Net illumination reduces fisheries bycatch, maintains catch value, and increases operational efficiency

• Published in: Current biology Vol. 32; no. 4; pp. 911 - 918.e2
• Main Authors: Senko, Jesse F., Peckham, S. Hoyt, Aguilar-Ramirez, Daniel, Wang, John H.
• Format: Journal Article
• Language: English
• Published: England Elsevier Inc 28-02-2022
• Subjects: Animals; bycatch reduction technology; Conservation of Natural Resources; Ecosystem; entangling net; Fisheries; fisheries sustainability; Fishes; gear modification; gillnet; Lighting; marine conservation; Mexico; resilience; small-scale fisheries; visual cues; Mexico; gear modification; small-scale fisheries; gillnet; marine conservation; visual cues; fisheries sustainability; entangling net; resilience; bycatch reduction technology
• ISSN: 0960-9822; 1879-0445
• DOI: 10.1016/j.cub.2021.12.050

Small-scale fisheries are vital for food security, nutrition, and livelihoods in coastal areas throughout the world’s oceans.1–9 As intricately linked social-ecological systems, small-scale fisheries require management approaches that help ensure both ecological and socioeconomic sustainability.7,10–14 Given their ease of use and lucrative nature, coastal gillnet fisheries are globally ubiquitous.10,15 However, these fisheries often result in high discarded capture of non-target organisms (bycatch) that can lead to significant cascading effects throughout trophic chains16–18 and costly fisheries restrictions that result in important revenue losses in coastal communities with scarce economic alternatives.19,20 Despite these challenges, few solutions have been developed and broadly adopted to decrease bycatch in coastal gillnet fisheries, particularly in developing nations.5,21 Here we used controlled experiments along Mexico’s Baja California peninsula to show that illuminating gillnets with green LED lights—an emerging technology originally developed to mitigate sea turtle bycatch—significantly reduced mean rates of total discarded bycatch biomass by 63%, which included significant decreases in elasmobranch (95%), Humboldt squid (81%), and unwanted finfish (48%). Moreover, illuminated nets significantly reduced the mean time required to retrieve and disentangle nets by 57%. In contrast, there were no significant differences in target fish catch or value. These findings advance our understanding of how artificial illumination affects operational efficiency and changes in catch rates in coastal gillnet fisheries, while illustrating the value of assessing broad-scale ecological and socioeconomic effects of species-specific conservation strategies.
•Illuminated gillnets reduce total discarded fisheries bycatch biomass•This includes decreases in elasmobranch, Humboldt squid, and finfish bycatch•Illuminated gillnets also reduce the time required to retrieve and disentangle nets•Illuminated gillnets do not decrease target fish catch or value
Senko et al. find that illuminating gillnets with green LED lights reduces total discarded fisheries bycatch biomass, which includes decreases in elasmobranch, Humboldt squid, and unwanted finfish, without compromising target fish catch or value. Illuminated gillnets also reduce the time it takes fishers to retrieve and disentangle nets.