Incidental catch (bycatch) and entanglement in fishing gear is one of the most significant human impacts to cetaceans globally. It affects both large and small cetaceans throughout the oceans. Smaller coastal species are particularly susceptible to entanglement in gillnets while larger whales are often entangled in static nets and ropes associated with pots and traps. Despite the fact that it is widely acknowledged to be one of the most important threats to cetaceans, research on fisheries interactions globally is limited. Our research aims to increase our knowledge of fisheries interactions within our study regions and contribute to the management of this serious issue.
In Hawai’i, entanglement in fishing gear is a growing problem. Interactions with fishing gear have been observed for humpback whales, common bottlenose dolphins, spinner dolphins, pantropical spotted dolphins, short-finned pilot whales, and false killer whales. To quantify the extent of this threat, we use our photo-identification catalogs to determine fisheries interactions by examining dolphins for mouthline scars, dorsal fin disfigurements, and other scarring. Knowing the extent of the problem is an important first step towards minimizing these injuries.
Our research in Ecuador has revealed that bycatch is a significant threat to cetaceans in this region. We have documented numerous species becoming entangled and drowning in gillnets and even discovered marine mammals being used as bait in homemade fishing equipment. For this study, we have developed a community reporting network that allows us to document stranded and entangled marine mammals. Our researchers are partnering with experts around the world to address entanglement in Latin America and work with the on-water community to develop mitigation strategies and provide assessment and response training.
Robin Baird, Cascadia Research Collective
Fernando Felix, Museo de Ballenas
Koen Van Waerebeek, Centro Peruano de Investigación de Cetáceos
2021: Machernis, A.F., Stack, S.H., Olson, G.L., Sullivan, F.A., Currie, J.J. External scarring as an indicator of fisheries interactions with bottlenose (Tursiops truncatus) and pantropical spotted (Stenella attenuata) dolphins in Maui Nui, Hawai‘i. Aquatic Mammals 47(5), 482-498. Download PDF
2020: Castro, C., Van Waerebeek, K., Cárdenas, D., Jose Alava, J. Marine mammals used as bait with improvised Fish Aggregating Devices in marine waters of Ecuador, Eastern Tropical Pacific. Endangered Species Research. 41:289-302. Download PDF
2018: Jiménez, P.J., Alava, J.J., Castro, C., Samaniego, J., Fair, P. Stranding of Small Cetaceans with Missing Fins Raises Concerns on Cetacean Conservation in Ecuador: Bycatch or Targeted Fisheries? International Journal of Fisheries Science and Research 2(1): 1006. Download PDF
Aloha, We Are Open! Our PacWhale Eco-Adventures are open for booking as we welcome visitors back to Maui. Quarantine restrictions were lifted on Oct. 15th for those following the state’s pre-arrival COVID-19 testing requirements.