Thailand’s southern provinces produce about 70 percent of the country’s annual shrimp exports of 600,000 tons. Thailand exports around 100 billion baht ($3.31 billion) worth of shrimp annually, mostly to the United States, Japan and the European Union.

“About 50,000 to 60,000 tons of shrimp were washed away by the flood. Damaged roads also obstruct transportation from farms,” Panisuan Jamnarmwej, president of the Thai Frozen Food Association, said.

He said exports would be affected but it was too early to estimate by how much.

The floods and mudslides, which have forced railways to suspend services and cut off road and air transportation, have killed 35 people across four provinces and stranded thousands of tourists. Seven other provinces were also affected.

Shares in Thai Union Frozen, the world’s largest canned tuna producer, slid as much as 5.3 percent on March 29 on concerns that flooding in the south would increase costs and erode earnings from shrimp sales at the Thai-based company.

“The flooding will raise prices of shrimp over the next few months, cutting TUF’s profit margins,” Asia Plus Securities said in a research note on March 29.

TUF buys about 60 percent of its shrimp supplies from farms in the southern region.

Flooding has also affected nearly a million people, displaced thousands of villages, and damaged more than 112,000 hectares (276,800 acres) of farmland. At least 2,300 roads and over 800 houses were partially destroyed. The military evacuated tourists from some islands.

“The water came and went very quickly. There was no time to move anything to higher ground, only ourselves,” said Meena Suwannapongsa, whose electronics shophouse in Krabi province was briefly submerged.

Authorities said it was too early to estimate overall damage from the unseasonal rains which were expected to worsen rubber supply tightness during the typically dry, low-production season and ahead of Thailand’s Songkran festival holidays in mid-April.

The president of the Thai Rubber Association said on Thursday shipments of at least 50,000 tons of rubber had been delayed as some rubber producers were forced to temporarily shut factories and transportation was cut off.

“We expect more rains in four provinces, so there may be more flooding in these areas. But rains have subsided in most places,” said Wiboon Sangruangpong, director-general of the Department of Disaster Prevention and Mitigation.