What is bycatch?
Bycatch means sea animals caught unintentionally while fishing for a target species. In tuna fisheries, this includes sharks, rays, small fish, and sometimes turtles or seabirds.
Fishing vessels using purse seine nets, large nets that encircle schools of tuna, sometimes catch other marine life. Tracking how much bycatch occurs helps protect ocean biodiversity and supports sustainable fishing.
Longline gear also creates bycatch. Vessels set long lines with many baited hooks. Seabirds can take the bait and get hooked. Turtles can bite the hooks or become entangled.
Why bycatch estimates matter
Measure the impact of fishing on marine ecosystems
Improve conservation and management plans
Help members report and meet obligations under international agreements
Key bycatch species
Sharks
This page summarizes the status of key shark species in the Western and Central Pacific Ocean (WCPO) and the bycatch mitigation actions adopted by the WCPFC. The most recent conservation and management measure for sharks is CMM 2024-05, Conservation and Management Measure for Sharks.
Cetaceans
This page summarizes the status of key cetaceans species in the Western and Central Pacific Ocean (WCPO) and the bycatch mitigation actions adopted by the WCPFC. The most recent conservation and management measure for cetaceans is CMM 2024-07, Protection of Cetaceans from Purse Seine and Longline Operations.
Seabirds
This page summarizes the status of key seabird species in the Western and Central Pacific Ocean (WCPO) and the bycatch mitigation actions adopted by the WCPFC. The most recent conservation and management measure for seabirds is CMM 2018-03, Mitigating impacts on seabirds.
Rays
This page summarizes the status of key ray species in the Western and Central Pacific Ocean (WCPO) and the bycatch mitigation actions adopted by the WCPFC. The most recent conservation and management measure for rays is CMM 2019-05 - Conservation and Management Measure on Mobulid Rays caught in association with fisheries in the WCPFC Convention Area
Turtles
This page summarizes the status of key turtle species in the Western and Central Pacific Ocean (WCPO) and the bycatch mitigation actions adopted by the WCPFC. The most recent conservation and management measure for turtles is CMM 2018-04, Conservation and Management of Sea Turtles
Bycatch Management Information System (BMIS)
BMIS is an open resource on bycatch mitigation and management in the tuna and billfish fisheries. It provides species pages, mitigation techniques, safe handling guides, regulations, and references. Visit: bmis-bycatch.org
Bycatch Data
About the Bycatch Data Exchange Protocol
The Bycatch Data Exchange Protocol (BDEP) is a standardized format used by regional fisheries bodies to share and compare bycatch data.
The following datasets are available in Excel format, covering the years 2013–2023. These include both total fishing effort and observer data, including non-ROP observer data held by SPC:
Total fishing and observed effort per year and fishery.
Bycatch in Longline Fisheries (year): Observed and estimated captures/mortalities by
species group.
- Bycatch in Purse Seine Fisheries (year): Observed and estimated captures/mortalities by species group.
- Bycatch in Longline Fisheries (year/area): Breakdown by fishing area.
- Bycatch in Purse Seine Fisheries (year/area): Breakdown by fishing area.
Bycatch data Excel file (BDEP) - 11/2024
Purse Seine Bycatch Estimates
This provides an Excel file with purse seine bycatch estimates taken from SC17-ST-IP-06 (Tables 6 to 9). The file is presented in a more user-friendly format.
The estimates cover the large-scale equatorial purse seine fishery within the WCPFC Convention Area. More details on the coverage and how the estimates were calculated are available in SC17-ST-IP-06
Bycatch Estimates (XLSX) - Tables 6-9, SC17-ST-IP-06 (Updated PS bycatch estimates in the WCPO)