Grant: Discovery Grants Program - Individual

This study is all about taking it to the next level in marine food web research, both in terms of what we are studying and how we are doing it. Aquatic ecosystems occupy the largest part of the biosphere, and lipids in those systems provide the densest form of energy. Lipid dynamics can also strongly influence pollutant accumulation in marine food webs. Among the lipids, certain essential fatty acids and sterols are considered to be drivers of ecosystem health and stability. This study is a continuation of our ongoing program to investigate the importance of lipids in marine organisms and the cycling of these carbon-rich compounds in coastal ecosystems. The study of lipid production and transport through coastal food web levels is timely given continuing problems with fisheries, interest in new fishery species, habitat destruction, untreated waste water discharges, and increasing levels of aquaculture in this region. Objective 1 is to compare lipid production and transfer in warm and cold water coastal ecosystems. In tandem, objective 2 is to determine the extent of uptake and modification of dietary lipids in lab feeding experiments focussing on biomarker and nutritional lipids including omega-3 fatty acids and phytosterols. We will also investigate production of potentially harmful oxidation products of unsaturated lipids and we will measure the effect of certain lipid compounds on membranes of coastal animals. Thus, objective 3 is to investigate effects of temperature and diet on oxidative status and membrane fluidity in coastal marine food webs. The field and lab information on lipid transfer, oxidation and fluidity will provide a much more complete evaluation of the importance of lipids in coastal ecosystems and is critical to nutritional management of finfish and bivalve broodstock and larvae. In the context of accelerated climate change and growing pressures from fisheries and oil exploitation, this research will provide tools to help manage biological resources along our coasts. It will also offer interdisciplinary training for highly qualified personnel in use of sophisticated analytical instrumentation in the study of ecological consequences of natural and anthropogenic disturbances.