Spectator sport: Salmon spawning

By Susan Davis December 10, 2012 01:13 pm

 A spawning salmon in Mill Creek thrashes in the water as one of its final acts before expring after a journey from the sea.  Del Norte Triplicate file / Bryant Anderson
A spawning salmon in Mill Creek thrashes in the water as one of its final acts before expring after a journey from the sea. Del Norte Triplicate file / Bryant Anderson
 The “Hey Ranger” column written by employees of the Redwood National and State Parks is published monthly. Today’s column is by Park Ranger Susan Davis.

There! Right by that mossy rock, where that white stick is twitching in the current! Wait … well, I thought I saw it … maybe not.

The dark mass shifts ever so slightly, teasing with a brief flash that one doesn’t quite see; the shadow moves, then morphs into a different shape, then shifts again. And you’re still wondering in the quiet if something is really there. Suddenly the water explodes in a tumult of splashing as writhing forms tear against the current and you can see one, two, no — three —huge fish in improbably shallow water thrash their way up to the next deep sheltering pool.

 

The quiet closes in again and you find you’re holding your breath, marveling at what you just witnessed — salmon in their epic journey home.

The giant fish smelled this place — the unique smells of this stream where they were born years before — many months and many miles ago, while on the open Pacific. Every living and non-living thing in the cradling watershed above the rushing water speaks to the fish as home: the different trees that provide shady shelter as well as food for the insects that will later provide food for the fish’s young; the bank-roaming and burrowing animals who will benefit from the fish’s eventual death; even the composting smells of rock and soil.  

 Park Ranger Adam Friedrich assists young fish-watchers during salmon spawning season.  Courtesy Redwood National & State Parks
Park Ranger Adam Friedrich assists young fish-watchers during salmon spawning season. Courtesy Redwood National & State Parks

The stream calls the salmon home to carry out one singular purpose — to create new life, then cease to be, leaving the future up to other forces. 

Humans usually only get to witness the ageless spectacle of spawning salmon from television documentaries or vicariously from pictures in books. Not here! We get to see the real thing in true HD 3-D, “Wild Kingdom” every year right here in our own back yards, in the coastal watersheds of the Smith River and Redwood Creek, protected within Redwood National & State Parks.  Allow me to share my favorite front-row seats.

Intro to salmonids

First, some basics.  

All salmon are not created equal. “Salmonids” share three life history characteristics: anadromy (being born in fresh water streams, migrating out to the ocean and returning to fresh water as mature adults to spawn); homing (returning to the stream where they were born); and reproducing once before dying. That said, not all salmonids do all of those things regularly all of the time. Those general characteristics differ by species, watershed, stream, food availability, weather events, and even yearly climate changes.

Of the Pacific salmonids, five are best-known as “salmon” (chum, sockeye, Chinook, coho and pink), and an additional two species as “trout” (the coastal cutthroat, and the steelhead, an ocean-going version of the land-based rainbow).

Each species is recognized by its “race” (its river of origin), and within each race by several “runs,” populations grouped by the time of year they return to their birth rivers to begin their final spawning journey.

Of the five species of Pacific salmon, our local November and December fish are primarily 3- to 4-year-old Chinooks (Oncorhynchus tshawytscha) or kings. Smaller numbers of cohos (O. kisutch), also called silvers, will come in later in December. An occasional chum will wander in, but rarely sockeyes or pinks (they are found farther north, into Canada and Alaska).

Chinooks’ Latin name, Oncorhynchus, comes from the Greek roots onko (hook) and rynchos (nose), the facial feature acquired by mature males.

Chinook put on show

In Del Norte, we are treated to “fall-run Smith River Chinook.” Because of their large body size, Chinook need deeper water and larger gravel size (up to cantaloupe-size rocks) than other salmonids for their nests, called redds. The recent rains have finally raised water levels, providing salmon access to their birth streams and giving us tickets to the Big Show.

Upon entering the freshwater rivers, streams or creeks from the ocean, Chinook stop eating. Their stored fat and muscle acquired from years at sea must last long enough to get them past human and natural obstacles and sustain them while they build nests, fight for dominance, mate, and spawn. Their bodies change dramatically as they adjust to a fresh water world. They acquire spawning colors, their stomachs and intestines shrink, and their ability to fight disease and heal injuries declines. Males develop their hooked jaws and sharp fighting teeth. Females search for the perfect nesting site, with just the right combination of clean gravel, in water about a foot deep with good flow to provide oxygen for eggs.

The female digs her nest not by truly digging, but by rolling on her side and pumping her tail against the gravel, creating a vacuum that pulls the rocks off the bottom. The current carries loosened stones downstream. When the redd is deep enough, she crouches in the depression while males court her by quivering and crossing over her back and fighting off other males.

