SC/69B/HIM/15  

Document Number

SC/69B/HIM/15

Full Title

Using the Bycatch Risk Assessment Toolbox to assess Marine Mammal Bycatch Risk in Chilean Fisheries

Author

Ellen Hines, Maritza Sepulveda, Kelly Deforest, Fernana Barilari, Luis Bedrinana-Romano, Luis Cocas, Jorge Guerra, Carlos Montenegro, Maria-Jose Perez, Rebecca Lent, Barbara Galletti

Authors Summary

1. Which sites along the coast and pelagic shelf of Chile most accurately represent the myriad geographies, fisheries, marine mammal population structure, and bycatch situations of concern to Chilean policy-makers and scientists?
2. How can the ByRA toolbox, using varying quality and amounts of existing data, identify and quantify the risk of marine mammal bycatch in specific locations, scales, and seasons along the coast of Chile?
3. How can the ByRA toolbox be used to create data management tools and analysis systems for marine mammal bycatch in Chilean fisheries?
This paper will show examples of fisheries and marine mammal species with varying amounts of data and relevant techniques for modeling bycatch risk. Examples include: right whales/crab traps (high uncertainty), sperm whales/artisanal Chilean sea bass (medium uncertainty), dusky dolphins/artisanal pelagic purse-seine (low uncertainty).

Publisher

IWC

Keywords

Publication Year

2024

Abstract

In many countries, fisheries bycatch of marine mammals is poorly monitored or regulated. Data gaps in fishing effort, bycatch rates, and the fate of animals post-capture, and trends for populations impede assessment of bycatch and constrain management action. Working with governments that rely on fisheries exports to reduce bycatch has been a driver for the creation of the open-source Bycatch Risk Assessment (ByRA) toolbox, used to create spatially explicit bycatch risk analysis. This GIS toolbox allows spatial/temporal assessment and visualization of bycatch risk using any amount or type of data, identifying areas for research and management actions while accounting for uncertainty in results. In Chile, while there are laws that require diagnosing, reducing and monitoring bycatch, there are gaps in knowledge on distribution and abundance for species most affected. As part of a Lenfest Ocean project including national and international scientists and managers, since 2019, we have analyzed existing data and generated methods to characterize the spatial and seasonal distribution and abundance of fishing boats, gear, and marine mammals. We have chosen 15 areas of presumptive high bycatch risk nested in four larger regions along the coast of Chile, including industrial and artisanal fisheries. In this paper, we will show examples of fisheries and marine mammal species with varying amounts of data and relevant techniques for modeling bycatch risk. Examples will include: right whales/crab traps (high uncertainty), sperm whales/artisanal Chilean sea bass (medium uncertainty), dusky dolphins/artisanal pelagic purse-seine (low uncertainty). Building collaborations with researchers, institutions and stakeholders has been an important step towards identifying appropriate regulations for cetacean bycatch in Chile.
2
ByRA results will provide Chilean agencies with information on areas and seasons of bycatch risk, which will contribute to the process of concentrating management efforts where the risk is greatest and avoid over-regulation.