr Antony Jensen, Dr Joanne Preston (University of Portsmouth), Luke Helmer (Blue Marine Foundation)

 

 

Rationale: 

Globally, the restoration of ostreid bivalves is gaining momentum. In European waters the native oyster Ostrea edulis is the focus of extensive restoration efforts and in the Solent, Blue Marine Foundation (BLUE) have been leading the restoration of native oysters since 2015. The Solent historically represented the UK’s largest oyster fishery, but has been in decline since the 1970s and generally closed to fishing since 2013. The Solent represents a good model to understand how to restore an extinct habitat; insights that can be scaled to the wider Europe and beyond.

We have established the performance of small scale elevated culture of broodstock oysters in suspended cage culture in marinas with elevated reef culture on the sea bed and has explored the environmental controls of sex determination and gametogenesis in native oysters..  Research is also quantifying the services offered by oysters for nutrient regulation and microplastic removal from the environment.

This studentship will quantify the benefits, including ecosystem services, provided by relaid oysters in Langstone Harbour, the River Hamble and Newtown Harbour on the Isle of Wight, and will then quantify the impact of that strategy through monitoring. The project in the Solent is one of the largest in Europe.

Methodology: 

The project will have address the following objectives with associated methodology:

  1. assess the physiological performance of deployed oysters compared to both local and distant oyster populations This will employ environmental sampling, and laboratory assessments of metabolic rate (proxy: respiration rate), bulk, biochemical composition, and indices of cell function.
  2. assess the reproductive output of oysters by: sex ratio at maturity, larval output and spat settlement in locations where settlement is predicted, based on dispersal modelling. This will be assessed using standard histological techniques with haematoxylin and eosin staining, and hydrodynamic larval dispersal modelling.
  3. monitor the disease status of laid oysters with assessments of the incidence of Bonamia ostreae,. Analyses will contrast existing OIE-approved protocols (molecular detection using PCR) for these notifiable pathogens, with other more sensitive assays. Full training will be provided by Portsmouth.
  4. assess macronutrient uptake (nitrate/phosphate)l by Ostrea edulis through aquarium based experiments and field studies3.
  5. monitor the enhancement of ecosystem services by oysters by quantifying changes in benthic and fish biodiversity and changes in oyster density and sediment profile.  This will employ biochemical measurements with direct sampling of seabed community and remote drop-down videography approaches – full training will be provided by Southampton.

 

Location: 
University Of Southampton
Training: 

The INSPIRE DTP programme provides comprehensive personal and professional development training alongside extensive opportunities for students to expand their multi-disciplinary outlook through interactions with a wide network of academic, research and industrial/policy partners. The student will be registered at the University of Southampton and hosted atthe School of Ocean and Earth Science. 

We intend to recruit a student with suitable skills in organism physiology and/or benthic ecology and molecular biology. The student will be trained and supported in requisite techniques, including physiological assessments of performance, histology and histopathology as well as molecular parasitology and numerical modelling and coding in MatLab™. This will be provided by the supervisory team in Southampton and Portsmouth and via researchers in a wider network of native oyster research (ARCH-UK https://www.aquaculturehub-uk.com/; NORA https://noraeurope.eu/;  Native Oyster Network UK & Ireland).

Eligibility & Funding Details: 
Background Reading: 

1) Sawusdee A., Jensen A.C., Collins K.J., Hauton C. (2015) Improvements in the physiological performance of European flat oysters Ostrea edulis (Linnaeus, 1758) cultured on elevated reef structures: implications for oyster restoration. Aquaculture 444: 41-48.

 

2)  Zapata-Restrepo L.M., Hudson M., Williams I.D., Hauton C., Jensen A. (2019) Effects of the interaction between temperature and steroid hormones on gametogenesis and sex ratio in the European flat oyster (Ostrea edulis). Comparative Biochemistry and Physiology Part A: Molecular & Integrative Physiology. 236: 110523

 

3) Kamphausen, L., Jensen, A., Hawkins, L., (2011). Unusually high proportion of males in a collapsing population of commercially fished oysters (Ostrea edulis) in the Solent, United Kingdom. Journal of Shellfish Research 30: 217–222.

 

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