The scientists said that since the advent of industrialized fishing in the 1950s, the world had seen a 90 per cent drop in the population of large oceanic fish such as bluefin tuna and giant blue marlin.

Learning more about the lives of fish and their surroundings would help governments ensure their continued survival, the team said.

"The knowledge it (the network) generates will transform conservation and fisheries management practices," said Eliot Phillipson, president of the Canadian Foundation for Innovation that is giving most of the money.

The eventual goal is to create a network of 5,000 sensors in 14 ocean regions tracking up to one million animals. Larger animals such as tuna would be monitored via satellite.

The Canadian funding was needed to unlock funds from other donors to pay for the C$160 million six-year project. The tracking network will be based at Dalhousie University in the eastern Canadian city of Halifax.

The plan is to attach small tagging devices with embedded microchips to fish, sharks and other animals, which will send signals to an array of sensors on the sea floor.

The tags -- which vary in size from an almond to a AA battery -- will provide data on where the fish are swimming as well as information on water temperature, salinity, light and other marine conditions.

Ron O'Dor from Dalhousie University said the tags would allow the transfer of information. That way, he said, fish swimming out of the range of the receivers could collect the data from each other.

Once one of the fish moves close enough to a receiver the tag will transmit the information from all the tagged fish it has been in contact with.

"This is the BlackBerry for fish. Every fish will be able to talk to every other fish and when they get home they will report the data to one of the receivers," O'Dor told reporters on a conference call.

Until recently, scientists had little idea how far fish can swim. Tuna crisscross the Pacific, great white sharks travel from Africa to Australia and turtles from Central America have been found off Easter Island.

As well as fish, tags could be attached to penguins and polar bears.