Science Spotlight

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  • February 23, 2018

Grass and shrub-covered dunes next to estuary waters, under a cloudy sky
Restoration project area. CDFW photo by Andrew Hughan.

Map with orange and yellow areas to be restored, between Humboldt Bay and the Eel River
Yellow and orange indicate restoration areas at the Ocean Ranch Unit of CDFW's Eel River Wildlife Area.

How does one best go about making an already bountiful and bucolic part of the Golden State even better? Sometimes, perhaps paradoxically, it pays to look to the past in order to be forward thinking in the present.

CDFW, Ducks Unlimited, and many partners have undertaken the Ocean Ranch Unit of the Eel River Wildlife Area Integrative Ecosystem Restoration Project Planning Process to enhance the estuarine and coastal dune ecosystem of the Ocean Ranch Unit in Humboldt County

The approximately 2,600-acre Eel River Wildlife Area was acquired to protect and enhance coastal wetland habitat, and was designated as a wildlife area by the California Fish and Game Commission in 1968. The initial decision to undertake an estuary restoration-planning project began more than a decade ago. After several years of monitoring to gather necessary data, Ducks Unlimited completed a feasibility study, funded by CDFW’s Fisheries Restoration Grant Program and the California State Coastal Conservancy, in December 2015.

The primary goal is to restore and expand natural estuarine and dune ecosystem functions, including the recovery and enhancement of native species (including fish, invertebrates, wildlife and plants) and their habitats. These changes should also help mitigate current and future impacts of climate change. Sea level rise will likely result in saltwater inundation further upstream, which is expected to modify habitats (for example, the loss of tidal marsh migration inland) and the size and shape of the estuary.

The project has been a revelation for Michelle Gilroy, a CDFW district fisheries biologist who works primarily in Humboldt and Del Norte counties.

“For the first time in my 30-year fisheries career, which began in the Eel River watershed, I am achieving a long-time goal of mine: To envision, develop and work through to completion, or near completion, a large restoration project,” said Gilroy. “This exciting project and the extraordinary team I am so very fortunate to work with is making that dream a reality – and in the Eel River estuary, one of California’s largest estuaries. It is definitely one of the highlights of my career.”

Improving the connectivity of tidal and freshwater habitats, and controlling or eradicating invasive plants, are key goals of the restoration project.

A feasibility study guiding the project analyzed the potential for expanding tidal functions within 475 of the 933 acres of the unit to aide in the recovery and enhancement of estuarine habitat and native species. Restoration of these essential habitats is vital to the recovery of anadromous salmonid populations in the Eel River, as estuaries provide critical nursery and rearing conditions for juveniles prior to ocean entry.

The unit is located within the Eel River estuary, a mile and a half north of the mouth of the Eel River and approximately four miles northwest of Loleta. The unit is comprised of a diverse set of habitats, including coastal dunes, riparian woodlands, tidal mudflats, tidal slough channels, salt marshes and managed freshwater marshes.

Prior to second-wave human settlements, this portion of the estuary, then inhabited by Native Americans, consisted primarily of salt-marsh habitat dotted with areas of spruce and hardwood forest, and native grasslands. An abundant fishery, which included the prized salmon, along with native plants, provided sustenance for the Wiyot people who lived around Humboldt Bay and the estuary. As Euro-Americans settled this region, however, they largely drove the Wiyot people off their traditional lands and began to repurpose portions of the environment.

By the end of the 1800s, most of the salt marsh and forestlands were drained and converted to farm and grazing land. This conversion of tidal marshes to pastures was done with purpose – but such perceived progress carried an ecological cost.

The construction of levees and tide gates to drain salt marsh increased sedimentation, flooding, and the amount and diversity of habitat and food supply for fish and wildlife declined throughout the estuary. This degraded the prior functioning, highly productive estuary ecosystem. In addition, invasive species now threaten the diversity or abundance of native species through competition for resources, predation, parasitism, interbreeding with native populations, transmitting diseases, or causing physical or chemical changes to the invaded habitat.

