As the Gulf of Maine warms, its fishing-dependent communities are vulnerable to increasing volatility in fisheries returns. Seaweed aquaculture is emerging as a potential income-smoothing strategy for residents of coastal communities where traditional wild-capture fisheries are declining or have already collapsed. The global seaweed aquaculture industry had a growth rate of 8% in 2015 and is expanding particularly rapidly in New England, USA. Compared to other forms of aquaculture, seaweed may be a uniquely valuable addition to fishing portfolios due to secondary environmental benefits, harvest timing, and greater social acceptability. The rapid expansion of seaweed aquaculture in this region necessitates a better understanding of its capacity to diversify income streams.
In our study, we first use state and federal data on landings by port to describe geographic and temporal trends in fisheries income diversification for coastal Maine. We show a decline in the diversity of wild harvest landings that has been offset by an increasing reliance on aquaculture. Then we use census data from other industries to examine whether rural communities with working waterfronts have seen a shift in access to alternate livelihoods. Finally, we incorporate data on seaweed lease sites and the suitability of other offshore sites to forecast how seaweed aquaculture will expand over three different time horizons.
We use our forecast of seaweed aquaculture’s expansion capacity to quantify the reduction in rural income volatility. The stabilization of income is highly sensitive to assumptions about the market price of seaweed products. Additionally, we compare the contribution of seaweed aquaculture to marine resource portfolios and the entire suite of alternate coastal livelihoods across industries.