Improving brown pelican population estimates in the Mexico Pacific sardine fishery

• Estimating brown pelican populations
• Improved knowledge of ecosystem and seabird impacts.
• Increase understanding of brown pelican life histories and fishery impacts on the species
  

Sardine fishery and brown pelican interactions

The Mexican Pacific sardine temperate stock fishery harvests its catch in a region of high biodiversity on the western coast of the Baja California peninsula. The Pacific sardines (Sardinops sagax) comprise 70% of Mexico’s small pelagic fish landings and sustainable fishing practices are of utmost importance to both the ecosystem and economy.

The fishery is part of the In-Transition to MSC Program and aims to enter assessment against the MSC Fisheries Standard by 2026.

Key to its management strategy and ability to meet assessment criteria is evidence that it is minimising its impacts on endangered, threatened, and protected (ETP) species, particularly seabirds. Mexican brown pelicans (Pelicanus occidentalis) are of special interest as their distribution falls within the fishery’s range and Mexican authorities have listed this species as endangered.

Brown pelicans fly in squadrons along the coastline of Baja California, frequently following fishing vessels to plunge-dive for fish. This feeding behaviour can result in the pelicans being caught as incidental catch in fishing nets.

Assessing brown pelican population trends

To improve understanding of the fishery’s impacts on brown pelicans, graduate student Rocío Nayeli Avendaño Villeda has been awarded funds from the Ocean Stewardship Fund (OSF) Student Research Grant. Villeda’s research project is funded through a donation to the OSF by retailer Carrefour Italy and seafood brand Delicius, as part of MSC Italy’s Sustainable Seafood Week, 2023.

The project focuses on accurate estimates of the pelican population. Villeda will make a field trip to Isla Todos Santos, near Ensenada. The island is a brown pelican breeding site and research here will include quantitative surveys of the birds’ reproductive success and survival rates, and breeding population size.

Villeda will use modelling software to calculate pelican population size and assess the effect of mortalities on the population. Population trends will be analysed for both environmental impacts caused by natural phenomena (such as the El Niño-Southern Oscillation), and bycatch from the fishery.

Project completion is expected by the end of 2024 and research outputs will contribute to the evidence requirements needed by the fishery on its journey to sustainability and MSC certification.