Monday, November 7, 2011
Schmidt et al. 2011. Historical and contemporary trophic niche partitioning among Laurentian Great Lakes coregonines. Ecol. Appl. 21:888-896.
An ecologically unique and diverse species assemblage once roamed the deep waters of the Great Lakes, prior to overfishing and non-native species introductions. Now extirpated from Lakes Michigan, Huron, and Ontario (and in low numbers in Superior), the deepwater coregonines were important prey fish for top predators and supported a productive commercial fishery. Rehabilitation of native deepwater fish communities is now a top management priority, yet little is known about their historical ecology.
Stephanie Schmidt and her colleagues collected coregonine tissue samples from museum specimens and from contemporary populations in Lakes Superior and Nipigon. They used stable isotope analysis – a technique that uses carbon and nitrogen information to decipher diet – to reconstruct the food web from the 1920’s to the present.
In each lake, the coregonines were ecologically distinct from one another, their distinctness was maintained throughout a period of tremendous ecosystem change, and the most distinct species was most likely to persist over time. Stephanie suggests that the rehabilitation of ecological diversity be considered in reintroduction programs.
Jennifer Winter is a senior scientist with the Ontario Ministry of the Environment, and directs nutrient monitoring programs for inland lakes and the Great Lakes. She also is acting supervisor for the Sport Fish and Biomonitoring Unit, the group responsible for the monitoring of contaminant levels in fish tissues throughout Ontario.
Jennifer’s path to a career in science began in England, where she earned a B.Sc. in Environmental Biology (Univ. of Liverpool) and a M.Sc. in Pollution and Environmental Control (Univ. of Manchester). She then moved to the Univ. of Waterloo (not England!) and the Ministry’s Dorset Environmental Science Centre (www.desc.ca).
Jennifer’s interest and background in environmental sciences forms the basis of a diverse research program on lakes at risk. She has studied the recovery of Sudbury area lakes, the effects of multiple stressors on the phytoplankton communities of Canadian Shield lakes and Lake Simcoe, trends in nutrient and chloride loading to Lake Simcoe, and trends in algal bloom reporting by the public. Currently, she is involved with a large, collaborative research project on Lake Simcoe which explores how key processes such as nutrient loading and climate variability affect the ecology of the lake.
Michelle Palmer, a Ph.D. student at York University in Toronto, is interested in large scale questions concerning ecosystems and their responses to multiple, interacting stressors. Her research focuses on ~40 Ontario lakes and how their physical, chemical and biological properties changed following changes in climate, acidic deposition, nutrients and development, and species introductions. Michelle will also assess whether widespread stressors such as climate change should be used to inform restoration targets for stressed lakes.
Michelle’s first research experience was on cuttlefish communication at Dalhousie University (Nova Scotia), while still an undergrad. After completing her B.Sc. in marine biology and statistics, she moved to McGill University to do an M.Sc. Here, her research focused on biological invasions in the St. Lawrence River.
Michelle’s integration of quantitative approaches and ecology is a winning combination. She has 11 publications in press or submitted, six of which are first-authored! Along the way, she has received several prestigious scholarships and awards.
Michelle is also passionate about teaching and knowledge sharing. She has been a TA for several courses, a coordinator for 1st year Biology, and even found time to found a taxonomic and statistical consulting business!
Tuesday, May 24, 2011
Trebitz et al. 2010. Status of non-indigenous benthic invertebrates in the Duluth-Superior Harbor and the role of sampling methods in their detection. J. Great Lakes Res. 36:747-756.
Invasive species can cause considerable ecological and economic damage, so it is important to have a monitoring system in place to detect new arrivals early enough to mount an effective response. But how could early detection monitoring be accomplished most efficiently, given time and budgetary constraints?
Anett Trebitz and her colleagues sought to answer that question. They conducted intensive sampling in a known exotic species ‘hotspot’, followed by numeric ‘what-if’ analyses to determine methodological efficiencies. One major finding: combining multiple search strategies is better than traditional single-gear monitoring. Through their efforts, they discovered several new invertebrate exotics in the Duluth-Superior Harbor.
Anett is a research ecologist with the US EPA Mid-Continent Ecology Division in Duluth. She received her MS from the University of Tennessee and her PhD from the University of Wisconsin-Madison.
Annett cares about how people affect aquatic ecosystems, and currently is part of a team studying linkages between watershed development and the health of Great Lakes coastal wetlands.
In the world’s largest deepest lakes, phytoplankton photosynthesis is an important source of new carbon that fuels whole lake productivity. Research by Stephanie Guildford, an Associate Professor at the University of Minnesota-Duluth, focuses on determining rates and controlling factors on primary production (PP) and, importantly, fates of PP.
Great Lakes, especially those with low nutrient concentrations and low phytoplankton biomass, pose extreme logistical challenges. Stephanie and her colleagues use advanced fluorometric instruments to characterize phytoplankton composition and photosynthetic capacity at highly-resolved spatial and temporal scales.
Using data collected from Lake Superior during five cruises in 2010, Stephanie’s lab and colleagues at UMD are studying the deep chlorophyll layer (DCL). In particular, is the DCL light limited, nutrient limited, controlled by grazers, or the sinking of phytoplankton? What links exist between the DCL and the vertical migrating zooplankton Limnocalanus and Mysis? Do these zooplankton feed in the DCL and, if so, how much of their productivity is derived from the DCL? Do the phytoplankton in the DCL use the nutrients excreted by the migrating zooplankton? If so, the connection between the DCL and migrating zooplankton may be an important control point of primary production.
Jessica Van Der Werff is a Master’s student in Water Resources Science at the University of Minnesota–Duluth. Her keen interest in water resources and their management began during her undergrad years at the University of Wisconsin-Stout. During this time, she obtained skills and experience in an aquatic ecology laboratory and as a water quality intern in southeastern Minnesota.
Jessica’s Master’s research focuses on nutrient and light stress in phytoplankton in Lake Superior. The first challenge is to collect phytoplankton and water samples at this vast scale, which means multiple cruises for Jessica throughout the summer months. This is followed by sophisticated analytical techniques (e.g., bioassays and fluorometry) to measure key indicators of stress and nutrient composition of water.
Jessica’s research occurs within the framework of a larger project on nutrient cycling dynamics, translocation of nutrients by biota, and overall productivity of Lake Superior. By describing the spatial and temporal patterns in indicators of nutrient stress in this system, Jessica will contribute important information about nutrient cycling in Lake Superior.
As Jessica plans her second summer of research cruises, she is looking forward to presenting preliminary data at the 2011 IAGLR conference in Duluth.