Concurrent bycatch and population assessments of Burmeister’s porpoises in northern Peru reveal unsustainable levels of mortality

Authors
Ortiz-Alvarez, C., Ortés-Villauriz, R., Mangel, J.C., Alfaro-Shigueto, J. and Heinrich, S.
Year
Journal/Publisher Name
ICES Journal of Marine Science
Volume (Issue #)
82(8)
Page #s
15
Contact information
Clara Ortiz-Alvarez, Sea Mammal Research Unit, University of St. Andrews, UK- caoa1@st-andrews.ac.uk
Summary

The authors performed onboard surveys (line transects and passive acoustic monitoring) and interviewed gillnet fishers to assess abundance and bycatch of the endemic Burmeister’s porpoises (Phocoena spinipinnis) in northern Peru in 2023. The population abundance in the study area was estimated at 1,696 spatially distributed individuals, with the highest densities found within 25km of shore and within shallow waters ≤50 m. Fishers' descriptions of bycatch aligned with survey results, and most fishers reported experiencing porpoise bycatch the previous year. The annual bycatch rate was estimated to be 420 porpoises across the entire artisanal gillnet fishery of Salaverry, which far exceeds sustainable limits and highlights the urgent need for bycatch mitigation measures.