Reducing Obstacles to Fish Migrations

For many years, the Gold Hill Dam blocked fish passage and limited recreation on the Rogue River.

Photo Credit: NOAA

by Rachel Brittin

Who hasn’t heard of the monumental migrations of salmon, sturgeon, and shad? They return from the ocean to the river where they were born and swim up to hundreds of miles upstream for the single-minded purpose of breeding. As impressive as this feat may be, dams and other artificial barriers have blocked many fish from reaching their former spawning grounds. In these cases, an uphill swim becomes not just a challenge but a serious battle for survival of the species. This is particularly true for fish that are threatened or endangered.

The National Marine Fisheries Service (NMFS), through its Open Rivers Initiative and its participation in the National Fish Habitat Action Plan (a public-private partnership), is working to protect and restore access to historic fish migration routes while engaging communities and the power industry to help in the restoration process.

Currently, an estimated two million dams and other barriers block countless miles of rivers and streams throughout the United States. Although large dams without proper fish ladders are obvious barriers to migrating fish, thousands of smaller, obsolete dams and culverts can pose problems that are just as serious.

"Many small, in-stream structures look innocent enough," says Tisa Shostik, coordinator of the Open Rivers Initiative. "But even small structures, if not properly designed, can have big consequences for fish populations."

Local supporters of the restoration watch as the Gold Hill Dam is removed.

Photo Credit: NOAA

Many dams provide clean energy benefits, while others sit abandoned and in disrepair long after they have outlived their intended use. These dams not only cause ecological problems but are safety concerns for local communities. Since its launch in 2006, NOAA’s Open Rivers Initiative has received 150 requests from communities and organizations across the country to support the removal of small, obsolete dams and fish passage barriers. In 2008 alone, NOAA supported 35 such projects, which were prioritized by economic and ecological impacts, timing, feasibility, and level of safety concern. To date, NOAA has supported about 62 barrier removal projects.

"We have been flooded by requests," says Shostik. "In just the first year of the initiative, communities requested over $20 million to carry out barrier removal projects in their rivers and streams, far exceeding the available funding."

One such project is the Gold Hill Dam near Medford, Oregon. It was removed last summer after a century of diverting water, blocking fish passage, and limiting recreation on the Rogue River. Once stretching 900 feet (275 meters) across the river, the dam was constructed in the early 1900s to generate power for the city of Gold Hill. In recent years, the generators were no longer in operation, and the dam only presented a significant barrier to fish passage and safety concerns for the Gold Hill community.

The successful removal of this structure through the Open Rivers Initiative took place in concert with many local and regional partners. It resulted in access to 2 miles (3.2 kilometers) of spawning and rearing habitat for coho, Chinook, and steelhead salmon.

"At first, two miles may not sound like a lot of fish habitat," explains Shostik. "But it’s actually part of a series of three dam removals on the Rogue that will open more than 150 miles of the river. The Savage Rapids Dam will be removed in 2009, and we’re hoping that studies on the Gold Ray Dam, the third and final dam on the mainstem, will indicate that we can remove it within the next few years."

In addition to the Open Rivers Initiative, NMFS works with power companies to help them address passage for threatened and endangered fish at hydropower dams, the largest type of fish barriers. More than 2,000 hydropower dams block fish migrations to and from their spawning habitats. They provide clean energy for communities around the country, but many were constructed 50 years ago and do not incorporate modern fish passage technology. Since dam licenses have operation terms of 30 to 50 years, NOAA’s involvement in relicensing provides a rare opportunity to open many miles of upstream habitat while maintaining valuable energy production.

For example, in 2006, the completion of the Columbia Fishway on the Broad River — the first for South Carolina — reopened 24 miles (39 kilometers) of habitat for the Santee Basin’s shortnose sturgeon, shad, striped bass, and herring for the first time since the 1800s. The fishway has unique features intended to accommodate the distinctive swimming habits of the shortnose sturgeon. The fishway ladder is designed to allow fish to pass around the dam by swimming up a series of small pools or "steps" of water until they can continue on the other side. NOAA worked cooperatively with state, private, industry, and federal partners in planning and building the fishway.

Partnerships are a big part of NOAA’s work to prevent fish populations from further decline. In the southeastern U.S., where more than 40,000 dams and failing culverts affect the passage of endangered fish like the Gulf sturgeon, NOAA hopes that the new Southeast Aquatic Restoration Partnership (SARP) will help.

The SARP was formed specifically to address aquatic resource issues in this region. It is a voluntary collaboration of natural resource managers and professionals, both inland and coastal, working together to protect, conserve, and restore aquatic resources throughout the Southeast.

SARP is also one of the first regional Fish Habitat Partnerships recognized under the National Fish Habitat Action Plan (for details, see fishhabitat.org). The Action Plan is an investment strategy to make dollars go farther in protecting, restoring, and enhancing our nation’s waterways to sustainable health.

"It’s a great example of how organizations can set aside what divides them and come together for a common cause," says Susan-Marie Stedman, a fishery biologist in NMFS’ Office of Habitat Conservation and staff to the National Fish Habitat Board. "With healthy habitats and healthy watersheds, we can help prevent new species from reaching the endangered species list."

Rachel Brittin, the senior communications specialist with the NMFS Office of Habitat Conservation, can be reached at Rachel.Brittin@noaa.gov or 301-713-0174.