Mortality Rate Estimates for Sea Turtles in Mid-Atlantic and Northeast Fishing Gear, 2012-2021

  • Carrie Upite
  • Bridget Harner
  • Kimberly Murray
  • Brian Stacy
  • Lesley Stokes

Abstract

The NMFS Northeast Sea Turtle Injury Workgroup reviewed all sea turtle interactions from 2017 to 2021 recorded by the Northeast Fisheries Observer Program (n=55) and Industry Funded Scallop observers (n=5) and reported to the Sea Turtle Disentanglement Network (n=121). For the first time, all available records from 2012 to 2021 were combined as well. Interactions were assigned to one of four categories with associated post-interaction mortality rates according to the criteria in NMFS (2022). Sea turtle records are presented by major gear type for the fishery observer records (trawl, gillnet, dredge, pot gear) and by vertical fishing line, fish trap, or aquaculture gear for the entanglement records. From 2017-2021, the resulting estimated mortality rate for observable interactions in trawl gear is 46%, gillnet gear is 62%, dredge gear is 30%, vertical line gear is 55% (or 62% if we include turtles not disentangled that we assumed died), and fish trap gear is 40%. For the longer time series of 2012-2021, the resulting estimated mortality rate for observable interactions in trawl gear is 47%, gillnet gear is 74%, dredge gear is 35%, vertical line gear is 54% (or 61% including the assumed dead cases), and fish trap gear is 56%. The limited information on the pot and aquaculture records precluded mortality rate estimates for that gear. Comparing the most recent 5-year period to the longer range is informative in assessing the consistency of sea turtle mortality rates.

Published
2023-03-07