Fish: Forage Fish

Forage fish populations are affected by many factors. Some of these factors are environmental stressors like warming waters, regulations like policies that prevent overfishing, as well as habitat restoration efforts.

Tracking population stability of these fish can be an indicator of the Partnership’s efforts to protect and enhance the health of offshore habitats and their associated species for the Offshore Habitat objective.

Forage fish are small, fast-growing fish that are a major food source for many birds, reptiles, crabs, fish, and even mammals like seals. These small forage fish can include juvenile stages of larger fish species (e.g., weakfish, bluefish, and scup) or small-sized adult fish (e.g., blueback herring, butterfish, and menhaden). The Partnership tracks forage fish abundance to understand how this major food source for Long Island Sound creatures is doing. Also, understanding forage fish abundance can shed light on the availability of their food sources, such as phytoplankton and zooplankton.

The Open Water Forage Index, which is a composite geometric mean biomass/tow of 14 common forage fish species, shows a stable trend. The stable trend indicates that the Sound has a sufficient food base to support the wide diversity of resident marine species as well as those that migrate into the Sound specifically because it is a rich feeding ground. Although there is high annual variability (i.e., the count per haul fluctuates every year), since mid-90s, the Connecticut and New York Coastline Forage indices have been higher but stable, indicating that productivity in the intertidal zone and marshes is good. For both indices, 2012 and 2013 were poor years, which may have been a result of the destruction of habitat from Hurricane Sandy. The numbers rebounded in 2014. The Long Island Sound Partnership is working on developing a methodology to accurately assess the status of this indicator. Check back in soon.