Scientists are tracking alarming changes in dolphin populations that reveal much about the health of our oceans
It begins with an empty stretch of ocean where dolphins once played. Scientists scanning the Bay of Biscay off the French coast are noticing something alarming—the common dolphins that typically fill these waters with their acrobatics and social chatter are still present, but they're dying younger. Much younger.
In the Bay of Biscay alone, an estimated 6,900 dolphins died as bycatch in 2021 from a winter population of 180,000 individuals 1 .
Dolphins are suffering from neurodegeneration linked to toxic ocean blooms, with toxins accumulating up to 2,900 times higher during peak bloom periods .
When traditional counting methods failed, researchers turned to studying stranded dolphins. Between 1997 and 2019, the team studied 759 common dolphins stranded along the Bay of Biscay 1 .
Growth layer groups in teeth provide precise age data 1
Reveals dietary changes and trophic positioning 8
Assess immune function and contaminant impacts 5
Groundbreaking research reveals dolphins may actually "touch" with sound rather than "see" with it as previously thought 3 7 .
Dolphins have enhanced connections between the inferior colliculus and the cerebellum, suggesting echolocation is more like touching than seeing 3 7 .
The question "Where's that dolphin?" leads us far beyond simple curiosity about marine mammal movements. It brings us to the heart of our ocean's health—and by extension, our own.
The same cyanobacterial toxins found in dolphin brains accumulate in seafood consumed by humans .
French fishing closures in the Bay of Biscay represent a step in the right direction 1 .
"As humans, we should make conscious decisions to protect the living and non-living things around us" 1 .