INDUSTRIAL FISHERIES - Mobula Conservation
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Mobula habitat overlaps with the main tuna fishing grounds in the Eastern Pacific Ocean. The tropical tuna purse seine fishery captures the highest numbers of Mobulas per year (on average, 1,200 individuals) compared with other purse seine fisheries.

This fishery uses different strategies for finding tunas depending on how the set is performed:

1) school sets (schools of tunas detected by sonar marks, breezers, radar, or jumps)

2) dolphin sets (schools of tuna associated with group of dolphins) and

3) drifting fish aggregating devices (FAD) sets (school of tuna associated and aggregated around floating objects).


Mobula rays are often caught in dolphin and school sets, showing less association with FAD sets. 

Species Distribution modeling



Our work is to identify the main areas of importance for each species and understand the habitat conditions where these species are usually captured. The use of species distribution models (SDMs) helps to identify important spatial and temporal regions, and at the same time provides first steps to advise tuna fisheries on potential spatial management strategies.


Collaborative Solutions to Reduce Mobula Bycatch Mortality in Purse Seine Fisheries



We host or cooperative workshops with purse-seine skippers, crew, mechanics and observers to incentivize the design, testing, and onboard implementation of feasible, scalable techniques for safely removing rays from vessel decks. These workshops allow scientists and tuna fishers to work together to collaboratively problem-solve. Workshops began in January 2021 in Ecuador and will continue through the year. As part of this work, we are distributing posters for vessels to hang on board to help with onboard species identification and proper handling and release techniques.


Analyses of Mobula bycatch data from observer programs in purse-seine fisheries surveys

Species Distribution Models

Cooperative workshops with the purse-seine crew to find solutions to reduce mobula bycatch mortality in purse seine fisheries


Eastern Pacific Ocean

Western Pacific and Indian Ocean

Atlantic Ocean

In the Field



Harnessing stakeholder knowledge for the collaborative development of mobulid bycatch mitigation strategies in tuna fisheries.

Spatio-temporal distribution of spinetail devil ray Mobula mobular in the eastern tropical Atlantic Ocean

Using a Bayesian modelling approach (INLA-SPDE) to predict the occurrence of the Spinetail Devil Ray (Mobular mobular)

Biodiversity and environmental characteristics of the bycatch assemblages from the tropical tuna purse seine fisheries in the eastern Atlantic Ocean

Biodiversity and habitat characteristics of the by-catch assemblages in fish aggregating devices (FADS) and school sets in the eastern Pacific Ocean

Biodiversity in the by-catch communities of the pelagic ecosystem in the western Indian Ocean

Environmental characteristics associated with the presence of the spinetail devilray (Mobula mobular) in the eastern tropical Pacific

Spatial and temporal distribution of mobulid ray species in the eastern Pacific Ocean ascertained from observer data from the tropical tuna purse-seine fishery 

Institutions participating in this Project