When I finally track down Tammy Horton of Southampton Oceanography Centre, she gleefully describes her location. She is spending an entire month on a research ship in the Atlantic Ocean, north of Britain's Shetland Islands, investigating plants and animals that live thousands of metres below the surface. Someone from the ship's onboard team of researchers is hard at work every hour of the day and night, and no one gets a day off. Horton sounds incredibly happy.

Meanwhile in Texas, on the shore of the Gulf of Mexico, Kim Larsen from Texas A&M University is also sounding chipper. He's examining samples and video footage of organisms living on top of, or in, the mud of the Gulf's deep seabed. Although his area of speciality is a group of tiny shrimp-like creatures called tanaids, he's recently had some fun with a "deep sea frog."

It's lucky that Larsen could correctly identify the "frog" as a lobster because in most cases he and Horton don't know the animals they're looking at. That is because humanity's collective knowledge of deep sea biodiversity is extremely limited. As a result, 70 percent of the species Larsen is pulling up are entirely new to science. With oceans covering a whopping two thirds of the Earth's surface, our ignorance about life on this planet is much greater than we generally imagine. A desire to chip away at that ignorance is the primary reason BP has awarded Horton and Larsen three-year research fellowships in taxonomy, the painstakingly slow but essential business of identifying and classifying species.

"We need to plug the gaps in our knowledge," says John Addy, BP's senior environmental advisor. "If you don't know what you're looking at then how can you possibly talk about behaviour and implications for environmental impacts."

The two fellowships are part of a concerted effort by BP to take a leading role in improving our understanding of how deep sea ecosystems work. How many species are down there? We don't know yet. How do very small animals living in the mud influence populations of larger life forms such as coral reefs that stretch for several kilometres or 200-year-old fish? We know that all organisms are dependent on each other in a complex web of food chains, but we don't yet have an accurate picture of how these operate thousands of metres below the ocean surface.

Deep sea biodiversity is increasingly a priority for BP because oil and gas exploration and drilling is moving down the continental shelves and into deeper waters. Currently, this shift is taking place off the coasts of Brazil, Angola, Norway, northwest of the Shetland Islands and in the Gulf of Mexico. Biodiversity not only varies region to region, but the biodiversity found in deep waters is very different from that in nearby, shallow waters. This means that as BP develops new technologies to drill in the deep sea it also has to take new approaches to assessing environmental impacts.

Scientific Disciplines: An essential tool in biodiversity investigations is the old-fashioned science of taxonomy. In the 18th and 19th centuries, taxonomy was the king of scientific disciplines and even into the 20th century every biologist worth their salt was a competent taxonomist. This is no longer the case, as other areas such as molecular biology and genetic engineering grab the headlines. But the fortunes of taxonomy are looking up and it's no coincidence that BP has awarded its first fellowships into deep sea biodiversity to two young scientists who have bucked the trend and therefore possess crucial taxonomic skills. "Without knowledge of what is in the oceans, we cannot see if environments are changing," explains Horton.

What lies ahead? For a start, many hours at the microscope for Horton and Larsen, unravelling the differences between tiny but often ecologically significant creatures. They're also hoping to experience their first trips to the deep sea floor in small submarines. Just as illuminating will be the photos, videos and specimens they receive from BP contractors exploring the deep sea, and from monitoring equipment. Specimens have been collected for years, but now a concerted effort to create a bank of data is underway. Examples that used to get put on a shelf and forgotten will become part of an expanding library of information that will gradually allow us to transform the deep sea from a place of mystery into an environment we understand well.

Drilling in the deep sea inevitably creates environmental impacts and BP expects taxonomic-based research to help it keep negative effects to a minimum. However, BP's chief executive Lord Browne has made it clear that the company's commitment to biodiversity extends to having a "real, measurable and positive impact." Deep sea research offers one way for BP to fulfil this goal because the data will also provide information about other human-induced impacts on the oceans. Organisms aren't just affected by small areas being drilled, but also by bigger issues such as climate change.

One of the industries that environmentalists are most concerned about is the largely unregulated fishing industry, whose trawlers drag nets over huge areas of the deep sea floor. Massive scarring has been discovered, proving that coral reefs and other sensitive organisms have been damaged.

There's no telling what we'll be seeking to harvest from the seas in the future. Larsen has heard of one possibility: "People have been talking about dredging for manganese noodles in the deep Pacific," he says. Both he and Horton believe that the research they're undertaking now will help a range of industries modify their activities in order to limit their impacts on the flora and fauna of the deep oceans.