2013 The International Institute for Sustainable Development
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www.iisd.org ©2013 The International Institute for Sustainable Development **Subject to final design and copy edit However, the many less obvious and less predictable changes in the system are likely to be equally, if not more, important.
Some of the complex linkages and components of the Hudson Bay marine system are illustrated in Figure 4. The ice cover serves as a barrier that insulates the sea surface from the atmosphere and its presence or absence has much to do with how the system functions. While many ice-dependent species will undoubtedly be affected, the complex systemic nature of the ecosystem components and linkages will inevitably lead to surprises where there will be major winners as well as major losers. This figure is also intended to provide a perspective on the aspects that are most directly observed and valued by aboriginal hunters and gatherers, as well as other aspects that are typically used by Western scientists to help understand causes and relationships.
Figure 4. Selected pathways and valued ecosystem components within the Hudson Bay marine ecosystem. Predictions made in the recent Arctic Climate Impact Assessment suggest that the Arctic will be dramatically altered as a result of global climate change, that the warming trends that have occurred in Volume, extent and safety of ice cover Snow Light
Wind Temperature Precipitation Evaporation Runoff Nutrients Mammals Birds
Fish Salinity Ice Algae Currents circulation Phytoplankton Periphyton Seston
Zooplankton Benthic
invertebrates Temperature Tides Major components and connections within the Hudson Bay Complex. Blue components and connections indicate TEK emphasis Waves
Reflected energy
www.iisd.org ©2013 The International Institute for Sustainable Development **Subject to final design and copy edit the Arctic will continue and that temperatures, especially in winter months, are likely to be many degrees warmer than in recent decades
As a consequence of sustained effort, contaminants in Arctic food chains have been recognized as a global challenge that warrants a global response. Indian and Northern Affairs Canada led much of this effort, mobilizing research and monitoring efforts to assess the nature, scope and significance of the contaminants threat. The active participation of northerners and the leadership roles played by Inuit leaders were especially important in building public and political support. The Stockholm Convention is an international recognition of the need for coordinated global actions to address the long-range atmospheric transport of persistent organic pollutants. 6 On our Understanding of the Bay: Recognizing Ominous Signs Without Knowing Where We Are Headed
Many scientific disciplines have contributed to our understanding of the Hudson Bay, and the satellite observing systems have provided a means of watching selected parameters over both short and long periods of time. They also make it possible to watch some of what is happening over vast areas. Periodic cruises of research vessels (usually in August, September and October) provide a means of validating the satellite Earth observations as well as opportunities to carry out detailed investigations of oceanographic conditions along specific transects.
Several major compilations of research on the Hudson Bay system have recently added substantially to our understanding of the Hudson Bay Complex. Peter Sly’s 1995 comprehensive review of human impacts on the Hudson Bay system is a very useful basin-wide summary. Stewart and Lockhart (2005) provide an encyclopedic review of research on Hudson and James bays while Stewart and Barber (2010) provide a summary of the ocean-sea ice- atmosphere system of the Hudson Bay Complex.
Over countless generations, Inuit and Cree have depended upon their practical knowledge of the sea and coastal regions. Their TEK of the coastal zone, sea-ice conditions and the wildlife that are harvested is another source of complementary understanding. This knowledge provides a common-sense perspective on both the short-term and long-term changes that may be occurring in the Hudson Bay Complex. Voices
knowledge of elders, hunters, trappers and others who have lived in the Hudson Bay area.
www.iisd.org ©2013 The International Institute for Sustainable Development **Subject to final design and copy edit Hunters from Sanikiluaq and others who process the animal skins have observed that the condition and quality of pelts of the seals that they are harvesting from around the Belcher Islands has declined. They have also noted major changes in stomach contents of these harvested seals. They can speculate as to whether or not these changes are associated with changes in the ice regime, with high winter discharges of freshwater into James Bay, or a manifestation of climate warming. Similarly, Western scientiss can document changes in the feeding behaviour of marine waterfowl and link these to changing ice conditions and regional warming (Mallory, Mallory, Loseto, & Ferguson, 2010).
The Hudson Bay Complex is a very large, diverse and remote ecosystem that is very difficult to study, especially during the winter months when it is ice covered. Research initiatives have gathered information outside the usual August–October sampling window, but these initiatives have typically been spatially very restricted, often to James Bay, southeastern Hudson Bay and the Nelson and Churchill River estuaries. Generally, the scientific initiatives have had a local focus and have addressed manageable and narrowly defined research questions. While these research initiatives provide useful insights, their findings are difficult to compare and are of limited value for extrapolating over space and/or time. They are, similarly, of limited value in assessing the overall implications of climate warming on the marine system. Our very limited ability to document and assess the cumulative effects of multiple and diverse stresses on the overall system is a major shortcoming that limits our capacity to anticipate, plan and adapt to the future.
For some parameters—such as ice cover, stratification, salinity and temperature—it is likely that models of the system may be the best available means of examining the interrelationships between these and other characteristics of the Hudson Bay Complex. Nevertheless, real data from the system, especially for seasons that are especially data-sparse, are essential to validate and refine the models developed for the system. Joly et al. (2010) have coupled a very promising sea-ice-ocean model of the seasonal cycle in the Hudson Bay Complex (Saucier et al., 2004) with GCMs as a means of estimating future conditions in the system.
Documenting and assessing the cumulative effects of hydroelectricity developments, especially in combination with one another and with other major developments—all in the context of climate change/warming—is a specific challenge that begs for attention. Common sense tells us that project-by- project assessments can, at best, only provide a sense of the incremental effects of the latest project. The Hudson Bay Complex has a downstream, downwind problem. The diversion and regulation of rivers clearly have an impact on the timing, locations and magnitude of river runoff (Déry et al., 2011). Upwind atmospheric loading of contaminants is related to contaminant levels in the Hudson Bay food web. The cumulative effects of the long-term greenhouse gas loading into the atmosphere has implications for global climate and is apparently a major driver of climate warming signals from the Hudson Bay region. Yüklə 0,96 Mb. Dostları ilə paylaş:
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