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You Shall Not Pass

Chinook Salmon

Removing Fish Barriers

In 1969, a burning river helped draw attention to the polluted state of many United States waterways. Since then, much progress has been made to clean them up, allowing wildlife to thrive in habitats that were once dead. It’s only more recently that attention has migrated (pun intended) to fish passage problems.

According to NOAA, In the United States, more than 2 million dams and barriers block fish from migrating upstream to spawning and rearing habitat. The Washington State Department of Transportation (WSDOT) says that a little under two thousand culverts block fish passage along Washington highways. As of last year, WSDOT completed 319 fish passage projects, but there is still much to accomplish.
Read on for an example of a recent project, what services are needed to clear the way, and information about Washington, Oregon, Hawaii, and Alaska organizations that are trying to make a difference.

Example of a Fish Passage Project—Rue Creek

Before construction

Rue Creek before construction.

After construction

Rue Creek after construction.

The Pacific Conservation District received a Washington Coastal Restoration Initiative grant from the Washington State Recreation and Conservation Office. Hart Crowser supported the Pacific Conservation District with design and development of two culvert replacements on Rue Road in Pacific County.

Fish passage and flow conveyance capacity were restored by removing the existing culverts and overlying fill, and installing a 50-foot bridge that met design requirements in the Washington Department of Fish and Wildlife’s Water Crossing Design Guidelines and Washington State Department of Transportation’s Standard Specifications for Road, Bridge and Municipal Construction and Design Manual. Staff then used the stream simulation approach (one of the methods to size and design culverts that is an option in the Washington Department of Fish and Wildlife’s Water Crossing Design Guidelines) to design the pattern, dimensions, and other features of the stream channel at the crossing, which would enable safe passage of juvenile and adult salmonids both upstream and downstream. An added benefit was that the replacement should prevent the creek from flooding Rue Creek Road and nearby residences.

Services Needed for Fish Passage Projects

These projects can require:

  • Hydraulic engineering
  • Geotechnical engineering
  • Stream reach assessment
  • Wetland delineation
  • Permit applications to comply with Section 404 of the Clean Water Act, Section 7 of the Endangered Species Act, and other federal, state, and local permit requirements. For the Rue Creek example above, this included preparation of a JARPA, SEPA checklist, ESA Section 7 Biological Assessment, Essential Fish Habitat assessment, and Stewardship Plan.

Action on the Local Level

Washington

In 2014, the Washington State Legislature created the Fish Passage Barrier Removal Board to develop a coordinated barrier removal strategy and provide the framework for a fish barrier grant program. Its stated mission is to “identify and expedite the removal of human-made or caused impediments to anadromous fish passage in the most efficient manner practical through the development of a coordinated approach and schedule that identifies and prioritizes the projects necessary to eliminate fish passage barriers caused by state and local roads and highways and barriers owned by private parties.”
The board has monthly meetings; agenda and meeting handouts are available on its website. It advanced its first project list to the legislature, which has been funded.

Oregon

The Oregon Department of Fish and Wildlife has a nine-member Fish Passage Task Force, which “advises the Oregon Department of Fish and Wildlife and the Fish and Wildlife Commission on matters related to fish passage. These matters include, but are not limited to, rulemaking to implement statutes, funding and special conditions for passage projects, and exemptions and waivers.” The most recent agendas and minutes are at the link above; older ones are here.

Hawaii

The Pacific Islands Fish and Wildlife Office of The US Fish and Wildlife Service says that the Hawaii Fish Habitat Partnership “is composed of a diverse group of partners that have the capacity to plan and implement a technically sound statewide aquatic habitat restoration program. The partnership is committed to implementing aquatic habitat restoration in the appropriate landscape scale to achieve conservation benefits.”

They list “instream structures and barriers including stream diversions, dams, channel alteration, and road crossings” as one of eight key threats to freshwater species and habitat.
See the Pacific Islands Fish & Wildlife Office annual report for fiscal year 2017 for more information.

Alaska

The Alaska Department of Fish and Game has a fish passage inventory database with information about 2,500 stream crossings. They have partnered with other organizations to complete at least 33 culvert replacements.

