Ecosystem Targets and Supporting Indicators
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This target is ahead of schedule. In order to meet the 2035 target, an average of 10 stream miles per year from 2015-2034 need to be reconnected to restore 200 stream miles for fish passage to Long Island Sound. The initiative has so far reconnected 121.4 river miles, an average of stream miles a year since 2015, and is 60.7 percent of the way toward meeting the target.
No new stream miles were reported opened in 2021, a first in the annual reporting since the time series began in 1998. Two projects, a fishway and a dam removal, with the potential to open fish passage, however, were completed in Connecticut in 2021. These projects will not result in opening fish passage to Long Island Sound until barriers at downstream dams are removed. One of these projects, a fishway at the Upper Collinsville Dam in Canton, will open up 32 stream miles when the barriers are removed.
Trends in populations of diadromous fish that would benefit by reopening of fish migratory corridors are not tracked by the LISS, but the Connecticut Department of Energy and Environmental Protection (CT DEEP) and other partners keep track of population trends through the use of electronic fish counters, video surveillance, volunteers, and other means. LISS has supporting indicators compiled by CT DEEP of spawning runs in Long Island Sound tributaries that track populations in rivers that have completed all fish passage projects and those rivers where projects are still being proposed (see sidebar).
Fish count data also can be found at the Connecticut River Salmon Association website and in the 2016 US Fish and Wildlife Association Connecticut River annual report.
It is difficult to determine trends in stream miles reconnected. The number of miles reconnected from a single fishway or dam removal has nothing to do with the size of the dam, cost of the project, or river where the project is located. Furthermore, past performance of the restoration partners in terms of annual (or averaged) stream miles reconnected has no bearing on miles that will be reconnected in the near or distant future.
In the last decade, there has been spikes in reconnected stream miles in some years and lulls in other years, which can be attributed to funding support. When a large funding source becomes available, the restoration partners focus on engineering and permitting for numerous projects. During these years we see lulls in miles reconnected, but the partners are generally busy with planning for larger-scale and expensive projects. Many of these are completed within a year or two of each other, and that’s when we see these spikes in miles reconnected (2007, 2012-2013, and 2016).
The LISS Habitat Restoration Coordinators at CT DEEP and the New York State Department of Environmental Conservation (NYSDEC) track riverine migratory corridor restoration projects that are in progress within the watershed, led by various partners, and report the total stream miles reconnected annually.
This target will be attained by reconnecting, either through dam removal or other fish passage methods, an additional 200 miles of riverine migratory corridors (RMC). The 2014 baseline is 304.56 reconnected riverine migratory corridor miles in Connecticut and 3.2 reconnected riverine migratory corridor miles in New York. For context, there are an estimated 1,850 total riverine migratory corridor miles in Connecticut, more than half of which are dammed or otherwise not passable for fish. The length of New York’s total riverine migratory corridor miles within the Long Island Sound watershed has not been estimated but is much smaller. The Habitat Restoration and Stewardship Work Group track fish passage projects that are in progress within the watershed by various partners and reports the total miles reconnected annually.
[Note: 307.76 miles is currently the 2014 baseline, but is also subject to change as new GIS data for older fish passage projects become available].
Riverine Migratory Corridors, rivers, and streams that connect Long Island Sound to inland habitats that are a necessary part of the life cycle of diadromous fish species must be cleared of obstructions, and kept clear, in order to connect fish with their historic spawning grounds.
Diadromous species of fish are a critically important part of the LIS food web. Adults are eaten in large numbers by birds of prey such as eagles and osprey, while juveniles are a primary source of food, seasonally, to other small fish and smaller coastal birds. Commercially important species such as salmon, bluefish, and striped bass (some of which are anadromous themselves) also depend heavily on smaller anadromous species as a food source, such as alewife, blueback herring, and the catadromous American eel.
The Long Island Sound Study has a database to track and describe every restoration project in the Connecticut and New York portions of the Long Island Sound watershed since 1998.
Diadromous species can be further divided into two primary groups: (1) catadromous, or those which migrate downstream, from inland freshwater systems to spawn in the ocean – the only example in LIS is the American eel (Anguilla rostrata); and (2) anadromous, or those which migrate upstream, from ocean to inland freshwater systems for spawning. Anadromous species in LIS are:
Depending upon the species, the riverine migratory corridor may provide the actual spawning habitat, or may simply provide the necessary access to spawning habitat (e.g., a wetland or lake).
Victoria O’Neill, NYSDEC[email protected]
Harry Yamalis, CT DEEP[email protected]
CT DEEP, NYSDEC, and Long Island Sound Study Partners