| dc.description.abstract | The way in which animals use their sensory systems to perceive their environment can be described under the discipline of sensory ecology. A growing area from this discipline is its application to tackle wildlife conservation issues. One such example is in fishing, where sensory-driven technologies have been applied to reduce the unintended capture of non-target species (bycatch) in nets. Specifically, artificial light (which has historically been used for attracting species) is being increasingly trialled to repel bycatch from gear. However, with past light deployments, there has been little consideration of how species might view different light colours, as well as how underwater conditions might affect light visibility. As bycatch-reduction with light has sometimes been unsuccessful in certain fishing contexts, I adopted a sensory ecology approach to optimise light-use in fishing. By using a vision model, I predict which light colours might be most visible to target and bycatch species when considering their vision, the ambient light at depth, and LED (light-emitting diode) emission spectra. I then explore whether the model output could be linked to behaviour towards light in fish within captive and wild contexts. Although I found that a UK shark species (Scyliorhinus canicula) had increased interactions with more visually stimulating light colours in captivity, light was generally less effective as a behavioural stimulant for marine species in both a non-invasive ocean setting and a trawling scenario. My thesis results suggest that other sensory factors might be more influential on behaviour in wild contexts, and that LEDs can be less contrasting to the background with increased ambient light levels, which might reduce their effectiveness. However, where light-use is already successful in fishing, the sensory ecology approach could be applied to further increase the likelihood of a bycatch species’ receptiveness to light, by considering their vision within a fishing context. | en_GB |
