Population productivity of shovelnose rays: Inferring the potential for recovery

PLoS One. 2019 Nov 21;14(11):e0225183. doi: 10.1371/journal.pone.0225183. eCollection 2019.

Abstract

There is recent evidence of widespread declines of shovelnose ray populations (Order Rhinopristiformes) in heavily fished regions. These declines, which are likely driven by high demand for their fins in Asian markets, raises concern about their risk of over-exploitation and extinction. Using life-history theory and incorporating uncertainty into a modified Euler-Lotka model, the maximum intrinsic rates of population increase (rmax) were estimated for nine species from four families of Rhinopristiformes, using four different natural mortality estimators. Estimates of mean rmax, across the different natural mortality methods, varied from 0.03 to 0.59 year-1 among the nine species, but generally increased with increasing maximum size. Comparing these estimates to rmax values for other species of chondrichthyans, the species Rhynchobatus australiae, Glaucostegus typus, and Glaucostegus cemiculus were relatively productive, while most species from Rhinobatidae and Trygonorrhinidae had relatively low rmax values. If the demand for their high-value products can be addressed then population recovery for some species is likely possible, but will vary depending on the species.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Algorithms
  • Animals
  • Biodiversity
  • Models, Theoretical
  • Monte Carlo Method
  • Population Density*
  • Skates, Fish*

Grants and funding

This project was funded by the Shark Conservation Fund (Small Grant Program 2018 to BMD), a philanthropic collaborative pooling expertise and resources to meet the threats facing the world’s sharks and rays. The Shark Conservation Fund is a project of Rockefeller Philanthropy Advisors. The corresponding author (BMD) is supported through an Australian Government Research Training Program Scholarship (RTPS). The scientific results and conclusions, as well as any views or opinions expressed herein, are those of the author(s) and do not necessarily reflect those of NOAA or the Department of Commerce. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.