Sharks Have Brains Like... Ours
After five shark fatalities in the past year, the Western Australian government announced a plan to hunt and kill great white sharks, an endangered species, in September. Conservationists have harshly criticized the new "shark mitigation plan to protect beach goers" which provides $6.85 million in funding for the tracking, catching and "if necessary," killing of sharks identified as being close proximity to beach goers.
There are other ways to prevent shark attacks besides killing them. New research about the neurology of sharks published in a special edition of the journal Brain, Behaviour and Evolution on the nervous systems of cartilaginous fishes could be key to developing "repellents" to keep them away from marine areas used by humans.
From dissecting the brains of more than 150 sharks, University of Western Australia shark researcher Kara Yopak discovered that their brains have a number of features like that of humans. As Yopak says to AFP, great white sharks actually have "quite large parts of the brain associated with their visual input, with implications for them being much more receptive to repellents targeting visual markers."
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Currently, most of the repellents send off a strong electronic signal that targets the electrosensitive pores sharks have on their heads for picking up the currents created by prey. But such technologies have been shown to be only partially effective in deterring great white sharks. As Yopak says,
A shark may recognise a poisonous sea-snake's markings and swim away, for example, and we can use this information to cue a response. It's about understanding how their neurobiology affects their (behaviour).
Yopak, who is part of a team of scientists at the university's Oceans Institute, also found that sharks' brains are of the same relative size as those of mammals or birds, thereby confuting the notion that they are "tiny-brained eating machines."
As Kopak writes in a preface (pdf) to the journal:
To the general public, the term 'shark' is often synonymous with mystery, fear, and morbid fascination. To an evolutionary neuroscientist, however, sharks and their relatives (skates, rays, elephant sharks, and chimaerids) represent a key a stage in the evolution of gnathostomes, with the appearance of the first fully formed neural 'bauplan' that is present in all extant jawed vertebrates.
That is, studying how the shark nervous system has evolved, as well as how sharks and their relatives "receive and process information from their environment" and the implications of these "evolutionary adaptations in sensorimotor function" for their nervous systems, can teach us something not only about their neurology but our own.
The Western Australian government's shark mitigation plan also included funds for trial shark enclosure, a shark tagging program, more jet skis for rescuers and more helicopter patrols of beaches - and more research funds. Clearly it would be a positive step for the latter to be used to support research like Yopak's. Her discovery about the similarities between sharks' brains and ours makes it all the more important to find other ways for all of us to share the ocean and, to the extent possible, co-exist.
If sharks' neurology resembles ours, hunting and killing them seems even more cruel and unnecessary.