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Impacts of fisheries on elasmobranch reproduction: high rates of abortion and subsequent maternal mortality in the shortnose guitarfish

journal contribution
posted on 2023-05-20, 01:14 authored by Wosnik, N, Cynthia AwruchCynthia Awruch, Adams, KR, Gutierre, SMM, Bornatowski, H, Prado, AC, Freire, CA
The fate of bycatch species released back into the water is crucial to estimate population status and consequent decisions to implement adequate management measurements for elasmobranchs. The shortnose guitarfish, Zapteryx brevirostris, is an endemic species of the Southwest Atlantic. It is currently listed as ‘Vulnerable’ both in the International Union for Conservation of Nature and Brazilian red lists. Although this species displays high tolerance to capture and transportation by fishers from the capture site to the fish market, a significant reduction in survival rates is observed during the reproductive period. Thus, the aim of the present study was to examine post‐capture and post‐commercial transportation consequences in pregnant females obtained as bycatch from artisanal fisheries in Southern Brazil. Results showed high abortion rates and reduced maternal survival after abortion, with all abortions occurring within 28 h of monitoring in laboratory. Stress plasma markers were also evaluated, to determine the physiological consequences of capture‐induced parturition to pregnant females. Results showed alteration in all markers measured (plasma urea, pH, lactate, phosphorus, and potassium) with values for dead pregnant females being different from non‐pregnant females and those which survived capture and subsequent abortions. The mortality caused by fisheries bycatch may prove difficult to manage, with immediate release and specific handling protocols for pregnant females implemented through environmental education environmental education and fishermen training programs, potential options to maintain adequate maternal survival and recruitment for this species.

History

Publication title

Animal Conservation

Pagination

1-9

ISSN

1367-9430

Department/School

School of Natural Sciences

Publisher

Cambridge Univ Press

Place of publication

40 West 20Th St, New York, USA, Ny, 10011-4211

Rights statement

Copyright 2018 The Zoological Society of London

Repository Status

  • Restricted

Socio-economic Objectives

Marine biodiversity