What is Biomonitoring?
Biological monitoring provides information on the health of an ecosystem based on which organisms live in a waterbody. The types and numbers of organisms collected from polluted water differ from those collected in clean water, helping us determine "how clean" (level of water quality) the water is and to detect water quality changes over time.
Macroinvertebrates, fish, and algae are all widely used in biomonitoring. Although DEC collects information on all of these aquatic organisms, macroinvertebrates are collected and analyzed the most.
When and where are biomonitoring data collected?
Each major watershed in the state is monitored on a five year schedule as a part of our Rotating Integrated Basin Studies (RIBS) program. Each sampling season (June-September), three or more basins are sampled following this schedule.
2020 Sampling
In 2020, DEC's Stream Biomonitoring Unit is collecting macroinvertebrates from approximately 75 streams and rivers in each of three watersheds: Lake Ontario, Erie/Niagara, and Mohawk, as part of the RIBS Screening Network.
How are biomonitoring data collected?
DEC adheres to the procedures outlined in the Standard Operating Procedure: Biological Monitoring of Surface Waters in New York State, 2021 (PDF) to collect, process, and analyze biomonitoring data. This ensures uniformity of methods and accuracy of data when performing biological monitoring of surface waters in New York State. View the Biological Assessment Profile (BAP) Fact Sheet (PDF) for more information on water quality assessment using biological data.
How does DEC use biomonitoring data?
- Waterbody Inventory and Priority Waterbody List (WI/PWL) and 303(d) List of Impaired Waters Water quality assessments in the Rotating Integrated Basin Studies (RIBS) and NYS Section 305(b) Water Quality Report
- State Permit Discharge Elimination system (SPDES) permit writing, compliance and enforcement, and setting permit limits that are protective of aquatic life
- 30 Year Trends Monitoring Reports for watersheds. "30 Year Trends in Water Quality of Rivers and Streams in New York State, Based on Macroinvertebrate Data" (links to PDF at NYS Library) presents a summary of the trends seen statewide, as well as those for many individual rivers and streams.
- 40 Year Trends Monitoring Reports update. " Long-term trends in biological indicators and water quality in rivers and streams of New York State (1972-2012): Water Quality Trends in New York State" (links to PDF at NYS Library)
- Development and implementation of watershed plans
- Development of numeric criteria that better define the levels of nutrients that result in impairment of water uses
- Assessment of NYS Areas of Concern (AOCs) as part of the Great Lakes Restoration Initiative (GLRI)
