Sacramento River Animals
On a cool and misty morning somewhere south of Redding, California, jet boats roar across the tranquil Sacramento River. Armed with tridents, machetes and poleaxes, it seems akin to a scene from an action movie; except that “California Department of Fish and Wildlife” is painted on the boats. One by one, the boats peel out of formation and hole up in eddies and backwaters beside the main river channel. Then, they wait.
Once a pale shadow is spotted within the murky depths of the riverbed, someone onboard thrusts a trident into the water and sinks its barbed prongs into something fleshy. Then, they raise it back out of the water and pivot the catch toward the bow. Glistening in the morning light, covered in welts and sores with blood streaming, a creature resembling something from a horror films slaps onto the deck. The catch lands on a measuring board and the team flies into action, calling “Fork length: 870mm, male, spawned, disk tag ready.”
It is an adult Fall Run Chinook Salmon, just past the end of its life cycle. It takes on a zombie-like appearance as it consumes its own body for energy on the journey upstream to spawn. After spawning, the fish died and continued decomposing before crossing paths with the Carcass Crew.
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Aboard the jet boats, the fishy bodies are dissected in the name of science. With knives and forceps, researchers extract eyeballs and otoliths (ear stones) from the fish. Putrid carcass residue spills across the bow and splatters the boots and pants of the team. Eyeless and mutilated, the fish is clamped with a metal tag and tossed back into the current. This floating horrorshow is one example of the length that people will go to understand and protect Chinook salmon.
This fish was, despite being slaughtered after its death, one of the lucky ones. It completed its life cycle in a largely hostile landscape: it survived variable ocean conditions, slipped past salmon fishermen, and avoided Delta water diversions on its way upstream to spawn. Something of a feat since only thousands of salmon are able to make the journey homeward now, when millions once did (Gresh 2011). Its tissues bear chemical traces from the waterways and food webs that sustained it across its lifespan. Its metal tag helps researchers compute the total number of returning adults by comparing the number of tagged to recaptured carcasses. This carcass is part of a massive effort to quantify how many spawning adults return, and what helps them survive the long watery journey.
Scientists aren’t the only ones looking for salmon carcasses. All along the Pacific Coast, organisms of all trophic levels, and even the next generation of juvenile salmon, sustain themselves on nutrient-rich carcasses. In Salmon streams in Alaska and the Pacific Northwest, bears and wolves feast on carcasses and carry their leftovers into adjacent riparian forests. This enables trees to uptake the nutrients of decaying fish. Marine-derived nutrients can restructure entire forest ecosystems, and provide nutrient-limited headwaters a pathway for growth (Naiman 2009).
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In California’s Central Valley, much of the water and its nutrients are appropriated for agriculture. In 2018, the Pacific Fishery Management Council estimated 108, 000 returning Chinook Salmon adults in California’s Central Valley (Pacific Fishery Management Council, 2019). Assuming the average adult Chinook Salmon weighs 20kg and contains about 5% Nitrogen, Chinook Salmon delivered roughly 126 metric tons of marine-sourced nitrogen fertilizer to the Central Valley last year. Isotopic tracing has shown that these nutrients make their way into wine grapes, and possibly other crops, irrigated from salmon streams (Moyle and Merz 2006). This Halloween, consider something truly spooky: when you prepare a fresh salad or pour a glass of Pinot Grigio, you might be giving second life to the carcass of a long dead Chinook Salmon. Cheers!
Gresh T., Lichatowich, J., Schoonmaker., P. An Estimation of Historic and Current Levels of Salmon Production in the Northeast Pacific Ecosystem: Evidence of a Nutrient Deficit in the Freshwater Systems of the Pacific Northwest. Fisheries 25:1. 2000
Merz, J. and P. Moyle, Salmon, Wildlife and Wine: Marine-Derived Nutrients in Human Dominated Ecosystems of Central California. Ecological Applications 16(3) 2006.
Sacramento River Watershed
Pinay, G., O’Keffe, T., Edwards, R., Naiman, R., Nitrate removal in the Hyporheic Zone of a Salmon River in Alaska.” River Research and Applications 25. 2009What’s a float down the river without seeing some spectacular wildlife along the way? The American River Valley has more than its fair share of critters that swim, soar, and slink. Here are just a few of the wild things you might see…if you keep your eyes open.
Fishermen (and women) have claimed to pull 50+ pound bass from the waters in mid-summer, but we all know how fishermen embellish the facts, so it’s probably best to see for yourself!
Keep your (waterproof) camera at the ready on a trip down the American. The banks are teeming with creatures that line up to point and laugh at the silly humans being bounced out of that giant rubber boat. OK, maybe not really, but there’s plenty of furry creatures to see. Aside from the normal forest animals, such as deer, chipmunks, and squirrels, you might be lucky enough to see one of these easily missed animals:
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Don’t panic though! According to a Wikipedia article, the last attack was nearly 20 years ago, in 1994, when a 40-year-old Placerville resident was killed by a cougar (yikes!) while jogging on a trail along the American River. So the chance of an encounter with one of these great cats is amazingly remote, but do stay alert out there and always keep to a safe distance from
The American River Valley is a playground for birdwatchers. You can expect to see common birds, such as wood ducks and woodpeckers, but there are some pretty spectacular creatures in the treetops if you’re willing to look hard enough. Birdwatchers should be on the look out for these winged wonders:
Check out the shores of the American and see if you can spot a Green Heron, or watch the tree line for a glimpse of the wild turkeys that roam there.
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The American River Valley is home to more critters than you can count in a day, but not all of them are willing to pop right out and mug for the camera. Keep looking! That movement you detected out of the corner your eye could be a Fallow deer smiling at you from the shores of the river as you drift past. Or it could be a puma…The North American river otter is solitary except when mating or raising young. They have large territories of up to 75 square miles that they mark with musk, an oily liquid secreted from scent glands at the base of the tail. Although they are sometimes seen foraging for food or sunning themselves on rocks during the day, these otters are most active during the night.
River otters keep their eyes open underwater, which aids in their hunting. When submerged, they also use their stiff, sensitive whiskers and excellent hearing to help find their prey.
Even though these otters are mostly aquatic, they do spend some time on land. Because of their large territories, they may travel several miles to reach another lake, river or stream. Although their dense fur is water-repellent, it is not waterproof. The fur acts much like a dry suit does for humans, trapping a layer of air between it and the skin to keep the otter insulated in cold temperatures. To properly maintain their fur’s insulating quality, the otters must sun themselves on land and groom their fur after spending many hours in the water.
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North American river otters breed in the spring and due to delayed implantation, give birth in the following spring. The embryo remains undeveloped in the female until it is evident by her health that there is plenty of food for her offspring. If her health is not good enough to continue with the gestation, the embryo is aborted naturally.
The den is usually made in an abandoned muskrat or beaver lodge but can be made in a hollow in the riverbank and secluded in the vegetation. The pups are born blind but their eyes open within the first month. At three months of age, the mother begins to teach her pups to swim and forage for food. They are fully weaned at four months, and by the time they are seven months of age the pups are proficient swimmers and hunters. Although not fully grown until two years of age, they are independent at one year old.
While some otter species are threatened with extinction, North American river otter populations are stable. For years, they were hunted by the thousands for their pelts and were a mainstay of the fur trade of this country for the better part of the 17th and 18th centuries. Now, the largest threat to this otter is human encroachment, which causes loss of habitat, polluted water sources, and loss of adequate food.
Sacramento River Wildlife Area, Ca, Us · Inaturalist
Although this species of otter is rather adaptable in its lifestyle, researchers are concerned that the otters
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