A critical review and knowledge gaps to assess and manage threatened parrotfishes’ stocks in Brazil

Given the increasing exploration of endemic Brazilian parrotfishes and their classification as threatened, there is an emergent need to gather biological and fisheries information to assess their stocks. We performed a comprehensive review of 134 studies addressing key topics of information related to stock assessments: (1) the distribution and population structure; (2) age, growth and mortality; (3) reproductive biology; (4) feeding ecology; (5) fishing data, and (6) management actions. This review focused on the most explored Brazilian parrotfish species: Scarus trispinosus , Scarus zelindae , Sparisoma amplum , Sparisoma axillare , and Sparisoma frondosum . The most abundant species, Sp. axillare , and the most threatened, Sc. trispinosus , are better studied; hence data-moderate stock assessments are viable for both species. As information gaps are largest for Sp. zelindae , only simple Risk analyses are possible for this species. Stock productivity and status may be obtained for the remaining species, enabling data-limited assessments. The few official fisheries statistics available are inaccurate and have been discontinued since 2010; scientific studies represent the main source of information about Brazilian parrotfishes’ captures but are sparse. How stocks are structured and distributed along the coast must be defined, thus genetic structuring and site fidelity studies are necessary. Life-history traits such as mortality, growth, sexual modes, social organization, and maturity must be a subject prioritized for all species. Brazilian fisheries statistics programs must be resumed and improved urgently. The academic community and stakeholders must focus on filling these essential knowledge gaps to promote the successful evaluation of their stocks and solid recovery actions. Otherwise, Brazilian parrotfish populations—and the fisheries and ecosystem functions dependent on them—may be at risk.