Plants & Algae

 
Plants

Coastal plants are adapted to be able to withstand the extreme conditions of living on the coast. They must be able to cope with being rooted in what is often low nutrient, unstable substrate like rock crevices, sand and gravel, endure being immersed in salt water at high tide or fresh water from heavy rain and flooding and survive the often strong wind and sun which increase the effects of desiccation. Marram grass is a coarse grass which stabilises dunes with its creeping roots. Thrift is sometimes called sea pink although it can also have white flowers.

It is most noticeable during its flowering season between April and September, growing on rocky outcrops and sand dunes. Common glasswort or samphire grows in saltmarshes in the bare mud.

Algae

Algae are a diverse group of plant species ranging from phytoplankton, tiny primitive plants that live suspended in water, to large complex species such as seaweeds. Algae play a crucial role in the functioning of marine ecosystems. The larger seaweeds have been used as fertilizer and are commercially harvested.

The range of microscopic algae that occurs in Northern Ireland is not known but is likely to be vast. Larger species are better known and include the macro-algae or seaweeds, which occur around our coasts. In total, about 500 species of marine macro-algae have been recorded in Northern Ireland. Many algal species are vulnerable to changes in water quality and a number of species have probably declined or even disappeared from Northern Ireland because of increased eutrophication.

Introduced marine algae also pose a significant threat with the highly invasive wireweed having become established in Strangford Lough in the last few years.