POPULATION MODELS FOR MARINE RESERVE DESIGN: A RETROSPECTIVE AND PROSPECTIVE SYNTHESIS

TLDR

Marine reserve models are a nascent field, largely post‑1990, that has focused mainly on fishery management while largely neglecting conservation, science, recreation, and tourism, and most studies are single‑cohort or limited in larval dispersal and spatial configuration. This study synthesizes existing marine reserve models to pinpoint well‑understood theoretical issues and identify gaps that warrant further research, thereby advancing understanding of reserves’ conservation potential. The authors reviewed 34 theoretical papers, extracting and comparing model results to assess key theoretical issues and highlight areas needing additional analysis. The synthesis shows that complete population models generally predict yield gains from reserves when populations are overfished, while single‑cohort models suggest reduced benefits for highly mobile species, indicating that reserves can protect marine systems against overfishing.

Abstract

We synthesize results from existing models of marine reserves to identify key theoretical issues that appear to be well understood, as well as issues in need of further exploration. Models of marine reserves are relatively new in the scientific literature; 32 of the 34 theoretical papers we reviewed were published after 1990. These models have focused primarily on questions concerning fishery management at the expense of other objectives such as conservation, scientific understanding, recreation, education, and tourism. Roughly one-third of the models analyze effects on cohorts while the remaining models have some form of complete population dynamics. Few models explicitly include larval dispersal. In a fisheries context, the primary conclusion drawn by many of the complete population models is that reserves increase yield when populations would otherwise be overfished. A second conclusion, resulting primarily from single-cohort models, is that reserves will provide fewer benefits for species with greater adult rates of movement. Although some models are beginning to yield information on the spatial configurations of reserves required for populations with specific dispersal distances to persist, it remains an aspect of reserve design in need of further analysis. Other outstanding issues include the effects of (1) particular forms of density dependence, (2) multispecies interactions, (3) fisher behavior, and (4) effects of concentrated fishing on habitat. Model results indicate that marine reserves could play a beneficial role in the protection of marine systems against overfishing. Additional modeling and analysis will greatly improve prospects for a better understanding of the potential of marine reserves for conserving biodiversity.