This article was initially printed in Hakai Magazine.
Fishers around the globe are determined for a dependable strategy to cease dolphins from plundering their catch. Dolphins’ internet burgling—referred to as depredation—prices fishers revenue and in addition places dolphins prone to damage and entanglement. Proposed options, corresponding to utilizing noisemakers, have had combined outcomes. So researchers in Greece went again to the drafting board in quest of the right deterrent: one thing so disagreeable that it might beat back dolphins and hold them away. They got here up with fishing nets coated with a resin laced with capsaicin, the chemical compound that provides chili peppers their signature warmth.
Giving predators a spicy shock may seem to be a far-out answer, however capsaicin-based deterrents have proved profitable on land with different mammals corresponding to deer, squirrels, and rodents.
Yet after 5 months of test-fishing with capsaicin-coated nets, the analysis group, co-led by Maria Garagouni, a marine biologist at Aristotle University of Thessaloniki, in Greece, got here to a tricky realization: Their concept didn’t work. The bottlenose dolphins that interacted with their nets have been totally unfazed.
Despite the disappointing consequence, Garagouni says she was wowed by how adept the dolphins have been at pilfering from their nets. Garagouni started collaborating with fishers a decade in the past to review depredation within the Aegean Sea; even so, the animals’ prowess shocked her. When dolphins are available in for a netted meal, she explains, it’s greater than a smash-and-grab job: In many circumstances, the animals run methodical missions into the nets till they’ve eaten their fill.
“The initial shock for me was seeing it happen in real time,” Garagouni says. The first time dolphins interacted with the hot-sauce-spiked nets, two people spent not more than quarter-hour tearing 217 holes within the gear.
“And then the victory laps!” Garagouni says. “The play afterwards, when there were young calves in the group—after they’d get their fill of fish, the young ones would go off and do leaps in the air, almost as if to burn off all this new fuel. If this was our livelihood, I think it would be the most infuriating element to watch. But for me, obviously, it was amazing.”
So does this imply dolphins might slurp down Da Bomb Beyond Insanity on their strategy to Hot Ones glory? Aurélie Célérier, a neuroscientist on the University of Montpellier, in France, who makes a speciality of marine-mammal communication and was not concerned within the research, says it’s too early to make that decision. Although it’s recognized that many cetaceans, together with bottlenose dolphins, lack 4 of the 5 major tastes—they’ll solely choose up salty—spiciness is registered by a unique set of sensory cells by means of chemesthesis. This course of, which indicators sensations corresponding to ache and warmth, is little studied within the species. Other toothed whales do seem to have the {hardware} required for capsaicin detection, Célérier notes, however there’s rather a lot left to study.
There might be one thing else at play within the dolphins’ conquer spice: cetacean supersmarts. From corralling fish with plumes of mud to tenderizing powerful prey by tossing it sky excessive, dolphins are recognized for all kinds of clever feeding methods. Their propensity to innovate, mixed with the truth that they’re notoriously unfussy eaters, helps them survive, but it surely’s additionally partly what places them in rising battle with fishers. The dolphins might merely have discovered a strategy to break into the spicy nets with out making a lot contact.
The capsaicin coating didn’t deter dolphins, however intriguingly, it did seem to have an effect on one other animal. An unidentified predator, probably a sea turtle, seal, or shark, tore giant holes within the scientists’ plain management nets however not the spicy nets.
The analysis group is placing a pin of their red-hot analysis for now, however Garagouni hopes it is going to function a springboard for others on the hunt to outwit dolphins. Even a research that fails, she says, affords useful clues and results in new questions.