RESEARCH suggests that climate change is posing a serious threat to habitats on Lower Lough Erne’s Cruninish Island.

According to a recent Conditional Assessment Report  for the island, which is deemed an Area of Special Scientific Interest (ASSI), “significant pressures” are leading to a gradual deterioration in the overall habitat of quality of the Island. 

Pressures include overgrazing, poaching and the invasion of agricultural species, and the report warned that without urgent intervention, the island’s “fragile ecosystem” will continue to decline.

One of the most significant threats identified in the report is the trampling and destruction of soil and vegetation by heavy livestock, aka poaching. The main culprit are cattle.

According to a specially-commissioned report in 2022, several areas of Cruninish have been significantly impacted by poaching, particularly in once species-rich wet grassland areas.

Loss of habitat quality has been observed at several points. One area, previously regarded as a species-rich fen meadow. has been downgraded due to heavy grazing and trampling.

Similarly, a once diverse rush pasture was forced to be reclassified in 2022 as “species poor”.

Well-intentioned grazing patterns have had a negative impact, research shows. 

The current grazing regime on the island, designed to manage habitat for breeding waders, has seen high-pressure grazing, with cattle proving too heavy for waterlogged soils.

The main victim of this is purple-moor grass and rush pastures, with loams now dominated by Yorkshire Fog and Daisy bells, which are regarded as "agriculturally favoured" species. This is an indication of poor biodiversity management, the report claims.

Data on the proliferation of these weeds paints a sobering picture.

In a 2022 study, daisy was recorded on 50 per cent of plots on Cruninish, with the amount of this species hitting “a level of concern”.  

Meanwhile. Creeping Thistle, which was not previously recorded in 2016 or 2005, was found in 13 per cent of plots in 2022. This marked arking the first time this invasive agricultural species had been recorded on the island.

The cause for this boom in invasives is clear: agricultural plant species are outcompeting native plants, and in the process reducing biodiversity and altering the dynamics of the ecosystem.

The advent of these species comes at the cost of others. 

The report explores a marked decline in herbaceous and sedge species – key indicators of habitat quality – as another critical issue on Cruninish.

In 2022, herb and sedge cover had fallen to 37 per cent, compared to 51 per cent in 2016 and 2005.

This level of cover barely falls within the acceptable range for habitat conditions (35 to 90 per cent), and is a clear indication of a downward trend.

The report warns: “The loss of herb and sedge species is particularly worrying as these plants support a variety of wildlife, including pollinators and invertebrates that are crucial for maintaining the ecosystem’s health.”

Although not explicitly detailed, the report also strongly hints at the indirect impacts of climate change on Cruninish.

This is through changes in seasonal water levels and wetter conditions that may be exacerbating poaching and overgrazing issues.

“Wet conditions in particular make the soil more susceptible to poaching by cattle, causing more damage during wetter periods,” the author of the report said.

“This aligns with broader concerns about how climate change may increase the frequency and severity of extreme weather events, leading to longer et seasons or more intense rain events that could further degrade the habitat.”

Despite the multiple challenges, the report does highlight some positive management practices currently happening on Cruninish Island, which could be enhanced in the coming years. 

The Royal Society for the Protection of Birds (RSPB) has been actively managing the island with conservation in mind, with one successful initiative seeing the use of a ‘Soucy Tractor’ (a tractor which travels on tracks) and flail mower.

This has been in use since 2018 to manage rush dominance, and particularly bulky rush species that tend to overgrow and reduce habitats for breeding waders (birds).

There is evidence that this flail mowing technique is having a positive impact on the island, the report outlines. One survey plot showed an improvement in habitat condition since 2016, shifting from a “species poor rush pasture” to “jointed rush-dominated pasture” in 2022.

The report also provides several recommendations to address the mounting pressures on the Island.

An urgent need to revise the grazing strategy on the island has been identified, including reducing the number of grazing animals, shortening the grazing period, and even switching to lighter breeds of cattle which could be removed during particularly wet periods.

It is also recommended that a tight eye is kept on invasive species such as Creeping Thistle and Thistle. Calls have been made to the Northern Ireland Environmental Agency (NIEA) to implement control measures to prevent these species from further dominating the habitat.

Emphasis has also been placed on building on positive management practices, and flail mowing improved by the lifting of mulch in order to enhance biodiversity. 

Care must also be taken to avoid mowing in sensitive areas, such as dry banks and wetter parts of the island, where habitats are susceptible to damage from heavy machinery, the author of the report said. 

The report concludes by reiterating the need for “urgent intervention”.

“With the right management actions, there is hope that the habitat can be restored and protected for the future”, the report said.

“However, without urgent intervention, the island’s fragile ecosystem may continue to decline, leading to the loss of its unique biodiversity and natural character.”