The effort has "given us a much clearer window into marine life," said Shirley Pomponi, executive director of the Harbor Branch Oceanographic Institute at Florida Atlantic University in Fort Pierce.
The research, which has involved thousands of scientists from around the world, got under way in 2000 and the final report is scheduled to be released in London on Oct. 4.
Last fall the census reported having added 5,600 new ocean species to those already known. Ron O'Dor, a professor at Dalhousie University in Halifax, Canada, said there may be another 100,000 or more to be found. "Add microbes and it could be millions," he said.
One benefit of learning more about ocean life is the chance of finding new medical treatments, Pomponi said.
For example, a chemical discovered in deep water sponges is now a component of the cream used to treat herpes infections, Pomponi said. Other research is under way on pain killers and cancer treatments based on ocean life.
Kristina Gjerde, of the International Union for the Conservation of Nature, in Konstancin-Chylice, Poland, said the research will help guide governments in setting up marine protected areas to preserve species both for food and of value for other reasons.
O'Dor said the ocean is large and resilient, so that when a region is protected life there can rebound, "but we can't keep insulting the ocean."
O'Dor noted that many people are concerned about the decline of tigers in the wild, and said the same may be true of great white sharks.
Noting a marine census project that places sonar trackers on fish and marine mammals, O'Dor pointed to an Australian program that senses those trackers and warns people ashore when to close a beach because a shark is nearby.
"See, we can coexist," he said.
