The potential socio-environmental advantages of repurposing lobster impoundments for eastern oyster (Crassostrea virginica) aquaculture

Abstract

Tidal impoundments have been used for centuries to enhance aquaculture production worldwide. Here, we examine the potential for lobster pounds, tidal impoundments common to Maine, USA, and Atlantic Canada, to serve as boundary objects that bridge the gap between the fishing and aquaculture industries. Proponents of coastal-economic diversification have heralded aquaculture as a means of creating new revenue streams for the working waterfront, thus increasing resilience to socioeconomic and environmental disruptions. However, various barriers to entry have thus far led to little crossover between the fishing and aquaculture communities in the Northwest Atlantic. Lobster pounds are uniquely positioned to overcome these barriers as (1) pounds are usually located near traditional lobster landing locations and integrated within existing seafood distribution systems, (2) pounds are typically owned by fishing communities or cooperatives and can thus be permitted for aquaculture with relative ease, and (3) pounds have historically been used to store and cultivate economically important marine species. To assess the spatial potential and validate repurposing lobster pounds for eastern oyster (Crassostrea virginica) aquaculture lease sites offer comparable if not advantageous growth to standard oyster farms, we compiled the location and size of all known pounds in Maine and tracked oyster growth and surface temperature over two growing seasons both within and outside a lobster pound. We documented 87 pounds representing approximately 1 km2 along Maine's coast, a potential 15% increase in bivalve lease acreage if all were converted to aquaculture. Oysters held within the study pound reached market size in two growing seasons. We also identified multiple weeks in which the shell lengths of oysters inside the pound were significantly greater than those outside. These growth differences were correlated with greater surface temperatures inside the pound. We suggest that pounds are potentially positioned to both provide environmentally suitable spaces for oyster growth and remove barriers to enter the aquaculture industry.