Abstract

Commercialized harvest for invasive species harvest offers a compelling approach to concomitantly control their abundances and create market opportunities. However, harvest rates that result in ecologically meaningful reductions may surpass those that produce maximum sustainable yield (MSY) will result in harvest that is inefficient. We numerically examined this paradox with bioeconomic models of the nascent commercial spearfishery for invasive lionfish (Pterois volitans) on artificial reefs in the northern Gulf of Mexico. We estimated population parameters for carrying capacity (K) and intrinsic rate of growth (r) by fitting both biological production models and age- structured life history models. Estimates of K were robust while r-values were uncertain, range from 0.66–2.50. We then developed bioeconomic models to (1) run time-dynamic fisheries simulations and (2) estimate open access equilibrium solution points for stock, effort, and yield. Alternative scenarios considered the range of values for r-values and alternative economic conditions in terms of price, costs, and harvester stiffness. Even in the lowest r scenarios, lionfish populations demonstrated strong compensation and were robust to overfishing. Current harvest rates were well below those that produce MSY and were predicted to achieve only marginal reductions in the stock biomass from K. Alternative economic scenarios, however, suggest that changes in price and cost could increase harvest rates enough to reduce the population below the level that produces MSY Collectively, these models quantitatively test key assumptions to commercialized invasive species harvest and numerically forecast how economic strategies (e.g., subsidies or marketing) could be applied to support lionfish and invasive species control.

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