Fresh fish prices in Southeast Asia have been on the rise in recent weeks. While this can be attributed to the monsoon season, supplies are down.

But environmentalists say the rise is also a symptom of a deeper discomfort: depleted resources in the ocean due to overfishing and climate change.

"Reduced stocks during the monsoon season used to be a seasonal thing," says Serina Abdul Rahman, a lecturer in the Department of Southeast Asian Studies at the National University of Singapore. "But now these stocks seem to be declining over a long period of time."

"It's a phenomenon that's happening in Southeast Asia - small-scale fishermen are going back empty-handed. Their traditional livelihoods seem to be coming to an end." Fishermen, she said, are "really struggling."

Rahman, an environmental anthropologist who has studied Malaysian fishing communities extensively, said overfishing by high seas and deep-sea trawlers has depleted the oceans over the years, and the problem has spread to coastal areas where traditional fishermen depend on the sea for their livelihoods.

Climate change has exacerbated the situation by causing changes in currents and temperatures that harm the productivity of species and destroy coral and seagrass areas.

The retail price of fresh fish sold in Indonesia, Malaysia, and Singapore has increased by about 20 percent this year, according to a recent report by the Singaporean news network Channel NewsAsia. Prices are expected to rise further in the coming months as demand increases after the holidays.

Neil Hutchinson, senior lecturer in environmental sciences at James Cook University in Singapore, said fluctuations in catches usually occur because of changes in the monsoon. But in the long run, "there is a real problem in the world's oceans around the decline in fish stocks," he said, noting that wild-capture fisheries "have peaked and stabilized.

Half of the world's 1,400 assessed fish stocks are now overfished, and nearly one in 10 global fish stocks is now on the verge of collapse, according to the 2021 Global Fisheries Index report released by the Mindray Foundation of Australia.

A paper published Sept. 1 in the journal Global Change Biology says climate change has led to reductions in fish stocks in 103 of the 226 marine areas studied compared to historical levels.

According to the study, conducted by researchers at the University of British Columbia in Vancouver, the Stanford Centre for Ocean Solutions in California, and the University of Bern in Switzerland, fisheries management is concerned about the highest sustainable annual catch and the additional climate impacts on fish from 1.8 degrees Celsius warming will prevent fish stocks from rebuilding themselves.

Dennis Calvan, senior manager of policy and government engagement for the marine conservation group Rare Philippines, said "we need to understand what the science says" when it comes to managing fishery resources.

Calvan said that in addition to imposing fishing closures, the government needs to implement other measures, such as gear restrictions.