Expanding horizons of shark bycatch reduction research
Following on my most recent shark research, which involved testing certain metals to see if they could repel sharks from bait Sharks, metal, and food?, one of my coauthors and I embarked on a new project. We put together a team of shark & ray experts and fisheries/conservation specialists to look at elasmobranch (sharks, skates, and rays) bycatch reduction from new angles. Because this field of research is relatively new and has only recently been recognized for its importance, due to dramatic drops in shark numbers worldwide, the relatively small number of studies have centered around sharks' superbly sensitive electrosensory system. Because most fish targeted by fishermen don't have an electrosensory system, sharks and rays that are caught incidentally could potentially be kept away with electrical signals that the other fish can't sense. But as we, and several other researchers have found out, using electrical signals to keep sharks away from fishing gear is not so straightforward, and may not be the best or only solution for many shark, ray, and skate species. So, we decided to broaden our horizons and reflect not only on the electrosensory system but on all of the different sensory systems elasmobranchs possess that help then navigate their salty world, find food and each other, and identify potential dangers.
Jordan et al., 2013. Conservation Physiology.
Sharks and rays are a very diverse group with fascinating differences in their sensory biology, ecology, and feeding behavior (see Making sense of stingray sensory anatomy). Through carefully reviewing all of the research we could find on elasmobranch sensory biology and feeding behavior, comparing it with fish that the fishermen are targeting, and thinking critically about different types of fishing gear, we came up with some new ideas on ways to keep elasmobranchs off of fishing lines and out of fishing nets.