Study: Climate change could make seaweed less appetising

Grazing from marine herbivores determines the amount of seaweed in the sea. Credit: David Roberts
Tuesday, 25 June, 2013

Changing ocean temperatures and acidity could make seaweed less palatable to marine crustaceans, a new study led by Associate Professor Alistair Poore has found.

The findings, reported in the journal Oecologia, suggest climate change may affect how much marine grazers eat, altering the ecology of environments such as coral reefs.

"These results indicate that, in addition to the direct effects on herbivore abundance, climatic stressors will affect the strength of plant-herbivore interactions by changes to the susceptibility of plant tissues to herbivory," Associate Professor Poore and colleagues write.

While a number of studies have shown that warmer waters can affect the abundance of predator and prey species, few have looked at the impact of marine herbivores on seaweed.

And fewer still have studied the combined impact of increasing temperatures and ocean acidification.

The team studied the effect of temperature and pH on the consumption of the brown seaweed Sargassum linearifolium by a tiny common shrimp-like herbivore called Peramphithoe parmerong, which lives within the plant.

A surprising finding was that temperature and pH affected feeding rates by changing the quality of the food.

A full report on the study can be found at ABC Science online.

UNSW Science media: Deborah Smith, 9385 7307, 0478 492 060,