Laura writes: “I am currently entering my second year of study of Environmental Science BSc at Teesside University. During my first year, I carried out a Student as researcher position with Ambroise, which was a fantastic opportunity to develop my skills as a researcher. Below is a description of my project as presented at the Tees Valley Nature Partnership annual conference in June 2019 hosted by Teesside University’s Ecology and Environment group.”
“This project sought to determine whether there was a link between the age of freshwater habitats and the diversity of resident molluscs. Data was collected across Cumbria, Norfolk and Glasgow to analyse biodiversity while a variety of historical mapping software was used to determine the approximate age of said sites.”“Sources used were: Oldmaps.co.uk, GoogleEarth and GIS. National grid references (NGR) were used to access historical maps of the area, which were compared in a GIS to determine the appearance of the water body. The times in which the water body first appeared in historical mapping were compared to that of previous maps to determine approximate age. Man-made water bodies had specific build dates, which were found by contacting various land managers and local bodies. Any water bodies that existed without change from the oldest available maps were recorded as 0 and they were assumed to be of natural origin.” “I found that younger ponds have a higher species richness on average. The opposite result was found for lakes as there is a apparent decrease in species richness with younger lakes. The oldest lakes show some of the highest species richness throughout the sample group, suggesting that more mature lakes yield the highest mollusc species richness.”
“There are many potential reasons for this trend in mollusc diversity in relation to age. For example, eutrophication and accumulation of sediments may be the reason for the trend in pond mollusc species richness. As sediments build up over time, there may be less available habitat.
Over time ponds may also experience encroachment from vegetation, particularly trees which may lead to eutrophication; building up over time and leading to a poorer water quality of which some mollusc species may be unable to tolerate.”
“Whereas, it may be that the lakes that have been established for a longer period have accumulated more mollusc species over time. This could be for a number of reasons such as: colonisation, establishment of plant species (food source and habitat) as well as the quality of the water and the maturity of natural water purification systems. Younger lakes may not have developed these yet and so cannot support the same number of species; particularly those more delicate and vulnerable to sudden change.”
“These data suggest that there is a correlation between the age of a water body and the species richness of molluscs. While older ponds decrease in biodiversity with age, lakes behave in an opposing manner.
The implications of this is a call for increased protection of older lakes as these harbour the highest diversity. Findings also suggest a reduction in richness with age in ponds may be down to accumulation of pollutants as well as sediments. This, too, may call for increased management to regenerate ponds, maintaining diversity.”
“Further research will be carried out on other organisms such as aquatic plants, beetles and dragonflies to determine any wider correlations.”
“Thank you to LTE for funding this research project and to Dr Ambroise Baker, Dr Alan Law and Dr Carl Sayer for help with research. Thank you also to NERC Hydroscape research project for providing biodiversity data.”