PARENT SESSION
Organized Oral Session 17: Coastal indicators of ecological condition: Integration of spatial scales
Organizer(s): GJ Niemi, H Paerl, and B Levinson
Tuesday, August 9, 8:00 AM - 11:30 AM, Meeting Room 516 A, Level 5, Palais des congrès de Montréal

Using microbial indicators to assess scales of human and climatic impacts on structure and function of the coastal zone.

Paerl, Hans^*,, Valdes, Lexia, Dyble, Julianne, Pinckney, James, Piehler, Michael, Moisander, Pia,

ABSTRACT- More than half of the global human population resides within 100 kilometers of the coast, and this fraction will grow in the foreseeable future. Increases in nutrient and other pollutant discharge have accompanied this trend. Understanding the magnitude, duration and spatial extent of ecological responses (biodiversity, water quality, food web dynamics, habitat condition) to these stressors in coastal ecosystems is a major research challenge. Coastal ecosystems are additionally affected by natural perturbations, including droughts, storms, hurricanes and floods; the frequency and extent of which may be increasing. Distinguishing and integrating the impacts of natural and human stressors is essential for understanding environmentally-driven change, starting at the base of coastal food webs and culminating at higher consumer levels (e.g. fisheries). Microbial indicators play a major role in detecting and characterizing these changes. Complementary use of analytical and molecular indicator tools shows great promise in clarifying the processes underlying microbial population, community, and ecosystem change in response to environmental perturbations. This is illustrated for phytoplankton community changes in US estuarine and coastal ecosystems experiencing increasing watershed development and climatic changes (increasing hurricane frequency). Phytoplankton and other microbial indicators are used as criteria and standards for evaluating water quality (i.e. TMDLs) and habitat conditions. These indicators can be adapted to monitoring and assessment programs employing small boats, larger vessels including commercial ships and ferries, moored instrumentation, fixed platforms, and remote sensing, in order to evaluate environmental controls on aquatic ecosystem structure and function over a range of temporal and spatial scales.

Key words: microorganisms, indicators, estuaries, coastal