Analytical Science news

Cawthron's biotoxin team behind the revolutionary new food safety test. Pictured clockwise from top: Tim Harwood, Carl Sheehan, Bryan Stokes, Mike Boundy, Catherine Moisan, Andy Selwood (absent)
21 March 2016

Revolutionary new seafood safety test

Consumers can feel even more secure that New Zealand shellfish are safe to eat thanks to a revolutionary new food safety test developed by scientists at Cawthron Institute and the UK's Cefas (Centre for Environment, Fisheries & Aquaculture Science).

The new test for Paralytic Shellfish Toxins (PSTs) can be used on a variety of commercial shellfish species and is quicker, simpler and more sensitive than the previous test method.

Industry thrilled

Aquaculture farmers and regulators are thrilled with the innovation.

"We think it's world-leading, and it's really improved our credibility among our customers and the aquaculture and shellfish industry worldwide," New Zealand Oyster Industry Association committee member and Biomarine chief executive Jim Dollimore says.

He says the development will avoid situations in the past, where levels of some toxins have been sufficient to close shellfish harvest areas and trigger much more expensive testing – which always came up negative, meaning production was put on hold unnecessarily.

Serious health risk

PSTs are an internationally regulated class of marine biotoxin. Produced by microscopic algae, these toxins can naturally accumulate in filter-feeding shellfish such as mussels, oysters and scallops. They pose a serious human health risk, and can lead to prolonged closures of commercial and recreational shellfish harvest areas, and financial loss to industry. Tests are conducted regularly to protect public health and ensure access to export markets.

"Although several methods exist to monitor these toxins, they remain time consuming and complex," Cawthron marine toxin chemist and Safe New Zealand Seafood programme co-leader Dr Tim Harwood says.

International collaboration

The new testing method, in development since 2013, was a collaborative effort between scientists from the Cawthron Institute and the UK's Centre for Environment, Fisheries, and Aquaculture Science (CEFAS). It uses LC-MS (liquid chromatography-mass spectrometry), an analytical chemistry technique that separates, detects, and identifies particular compounds of interest.

"Through research we've been doing as part of the Safe NZ Seafood programme we knew we had something to offer to overcome these issues - we could provide a test that was more accurate, faster, and would benefit the New Zealand seafood industry."

Sound science

Ministry for Primary Industries specialist adviser for seafood Brian Roughan says the test has certainly achieved that.

"It's sound science and a testament to the calibre of scientists at Cawthron who coordinate this programme and developed this method."

Aquaculture New Zealand chair Bruce Hearn says Cawthron's work is "outstanding".

"This group of people dealing with biotoxins have always been right up dealing with the world's best, and have in fact led the world. Chemical testing for biotoxins was a world first and they've continued it on, and this will become the world standard once again."

Cawthron has validated the test's use and obtained approval from the Ministry for Primary Industries to use it as part of the New Zealand marine biotoxin monitoring programme.

Taking it to the world

"We would like to get international acceptance for the method," Dr Harwood says. "True success is that other labs around the world acknowledge how good it is and start using it."

To do that they have to go through a multi-lab validation study, meaning different labs from around the world test the method, analyse provided samples blind, and then report the results back to Cawthron, where they are collated and reviewed.

"If it's a robust method, there should be good agreement between the results," Dr Harwood says.

Jim Dollimore says the test is clearly better than the "medieval" methods around in the 1990s.

"To be there with New Zealand leading it is an excellent initiative, proving New Zealand aquaculture is innovative and a leading player in food safety issues."

Find out more:

Contact Dr Tim Harwood, Safe New Zealand Seafood programme leader, Cawthron Institute
Phone:+64 3 548 2319 ext 325