Tropical invertebrate response to marine reserves varies with protection duration, habitat type, and exploitation history

Abstract

Abstract Macroinvertebrates play a critical role in marine processes, are important in global fisheries, and make up the vast majority of ocean biodiversity, yet are largely overlooked in fisheries stock assessment and conservation. Marine reserves are a heavily advocated method for promoting recovery of marine biodiversity, but the design of reserves and the methods for evaluating their performance often neglect invertebrate taxa, instead assessing changes in fish abundance or biomass. The purpose of this study is to (1) measure the impacts of no‐take marine reserves on marine macroinvertebrates, (2) identify the correlates of changes to macroinvertebrate abundance, and (3) determine if the typical taxa used to measure reserve success (finfish) can predict changes in invertebrate abundance. Non‐coral, non‐sponge, macroinvertebrates were sampled inside and outside of 10 community‐managed marine reserves in the Central Philippines and compared with abundances found at distant fished sites. Using generalized linear mixed effects models with multimodel inference, positive reserve effects were found in exploited invertebrate taxa both inside and outside of reserves (1.5–2.3 times greater abundances), but no effect was found in unfished taxa. Habitat composition and complexity were consistently associated with higher invertebrate abundance. Most surprisingly, invertebrate abundance was not consistently predicted by that of fish. These results indicate fish, in isolation, may not be an ideal indicator for biodiversity response to reserves, and habitat considerations are important when creating reserves that support invertebrates. These results are particularly relevant to practitioners in developing regions, where community‐managed reserves are common and invertebrates are important in fisheries.