Ecosystem Dynamics

Program Leader: Henry Vanderploeg


Overview

image of plankton net
Neuston Net, Lake Michigan
The Ecosystem Dynamics (EcoDyn) branch makes long-term ecological observations, conducts targeted fundamental research on ecological processes, and provides data to develop models critical to understanding ecosystem structure and function. EcoDyn also develops models to forecast impacts of multiple stressors e.g., invasive species, climate, and nutrients on Great Lakes water quality, food webs and fisheries. EcoDyn observations, laboratory, and field experiments support the development of new concepts, models, forecasting tools and applications to evaluate and forecast impacts of, and mitigation strategies for, present and future stressors.

The EcoDyn branch strives to anticipate, monitor, analyze, understand, and forecast changes in the Great Lakes and coastal ecosystems to strengthen capacity for managing water quality, fisheries, and ecosystem and human health.

image of sampling in Lake Erie
Sampling a harmful algal bloom in western Lake Erie near the Toledo water intake crib

Observations and Experiments

EcoDyn’s field observations and process-based studies are supported by the laboratory facilities in Ann Arbor as well as the laboratories and vessel fleet housed at the Lake Michigan Field Station (LMFS) in Muskegon. GLERL’s largest vessel, the R/V Laurentian, is equipped with gear capable of sampling the entire food web from microbes to fishes (see sidebar). The LMFS’s proximity to Lake Michigan provides the capacity to process time-critical samples immediately after collection and the ability to sample during episodic events e.g., upwelling, spring flooding or short weather windows during inclement periods. The laboratories in Ann Arbor allow measurement of a suite of variables in support of field observations and process experiments. Key to EcoDyn’s operation is acquisition and maintenance of critical equipment. For more details on GLERL’s critical equipment, see Appendix H in the GLERL Strategic Plan.

EcoDyn’s Long-Term Research (LTR) program on Lake Michigan integrates a core set of long-term observations on biological, chemical, and physical variables, accompanied by process studies and field experiments, for understanding and forecasting ecosystem change. The LTR program makes seasonal observations of pelagic (water column) and benthic (bottom) habitats of food webs in nearshore and offshore waters. For pelagic observations, two sampling strategies are used: (1) biweekly sampling from March to December at fixed stations for nutrients, phytoplankton, zooplankton and Mysis; and (2) seasonal spatial cruises using towed sampling gear (Plankton Survey System and fisheries acoustics), advanced net technology (MOCNESS- Multiple Opening Closing Net Environmental Sampling System) and water sample analyses. An important outcome of LTR pelagic observations is quantifying fine-scale diel spatial interactions among nutrients, environmental factors, and the food web. EcoDyn’s process and experimental research includes impacts of dreissenid mussels and other invasive species.

image of Dreissenid mussel samples
Dreissenid mussel samples

In addition to the LTR program in Lake Michigan, the EcoDyn branch carries out observations and experiments in other Great Lakes including Lake Erie and Lake Huron. An important focus is understanding and forecasting species, abundance, distribution, and toxicity of harmful algal blooms (HABs) in western Lake Erie and other eutrophic regions of the Great Lakes. EcoDyn is part of a large cross-branch and CIGLR program that has been monitoring the HAB events in Lake Erie and Saginaw Bay since 2009 using discrete sampling as well as a suite of remote sensing equipment. This is one of the longest HAB monitoring datasets in both of these regions. An overview of the HABs program, conducted jointly by GLERL and CIGLR scientists, is presented in the case study, Harmful Algal Bloom Research: A Model Program for Adaptive Integrated Research (page 29 of the GLERL Strategic Plan).

Models & Applications

EcoDyn modeling consists of nowcasts and scenario-based forecasts to predict the effects of invasive species, climate, nutrient loadings, and meteorology on Great Lakes food webs, fisheries productivity, and water quality. Data, observations and related process studies are used in ecosystem models to forecast the effects of stressors and management options.

EcoDyn Guiding Principles:



Research Projects

Ecosystem Dynamics: Long-Term Observations

Recognizing the value of a long-term perspective on how ecosystems change over time, GLERL has invested in researching the southern basin of Lake Michigan since the 1970s. GLERL's focus on Lake Michigan has led to the establishment of the Long-Term Research (LTR) program. GLERL's LTR approach integrates a core set of long-term observations on biological, chemical, and physical variables, with short-term process-based studies for understanding ecosystem change. Such information is essential for the development of new concepts, models, and forecasting tools to explore impacts of various stressors on the ecosystem.

