The Department of Agriculture, Environment and Rural Affairs (DAERA) has said that excess nutrients from agricultural activities and wastewater pressures are “primarily” to blame for a growth of blue-green algae in Northern Ireland’s waters.

Blue-green algae has been detected in multiple locations across Northern Ireland, including Lough Neagh and Lough Erne, and can potentially produce toxins that may be fatal to livestock and pets.

“The key reason is that excess nutrients are entering our water bodies, primarily from agricultural land use activities and from waste water pressures,” it said in a statement to Agriland.

“Algal blooms occur naturally due to the combination of factors such as water temperature, water clarity, sunlight and nutrient availability.

“However, excess nutrients can compound blooms and lead to the growth of blue-green algae, exacerbated by invasive Zebra mussels leading to clearer water conditions.”

DAERA, as well as the Northern Ireland Environment Agency (NIEA), has been the subject of criticism on social media in recent weeks due to the water pollution incidences.

Lead singer of punk band The Undertones, Feargal Sharkey, has been active on Twitter regarding incidences of water pollution in Northern Ireland and Great Britain.

In one post, Sharkey agreed with a Twitter user that the department was “complicit in creating this ecological disaster”.

DAERA has said it is fully committed to protecting the environment and working with partners to ensure Northern Ireland’s waterways are healthy.

It said the pollution incidences in the lakes may see algae wash up on any part of the shoreline.

“Farmers and pet owners should ensure that animals do not have access to water that appears to be subject to a bloom, as the algae can potentially produce toxins that may be fatal to livestock / pets,” it said.

The department said it recognises that work must be done to improve water quality and reduce pollution in Northern Ireland, but said responsibility for this does not just fall on itself and the NIEA.

“Whilst it is recognised that significant pieces of work are progressing, improvements in water quality will take a considerable period of sustained effort over many years, and DAERA and NIEA cannot deliver this on their own.

“Every person in Northern Ireland needs to consider how their behaviour impacts on the water environment. We all have a part to play in this long-term effort to positively contribute to a sustained improvement in the status of our water bodies.”