Despite these declines, the Eel River delta, which includes the Eel River Wildlife Area, today continues to provide vital habitat for many aquatic and terrestrial organisms, including state and federally threatened and endangered fish, wildlife and plant species, and many state species of special concern. More than 40 species of mammals and 200 species of birds use the delta area and researchers have documented at least 45 fish species in the Eel River estuary alone.

The area provides essential spawning, nursery and feeding grounds to several commercially and recreationally important species, including Dungeness crab. Estuaries are among the most productive and diverse ecosystems in the world and are one of the preferred habitats for young Dungeness crabs.

Dungeness crabs use estuaries as critical nursery habitat in their juvenile stages, as not only a refuge from predation – particularly in estuaries with structural habitat such as eelgrass – but also because of the abundance and diversity of prey provided by estuaries. Dungeness crabs are opportunistic feeders – clams, fish, isopods and amphipods are their preferred food sources, as well as other Dungeness crabs. Their predators include those larger crabs, octopuses, and fish, including salmon, lingcod and various rockfishes.

Wildlife, of course, is not the only form of life to reap the benefits of this region, as humans enjoy a range of outdoor activities, including fishing, bird-watching, boating, hiking and hunting.

The project is expected to begin in the summer of 2019.

CDFW photos and map

Top photo: CDFW Senior Environmental Scientist Kirsten Ramey and Eric Ojerholm of the Pacific States Marine Fisheries Commission.



Partners, Funding and Staff

Ducks Unlimited, in partnership with CDFW staff, has recently secured project planning funds from the California Wildlife Conservation Board, and initial project implementation funds from the NOAA Restoration Center. To complete the restoration design and environmental compliance process, this second phase of restoration planning will consist of a continued CDFW and Ducks Unlimited partnership, with additional assistance from several local consultants and a Technical Advisory Committee (TAC). The TAC includes representatives from the U.S. Army Corps of Engineers, the Bureau of Land Management, U.S. Fish and Wildlife Service, National Marine Fisheries Service, California Coastal Commission, California State Coastal Conservancy, North Coast Regional Water Quality Control Board, California Sea Grant, California Trout, Humboldt County Resource Conservation District, Humboldt State University, Redwood Region Audubon Society, private landowners, and the Wiyot Tribe. Additional project partners include AmeriCorps, Tom Origer and Associates, Pacific Coast Fish, Wildlife and Wetlands Restoration Association, GHD Inc., H.T. Harvey and Associates, Moffatt and Nichol, Northern Hydrology Engineering, Pacific Coast Joint Venture, and the Pacific States Marine Fisheries Commission.

CDFW staff who have served on the project management team include Michelle Gilroy, Allan Renger, Scott Monday, Kirsten Ramey, James Ray, Mark Smelser, Gordon Leppig, Michael van Hattem, Jennifer Olson, Linda Miller, Clare Golec, Charles Bartolotta, Robert Sullivan, Tony LaBanca, Mark Wheetley, Scott Downie, Adam Frimodig, Jeff Dayton, Mike Wallace, Vicki Frey, John Mello, and Karen Kovacs.


Categories: General
  • December 6, 2017

a woman wearing a California Fish and Wildlife uniform, standing in waist-high grasses, connects cables in a 1-foot-square, plastic box.
CDFW Scientific Aide Aimee Taylor prepares electrofisher to harmlessly catch Paiute cutthroat trout in North Fork Cottonwood Creek.

an irridescent gray, purple, pink and white cutthroat trout hovers in the sunlit water of a shallow creek
The extremely rare Paiute cutthroat trout (PCT). Photo by William Somer for CDFW.

Two people wearing Fish and Wildlife uniforms stand in a shallow mountain stream, surrounded by lush Alpine vegetation
Aimee Taylor and Senior Environmental Scientist Jeff Weaver electrofish PCT in North Fork Cottonwood Creek.

Four people kneel in green grass next to a stream, huddled around something on the ground
Jeff Weaver, USFWS Biologist Chad Mellison and others take genetic samples from the fish.

