Baseline Data: 1997-2009 Last Updated: 2014
Diadromous (sea-run) fish are an important component of the native ecosystem in the region. River herring in particular are a major focus of restoration efforts and are the best studied of the diadromous fish in the PIE-Rivers region. Annual spawning run estimates have been calculated using visual counts, fish traps and electronic counters at various times over the past two decades in the Parker, Ipswich and Essex watersheds. This metric tracks trends in those estimates relative to a baseline run for each watershed set at the median run size for available years between 1997 and 2009.