Scientists say far more species of marine megafauna use coastal habitats than previously thought.

New research has highlighted links between coastal habitats and the conservation of threatened marine species.

The study by The Global Wetlands Project shows marine animals, such as dolphins, sharks, crocodiles and sea turtles are more reliant on coastal habitats than many had believed.

“When we think of mangroves, we don’t immediately think of habitat for sea turtles or dolphins”, said lead author Dr Michael Sievers from Griffith University.

“However, green turtles are known to eat mangrove leaves and fruits, and bottlenose dolphins hunt for fish around mangroves.”

The findings tie in to details uncovered last year by US researchers; that the bonnethead shark – a close relative of hammerheads – is the first known omnivorous shark, eating and digesting seagrass.

The study comes after the United Nations reported earlier this month that more than 1 million animal and plant species are at risk of extinction in the next few decades due to human activity, such as habitat destruction for agriculture.

Dr Sievers and his team are encouraging scientists and conservationists to include habitat links in species’ extinction assessments and recovery plans.

“We now know that over 100 species of these big, iconic marine species use coastal habitats,” Dr Sievers said. 

The problem is that these habitats are declining globally, and the links to populations of marine megafauna have been largely overlooked.

“We need to be really clear about what the ecological links are, what habitats are most important and how threatened species are actually affected by our actions.”

The team believes the findings are particularly important as the international community mobilises to tackle climate change and preserve biodiversity at the global scale.