You Shall Pass

A blocked river isn’t as dramatic as a burning river, which makes it harder to draw attention to the plight of the remaining blocked fish. But the hope is that continued effort will forward the progress that is already being made.

STEM for Future Generations

Jessica teaching about salmon

Science, Technology, Engineering, and Mathematics (STEM) schools in our area and across the country are working to improve the way our students learn in these subject areas. These STEM-focused schools offer a more hands-on approach to teaching, from using objects students can physically manipulate to working with resources and companies in the area to bring in experts to teach the students more about these fields.

This is why Jessica Blanchette, a marine biologist at Hart Crowser, volunteered her time to educate the 4th graders of Odyssey Elementary on the life cycle of salmon, a crucial element of the ecological community of the Pacific Northwest.

Using multiple instructional strategies, including hands-on activities and colorful presentation materials, Jessica captivated Mukilteo School District students with her knowledge of fry, parr, and smolt—the salmon life cycle. Students had many questions and Jessica had plenty of answers!

Jessica led a thoughtful discussion about the human relationship with salmon, our impacts on them, and ways in which we can promote a successful co-existence. There was excitement in the classroom as the lesson wrapped up: not only because of the activities and new knowledge, but also because the students were beginning to see that one day they, too, can be scientists.

When scientists like Jessica share their time to promote STEM, it has a positive and lasting impact in the community. Hopefully, with more endeavors such as this, local scientists will make a positive difference in our world and for future generations.

Salmon Life Cycle

eDNA: A Powerful Tool for Scientists and Managers

Sampling eDNA in a stream

Using a pump to filter stream water to get an eDNA sample to determine whether salmon are in the stream.

Detecting the presence or absence of a species of interest is a common challenge for scientists and fisheries managers. Whether you’re interested in protecting an endangered species or removing an invasive species, knowing where they are or are not is crucial. Many techniques can be time-consuming or damaging to the local environment, and they don’t always work on more cryptic species. An emerging technique has the potential to address some of these pitfalls: environmental DNA, or eDNA.

eDNA is DNA fragments found in the environment (usually in soil or water) that come from an animal. Animals shed cells from their bodies through routes such as mucous, feces, or skin flakes. Each cell contains a full set of nuclear DNA and many copies of mitochondrial DNA. As these cells break down, the DNA is released into the environment. A researcher can collect samples (such as water or soil samples) and analyze any DNA present (typically mitochondrial DNA) for a match with the target species.

A useful application of this technology is to learn when and where endangered/threatened salmonids are present. Knowing which drainage systems these fish spawn and rear in is essential to managing and restoring their populations. Scientists can take water samples along river and creek systems where they suspect salmon will be. They then analyze the water samples for salmon DNA, and generate maps of fish distribution. If sampling is repeated over time, temporal trends along with spatial trends in salmon populations can be mapped, providing powerful information to managers and policy-makers.

In the future, eDNA may also help determine how many of each species of interest are in a given area. Research into the relationship between quantity of eDNA obtained and population numbers is ongoing.

For more information on eDNA methodologies, see this USGS factsheet.

What Do Tree Trunks and Fish Ears Have in Common?

Burbot Otolith

Burbot otolith (Photo: Maria Sandercock)

Long-nose sucker otolith (Photo: Maria Sandercock)

Long-nose sucker otolith (Photo: Maria Sandercock)

Most of us know about tree rings—a tree forms a new one every year in its trunk. When counted, they tell us the tree’s age. But trees are not the only living things to produce annual rings. All fish produce small calcium carbonate structures just below their brains called “otoliths.” Fish add calcium carbonate and protein to these structures throughout their life. In a similar process to trees, rings occur on an otolith when a fish’s growth slows down during colder months and the deposit appears white, compared to darker/translucent deposits as their growth speeds up in warmer months. This results in yearly rings that coincide with the fish’s age.

Biologists can extract a fish’s otoliths and, using a microscope, count the rings to get an estimate of the fish’s age. Aging fish is useful for understanding age structure and population trends in a fishery. Otoliths vary in size and shape from one species to another, and can be used to identify the species it came from. This helps biologists trying to understand marine food webs—they can use otoliths found in the stomachs of seals, sharks, and other fish to identify what fish they eat.

Try your hand at aging an otolith