Marine reserves have rapid and lasting effects

TLDR

Marine reserves are increasingly used for conservation, yet their effects on protected areas have been poorly understood and few reviews have examined temporal patterns of density, biomass, size, and diversity changes. The study reviews 112 independent measurements of 80 reserves to determine how quickly and persistently density, biomass, size, and diversity increase inside marine reserves. The authors analyze these measurements to show that higher average values reach mean levels within 1–3 years and remain consistent across reserves up to 40 years old. Biological responses inside marine reserves develop quickly and persist over time, supporting their use in marine resource management.

Abstract

Abstract Marine reserves are becoming a popular tool for marine conservation and resource management worldwide. In the past, reserves have been created with little understanding of how they actually affect the areas they are intended to protect. A few recent reviews have evaluated how reserves in general affect the density and biomass of organisms within them, but little work has been done to assess temporal patterns of these impacts. Here we review 112 independent measurements of 80 reserves to show that the higher average values of density, biomass, average organism size, and diversity inside reserves (relative to controls) reach mean levels within a short (1–3 y) period of time and that the values are subsequently consistent across reserves of all ages (up to 40 y). Therefore, biological responses inside marine reserves appear to develop quickly and last through time. This result should facilitate their use in the management of marine resources.