Aquaculture Europe 2023

September 18 - 21, 2023


Add To Calendar 20/09/2023 11:00:0020/09/2023 11:15:00Europe/ViennaAquaculture Europe 2023COCULTURE OF GRAZERS AND OYSTERS IN THE UNITED STATES: A LOCAL NATURE-BASED SOLUTION ADDRESSING FOOD SECURITYCongress LoungeThe European Aquaculture Societywebmaster@aquaeas.orgfalseDD/MM/YYYYaaVZHLXMfzTRLzDrHmAi181982


 Darien  D.  Mizuta*, William C. Walton


Virginia Institute of Marine Sciences (VIMS) ,  1370 Greate Rd Gloucester Point, VA , 23062 United States




 Aquaculture can potentially adhere to the standards of the Nature-based Solutions (NbS) framework and contribute to the scaling up of NbS. Thus, this industry may take advantage of ideas that are both environmentally friendly and provide the best social-economic outcomes. The farming industry has  recently been in search of added sustainable practices and  new possible farming species , which have the potential to  increase  the availability of nutritious seafood and  also  promote higher food security.  One such approach is the coculture of different species with a focus on positive socio-environmental outcomes , in addition to  increased seafood provision.

 The US is the top seafood importer in the world and a  big consumer of shellfish . Given this opportunity for domestic production, growers, and related seafood businesses (e.g. restaurants) have  expressed  interest in  innovative forms of aquaculture that  bridge farming  efficiency and  marine conservation spheres ( e.g. restorative aquaculture, regenerative aquaculture). At the same time, aquaculture  management  that increases shellfish quality ,  and  is less  time-consuming and  less  costly for biofouling control is required.  Within that context, this work explores the feasibility of coculture  of native grazers, Atlantic Purple Sea urchins (Arbacia punctulata) , and the Common periwinkle ( Littorina littorea) , with suspension feed er Eastern oysters (Crassostrea virginica) as two separate projects, and discuss how the approach  can  fit the framework of NbS.


 Using traditional bottom culture cages, and farming bags, different treatments were deployed in selected locations in  the Chesapeake Bay area , where oyster culture is common, using a randomized design.  Oyster stocking density in farming gear was maintained constant and similar to standard commercial  densities in all treatments. Experimental designs involved the collection and use of two different sizes and stocking densities for urchins ; whereas  periwinkles  were deployed  in different coastal culture zones  with varying  stocking densities . Treatments  within projects  are being  compared in terms of potential effects on farming  efficiency, farming management improvement, and species’ conditions and survival.  We additionally discuss how the design of grazer-oyster coculture can contribute directly or indirectly as a  NbS based on IUCN’s ‘Global Standards for Nature-based Solutions’ (Fig.1) .


 Preliminary results show positive effects of the coculture choice upon oyster production  relative  to the monoculture, such as less biofouling attached to farming gear (Fig. 2), and improved target bivalve species quality (e.g. higher condition index, shell cleanliness), with additional potential environmental outcomes (less use of freshwater in operations, energy) .


 Although this research is ongoing and  projects are  still in  the initial phase, grazers could potentially be a useful tool to improve shellfish farming management and bivalve shellfish product quality. Several technical aspects and economic considerations to bring grazers to  the seafood market still need to be carefully assessed , but broadly, we expect  the advantage of deploying  cocultures to be at least two-fold for the farmer: coculture can increase  the  revenue of the farms with a secondary product and lower farming management costs ; besides potentially being  a suitable  strategy  to small-scale farmers. Moreover ,  coculture with these grazers uses the same in-use farming  space and  can be designed to link with  marine conservation initiatives , resulting in additional positive environmental outcomes. ¨