Shedd Aquarium, on the shores of Lake Michigan, in Chicago, has opened its newest attraction - a south-east Asian coral reef.

Wild Reef, a recreation of Apo Island, a volcanic peak in the Philippines, allows visitors to get a divers-eye view of the marine eco-system of a coral reef.

The $45m, 28,000sq ft, 10-room exhibit is an extension of Shedd's existing Oceanarium and - at 750,000 gallons - more than doubles the capacity of the original aquarium.

It incorporates a curved overhead 400,000 gallon shark habitat, occupied by more than 25 sharks of around eight different species, separated from visitors by only five inches of acrylic.

Wild Reef also contains over a million individual corals and fish of about 540 different species, doubling the number in the aquarium.

The Wild Reef project is intended to highlight the gradual destruction of coral reefs - which cover less than 1 per cent of the ocean floor but support about 25 per cent of all marine life - and what can be done to both prevent this and restore them to health.

The exhibit is the culmination of a 5-year, $97m renovation and expansion programme for the aquarium, funding for which was provided by a $47.5m campaign as well as the City of Chicago and the State of Illinois.