When both are ready, he moves alongside her and at the same time they deposit eggs and milt in the redd. The eggs settle into the spaces between the rocks, the female covers the nest with loose gravel, and the deed is done. Some salmonids build several redds, each one upstream of the other, loosened gravels from each covering the prior downstream one.

Each redd will contain thousands of fertilized eggs, packets of future life. The female will defend her nest until she is too weak to do so, but both parents are totally spent and will die within days.

If stream conditions stay good, the hatching fishlets will emerge from their protective gravel bed in three to five months, in time to take advantage of the spring aquatic insects who will be food, and who have been feeding on the decaying leaves dropped by the stream-side trees just before the salmon’s eggs were laid. Chinook salmon “go and grow,” heading downstream as soon as they emerge, feeding as they travel, rearing in the estuary at the river mouth for several months before heading to sea in the first year of their life.

It is estimated that of every 10 million eggs laid, only 10 mature Chinook will make it back to repeat the eons-long ritual of life, death and life.  The fish we see in the next few months are genetically the fittest of their species, having survived all the odds and obstacles placed before them in their lives, to returnhere and teach us.

See for yourself

You can personally be a part of it! You will only need warm clothes, polarized glasses that help to cut water surface glare, and patience.  Stay well back from bank edges; fast water may have undermined the bank, and your weight could collapse what you can’t see. Approach creek areas slowly and quietly to avoid frightening fish by approaching too closely. Do not disrupt courtship rituals! 

Look for redds — usually 4- to 6-foot-long white ovals in the center of the stream bead, the turned-over gravels exposing their non-algae sides. Redds are commonly just upstream from riffle breaks where water is moving faster.

Look for fish!  If not actively swimming in the main channel or crouching in the redd, fish will often be seen sheltering along banks under overhanging woody debris, or in shadows below bridges.

Here are my favorite creek areas for salmon-watching within Redwood National & State Parks (maps available at park visitor centers in Crescent City and Orick):

NORTH

Clarks Creek: Walker Road Day Use Area, Highway 199, viewing from bridge or continue on Walker Road, bear right at the fork to drive to the mouth of the creek, walk upstream.

Mill Creek: Mill Creek Trail Highway199 trailhead, Howland Hill Road, Stout Grove (make lefts on the loop trail to get to mouth of Mill Creek, walk upstream if water levels allow), Breen Bridge, Nickerson Ranch Trail

Upper Mill Creek Watershed: Accessible via Hamilton Road off Highway 101, Saturdays and Sundays. There are several viewing areas along the various branches of Mill Creek within easy walks of the gates and parking areas, including Picnic Road, which parallels the West Branch. 

SOUTH

Chinook enter the southern half of RNSP from the ocean into Redwood Creek, south of Orick. 

Prairie Creek: Prairie Creek Trail, access from the Elk Prairie Visitor Center. Or, plan an overnight at Elk Prairie Campground to watch salmon right from your campsite!

Lower Redwood Creek: from the Picnic Area off Bald Hills Road, Redwood Creek Trail provides access a short way to the creek.

Upper Redwood Creek: access from the Tall Trees Trail off upper Bald Hills Road. Free permit for trailhead parking available at Kuchel Visitor Center, Orick. It’s a 1.3 mile steep hike from parking lot to creek.

Lost Man Creek: viewing possible from bridge just before parking area, or first part of Lost Man Creek Trail.

Or, attend one of the free salmon spawning programs offered by RNSP and the Redwood Parks Association, Saturdays 1-4 p.m., today, Dec. 8, 15, 22 and 29. Call 465-6191 for information.

The end? Or, just the beginning? For salmon, their saga continues even after death. Spawning salmon reverse normal downstream nutrient flow and move ocean nutrients back upstream into fresh water — like a nutrient conveyor belt. The marine nutrients salmon absorbed during their years in the ocean are transferred yet again as their bodies decompose.

Bears, eagles, raccoons, otters, and many other land animals re-use that same energy when they consume the dead salmon. Ocean nutrients have also been detected in surrounding land ecosystems. Plants along the stream share the rich bounty, further passing it along through their leaves, which in turn feed the insects that feed the baby salmon who will hatch next spring.  

INFORMATION SOURCES

• http://redwoodhikes.com  Extensive maps of RNSP, available for purchase at Park Visitor Centers 

• U.S.Fish and Wildlife Service, Pacific Region, www.fws.gov, “Salmon of the Pacific Coast”

• Pacific States Marine Fisheries Commission, StreamNet Project:  “Anadromous Fish of the Pacific Northwest”

• http://www.csgc.ucsd.edu/RESEARCH/PROJPROF_PDF/WALDVOGEL_2.pdf  “Fall Chinook Spawning Escapement Estimate & Age Composition for a Tributary of the Smith River, California – 23-Year Analysis” by Jim Waldvogel, California SeaGrant Marine Advisor

• www.thomasdunklin.com/gallery/   (underwater photography of salmon in northwest California rivers)