Spatial Planning of Marine Aquaculture Under Climate Decadal Variability: A Case Study for Mussel Farms in Southern California

Jade Sainz, University of California Santa Barbara, Bren School of Environmental Science & Management, Santa Barbara, CA, United States, Emanuele Di Lorenzo, Georgia Inst Tech, Earth and Atmospheric Sciences, Atlanta, GA, United States, Thomas W. Bell, University of California Los Angeles, Department of Geography, Los Angeles, CA, United States, Steven D Gaines, University of California Santa Barbara, Bren School of Environmental Science and Management, Santa Barbara, United States and Robert J. Miller, University of California, Marine Science Institute, Santa Barbara, United States
The growth of marine aquaculture over the 21st century is a promising venture for food security because of its potential to fulfill the seafood deficit in the future.
However, to maximize the use of marine space and its resources, the spatial planning of marine aquaculture needs to consider the regimes of climate variability in the
oceanic environment, which are characterized by large-amplitude interannual to decadal fluctuations. It is common to see aquaculture spatial planning schemes that do not take
variability into consideration. This assumption may be critical for management and for the expansion of marine aquaculture, because projects require investments of capital
and need to be profitable to establish and thrive. We analyze the effect of climate variability on the profitability of hypothetical mussel aquaculture systems in the Southern
California Bight. Using historical environmental data from 1981 to 2008, we combine mussel production and economics models at different sites along the coast to estimate
the Net Present Value as an economic indicator of profitability. We find that productivity of the farms exhibits a strong coherent behavior with marketed decadal fluctuations that
are connected to climate of the North Pacific Basin, in particular linked to the phases of the North Pacific Gyre Oscillation (NPGO). This decadal variability has a strong impact
on profitability both temporally and spatially, and emerges because of the mussels’ dependence on multiple oceanic environmental variables. Depending on the trend of
the decadal regimes in mussel productivity and the location of the farms, these climate fluctuations will affect cost recovery horizon and profitability for a given farm. These
results suggest that climate variability should be taken into consideration by managers and investors on decision making to maximize profitability.