Stream Health Ratings in the Chesapeake Bay Watershed First Interval (2012-2017)

<p><b>Open the Data Resource:</b> <a href='https://gis.chesapeakebay.net/ags/rest/services/ChesapeakeProgress/cpStream_Health/MapServer/2' rel='nofollow ugc'>https://gis.chesapeakebay.net/ags/rest/services/ChesapeakeProgress/cpStream_Health/MapServer/2</a></p> <p>This Chesapeake Bay Program indicator measures progress toward the <a href='https://www.chesapeakeprogress.com/abundant-life/stream-health' rel='nofollow ugc'>Stream Health Outcome</a>. It shows stream health ratings according to the Chesapeake Basin-wide Index of Biotic Integrity, or Chessie BIBI, for 2012-2017. The Chessie BIBI describes the biological quality of macroinvertebrate communities in assessed streams in relation to all the streams in the watershed. When a sampling site receives a Chessie BIBI score above a bioregion-specific reference threshold, which is the tenth percentile of all scores in that bioregion’s reference populations, it is considered in fair, good or excellent condition. When it receives a score that is below that threshold, it is ranked poor or very poor. All samples within a single subwatershed are given equal weight and their average score is used to rank the subwatershed’s overall stream condition.</p>