In 1992, the Bureau of Freshwater & Biological Monitoring
reactivated its Ambient Biomonitoring Network (AMNET) which, at
the time of its last sampling in 1988, consisted of only 18 sampling
sites statewide. The old network was determined to be inadequate
to support the department's 305(b) [water quality inventory report], 303(d) [list of impaired waters] and watershed programs, so bureau staff designed a new program.
The new AMNET program established
sampling stations in each of the 20 freshwater Water Management Areas, statewide, where the health of instream benthic macroinvertebrate (sometimes called bottom-dwelling "bugs") communities are evaluated using a USEPA-developed statistical methodology referred
to as Rapid Bioassessment Protocol (RBP). Under AMNET, each of the State's five major Water Regions are sampled for benthic macroinvertebrates (bottom dwelling organisms visible to the naked eye) on a rotational schedule of once every five years. Visual observations,
Stream Habitat Assessments and limited physical/chemical parameters are performed on each site.
To date, all of the major drainage basins have been biologically monitored for the third time with over 760 non-tidal sampling sites established.
The AMNET results have been incorporated into the
National Environmental Performance Partnership System (NEPPS) as a primary environmental indicator of water quality impairment. Statewide AMNET monitoring is a commitment in the NEPPS PPA with EPA Region 2, and a key element of NJ's Long-term Water Monitoring and Assessment Strategy. Other uses of the AMNET data include:
AMNET reports of results are published by the bureau as analysis of each Water Region is completed; copies are available from this web site. The biological and habitat ratings are also available from this web site for Round 1, Round 2, Round 3, and Round 4 (in part) data. The chemical and biological data will also soon be available from STORET, EPA's computerized data system. GIS data shapefiles cans be found at this address: http://dep-inet2.dep.state.nj.us/gis/stateshp.html#AMNET
AMNET employs a multimetric index approach for assessment of biological condition, and regulatory thresholds for use attainment. New Jersey benthic macroinvertebrate communities can be statistically grouped into three distinct structures based on geographical regions: high gradient (above the Fall Line), low gradient (Coastal Plain excluding the Pinelands), and Pinelands. To accurately assess biological condition, an index was developed for each distinct region using guidelines outline in USEPA's Rapid Bioassessment Protocols (RBP) for Use in Wadeable Streams and Rivers. The indices assess sites from two perspectives: the condition of the macroinvertebrate community and the regulatory use attainment. An assessment framework was outlined to address both concerns, and a development report was prepared for each index: High Gradient Macroinvertebrate Index (HGMI), Coastal Plain Macroinvertebrate Index (CPMI), and the Pinelands Macroinvertebrate Index (PMI).
A Standard Operating Procedure (SOP) is available for all aspects of the AMNET program including sampling, analysis, assessment, and a summary of the index development and scoring criteria.