Species → Common Bottlenose Dolphin

Common Bottlenose Dolphin

Tursiops truncatus

no reliable global figure — the IUCN describes a large, widely…
Extinction risk Least Concern
PredatorMarine environment
Common Bottlenose Dolphin (Tursiops truncatus)
Photo: Giles Laurent, Wikimedia Commons (CC BY-SA 4.0)

What if it disappeared?

Impact Low
Every day

A bottlenose dolphin expends an amount of energy directly measured by recent metabolic studies — enough to catch the equivalent of several kilograms of fish every day, a real and quantified individual predation pressure, but one that has never been directly linked to a measured effect on a wild prey population.

Documented
Detail

Rimbach, R., Amireh, A., Allen, A., Hare, B., Guarino, E., Kaufman, C., Salomons, H. & Pontzer, H. (2021). Total energy expenditure of bottlenose dolphins (Tursiops truncatus) of different ages. Journal of Experimental Biology, 224(15), jeb242218.

The study measures total energy expenditure using the doubly labeled water method in dolphins of different ages — the most direct measurement available for this species. It documents how much a dolphin expends, and therefore roughly how much it must consume, but doesn't track what that consumption changes in the fish population it feeds on.

Today

What the disappearance of dolphins would change for fish populations and the structure of the coastal ecosystems they frequent has never been directly measured — unlike other large marine predators in this reference (tiger shark, great white shark, killer whale), whose effect on the rest of the ecosystem has been the subject of dedicated experiments or monitoring.

Insufficient
Detail

The dolphin is one of the most studied marine mammals in the world for its behavior, cognition, and physiology — but surprisingly little for its exact role in the food web at the scale of an entire ecosystem. General claims presenting it as a marine "keystone species" circulate widely in popular science without a removal or exclusion study comparable to those conducted on the sea otter or tiger shark elsewhere in this reference.

Related species