Science Centres: Fisheries

Ginseng of the Sea (Photo: Kimberley Maxwell, NIWA).

Sea cucumbers may offer a way to reduce organic waste in aquaculture systems, while providing a lucrative added revenue stream.

NIWA student Kimberley Maxwell (Whakatōhea, Te Whānau-ā-Apanui, Ngāti Porou, Tainui) has been investigating sea cucumber energetics at our Mahanga Bay aquaculture facility in Wellington as part of a pilot polyculture study.

Polyculture involves growing multiple commercial species in a single system to maximise the use of space, food, and water while reducing waste products. NIWA are trialling a system involving paua, mussels, sea cucumbers, and seaweed in collaboration with the Hongoeka Development Trust Ltd (Ngāti Toa).

Ms Maxwell’s experiments showed that, on average, 135 sea cucumbers could potentially remove all the organic waste (faeces and uneaten food) produced by 120 kg of paua. However, the sea cucumbers could only grow on the waste of paua fed a diet of fresh algae or kelp flakes, not the artificial diet currently used in industry.

These results suggest that sea cucumbers will not make commercial partners with paua, but provide a sound basis for exploring their use in other aquaculture systems and the role of waste-feeders in polyculture generally.