Migratory Fish

A variety of diadromous fish are native to Narragansett Bay. These species rely on both fresh and salt water habitats during various life history stages, migrating up and down rivers and streams to effect this survival strategy. Diadromous fish include anadromous species, which spawn in fresh water but migrate to salt water as adults; and catadromous fish, which spawn in salt water but live as adults in fresh or brackish systems. These species play a vital role in watershed ecology, transporting nutrients between ocean, estuarine, and watershed environments. They can be remarkably abundant where suitable habitat conditions are present, serving as important prey species for marine and fresh water fish, birds and mammals-several studies have shown anadromous herring to constitute up to one-third of the diet of bluefish and striped bass at certain times (Environmental Defense Fund 2005). Historically, diadromous fish served as the basis for important food, bait and fertilizer fisheries, although this is no longer the case on Narragansett Bay.
Dams found in the Pawtuxet watersh
According to RIDEM (2005), species of anadromous fish native to Narragansett Bay are Atlantic salmon, American shad, two species of river herring, shortnose sturgeon and rainbow smelt. Of these, Atlantic salmon has been extirpated from the Bay watershed while the sturgeon is listed as endangered. The only significant catadromous fish present in the Bay is the American eel. Throughout the Northeast and in Narragansett Bay, populations of diadromous fish declined significantly over the past several hundred years as rivers and streams were dammed for water power, water supply and other purposes.

In the Bay watershed as elsewhere, fish passage restoration efforts are focusing on fish ladder construction, dam removal and other technologies to restore migratory pathways, primarily for herring, shad and eels. Several projects such as the Kickemuit River fish ladder [link to www.nbep.org] in Warren, R.I. have recently been completed; others such as the Lower Pawtuxet River Fisheries Restoration [link to www.nbep.org] are underway. However, with fish passage facilities in place or under construction on less than five percent of Rhode Island dams, diadromous fish are able to access a relatively small portion of their historic watershed habitat.

[anadromous fish map here]

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