An investigation into the causes and consequences of variability in community structure in a large freshwater loch

Macleod, Hazel (2004) An investigation into the causes and consequences of variability in community structure in a large freshwater loch. PhD thesis, University of Glasgow.

Abstract

In order to explore the causes and consequences of variability in community structure in Loch Lomond, submerged macrophyte biomass values were assessed. The introduction of non-native species and changing nutrient levels are identified as threats to the macrophyte communities of the loch. Loch Lomond is diverse in habitat and this is evident in fish and invertebrate community structure. For a single fish species, there was evidence of between site variability in a number of aspects of its ecology at relatively small spatial scales making Loch Lomond an ideal location for the investigation of the consequences of variability in community structure. An exploration was also made into a novel technique for the estimation of trophic niche width by use of the variance in stable nitrogen isotope signatures (delta15N) which lead to the conclusion that there are significant potential strengths in using as ameasure of trophic niche width. The delta15N technique was used to explore a number of hypotheses related to the effect of community structure on trophic niche width, leading to the conclusion that the physical factors of a study site were more important than community structure in controlling trophic niche width of ruffe in Loch Lomond. Finally, the consequences for individuals of modified trophic niche width were investigated and lead to the conclusion that in Loch Lomond there was no clear relationship between trophic niche width and individual fitness.

• Item Type: Thesis (PhD)
• Qualification Level: Doctoral
• Additional Information: Adviser: Colin Adams
• Keywords: Ecology, Limnology, Aquatic sciences
• Date of Award: 2004
• Depositing User: Enlighten Team
• Unique ID: glathesis:2004-74200
• Copyright: Copyright of this thesis is held by the author.
• Date Deposited: 23 Sep 2019 15:33
• Last Modified: 23 Sep 2019 15:33
• URI: https://theses.gla.ac.uk/id/eprint/74200