Official catch data underrepresent shark and ray taxa caught in Mediterranean and Black Sea fisheries

• Published in: Marine policy Vol. 105; pp. 1 - 9
• Main Authors: Cashion, Madeline S., Bailly, Nicolas, Pauly, Daniel
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01-07-2019
• Subjects: Conservation; Data; Elasmobranchii; Fisheries; Reporting; Fisheries; Elasmobranchii; Data; Reporting; Conservation
• ISSN: 0308-597X; 1872-9460
• DOI: 10.1016/j.marpol.2019.02.041

One in four fishes of the subclass Elasmobranchii (sharks and rays) is estimated to be threatened with extinction, according to the IUCN Red List. Their primary threat is overfishing, but data deficiency makes stock assessment difficult. Over 50% of shark and ray species are listed as Data Deficient, in part because the taxonomic resolution of existing catch statistics is too low to identify species-level trends of abundance. Less than 25% of the shark catch reported to the FAO is identified below the genus level; the other 75% is lumped into categories such as “sharks”, “rays”, or “elasmobranchs nei”, (not elsewhere included). This study evaluates the taxonomic resolution of domestic elasmobranch landings in the Mediterranean and Black Seas, where over half of shark and ray species are threatened with extinction, but data deficiency and ambiguity consistently limit conservation action. A Taxonomic Resolution Index (TRI) was calculated for the landings of 24 countries over 65 years (1950–2014) to evaluate the quality of catch reporting over time. The TRI revealed that less than a quarter of commercial elasmobranch taxa are represented in Mediterranean and Black Seas landings data, and reporting quality has hardly improved. Conservation and management policy exists for effective fisheries data collection in the Mediterranean and Black Seas, but lacks implementation.
•Ambiguous fisheries catch statistics impede stock management.•Mediterranean and Black Sea elasmobranchs are threatened but data are insufficient.•Overall catch taxonomic resolution is low but has improved slightly from 1950–2014.•Relevant conservation and management policy exists but lacks implementation.