Assessing the Health of Gull Lake


Assessing the Health of Gull Lake


Emily Grubb

Host Organization

Gull Lake Cottagers Association, Helga Sonnenberg

Supervising Faculty

Tom Whillans, Biology

Reference Number





Gull Lake, Minden Hills


Environmental Science


Gull Lake is an inland lake located in Northern Ontario in Haliburton County. The Gull Lake Cottage Association (GLCA) is concerned with the overall water quality of the lake as there has been increased shoreline development. According to Karr and Chu (1999), biological monitoring, measuring and evaluating the condition of a living system, or biota, is the first step in protecting life in waters or anywhere else. Biological evaluations and criteria can redirect management programs towards restoring the maintaining the chemical, physical, and biological integrity of aquatic systems. Three sites were chosen along the lake from distance end to end and sampled using the kick and sweep method. Assessments of species richness, species composition, relative abundances of species, and feeding relationships among resident organisms are the most direct measures of determining biological conditions within Gull Lake.

Amphipods were found to be the most dominate species at each site, representing over 50% of the benthic community. Results from functional feeding group analyses revealed that all sampling sites are collector-dominated, representing almost 80% of the benthic community, and were composed primarily of Amphipods. Site 1 was found to have the highest species richness and abundance across the three sites. Sites 2 and 3 species richness and abundance are relatively similar and not far from that of site 1. Based on the results of the Hilsenhoff Biotic Index, water quality is "fair" as determined by macroinvertebrate species assemblages. Studies have found that recolonization of other macroinvertebrates was reduced when Amphipod numbers were high indicating predation or some form of competitive exclusion (Waters, 1964) which could potentially explain why there are such large numbers of Amphipods found across sites sampled on Gull Lake. It is important that factors (such as landscape-level factors such as land use/cover, surficial geology, and surface area or geographic factors such as latitude (Richards et al,. 1997)) are further looked into in order to develop the real reasons as to why Amphipods are in such high abundance within Gull Lake.



Emily Grubb, Assessing the Health of Gull Lake, 2013