Chondrichthyan Diversity, Conservation Status, and Management Challenges in Costa Rica

Sebastián Hernández,Eric Díaz,Arturo Angulo,Tayler M Clarke,Mario Espinoza

doi:10.3389/fmars.2018.00085

Abstract

Understanding key aspects of the biology and ecology of chondrichthyan fishes (sharks, rays, and chimaeras), as well as the range of threats affecting their populations is crucial given the rapid rate at which some species are declining. In the Eastern Tropical Pacific (ETP), the lack of knowledge, unreliable (or nonexistent) landing statistics and limited enforcement of existing fisheries regulations has hindered management and conservation efforts for chondrichthyan species. This review evaluated our current understanding of Costa Rican chondrichthyans and their conservation status. Specifically, we (1) provide an updated checklist on the species richness, habitat use and distribution patterns, (2) summarise the most relevant chondrichthyan studies (scientific publications, theses, and official technical reports), (3) identify knowledge gaps, (4) discuss fisheries-related threats, and (5) highlight the management challenges and research needs to effectively protect their populations. A total of 99 chondrichthyan species are formally recorded in Costa Rican waters, from which 15% are threatened with extinction and 41% are “Data Deficient” based on the IUCN (International Union for Conservation of Nature) Red List. A total of 121 studies were published between 1891 and 2017; 82% in the Pacific (24% from Isla del Coco) and only 18% from the Caribbean Sea. These results highlight the need to redirect research efforts on specific taxonomic groups and geographic regions (i.e., Caribbean). Based on our review, improving the quality and quantity of fisheries landing statistics, as well as determining the degree of overlap between chondrichthyans and small-scale coastal/pelagic fisheries remains a priority. We proposed an adaptive management framework for chondrichthyan fisheries in data-poor countries where management goals/targets are clearly defined. This framework could strengthen the conservation of chondrichthyan populations in Costa Rica and the region.

Highlights

In many regions, chondrichthyan populations have been reduced to unsustainable levels (WardPaige et al, 2010; Davidson et al, 2016; Spaet et al, 2016), raising global concern over their conservation status (Dulvy et al, 2014, 2017)
Our search resulted in a checklist of chondrichthyan species with confirmed occurrence records as well as those expected to occur in Costa Rica
There are 99 chondrichthyan species formally recorded in the literature and/or with voucher specimens collected within Costa Rican waters

Summary

Introduction

Chondrichthyan populations (sharks, rays, and chimeras) have been reduced to unsustainable levels (WardPaige et al, 2010; Davidson et al, 2016; Spaet et al, 2016), raising global concern over their conservation status (Dulvy et al, 2014, 2017). Climatedriven changes in the physical, chemical, and biological conditions of chondrichthyan habitats have the potential to affect their distribution, movement, feeding ecology, reproduction, and growth (Chin et al, 2010; Dulvy et al, 2014; Pistevos et al, 2015). Understanding the range of anthropogenic and environmental drivers that influence (directly or indirectly) chondrichthyan populations is crucial to designing more effective management approaches to improve their conservation

Methods

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Conclusion