Hynes Lecture 2010
2010- Professor Stuart Bunn, Ph.D.
Prof. Bunn co-author of Global threats to human water security and river biodiversity released in Nature September 30, 2010.
Lectures
Wednesday, October 20th - Public Lecture, Balancing water needs for humans and nature, UNB Saint John campus, 7 pm, Hazen Hall Lecture Theatre. Video of lecture.
Friday, October 22nd - Science Lecture, Using stable isotopes to understand river foodwebs. UNB Fredericton campus, 3 pm, Room 146 Bailey Hall.
Professor Bunn is the Director of the Australian Rivers Institute at Griffith University in Brisbane. His major research interests are in the ecology of river and wetland systems with a particular focus on the science to underpin river protection and restoration, including the assessment of environmental flows and aquatic ecosystem health. Stuart has extensive experience working with international and Australian government agencies on water resource management issues. He is the Chair of the Scientific Advisory Panel for the Lake Eyre Basin Ministerial Council, Deputy Chair of the Scientific Expert Panel for the Southeast Queensland Healthy Waterways Partnership and leads the Australian Climate Change Adaptation Research Network for Water Resources and Freshwater Biodiversity. In 2008, he was appointed as an Australian National Water Commissioner.
Abstracts
Wednesday, October 20th - Public lecture in Saint John, UNB Saint John campus, 7 pm, Hazen Hall Lecture Theatre.
Balancing water needs for humans and nature
Rivers, lakes and wetlands contain only a fraction of the world's water and cover less than 1% of the Earth's surface, yet they support about 10% of the animal species, including about a third of all known vertebrates. They also sustain much of humankind, yet our exploitation of these resources threatens freshwater biodiversity - and our own water security. We have modified flow regimes and isolated rivers from their floodplains and the sea with barriers and dams. Changes to our climate have already resulted in lower rainfall in some regions, diminishing water supplies. Increased pollution of waterways has compounded the problem further by reducing availability of safe, clean water. While major technological investments have overcome many of the threats to human water security in the developed world, over 3 billion people still live in regions under high threat. Unfortunately, no similar investments in aquatic ecosystem protection have been made, and the threat to freshwater biodiversity remains high in rich and poor nations alike. Extinction rates of freshwater animals are twice as high as those on land and in the sea. Globally, at least 10,000-20,000 freshwater species are already extinct or at risk, and further declines in biodiversity are predicted as a consequence of climate change and an expanding global human population.
There is, however, much we can do to reduce the impact of human activity on freshwater biodiversity and, at the same time, to meet societal needs for water. In this presentation, I will discuss this global challenge and highlight some of the ways we can reduce the impact of human activity on freshwater biodiversity and the general health of our waterways.
Friday, October 22nd - Science Lecture, UNB Fredericton campus, 3 pm, Room 146 Loring Bailey Hall.
Using stable isotopes to understand river foodwebs
Stream and river ecosystems have long been regarded as heterotrophic systems, driven by inputs of terrestrial organic matter and nutrients from the surrounding watershed. However, only a small fraction of the total carbon present in a stream or river is likely to enter the aquatic food web: not all is of sufficient quality or is truly available for consumers. Identifying the source or sources of organic carbon that sustain populations of invertebrates, fish and other consumers remains a fundamental challenge. Stable isotope analysis has proved to be an effective tool in the study of food webs in aquatic ecosystems where there are often marked differences in the signatures of primary sources. However, its application to the study of stream and river food webs has often been confounded by considerable variation in the carbon isotope signatures of algae and overlap with terrestrial plant values. Despite these methodological problems, a consistent pattern seems to be emerging from studies across a range of biomes that inconspicuous sources of primary production are major contributors to the biomass of metazoan consumers.
In this presentation, I will review how stable isotope tracing has changed our views on river ecosystem function, discuss some of the limitations of this approach in food web studies, and highlight some future research directions.
