Besides causing immense loss to human life and property, tsunamis may have caused untold environmental damage, with reports of destroyed coral reefs and uprooted mangrove forests trickling in.
While attention is clearly focused on the rising human toll, some dive operators and marine biologists are reporting that corals are suffocating under layers of mud and heaps of rotten fish clogging beachfronts, and rare turtle nesting sites have been washed out to sea, reports Haveeru (Maldives) newspaper.
“There is a huge natural cost but what it is, is still to be determined,” said Lynne Hale, director of the global marine initiative for the Nature Conservancy, who worked in Thailand’s Phuket Island and Sri Lanka for many years. Both areas were hard hit by the tsunami.
Now based in Rhode Island in the US, Hale said the tsunami might have caused lasting environmental damage that may take decades or longer to recover from. “This is a massive, massive erosion event,” she said.
A UN task force based in Geneva now plans to assess whether environmental damage threatens human health and the toll on the ecological resources — many of which support tourism and the fishing industry.
The Indian Ocean region, with its aqua, shallow seas, hosts some of the most famous coral reefs in the world that support scores of fish species found nowhere else.
Mangroves are critical nurseries for many varieties of fish. And the beaches of Sri Lanka, the Andaman and Nicobar Islands and other places hit by the tsunami host prime nesting spots for some of the world’s rarest sea turtles.
Scientists say they expect marine life from shore to about a mile out to have suffered the worst damage.
However, some biologists speculated that marine mammals such as whales and dolphins swimming near shore when the tsunami struck may have sensed the strange seas and headed for deeper waters where the giant waves were barely noticeable.
Land animals may have had the same “sixth sense” to move to safety. Wildlife officials in Sri Lanka’s Yala National Park said they have not seen evidence that many animals died, despite the preserve’s closeness to the ocean.
Scientists don’t have comprehensive historical data about marine damage that tsunamis can cause, especially one of this magnitude. They do know that in 1883, when the Krakatoa volcano exploded and sent a giant tsunami washing over Indonesia, coral heads that weighed hundreds of tons were tossed hundreds of feet inland.
And in 1964, when a tsunami hit Alaska, news reports noted that baby salmons were killed, although it’s unclear how many.
This week, dive operators and researchers began sending e-mails to the WorldFish Center in Malaysia, an international fisheries research centre, painting an early bleak picture of the region’s treasured coastal waters.
On Phuket Island, one popular beach was piled with dead stag horn coral, starfish, gulper eels, sea cucumbers and sea grasses.
In the Maldives, dive operator Norbert Schmidt said the eastern part of the island was hit the worst, with dead coral and sand covering the runway at Hulule International Airport.
In Sri Lanka and Thailand, coral damage is reported to be severe, and trees have crashed down onto reefs, ripping apart many of the corals, some hundreds of years old.
Already stressed from fishing and tourism, many of the reefs may be covered in mud, which can block sunlight that fish and other organisms below them need.
Meanwhile, corals, which only grow a fraction of an inch each year, may be excreting mucus as a defensive mechanism against the mud — “expensive in terms of energy [that] weakens the coral,” e-mailed Marco Noordeloos of the WorldFish Centre.
Noordeloos said fish population have probably been damaged, too, although it’s far too early to get a complete picture.