If there’s one thing I’ve learned from the dulcet tones of David Attenborough, narrating yet another amazing animal documentary over a soothing soundtrack, it’s that dolphins are very smart. They use highly intelligent strategies to live their lives, hunt, and even play. They also love to eat—all the better if their meal is generously pre-caught for them, by human fishers who are deeply chagrined at the highway robbery occurring in their nets. After noisemakers and reflective material didn’t deter this dolphin behaviour (called depredation) in the Aegean Sea, a team of Greek researchers recently brought out the big guns: hot sauce-laced nets.
More precisely, they coated fishing nets with a resin that contained capsaicin, the chemical irritant that gives chili peppers their famous heat. Capsaicin has been used successfully on land to prevent squirrels, deer, and other mammals from eating what they shouldn’t (like seed from a bird feeder, or crops). But it had never been tried on dolphins…
“Yet after five months of test fishing with capsaicin-coated nets, the research team co-led by Maria Garagouni, a marine biologist at Aristotle University of Thessaloniki in Greece, faced a tough realization: their idea didn’t work. The bottlenose dolphins that interacted with their nets were entirely unfazed. […]
While it’s known that many cetaceans, including bottlenose dolphins, lack four of the five primary tastes—they can only pick up salty—spiciness is registered by a different set of sensory cells through chemesthesis. This process, which signals sensations such as pain and heat, is little studied in the species. Other toothed whales do appear to have the hardware required for capsaicin detection, notes [neuroscientist Aurélie] Célérier, but there’s a lot left to learn.
There could be something else at play in the dolphins’ triumph over spice: cetacean super smarts. […] The dolphins may simply have figured out a way to break into the spicy nets without making much contact. “
Intriguingly, a mystery predator, unseen by the researchers, did avoid the spicy nets, while massacring the control nets. The team is putting their research into who the strange snacker was, as well as their central question, on ice for now. The wheel of science turns slowly—which I’m sure the hungry dolphins appreciate!