A large number of fish were found dead on the shore of the central province of Quang Tri in recent days, sparking concern that the water might have been contaminated.
Local fishers are flocking to a beach stretching around 20 kilometers from Vinh Thai Commune to Cua Tung Town to pick up the dead fish.
Some of the fish such as batoids, groupers, and humphead snappers lived deep under the sea and were of high value, according to the fishers.
Hoang Van Toan, a resident in Cua Tung Town, said fishers usually caught only several individuals of these kinds a day, but now they could catch up to one ton just by casting a fishing net near the shore.
Traders said although fishers caught a lot of fish in recent days, local people were reluctant to buy them as they were afraid that the fish may have been contaminated.
Residents in coastal areas in the central provinces of Thua Thien-Hue, Quang Binh and Ha Tinh also reported an unusual number of fish that were found dying or already dead on their beaches recently.
On Tuesday, Quang Binh authorities announced test results blaming the deaths of fish on contaminated water.
They said the polluted water may have come from Ha Tinh Province, where there is a large industrial park, and spread to other central provinces.
It may require more time to test and confirm this claim.
The same day, a medical center in Quang Binh's Quang Phu Commune said an 8-year-old local child was admitted to the center with poisoning symptoms after reportedly eating dead fish that drifted ashore. The child has recovered after treatment.
The province's Department of Aquatic Resources Protection has taken sea water samples for further testing and warned local fishers not to eat fish found onshore before test results are officially announced.