NUI Galway study sees success in seaweed science

Sabrine Donohoe

Sea lettuce has a high nutritional value and could be used as animal feed. Credit: Sabrine Donohoe

Selected types of sea lettuce could improve aquaculture and agriculture on Irish coastlines, according to a study by NUI Galway researchers.

Sea lettuce is a type of coastal green algae that is widely found around the world but is common on Irish shorelines. It is usually found on moderately exposed rocks and shallow waters.

The day to day growth pattern among sea lettuce is unique compared to plants which grow on land. The plant has a high nutritional value and could be used as animal feed.

Member of the Ryan Institute and School of Natural Sciences at NUIG, Dr Ronan Sulpice, was the leading author of the study.

“This study is an important stepping stone towards the development of modern breeding approaches for seaweed aquaculture,” said Sulpice.

The 50 strains of sea lettuce that were tested varied in growth and metabolism, with growth rates varying from 0.09mg to 0.37mg. The strains were collected from beaches in Galway, Clare, and other areas along the east coast.

The plants have higher growth rates at night compared to the day, using nitrates rather than starch and sucrose to sustain its growth. Starch and sucrose contributed to just 35 per cent of the carbon required to sustain the night growth in the sea lettuce strains.

The study found that a total of six amino acids may be the contributing factor to the high growth rates in sea lettuce.

However, The Irish Times Columnist Michael Viney wrote in 2017 that sea lettuce on Irish coastlines “smothers our polluted bays”. Viney referred to a study by the Ryan Institute which found harmful metals in the sea lettuce on Irish beaches.

The best performing strains of sea lettuce are yet to be selected by the Ryan Institute for testing under the current environmental conditions in Ireland.

Further studies aim to identify the genes responsible for high growth rates of the sea lettuce, using 300 strains of sea lettuce collected from across Europe.

The study was funded by the EU Horizon 2020 project, GenialG. Sulpice was contacted for further comment but was unavailable at the time of publication.


Sabrine Donohoe

Image Credit: Sabrine Donohoe