Threats to coastal dolphins

Coastal development, boat strike, entanglement in fishing gear, pollution and climate change are all threats that converge on our coasts and could jeopardise the survival of snubfin and Indo-Pacific humpback dolphins.

Coastal development


Coastal development, including large-scale liquefied natural gas projects, coal industry expansion, land reclamation, dredging, port development and the building of marinas in river mouths can all cause a direct loss of habitat.

Increased human activity in these areas – from boat traffic and construction – can create noise disturbances. Increased chemical pollution can have devastating indirect effects on dolphins and interfere with their mating and reproduction.

Pollution

The introduction of toxic waste, pesticides, nutrients and lethal bacteria into their habitat is making coastal dolphins vulnerable. Marine debris, such as plastic bags and discarded fishing gear, also degrades the quality of coastal dolphin habitat and can contribute to population declines.

In particular, declining water quality not only impacts directly on coastal dolphin health but also threatens the productivity of the ecosystems upon which they depend.

Boat strike and entanglement in fishing gear


Globally, fishing is the major immediate threat to coastal dolphins. A number of species are now endangered as a result, such as Hector’s dolphins from New Zealand.

In Australia, inshore nets, entanglement in shark nets, entanglement in coastal fishing gear such as nets, boat strikes all poses an ongoing threat to snubfin and humpback dolphins, along with other marine species like turtles, dugongs and whales.

Coastal fishing, including net fishing in estuaries, often overlaps with coastal dolphin habitat and may target the same species that dolphins use as prey. WWF is working around the world to reduce bycatch and to ensure fishing is dome in a sustainable way.

In Roebuck Bay, in Western Australia, two out of every three dolphins assessed by WWF bore scars from vessel strikes, fishing nets and lines.

Click here to read more about WWF’s research into snubfin dolphins in Roebuck Bay.
Hector's dolphin calf killed in gillnet. Banks Peninsula, New Zealand. / ©: Stephen Dawson / WWF-Canon
Hector's dolphin calf killed in gillnet. Banks Peninsula, New Zealand.
© Stephen Dawson / WWF-Canon
Map showing the behaviour patterns of Snubfin Dolphins in Roebuck Bay, Australia / ©: WWF-Aus
Map showing the behaviour patterns of Snubfin Dolphins in Roebuck Bay, Australia
© WWF-Aus
Map showing the behaviour patterns of Snubfin Dolphins in Roebuck Bay, Australia.

Climate change

The impact of climate change on coastal dolphins is difficult to ascertain, however predicted sea level rise, and increases in water temperature and acidification could have disastrous consequences for the species themselves and the ecosystems upon which they depend.