Marine scientists and fishermen say that popular fish species -- especially the large and valuable ones -- have been caught indiscriminately, causing numbers to plunge dramatically.
For big fish "finding a mate is a difficult task. They have to swim a long distance to find one," said Edward Allison from the World Fish Center in Malaysia's northern resort island of Penang.
One of the culprits is bottom trawling, which involves dragging huge, heavy nets along the sea floor.
Large metal plates and rubber wheels attached to the nets move along the bottom and crush nearly everything in their path.
Allison said the habitat for young fish, or fry, is also shrinking because the mangrove swamps which provide food and protection are being obliterated by coastal development including tourist resorts.
Demand for top-quality seafood, from Southeast Asian nations themselves and from Hong Kong and China, is another major factor behind the emptying of the seas.
According to World Fish data, ther