Analytical Services news

Dr Tim Harwood has been working with the Tasmanian seafood sector
20 September 2016

Helping our Australian neighbours

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

The scientists have recently completed a research project on these toxins, partly funded by the Australian Fisheries Research and Development Corporation. Part of the research looked at the toxicity of a major paralytic shellfish toxin often found in Tasmanian shellfish.

“Over the past two decades our research team has built extensive knowledge and expertise around the analysis of a whole range of marine toxins,” Cawthron marine toxin chemist Dr Tim Harwood says. “We’ve applied that capability to helping New Zealand’s seafood industry and it’s great now to be lending a hand to our Trans-Tasman neighbours.”

Blooms an ongoing problem

Algal blooms have been a problem for Tasmania’s shellfish aquaculture industry for over 20 years. Toxins produced by the algae can naturally accumulate in filter-feeding shellfish such as mussels and oysters. Harmful algal bloom research is a top priority for the Tasmanian wild capture and marine farming sectors, and Cawthron’s research is aimed at reducing the impact of paralytic shellfish toxins on Australian shellfish industries.

Getting it right to save lives

Cawthron is ideally placed to conduct the research. It has extensive research and experience in marine biotoxin chemistry, which is supported by New Zealand’s drive to establish a safe seafood industry through the government-funded Safe New Zealand Seafood programme. It analyses various New Zealand shellfish and seawater samples every week to find out whether they contain toxins or toxin-producing microalgae.

Gymnodinium catenatum, a bloom forming microalgae and known producer of paralytic shellfish toxins. 

“The analysis of paralytic shellfish toxins is something you really want to get right,” Dr Harwood says. “They have the potential to make you really sick, or potentially kill you, so testing and regulation needs to be very robust.”

Good management is the key

Dr Harwood says that while we can’t get rid of the algal blooms we can get better at managing harvesting areas as well as assessing shellfish toxicity and how the toxins will affect consumers.

“We can measure how much toxin is in the shellfish; that’s relatively simple,” Dr Harwood says. “What isn’t clear is the toxicity, or how that toxin affects people. This project will result in a better assessment of shellfish toxicity, and there will be more confidence about saying whether shellfish contaminated with toxin actually poses a human health problem or not.”

He says the next step is to publish the findings and gain international acceptance of the information so international regulatory bodies can make use of it.