Southampton Island Marine Ecosystem Project (SIMEP)
Vulnerability to a particular pressure is largely dependent on direct resilience of the physical, biogeochemical, and biotic components (structure) and processes (function) that drive productivity and how people make use of a particular service, including its management. At the base, we lack a strong understanding of processes that control ecosystem productivity around Southampton Island. Overwintering of marine mammals in the area is made possible by the ice pack remaining unconsolidated throughout winter due to wind and tidal forcing. It is hypothesized that the same physical processes are responsible for greater primary productivity in these regions, supporting a larger and more energy-rich food web. Such processes could also be fairly resilient to climate perturbations and associated impacts, supported by archaeological evidence of human presence on the island during the Medieval Warm Period (950-1250) and Little Ice Age (1300-1850). In fact, Southampton Island is included in the southern reaches of the proposed “core area” of cultural development–a concept first proposed by McGhee (1976)–which saw continuous occupation by Palaeo-Eskimo peoples (i.e. Pre-Dorset and Dorset) throughout their 3500-year existence. Given the stability and reliable predictability of the marine ecosystem in the core area, populations living within it not only survived major climatic events, but thrived, leading to cultural and technological innovation that spread outward to adjacent locales . The hypothesized processes to explain the enhanced ecosystem production and their locations include: 1) Winter pre-conditioning of surface waters associated with large polynyas that form along the western coasts of Foxe Basin and Hudson Bay. Also known as ice factories, these polynyas produce dense salty brine that can sink, ventilating deeper waters while associated mixing replenishes surface nutrients. 2) Tidal mixing along the shoaled and constricted waterways of Rose Welcome Sound, Frozen Strait and Fisher Strait. Some of the world’s largest tides are observed in the HBC and as they move water back and forth across constricted straits, currents and mixing intensify, increasing water mass exchange and nutrient supply in the area. 3) North and west of Southampton Island, water masses originating in Atlantic (via Hudson Strait) and Pacific (via Foxe Basin) oceans are mixed and modified, and greatly influence production as large inventories of new nutrients are imported to the region. In particular, Foxe Strait and east into Hudson Strait have been identified as zones of greater primary production. In order to improve our predictive capacity of ecosystem vulnerability, we will investigate the following specific objectives.
(i) Ecosystem services: We will examine human use of the marine environment from the Dorset period to the present.
(ii) Ecosystem structure and function: We propose to establish an improved understanding of processes controlling ecosystem productivity around Southampton Island culminating in the first food web-based understanding of the northwest HBC ecosystem.
(iii) Pressures: We will examine the relative links of the marine ecosystem to climate sensitive variables (e.g., ice cover, ocean temperature) as well as quantify the regional state and impact of OA.