www.iisd.org
©2013 The International Institute for Sustainable Development
**Subject to final design and copy edit
2 Long-Term Climate Change Trends in a Highly Variable System
Climate change is not new to the Hudson Bay Ecosystem. Dramatic seasonal changes in temperature, as
well as interannual differences in air and sea
temperatures and in the nature, extent and duration of the
sea ice cover are commonplace. Periodic interdecadal warming and cooling periods occur and are also
features of this unique ecosystem. What are, however, unprecedented are the speed, magnitude and
significance of the climate changes that have occurred and are predicted to occur in the foreseeable
future. In essence, we now have undeniable evidence of a persistent and probably accelerating warming
trend that is being transposed upon a dynamic and variable system that has, until recently, fluctuated
within a predictable range.
The changes occurring in Hudson Bay and elsewhere in the Arctic are unlikely to be simple extensions of
past trends. It is important that serious effort be devoted to understanding and preparing for a future that
is likely to be fundamentally different from anything previously experienced. The scale and significance of
changes that are occurring and that can be reasonably predicted to occur in the future will almost certainly
lead to a fundamentally altered marine ecosystem. This shift will in turn present a host of unprecedented
cultural and economic challenges (and opportunities) for the aboriginal peoples that have lived with and
harvested resources from the system. The safety and predictability of the sea ice is a major concern for
Inuit hunters (Laidler et al., 2009). It is essential that Hudson Bay’s past, present and (especially) future
become more of an issue for Canada and Canadians. The Hudson Bay Complex is huge, but it is also a
vulnerable ecosystem that is the vanguard of a high-stakes, uncontrolled planetary experiment.
Major hydroelectricity projects, especially in Quebec and Manitoba, are fundamentally altering the
seasonal flow patterns in regulated rivers. The natural spring freshet no longer occurs in the La Grande
and Nelson Rivers, the two largest rivers discharging into the system. Instead, the maximum discharges
now occur in winter months (Déry, Miynowski, Hernandez-Henriquez, & Straneo, 2011). The implications
of altered discharges from these huge rivers on the circulation, stratification and mixing of freshwater and
marine waters on biological productivity of Hudson Bay, Hudson Strait and the Labrador Sea are not very
well understood.
While communities along the coast of the Hudson Bay Complex are increasingly concerned with the
changes that are taking place along their coastlines, this local concern is not widely shared by Canadians
in the rest of the country. Generally the Canadian public has shown little interest or concern as to the
scale and significance of existing trends and projected future conditions in the Hudson Bay marine
www.iisd.org
©2013 The International Institute for Sustainable Development
**Subject to final design and copy edit
ecosystem. Similarly, there is little understanding of the human-induced stresses that are driving many of
these changes to the system. Climate change, the cumulative impact of some of the largest hydroelectric
developments on earth, and the long-range transport of chemical contaminants to the region are three
major drivers of change.
Public concern, where it does exist, has focused primarily on the polar bear and its vulnerability to climate
warming and, to a lesser extent, contamination through the bioaccumulation of contaminants in the
marine food web. Excellent documentaries such as Polar Bear Fever have helped to make the polar bear
a very important symbol of the threats associated with climate warming. Changes in the ice regime of the
Hudson Bay Complex will clearly affect polar bear populations and other ice-adapted species such as the
ringed seal, but changes in ice cover will also have other major far-reaching consequences for the
chemical, physical and biological oceanography of the Hudson Bay marine ecosystem.
A challenge will be to focus greater public, political and scientific attention on the need to understand the
full scope of the stresses on, and the changes to, the Hudson Bay regional ecosystem. In so doing, it is
hoped that more Canadians will become better acquainted with the often unique challenges and
opportunities that are likely to arise in response to the changes in the world’s largest seasonally ice-
covered inland sea. An enhanced understanding of what is happening to the Hudson Bay marine
ecosystem is a prerequisite to the making of more informed decisions concerning the conservation,
protection and use of this magnificent ecosystem.
The Arctic Climate Impact Assessment (ACIA, 2005) indicates that the Hudson Bay region is likely to warm
at rate far exceeding the global average. Satellite surveillance is enabling scientists to track changes in ice
cover, sea-surface temperatures, and the timing of ice break-up and freeze-up over the entire region.
Locally, generations of Inuit hunters and trappers have relied on the coastal ice and their knowledge of
this habitat to enable them to safely hunt the marine mammals associated with the ice. Their observations
of coastal ice conditions as well as the changes that they see in the abundance, condition and foods of the
animals that they harvest provide a sense of what is really at stake with the declining ice cover that is now
being tracked by satellite.
These local observations, traditional ecological knowledge (TEK) of aboriginal observers, are increasingly
seen as being an important complement to Western science. McDonald, Arragutainaq and Novalinga
(1997) provide an excellent synthesis of the observations of Inuit and Cree living in coastal communities
around the Hudson Bay Complex. The knowledge of the ice and snow conditions is particularly insightful.
More recently, Feinup-Riordon and Carmack (2011) examine a number of ways in which shared
knowledge of sea ice and coastal swells can benefit both local communities and scientists working to