Working with our neighbours to advance algal toxin testing


Cawthron has been helping the Tasmanian seafood industry improve testing for paralytic shellfish toxins – a recurring problem for their shellfish aquaculture sector.

Scientists from Cawthron completed a research project on these toxins, partly funded by the Australian Fisheries Research and Development Corporation, last year. One element of the research looked at the toxicity of the major paralytic shellfish toxin often found in Tasmanian shellfish.

This is important as Cawthron marine toxin chemist Dr Tim Harwood explains, “The analysis of paralytic shellfish toxins is something you really want to get right. They have the potential to make you critically ill, so testing and regulation needs to be very robust.

“We can measure how much of each toxin is present in the shellfish; that’s relatively simple. What is not clear is how the toxins affect individuals and at what levels.

“This project working with our Tasmanian neighbours will result in a better assessment of shellfish toxicity, and there will be increased confidence around whether shellfish contaminated with paralytic shellfish toxins actually poses a human health risk or not.”

Toxin producing algal blooms have been a problem for Tasmania’s shellfish aquaculture industry for over 20 years as the toxins produced naturally accumulate in filter-feeding shellfish such as mussels and oysters. This risk to industry makes harmful algal bloom research a top priority for the Tasmanian wild capture and marine farming sectors.

Closer to home, New Zealand’s Government has been active in supporting Cawthron’s harmful algal bloom research by funding the hugely successful ‘Safe New Zealand Seafood’ programme. Cawthron analyses various New Zealand shellfish and seawater samples every week to discover whether they contain toxins or toxin-producing microalgae.

“Over the past two decades our research team has built extensive knowledge and expertise around the analysis of a whole range of marine toxins.

“We’ve applied that capability to helping New Zealand’s seafood industry, and it’s great to be supporting our Trans-Tasman neighbours,” Cawthron marine toxin chemist Dr Tim Harwood said.

We cannot eliminate toxic algal blooms, but we can better assess shellfish toxicity and manage harvesting areas. Whether here or across the ditch, we all stand to gain from improved understanding and testing of these toxins.

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