Frank A. Parrish

Tempering Expectations of Recovery for Previously Exploited Populations in a Fully Protected Marine Reserve

Centuries of resource extraction have impacted coral reef ecosystems worldwide. In response, area and fishery closures are often enacted to restore previously exploited populations and reestablish diminished ecosystem function. During the 19th and 20th centuries, monk seals, pearl oysters, and two lobster species were overharvested in the Northwestern Hawaiian Islands, now managed as the Papahānaumokuākea Marine National Monument, one of the largest conservation areas in the world. Despite years of protection, these taxa have failed to recover. Here, we review each case, discussing possible factors that limit population growth, including: Allee effects, interspecific interactions, and time lags. Additionally, large-scale climate changes may have altered the overall productivity of the system. We conclude that overfishing of coral reef fauna may have broad and lasting results; once lost, valuable resources and services do not quickly rebound to pre-exploitation levels. In such instances, management options may be limited to difficult choices: waiting hundreds of years for recovery, actively restoring populations, or accepting the new, often less desirable, alternate state.

Changing Perspectives in Hawaiian Monk Seal Research Using Animal-Borne Imaging

The use of animal-borne imaging devices on the endangered Hawaiian monk seal has greatly helped understand where and how they forage. Those devices provide high resolution data on the behavior, foraging habitat, and prey of seals, and the ecological community where they live. They have indicated that some monk seals regularly forage in mesophotic (100-300 m) and subphotic (>300 m) habitats rather than just in shallow reef habitats. The collected imagery is also helping to guide the development of further research, conservation, and management plans. Use of animal-borne imaging has resulted in substantial progress in understanding the foraging landscape of monk seals. Any refinements in this technology will certainly inform further population recovery efforts.