At a pack station with horses in the background, two men transfer fish by net, into an old-fashioned milk can.
The project’s lead biologist, Bill Somer, and Chad Mellison transfer the trout from CDFW’s tank truck to cans for the ride to Silver King Creek, by pack mule.

A pack train of seven loaded mules and three riders on horseback traverse a high mountain plain under a partly cloudy sky
The CDFW-FWS-USFS team packs pure PCT in milk cans through the Silver King drainage.

A man wearing hip waders and a California Fish and Wildlife uniform stands knee-deep in a stream that runs through a green meadow, where he lowers a white bucket into the water to release two small fish.
Bill Somer releases Paiute cutthroat trout into Silver King Creek, above Llewellyn Falls.

A trout lies in an elongated net with measuring marks, held next to a white bucket with water and other live fish in it.
Team members measured each Paiute cutthroat trout caught at White Mountain.

The California Department of Fish and Wildlife (CDFW), U.S. Fish and Wildlife Service (FWS), and U.S. Forest Service (USFS) have returned a rare trout species to its home water after a 71-year absence.

In 1946, poachers were decimating the Paiute Cutthroat Trout (PCT), a species whose native range was limited to a nine-mile section of Silver King Creek (Alpine County). To ensure the species’ survival, the USFS and Eastern Packers Association translocated 401 of these fish to North Fork Cottonwood Creek in Inyo County’s White Mountains. This population has persisted in isolation from other forms of trout and has recently provided important restoration options for resource managers. None of this would have been possible without the foresight of concerned biologists seven decades ago.

The conservation history of this rare trout is complex. The initial “conservation” measure was entirely inadvertent. In the early 1900s, Basque sheepherders in the area caught and transported PCT into the previously fishless portion of Silver King Creek above Llewellyn Falls. This early within-basin transfer was the salvation of the PCT, since non-native species were later introduced below the falls. The falls prevented non-natives from reaching the habitat above and protected PCT from hybridization and competition.

The FWS listed PCT as endangered under the Endangered Species Preservation Act of 1966 – the precursor to the federal Endangered Species Act (1973). The species was down-listed to threatened status in 1975, in order to facilitate management and restoration and to allow regulated angling. In 1994, CDFW, FWS and USFS began developing a restoration plan to remove non-native fishes from Silver King Creek and return the PCT to its native waters. From 2013 to 2015, the partner agencies treated 11 stream miles of Silver King Creek and three tributaries below Llewellyn Falls with a fish toxicant, rotenone, to remove all non-native fish species.

The PCT population in Upper Fish Valley, an area of Silver King Creek above the falls, has been considered a primary source for restocking the recovery area. Unfortunately, that population was heavily impacted by the extreme 2012-2016 drought. During this extended drought, lack of snow cover resulted in the stream freezing almost solid during cold snaps. In order to offset the resulting population decline, the partner agencies caught 86 pure PCT in North Fork Cottonwood Creek. On August 23, 2017, the fish were planted back into Silver King Creek above Llewellyn Falls.

Agency staff met in the White Mountain Wilderness (Inyo National Forest) and, along with volunteers and pack mules, hiked from their campsite to North Fork Cottonwood Creek. There, the team used electrofishers to retrieve descendants of the fish moved back in 1946. The fish were hauled out by mule, put in a specialized transport truck, and driven approximately 100 miles to the Carson Iceberg Wilderness. Another mule team then hauled them back to Silver King Creek. Thanks to careful handling by the collection and transport teams, every fish survived the trip home.

Due to its limited habitat, the Paiute Cutthroat Trout has been called the rarest, but most recoverable, form of trout in the United States. With the most recent success of this partnership, and due in large part to the foresight of conservationists in the past, the future looks bright for this beautiful native salmonid.

Learn more on the Paiute cutthroat trout web page.

Photos by Joe Barker, courtesy of U.S. Fish and Wildlife Service, except as noted.

Top photo:
Liz Vandentoorn, from the Inyo National Forest Region 5 Center of Excellence, leads a pack mule team and state and federal scientists to North Fork Cottonwood Creek to capture Paiute cutthroat trout and return them to Silver King Creek.

Categories: General