Ecological Monitoring and Forecasting of Harmful Algal Blooms in the Great Lakes

Recent increases in cyanobacterial HABs in the Great Lakes has caused significant concern for human and ecosystem health due to the production of toxins by bloom species. In the Great Lakes, Microcystis dominates the cyanobacterial bloom community and produces the hepatotoxin microcystin. Studies have documented the presence of microcystins in the Great Lakes, at times exceeding the recommended limit of 1 µg L-1 of microcystin established by the World Health Organization for drinking water supplies. GLERL research will directly address whether algal toxins could impact human health in the communities of the Lake Erie Islands and have broader implications for other communities using the Great Lakes as a drinking water source.

Aquatic Nuisance Species

Recognizing the value of a long-term perspective on how ecosystems change over time, GLERL has invested in researching the southern basin of Lake Michigan since the 1970s. GLERL's focus on Lake Michigan has led to the establishment of the Long-Term Research (LTR) program. GLERL's LTR approach integrates a core set of long-term observations on biological, chemical, and physical variables, with short-term process-based studies for understanding ecosystem change. Such information is essential for the development of new concepts, models, and forecasting tools to explore impacts of various stressors on the ecosystem.

Asian Carp

A collaborative team of NOAA Great Lakes Environmental Research Laboratory (GLERL) scientists and their partners developed a model to identify potential effects of Asian carp on the food webs in Lake Erie and other Great Lakes. Food webs are the feeding interactions of aquatic life. Prior efforts to predict Asian carp effects on the Great Lakes focused on potential suitability of Great Lakes habitats for Asian carp spawning, establishment or growth, but had not investigated Asian carp effects on food webs and fisheries. This information is critical to assess potential control measures and management options. The models used by GLERL-CIGLR (Cooperative Institute for Great Lakes Research) researchers simulate Asian carp population dynamics (growth and shrinkage over time, as controlled by birth, death and migration), ecosystem impacts, and food webs, and can help inform state and federal agencies working corroboratively to control the spread of Asian carp.

Additional information:
How would an Asian carp invasion affect fish in Lake Erie? (Infographic)
Asian Carp studies at GLERL – Understanding the impacts of an invasive species (Fact sheet)

Great Lakes Aquatic Nonindigenous Species Information System

To meet the challenges of managing ANS threats and informing the public of these threats, the NOAA Great Lakes Environmental Research Laboratory (GLERL) has created the database, Great Lakes Aquatic Nonindigenous Species Information System (GLANSIS). Serving as a critical source of species-specific information, GLANSIS houses a core list of established species that are not native to any part of the Great Lakes basin. Extremely valuable to ANS prevention efforts is the GLANSIS Watchlist — a list of species currently not found in the Great Lakes but assessed as likely to invade via current pathways based on peer reviewed scientific literature. GLANSIS, functioning as a Great Lakes node of the national U.S. Geological Service (USGS) Nonindigenous Aquatic Species (NAS) database, is searchable geographically (by watershed and lake) as well as by scientific and common name.

Invasive Mussels

Many people think of zebra mussels as the most destructive invasive species in the Great Lakes, when in fact they have been “out-musseled” by the closely related quagga. Both are native to Eastern Europe and were introduced to the Great Lakes via ballast water discharged from ships. Zebra mussels arrived in the 1980s and caused widespread ecological and economic damage. Quagga mussels arrived in the 1990s and have since outcompeted zebra mussels. Unlike zebra mussels, quaggas have the ability to adapt to cold temperatures and live in soft sediments like mud instead of requiring hard surfaces. Quaggas also have a longer siphon, the body part that sucks in water to filter out food. Because of these differences, quagga mussels are able to colonize deeper areas of the Great Lakes and have almost entirely replaced zebra mussels in many places. The dominant quagga mussel has become so widespread that the species has completely changed the Great Lakes ecosystem - with harmful impacts to native organisms

Additional information:
Invasive Mussels and Lake Productivity Infographic (Infographic)

Great Lakes Food Web Diagrams

GLERL has recently developed food web diagrams for all of the Great Lakes and Lake St. Clair. The major species in each lake are briefly described, along with a diagram summarizing the ecosystem energy flow (who eats or is eaten by whom!). These diagrams are based on a model from a paper published in 2003 supported by both NOAA and the Great Lakes Fishery Commission. Summarizing the model results in diagram form was accomplished by GLERL’s Sea Grant Extension Educator. They were updated and modified for each lake by a host of researchers.