Illumination of gillnets

GN LED illumination
© GFCM/Alberto Gennari in Sacchi 2021

LED illumination of gillnets has been used successfully to reduce sea turtle bycatch without reducing target catch. Studies evaluating their impact on the incidental capture of seabirds report conflicting results [3].

 

Effect on Other Bycatch Species

May increase ray bycatch (Bielli et al 2020). Effect on seabirds conflicting, depending on light colour, flash mode and species involved.

Cost Information

See Fishtek Marine's 'Netlight' or Centro's commercial fishing lights as a guide.

Further Research

Further evaluation of the efficacy of net illumination on bycatch reduction for different sea turtle species as well as on other taxa, including: examining the effects of light intensity on wavelength sensitivity; the number of lights deployed per net panel; different LED colours (e.g., green versus violet); and environmental conditions (e.g., water visibility, sea surface temperature, lunar light; soak time and duration)..

Socio-economic factors to be evaluated include: the potential cost savings associated with a reduction in fishing gear damage through avoiding bycatch events; and the effect on target catch weight or size.

References

  1. Allman P, Agyekumhene A, Stemle L (2021) Gillnet illumination as an effective measure to reduce sea turtle bycatch. Conservation Biology early view: https://doi.org/https://doi.org/10.1111/cobi.13647
  2. Darquea JJ, Ortiz-Alvarez C, Córdova-Zavaleta F, et al (2020) Trialing net illumination as a bycatch mitigation measure for sea turtles in a small-scale gillnet fishery in Ecuador. Latin American Journal of Aquatic Research 48:446–455. https://doi.org/10.3856/vol48-issue3-fulltext-2428
  3. Sacchi J (2021) Overview of mitigation measures to reduce the incidental catch of vulnerable species in fisheries. General Fisheries Commission for the Mediterranean. Studies and Reviews No. 100. FAO, Rome
  4. Wang J, Barkan J, Fisler S, et al (2013) Developing ultraviolet illumination of gillnets as a method to reduce sea turtle bycatch. Biology Letters 9:20130383–20130383. https://doi.org/10.1098/rsbl.2013.0383