Northern China’s demand for the regional delicacy has created an unsustainable market.

The best season to harvest sea cucumbers along the coast of the Yellow and Bohai seas is when autumn turns to winter and the waters become icy cold.

The marine animal is a crucial part of northern Chinese cuisine.

Records of people eating sea cucumbers for medicinal purposes date back over 2,000 years to the Han Dynasty, with the animal being described in texts as beneficial to your organs.

But sea cucumbers only became truly popular in recent decades as ordinary Chinese people had more money to spend.

When wild sea cucumbers became hard to find, fishers switched to aquaculture, buying young sea cucumbers from breeders and scattering them along the sea floor. After about three years, the animals – which hardly move during their lifetimes – are ready to be harvested.

The industry has grown to such an extent that every suitable stretch of coast in North China is now used for aquaculture, mostly to grow sea cucumbers.

This situation is cause for concern among ecologists. Coastline development has damaged over half of China’s coastal wetlands.

There are more than 1,200 known species of sea cucumber around the world.

About 20 kinds are eaten in China, but the Japanese spiky sea cucumber is the most beloved, expensive, and widely cultivated.

Sea cucumbers, which feed on organic debris from the sludge of the ocean floor, are perhaps best-known outside of China for their peculiar defense strategy: When threatened, they expel some of their intestines in order to survive. They move slowly, covering only a few square metres of seabed during their entire lives, but their importance to the marine ecosystem shouldn’t be underestimated.

Sea cucumbers fill the same role as earthworms.

They accelerate the decomposition of organic matter in the soil, and their own waste is food for microorganisms and other creatures that dwell on the seabed.

In turn, they are food for marine animals above them in the food chain.

Most Chinese academic studies on sea cucumbers are focused on their breeding and nutritional value, with little attention paid to their survival in the wild.

China’s soaring consumption of sea cucumbers has contributed to a rise in their harvesting around the world.

According to the “China Fishery Statistics Yearbook,” the country’s national output of cultivated sea cucumbers exceeded 200,000 tonnes in 2016. But that’s still not enough to satisfy demand, and so large amounts need to be imported.

From Ecuador to Indonesia, over 90% of the world’s tropical coastlines have joined the global trade in sea cucumbers.

A  2011 study estimates that approximately 38% of the world’s sea cucumber fisheries are being overfished, and 20% are already depleted.

Whenever one species of sea cucumber is overfished, fishers simply find another variety to take its place.

After analysing 377 sea cucumber species, the IUCN in 2013 listed seven species as being “endangered” and nine species as “vulnerable”.

On the Chinese market, the phrase “caught in the wild” conjures up images of uncontaminated natural environments, but even the sea cucumbers that have been artificially placed on the sea floor are labelled “wild”.

Truly wild sea cucumbers are becoming increasingly rare.

Source:  Sixth Tone