News Archive

You may not know it, but you are using and eating products with seaweed in them every day.

A derivative from seaweed called carrageenan is used as a thickening or stabilising agent in dozens of everyday products including toothpaste, lipstick and diet soft drinks. The farming of seaweed is a multi-billion dollar industry and it is growing.

Most of the world's commercial seaweed crop is grown in Indonesia and the Philippines, where it provides a livelihood for thousands of families. But the impact of the farming on coral reefs, seagrass beds and reef fish communities is not known, although it is suspected that the implications are not good for biodiversity and ecosystem function.

James Hehre, a PhD candidate from the University of British Columbia, has won an Australian government Endeavour Research Fellowship to conduct his research for six months at UWA's Centre for Marine Futures.

"I met up with Jessica Meeuwig (Director of the Centre) and I was keen to use some of the analytical and software techniques she has developed so she suggested I apply for an Endeavour Award to come here for a while," James said. "It's great to be able to build on the networks between UWA and UBC (where Professor Meeuwig is an Adjunct Professor)."

He has spent months on the Danajon Bank in the central Philippines, where the villagers farm seaweed in the middle of a world centre for reef fish biodiversity.

"On the one hand, it's a good way for these people to make a living, on a subsistence level. But on the other hand, most of it is done on shallow coral tidal flats and seagrass beds. Already 60 per cent of the coral on the planet is under threat. We expect that, by 2050, 100 per cent will be under threat," James said.

"Nobody has looked at the implications of big scale farming. When you put all the small subsistence farms together, it takes up a big area.

"But you have to be pragmatic: people have to be able to feed themselves. The question I am trying to answer with my research is how do we manage our resources correctly? And how do we Endeavours to balance livelihoods and fragile ecosystems decide what to save, how to save it, and where do we put the seaweed farms?"

He said the natural habitat of the Danajon Bank had already been degraded through trampling and fishing practices using dynamite and cyanide. "What happens when you put an agricultural matrix on top of that?

"If the most degraded parts of the reef are beyond rehabilitation, do we suggest they put the farms there and save what parts of the reef we can?

"Another idea that occurs to me is that the farms may act as a de facto protection area. Nobody is going to be dropping dynamite on their neighbours' seaweed farms. So perhaps these areas, under cultivation, have a greater chance of recovery?"

James said Professor Meeuwig's technology was helping him to look at coral cover relative to seaweed farming, and the positive and negative effects on fish in these areas.

"The most commonly eaten fish there is the rabbit fish, which feeds on seaweed.

"I am using UWA's stable isotope facility to tell me how much and what kind of seaweed the rabbit fish are eating.

"Perhaps the seaweed farms could serve a double benefit and underpin a successful fishery?"

James hopes that during his time at UWA, he will be able to understand the dynamics of the ecosystem on the Danajon Bank and find answers to his questions.

Published in UWA News , 30 April 2012