LE3 .A278 2019

2019

Spooner, Ian

Acadia University

Bachelor of Science

Honours

Geology

Earth & Environmental Sciences

This project focused on a lagoon and barrier beach complex known as Sitmu’k in Pictou Landing, Nova Scotia. This dynamic system has historically been of importance to the community of Pictou Landing First Nation for recreational and cultural purposes. Over the past few decades there has been significant landscape change and human activity in the area that has inhibited use and enjoyment of this valued landscape feature. Issues identified include water quality degradation, and the legacy of historical industrial impacts. The purpose of this thesis was to determine influences of environmental change through time in Sitmu’k by conducting a paleolimnological assessment of the geochemical changes recorded in the sediment archive. To determine anthropogenic and geogenic influences on Sitmu’k, the data was compared to nearby reference sites. Geochemical analysis was conducted using x-ray fluorescence (XRF), total carbon (C), total nitrogen (N) and stable isotope analysis (δ13C, δ15N). Total C/N and isotope analysis indicated that carbon input at Sitmu’k is predominantly from marine sources. XRF analysis indicated that metal concentrations were below sediment quality guidelines and reference site averages. Water quality tests were conducted throughout the summer 2018 season to determine current environmental conditions in the lagoon. Water quality data indicated gradual but persistent increases in temperature, total coliforms, nitrate and total phosphorus from May to August. Through air photo and satellite imaging, it is apparent that the barrier, Lighthouse Beach, is migrating towards mainland. Sediment redistribution from the beach into Sitmu’k has resulted in shallowing and restricting which is causing higher water temperatures, poor circulation and elevated nutrient and coliform levels. Collectively the data suggest that much of the water quality degradation noted in the past 50 years is likely due to natural landward migration of the barrier-beach complex, resulting in reduced water depth and circulation coupled with increased local anthropogenic land use; the data did not indicate significant industrial impact at the site.

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https://scholar.acadiau.ca/islandora/object/theses:3297