Predictive mapping of reproductive fish habitats to aid marine conservation planning

Abstract

Postsettlement spillover from marine protected areas (MPAs) can support adjacent fished populations and has been subject of many scientific studies. The larval subsidy effect, on the contrary, is more challenging to study and less demonstrated, although it, arguably, provides key benefits for fisheries. We modeled and predicted the spatial distribution of fish spawning biomass and fecundity across a temperate insular MPA network (Azores archipelago, Northeast Atlantic) and identified potential single- and multispecies reproductive habitats (RHs) in shallow reefs. Reproductive strategies or skewed sex ratios influenced spatial patterns of potential spawning biomass and fecundity. Predicted multispecies RHs covered 5%–20% of the studied reef habitat. Given their potentially high reproductive output, we argue that such sites should be considered in marine conservation planning to increase chances of achieving fisheries and conservation benefits. Spatial patterns of the reproductive output may function as surrogates for larval subsidy when limited or no larval connectivity information is available and also may assist in identifying potential larval sources and priority sites for conservation.