Answer: Yes, barriers, such as dams, that block fish migratory pathways remain. However, there has been significant progress in removing barriers and there is now a substantial amount of riverine connectivity for migratory fish. As of 2025, approximately 475 river miles were reconnected (see the Habitat Connectivity). While removing barriers increases migratory fish passage, a steady decrease in fish abundance indicates other pressures are impacting the migration of these species (see Anadromous Fish for more). These additional pressures and the fact that other species are dependent on this connectivity only add to the importance of restoring this key aspect of habitat quality and understanding the other pressures these species face.
Full barrier removals restoring migratory corridors in rivers and streams within the Long Island Sound watershed were quantified. The barrier projects that are currently quantified include full dam removals as tracked by the American Rivers Network. The Partnership is evaluating methods to track bridge and culvert projects that qualify as full barrier removals, stay tuned for updates.
Additionally, it is important to note there is recognition that other projects may provide some partial benefit to habitat quality. However, these benefits are not yet quantified here.
Since 2014, over 147 river miles have been reconnected, equating to over 76 full barrier removals (dam removals only are tallied in this total). This includes eight dam removals in 2025. To achieve the 2035, target, the Partnership must average ten removals per year. While it is recognized there is currently no mechanism to tally culverts and bridges for this purpose, they are an important effort for the Habitat Connectivity Objective. As such an effort is underway to coordinate this tally. It is important to note not every dam or culvert removal equates to the same river miles connected; this is very dependent on barrier density of a particular river/stream. Â
Tracking barrier removals is an indicator of the Partnership’s efforts to reconnect riverine migratory corridors for the Habitat Connectivity Objective. Priority sites for habitat connectivity must be selected, and options for tracking improvements in habitat connectivity within Long Island Sound need to be identified and evaluated. More specifically, priority sites may focus on opportunities to reconnect stream miles, through the removal of barriers (i.e., dams and culverts) in the New York and Connecticut portions of the watershed. Additionally, while barrier removal may be challenging in some areas due to restrictions, another approach is to restore or enhance the health of the streams (i.e., fish ladders). The Partnership specifically mentions the following sub-goal for habitat connectivity: Remove 100 barriers (dams and culverts combined) to reconnect stream miles in the New York and Connecticut portions of the watershed. These efforts will be essential for habitat connectivity of the Long Island Sound Watershed.Â
Barrier removals also benefit water quality and community coastal resilience. Thus, activities the Partnership takes under this action can have a compounding positive effect for the mission as a whole.Â
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