Why bottlenose dolphins are our cause of the month
CAUSE OF THE MONTH
Indo-Pacific bottlenose dolphin conservation
The celebrities of the sea
Bottlenose dolphins are perhaps the most famous of their species because of movies like Flipper and certain marine parks where they’re sometimes exploited for entertainment. They’re what most people imagine when you say “dolphin.”
What most people don’t know is that there are actually two species of bottlenose dolphin: the common bottlenose and the Indo-Pacific bottlenose. They’re similar in appearance, but have enough differences — like average length and weight, appendages, coloration, diet, behavior, and distribution — to make them unique species.
With the exception of the colder waters of the poles, bottlenose dolphins are found in almost every ocean in both coastal and offshore waters. The frequent overlap of human and dolphin habitats has made human activity the biggest threat to their survival.
Difficult to assess
Determining the conservation status of either bottlenose dolphin species is difficult on a global or range-wide basis.
Common bottlenose dolphins are considered “least concern” by the International Union for Conservation of Nature (IUCN); however, this can be deceiving because many populations are undergoing serious declines.
In the Mediterannean, common bottlenose dolphins are considered vulnerable to extinction. In the Black Sea, they’re considered endangered due to the last impact of previous hunting, live captures, and ongoing high rates of bycatch.
Indo-Pacific bottlenose dolphins tend to occur in fragmented coastal populations and their range includes many countries where little or no formal research has taken place. For now, the IUCN has designated their conservation status as data deficient.
Human activity is their biggest threat
Accidental entanglement in fishing gear is the leading cause of human-induced mortality for bottlenose dolphins. This is true for all cetaceans and is particularly common in coastal areas where large-mesh gillnets are often set and left unattended for long periods of time. Dolphins can become entangled as they travel or chase fish into the nets. There are some coastal areas where recreational fishing gear is the main cause of mortality and serious injury.
Agricultural and industrial runoff from densely populated areas and the buildup of toxins from plastic that dolphins and their prey consume can pose significant health threats and impact their ability to reproduce. High death rates among first-born calves have been linked to increased contaminant loads stored in their mothers’ milk.
Harmful algal blooms, sometimes called red tides, can also be fatal. These blooms occur naturally but can also be triggered by runoff from heavily populated or farmed areas.
In addition to these threats, Indo-Pacific bottlenose dolphins are also routinely hunted, captured, and sold to facilities that exploit them for entertainment. But everything we know about these highly intelligent creatures shows us that they don’t belong in concrete tanks performing tricks for our amusement.
PARTNER OF THE MONTH
We’re donating $1 to Ric O’Barry’s Dolphin Project for every Bottlenose Dolphin Bracelet sold this month. Our donation will be used to fund the 24/7 care of three rescued dolphins at the Umah Lumba Center in West Bali.