9 December 2011 Last updated at 10:33

Seamounts and coral: a conservation diary from the deep

A team of scientists has set out on a six-week mission, funded by the Natural Environment Research Council, to explore the Indian Ocean's underwater mountains, or seamounts.

The scientists aboard the research vessel, the RRS James Cook, will study life thousands of metres below the surface.

In the fourth of her BBC Nature diary entries, Aurelie Spadone from the International Union for the Conservation of Nature, who is part of the team, witnesses the exploitation of the seamounts she is exploring.

We are now in the 5th week of this expedition.

The ship has been adorned with Christmas decorations. Homesick feelings arise from time to time, it has been a long five weeks away from home. But we still have a lot of work to do.

We have been exploring three seamount areas and have reached "Sapmer" seamount, the fourth of five on our itinerary, on Monday.

On arrival, we noted another ship and realised that it was a large trawler actively fishing the area. We watched it repeatedly moving up and down, using a mid-water trawl. It fished all night.

The vessel was registered in Japan and must have sailed from a huge distance - about 7,500 miles (12,000km) emphasising the global nature of fishing on the high seas.

On Tuesday morning they hauled in their net and headed south-west. We cannot know for sure, but we assume they are going to fish the other seamounts in the area; the ones we have just left and that host life that we are yet to comprehend the complexity of.

It was an example of human activities impacting a remote area of the planet in front of our eyes.

On the very same day, in New York, US, the United Nations General Assembly (UNGA) adopted a resolution on Oceans and Sustainable Fisheries, which calls on high seas fishing nations to take stronger actions to protect deep sea life from the harmful effects of bottom trawling and other methods of deep sea fishing.

And this isn't the first resolution on that subject; the issue of protecting biodiversity in the high seas has been intensely debated over the last decade by the UNGA and in other international forums.

The problem is that the assessments of fishing activities - required by previous UNGA resolutions - have not been completed for the majority of bottom fisheries. Most fishing activities in the high seas remain unregulated.

This new resolution highlights the fact that environmental impact assessments have to be conducted and made public and that regulations have to be put in place before deep-sea bottom fishing in an area of the world's oceans is authorised by the country of origin of the fishing company.

An important component of what we are doing in this expedition is to bring to the attention of such bodies (UN and international institutions) the plight of the world's seamounts.

Today we have witnessed one of the graveyards of the south-west Indian Ocean Ridge. Fields of broken and dead coral ground up almost into sand.

Trawl marks are clearly visible on the slopes. Amongst the rocks we discovered a ghost net with animals dead and dying in the near invisible mesh. It's heart-breaking.

Let's hope that high seas fishing nations will take the necessary measures and commit themselves to ensure the protection of the rich and diverse life of the deep seas.