When you see sausages at a butcher, or purchase a barbecued fundraising snag, spare a thought for the sausage-shaped marine animals that formed one of Australia's first export industries. The trade in trepang between Chinese, Macassan and northern Australian Aboriginal people is the focus of the Trepang exhibition at Melbourne Museum which closes on 16 October.
The trade of trepang or sea cucumbers dates back before 1700. The product is known by several names: trepang (Indonesian), bêche-de-mer (French), hai-sum (Chinese) and namako (Japanese). While the live animals are shaped like a sausage, the product that is eaten is usually the dried skin (body wall) or pickled intestines. In Japan they are generally eaten fresh.
Namako (sea cucumber) for sale in a Japanese supermarket.
Image: Hector Garcia
Source: Used under Creative Commons (CC BY-NC-SA 2.0) from kirainet
Today, trepang fisheries exist throughout the Indo-Pacific area, including Madagascar, Ecuador, Canada, New Zealand and northern parts of Australia. The products are most often consumed in China, Korea, Japan, and some smaller Indo-Pacific islands such as Samoa and Indonesia.
The Australian trade began with 600 tonnes in the early years – about six million live animals – to 11,000 tonnes in the 1990s. This high demand resulted in over-exploitation in some areas because the animals were easy to collect, slow growing and had low reproductive rates. As a result, today's fisheries target deeper water species and are carefully managed, but some species are still over-fished.
A sea cucumber (Stichopus mollis) in its natural habitat.
Image: Julian Finn
Source: Museum Victoria
So they look like sausages but do they taste like sausages? I asked around. The closest response was from Mel, one of the museum's marine collection managers who has lived in Japan.
"I've only eaten sea urchin [a related echinoderm group] which tasted like mushed-up prawns, but I've heard sea cucumbers taste rubbery."
Nonetheless they are a delicacy for some. Sea cucumbers are rumoured to have anti-inflammatory and aphrodisiac properties, although the latter may be based more on the shape and behaviour of the live animal rather than any scientific proof.