Science mission finds glimmer of hope for marine biodiversity in ocean depths off Comoros

As world leaders meet at the COP30 summit in Brazil, the urgent need to hit a global target of protecting 30 percent of the world’s ocean by 2030 has been brought into stark focus by an international science mission which has just returned with new evidence from the depths of the Indian Ocean.

Sharks - the ocean’s apex predators - observed at depths from 300 metres and 900 metres down in the Indian Ocean off the coast of Comoros - a nation emblematic of many small island states bearing the brunt of climate destabilisation and biodiversity loss.

The presence of these magnificent creatures at such depths signals there is a food source to sustain them. That offers hope that, in spite of the Comoros facing enormous difficulties due to climate change and overfishing, there is still a functioning ecosystem in the deep. Although fragile, it has not yet been destroyed by the impact of global carbon emissions warming the waters of the Indian Ocean.

Filmed by Nekton and Comorian scientists using bait cameras deployed from the research vessel Angra Pequena, the effort is part of a systematic baseline survey of an area rich in biodiversity which has rarely been seen by human eyes below scuba diving depth.

“This expedition is crucial for the 30x30 objective because it allows us to explore areas we don't yet know," says Dr. Nadjim Ahmed Mohamed, the expedition's co-chief scientist.

"And based on the findings of this expedition, we can establish protected zones. This means that, globally, we will be able to meet the goal of reaching 30 percent by 2030.”

Race against time

But Comoros government leaders know this is race against time as the situation on land and in the shallows is worrying. A healthy ocean is vital for the Comoros in mitigating the impacts of climate destabilisation Rising sea levels, ocean warming, and biodiversity loss all pose an existential threat.

Abubakar Ben Mahmoud is the Comorian Minister of Environment: “Our country is going through enormous difficulties, mainly due to climate change. For example, we observe the rise in sea level every day. It even penetrates our homes, our crops, flooding our land with salt water.Today our coastline, our coastal reefs are dying little by little.“

Like so many island nations on the frontline of the climate crisis, the Comoros are not the world’s major polluters yet they face the challenge of trying to fix the damage. According to a recent World Bank estimate, more than one in five of the Comorian population lives in poverty.

The country relies on the ocean for its survival; so understanding how to conserve fish stocks, whilst using the bounty of the sea to responsibly feed its people, is pivotal. There’s a recognition that the fix includes educating the next generation on ocean literacy and tackling the issue of illegal fishing. Without both of those measures in place the ecosystem close to shore and around the reefs cannot sustain future generations.

Ocean depths

Already there is a worrying lack of predators like sharks being spotted in shallower waters down to 30 metres below the surface.

“The coral communities here in Comoros, some of them are stunning, they are really beautiful and this gives a lot of hope," says Nekton expedition co-leader, Dr. Lucy Woodall.

"This means that the coral can provide homes for the fish which are really important for the communities here. So now there's a great opportunity, an opportunity for protection, for long-term sustainable management."

But the Nekton science team and their Comorian partners emphasise it will take more than just sustained efforts locally to ensure at least 30 percent of the world’s ocean is protected by 2030. It will take world leadership by those nations around the COP30 table.

There is much to do and not much time left to do it to reach the goal of protecting 30 percent of the world’s oceans by 2030. So it is empirical data from expeditions like Nekton’s First Descent: Comoros which will give politicians and scientists a better understanding of what lies below and where to bring in marine protection measures before it’s too late.