Printer Friendly

'...It's like finding the grass has suddenly been replaced by bushes' CHANGES TO SEA ALGAE SPARK FOOD CHAIN FEARS.

Byline: GRAHAM HENRY

DRAMATIC changes to sea algae could have harmful knock-on effects for human health and the rest of the food chain, research from Welsh scientists has revealed.

Findings published by academics from Swansea University have uncovered huge changes in the make-up of North Sea and North Atlantic Ocean algae in the space of five years.

The changes seen in algal blooms - shifting from dinoflagellate to diatom algaes - could mean a build-up of toxins on feeder organisms.

But the health repercussions for humans if they were to eat shellfish that ingest the toxins are currently unknown.

The research also concluded that it was likely to go higher up the food chain to impact on much larger animals, such as fish and whales.

The findings have been published in the journal Nature Climate Change.

Professor Graeme Hays, from Swansea's Department of Biosciences in the College of Science, and an author in the study, said: "Imagine looking at your garden one morning and finding that the grass had suddenly been replaced by bushes.

"This may sound far-fetched, but we have found changes of this magnitude in the biology of the North Atlantic, with a dramatic switch in the prevalence of dinoflagellates to diatoms - two groups which include many of the microscopic planktonic plants forming the base of the ocean's food chain."

The findings of Prof Hays and fellow Bioscience colleagues - PhD students Stephanie Hinder and Emily Roberts and Professor Mike Gravenor, along with colleagues from Plymouth University - revealed that the change was partly driven by increases in water temperature, a well-known symptom of global warming.

But there was the unexpected discovery that the plankton shift was "strongly driven" by an increase in windy conditions in the North Atlantic region over the past 50 years.

The diatoms, which appear to thrive in the windier conditions, have increased in the last five years, while dinoflagellates have "almost disappeared", Prof Hays said.

"This increase in windiness is something that is often overlooked," said Prof Hays.

"In the ocean, windiness promotes vertical mixing of the water, which in turn has profound impacts on surface nutrients levels and the vertical distribution of plankton.

"In general, windier conditions seem to favour diatoms over dinoflagellates.

"The new patterns show major shifts in the distribution of economically important species known to cause harmful effects through toxin poisoning.

"The wider implications of this discovery are not fully known, but the switch from dinoflagellates to diatoms is likely to have propagated up the food chain to impact much larger animals such as fish and whales.

"There is also a possible threat to human health where, for example, biotoxins are ingested by filter feeding organisms, accumulate within their flesh, and then are transferred higher up the food chain to human consumption level, for example through the consumption of shellfish."

He said that the changes in algal blooms may have serious repercussions further up the food chain, as everything was dependent to some extent on the base of the chain.

He said: "There has been a profound change at the bottom of the chain, it is such a huge change that it is hard to envisage that there could not be knock-on effects.

"Our data is a strong case pointing to the effects of changes in the environmental conditions, and what we know about the two groups are that they survive to very different extents in windier conditions - diatoms do well in windy conditions, while dinoflagellates do not.

"The toxin effect is not known in great detail, as there are 'toxic' forms of both groups, and both toxic and non-toxic forms appear to be affected the same way.

"But with toxic forms, species further up the food chain feed on them and accumulate them.

"The most classic form of this might be for human health, through eating shellfish such as mussels that feed on it."

CAPTION(S):

[bar] Monitoring equipment is placed in the North Sea [bar] Scientists from Swansea University have been monitoring plankton like eucampia zodiacus, above
COPYRIGHT 2012 MGN Ltd.
No portion of this article can be reproduced without the express written permission from the copyright holder.
Copyright 2012 Gale, Cengage Learning. All rights reserved.

Article Details
Printer friendly Cite/link Email Feedback
Publication:Western Mail (Cardiff, Wales)
Date:Feb 13, 2012
Words:666
Previous Article:WRU give Gatland a Lions nod.
Next Article:QUIZ OF THE DAY.

Terms of use | Copyright © 2018 Farlex, Inc. | Feedback | For webmasters