University of Limerick's Biotic Index - Protecting UL's Freshwater Biodiversity

The Sustainable Shores team recently conducted ecological assessments of the University of Limerick's freshwater stream habitats. The disappointing results highlight a need for better conservation measures to be put in place on campus.

Aquatic snails and beetles photographed in a stream on the University of Limerick campus.

As part of the University of Limerick Sustainability Challenge, the project lead Éabha Hughes and supervisor Dr. Audrey O'Grady recently conducted ecological assessments of the university's freshwater stream habitats. As part of helping UL tackle United Nations Sustainable Development Goal 14: Life Below Water, the project needed to investigate the health of the local environment and establish a baseline from which to improve biodiversity and conservation efforts.

The assessments consisted of a biodiversity survey, which looked at the overall species present in freshwater habitats on campus, and two Q-Value biotic index assessments. A Small Stream Risk Score was then assigned to various campus habitats.

A biotic index is a measure of the biological quality of a waterway based on the diversity and abundance of certain organisms. The Q-Value Biotic Index gives a measure of ecological health based on the known tolerances of different freshwater macroinvertebrates to pollution. These tiny organisms are excellent indicators of water quality because some species are extremely sensitive to changes in pollution levels, while others are extremely tolerant.

The Q-Value ranges from Q5 which is pristine, unpolluted waters, to Q1 which is seriously polluted. By analyzing the presence and abundance of specific macroinvertebrate species, Sustainable Shores can assess the overall health of the university's stream habitats.

The Small Stream Risk Score (SSRS) is another method of assessing freshwater habitats. The SSRS does not directly assess whether a stream is polluted or not however, it only assesses the risk factor present for a given habitat.

An aquatic snail and Stickleback fish from a stream on the University of Limerick Campus.

The initial species diversity assessment revealed over 30 different species of macroinvertebrates which could be collected and identified with relative ease, but only one vertebrate species. Many of the campus species identified and recorded will be included in the Sustainable Shores: Ireland's Life Below Water book.

Unfortunately, the other ecological assessments found low levels of diversity and abundance of pollution sensitive macroinvertebrates, which suggests that the water quality in campus habitats is poor. The Q-value for the first habitat surveyed was estimated to be Q2-3 (moderately polluted) or lower due to the presence of certain species, with a Small Streak Risk Score of 1.6. A score of lower than 6.5 indicates that a habitat is likely at risk of pollution. These results indicate that the stream habitats are likely at risk of pollution.

The second habitat assessed achieved a better Q-value of Q3-4 (slightly polluted). However, a low Small Streak Risk Score of 4.8 still indicates that this habitat is at risk of pollution.

Despite disappointing results, the data from these assessments can now act as a baseline for water quality and species diversity on the University of Limerick campus to continue monitoring and improving habitats.

Aquatic snails on algae photographed in a stream on the University of Limerick campus.

The result of these assessments highlights the importance of monitoring and protecting our local waterways, especially in the context of SDG14, which aims to conserve and sustainably use life below water.

The National Biodiversity Data Centre in Ireland encourages citizen science initiatives, and our biotic index assessment is a great example of how students can contribute to the monitoring of local biodiversity. It only takes a few minutes to kick sample a stream, so why not give it go?

It is hoped that Sustainable Shore's findings will raise awareness about the importance of protecting our waterways and encourage further action to mitigate pollution and protect our local ecosystems. Through ongoing consultations with the university, Sustainable Shores will be using the data to inform new, sustainable policy and initiatives to protect our freshwater habitats. By working together and taking action, we can ensure that our natural resources are sustainably managed for future generations.