The death of a male short-finned pilot whale with a shocking number of plastic bags in its stomach in Songkhla province has sparked grave concerns about marine debris and the threat it poses to the marine ecological system.

The whale died on Friday, a few days after it was beached in Chana district on May 28, and drew wide public attention to yet another case of a marine animal ingesting human refuse after 80 plastic bags, weighing about 8kg, were found in its stomach.

As a result, the Department of Marine and Coastal Resources is seizing on this opportunity to raise public awareness about marine litter, especially plastics, which are known to be responsible for the deaths of seabirds and marine mammals.

Jatuporn Buruspat, the department's director-general, said on Friday, which was also World Ocean Day, that the agency will meet those in the plastic bag supply chain, including producers and users, to discuss how they can work to curb the amount of plastic that ends up in the sea.

He said more needs to be done to supplement proposed measures to reduce plastic waste which include limiting the use of plastic bags and placing traps at river mouths.

A study is under way into setting up buoys in Samut Songkram and Samut Prakan to trap rubbish before it flows into the sea, he said, adding that next year the department will buy waste-collecting vessels to clear the litter.

According to Mr Jatuporn, one of the challenges is to engage all state agencies concerned in dealing with mainland garbage. About 80% of the debris in the sea off Thailand comes from the mainland.

"The rubbish found in the stomach was not from Thailand alone, going by the product names on the plastic bags. The issue of marine debris needs collaboration from several countries in Asean and all stakeholders," he said.

Tara Buakamsri, Thailand country director for Greenpeace Southeast Asia, said the whale's death should serve as a wake-up call regarding marine debris and plastic waste.

The amount of plastics dumped into the sea is 100,000-400,000 tonnes yearly. Microplastics are also a cause for concern.

According to the Department of Pollution Control, Thailand generates 27.4 million tonnes of rubbish per year, of which just 11.7 million tonnes is properly managed with 8.52 million tonnes being recycled. It is estimated that around 80% of marine debris comes from ineffectively managed mainland waste.

Marine conservationist Thon Thamrongnawasawat said on Monday that the whale's death added weight to the claim that Thailand is a major contributor to marine debris.

He said the worldwide community is now watching Thailand after the whale's death made global headlines. He also expressed concerns that the country could face trade sanctions over "unfriendly practices towards marine life".

"The death of the whale only adds weight to the claim that we are the sixth-largest contributor to ocean waste. It means that all that we have done in the past, especially campaigns concerning appropriate refuse disposal, has failed. We must do something different to limit single-use plastic. If we do nothing, we risk trade sanctions," he said.

Mr Thon, who is also deputy dean of Kasetsart University's Faculty of Fisheries, noted that the European Union has already proposed a ban on plastic straws and cutlery.

He urged department stores to come together and charge customers for plastic bags, in order to limit their use.

A campaign by many department stores to reduce plastic bag use has had limited results, he said, adding that the government's attempts to address the use of plastic bags and straws have been inadequate.

To mark Tuesday's World Environment Day, under the theme "Beat Plastic Pollution: If You Can't Reuse It, Refuse It", the Department of Environmental Quality Promotion has picked Or Tor Kor market for a pilot project to encourage fresh markets to reduce plastic and foam packaging.

Or Tor Kor in Chatuchak district is Bangkok's highest-quality fruit and agricultural market.