In Australia, there has rarely been a better time to feast on lobster. So long as you don’t buy more than four.

The country began the coronavirus era with a run on toilet paper. Stores imposed buying caps, and images of empty shelves made news around the world. To end the year, Australian supermarkets have again imposed an unusual purchase cap, for very different reasons — this time on lobsters.

For toilet paper, demand briefly exceeded stocked supply. Lobsters, on the other hand, often reserved for special occasions, have become so inexpensive and abundant on the domestic market as a result of a mounting diplomatic crisis between Australia and China that several stores have imposed rations to stop them flying off the shelves, so as many customers as possible can partake.

In previous years, Australia exported more than 90 percent of its lobsters to China, where they are a popular delicacy, especially at weddings and banquets. But in the face of rising tensions between the two countries, China stopped importing them.

After Australia called for an independent inquiry into the origins of the coronavirus pandemic in China, Beijing unleashed economic measures, including high tariffs on Australian barley. Last month it added a de facto ban on live lobster imports.

Neither side appears willing to back down. But Australia’s export market relies heavily on China, and the fallout of the lobster trade war serves as an example of how costly a prolonged economic conflict could be for Canberra.

Australia is not the only country that has felt the effects of changes in the Chinese lobster market amid trade disputes and the pandemic. Tariffs and restaurants closures have hit the U.S. industry as well.

Rising income levels are set to make China the world’s key growth market for lobster sales in the years ahead.

Exclusion from that market could devastate Australian fisheries. The dispute has already resulted in a major drop in lobster prices, as an industry used to supplying a country of some 1.4 billion people turns its attention toward a domestic market of 25 million. In some Australian supermarkets, lobsters have become available for as little as $15 each in recent weeks — around half of last year’s price level.

“It’s good that people who enjoy them can actually afford a feed, I suppose,” fisherman Jason Hart told the Australian Broadcasting Corp. “But it’s making things hard for us.”

Operating his business costs Hart roughly $23 per kilogram of lobster, he told the broadcaster, meaning sales at current prices barely cover the fisherman’s expenses.

Meanwhile, Australian supermarkets and customers are rejoicing. “We’ve seen incredible customer demand,” said a spokesperson for Woolworths, a supermarket chain, adding that the newly imposed purchase limit applied “per customer, per transaction.”

“Customers can expect to see increased lobster availability in the days ahead,” the spokesperson said, according to news.com.au.

The Guardian published an article offering tips for home cooks looking to “take advantage of the cut price crustaceans.”

Some in the industry have put an optimistic spin on the glut. “Without the public, I think the whole cray industry would fall over now,” Kerry Tatnell, a commercial fisher, told the ABC this month.

But unless Australia’s lobster producers find a way to regain access to China, explore new export markets or increase domestic prices, their future looks dire.