Long-term Ecosystem Science

Long-term ecosystem science at the Dorset Environmental Science (DESC) focuses on the headwater lakes and streams located in south-central Ontario that are representative of tens of thousands of lake catchments on the Canadian Shield. This multiple stressor, watershed-scale approach is coordinated by a core of scientists at the Centre, but also provides the focal point and context for a number of university, government and NGO partners that also conduct work at DESC. This collaborative climate continues to grow at DESC and we welcome participation by any researchers that will benefit from using DESC long-term data as a backdrop for future work. Our research is encompassed by six major initiatives:

  1. An intensively-sampled group of nine lakes with over 30 years of data on chemistry, physics and biology focusing on the multiple and interacting environmental stressors that affect lakes (Dorset A-lakes).
  2. An integrated set of sampling sites monitoring fluxes of water and solutes from 20 upland catchments and 6 lakes small enough to study inputs, outputs, and apply mass-balance and modeling approaches (Dorset Streams).
  3. A regularly sampled (spring/summer/fall) group of lakes that increases the spatial extent of our physical, chemical and biological, monitoring program for over 20 years (Dorset B-lakes).
  4. Benthic macroinvertebrates and associated environmental variables are collected on ~20 lakes and ~15 streams in the Dorset area once per year (stream benthos=spring / lake crayfish=summer / lake benthos=fall).
  5. Spatial surveys (typically once per several years) that contribute to larger regional datasets on lake and stream ecosystems, including fisheries data from the A-lakes.
  6. Real-time high resolution temperature, oxygen and meteorology data from a remotely-sensed raft (THELMA) on Harp Lake.

Collectively, these monitoring initiatives are designed to collect data on three major components of wetlands, lakes and streams:


Water chemistry is an important control on the dynamics of lake ecosystems.  Using a wide variety of parameters analyzed by the Dorset Water Chemistry Laboratory we investigate the effects of various chemical inputs from catchments as they travel from stream and groundwater sources to lakes.


Watershed hydrology and lake dynamics are intensively monitored on the same lakes and streams that we visit for chemistry data. These data include temperature and oxygen profiles as well as the influence of climate, lake morphometry and internal mixing processes on several important aspects of lakes that impacts the availability of suitable haitat for aquatic organisms.


The plants and animals living in lakes are indicators of ecosystem health and function. They are a focus for a variety of sampling efforts that collect data on phytoplankton, zooplankton, macroinvertebrates and fish in lakes and streams of the Muskoka area. Aquatic organisms respond to chemical and physical conditions but are also important components of energy flow and nutrient cycling in ecosystems and therefore also generate some of the dynamics we see in lakes and streams.