Plant Spotlight – Grasses of Trinity

Posted on June 11, 2025June 11, 2025 by Kiana Abel

Oak woodlands near Weaverville in 2020. [Kiana Abel, Trinity River Restoration Program]

As the weather starts to warm, California’s hillsides turn golden as grasses dry and take on a reflective sheen. Not only does California’s nickname “the Golden State” refer to it’s historic connection to the gold rush, it also refers to the rolling golden hills of native flowers, like the California golden poppy and less distinct but no less important the native grasses of California. California’s grasslands are a subtle and complex community of individuals which each invite the passerby to slow down and look carefully. One can also trace the last vestiges of water and see where the moisture lingers on the landscape. These last little patches of green show photosynthetic organisms reluctant to take shelter from the summer heat.

Historically it was farmers who were in touch with the detailed eye and mind tuned to the life cycle of grasses. To be a farmer who makes hay, is to understand the boom-and-bust lifecycle of being a grass. As many ranchers will say – being a rancher is really learning to be a grass-farmer. It is an intimate relationship to learn the rhythm of grass growing, to slow down and tap into the cycle. There is a critical threshold in the season, where all the grasses race at a break-neck pace to produce seed. As part of a grass’s strategy, it tracks day-by-day weather in a race to produce and distribute seed in the heat of summer. As a hay producer, it’s best to harvest your hay before all the energy has gone up into the seed and hardened off. This will allow some of the sugars to be readily available for consumption when an animal goes to eat it. If the grass is too far along towards producing its seed, the sugars in the grass become all locked up and stored into their long term, harder to digest form.

Diagram of grasses. [Photo credit: PlantNet Diagram: SWL Jacobs Taxon Concept]

If you’ve ever been curious about grasses, Trinity County has some beautiful remnant examples of grasslands clinging on to the edges of areas where mining did not bury their seeds beneath the sorted rocks. When identifying grasses, I find that it can be easiest to start with the things that you’ll see a lot of and try to find “friends” in the population. Each person relates to plants differently, but I find that it can help to try to find a few native grasses and a few non-native grasses to learn to train your eye to their differences. Knowing a handful of native and a handful of non-native grasses is a great place to start.

Comparing grass cousins

*Bromus diandrus* or rip gut brome. [iNaturalist]

California Brome *Bromus carinatus*. [iNatrualist]

Here is Bromus diandrus or “rip gut brome” so named for its ability to get the long awns of the plant (the bristle or hairy growth that helps carry a seed) all tangled and poking into the skin, mouth or gut of herbivores munching in grasslands. Rip gut brome was introduced to California from European Mediterranean areas and is considered invasive and harmful to crops and foragers alike.

Because grasses are difficult to discern, I’ve noted to visit and reexamine them as the season progresses. With each stage of development from flower to seed each species can change significantly showing their true colors. As Bromus diandrus develops it changes colors and can look quite purple.

Here’s a common native grass that looks quite similar to Bromus diandrus. A cousin to B. diandrus, this is Bromus carinatus or California brome which is a native bunch grass that can be found quite often in many types of habitat.

California brome pollinates via wind, is a great asset in erosion control and is well adapted to survive under a regime of frequent fire. It is also an important food for bear, elk, black tailed deer and seed eating bird species of California.

Look closely when comparing these two brome species by looking at the hair-like awns sticking out of the flower.

In this photo *Bromus carinatus* is on the Left and *Bromus diandrus* is on the right. [Simone Groves, Hoopa Valley Tribal Fisheries Department]

Non-Native Grasses

As livestock were introduced to California farmers often seeded grasses as forage so their animals would be well-fed where they landed. The easy and short list of these species is a great starting place for starting to recognize grasses. These species include Orchard Grass (Dactylis glomerata), Rye grass (lolium perenne), Wild Oats (Avena sp). Avena or wild oats are the same oats that we eat for oatmeal or give to our horses for grain.

Orchard Grass (*Dactylis glomerata*). [iNatrualist]

Rye grass (*lolium perenne*) [iNaturalist]

Native Grasses

And now for some of the native species of grasses! There are three classics to get to know in our area which are blue wild rye (Elymus glaucus), California oatgrass (Danthonia californica) andpurple needle grass.

Blue wild rye (Elymus glaucus)

This grass is a tall hearty looking grass with a large seed. It’s very hard to photograph the whole seed head because it is so long and tall, but once you get to know this plant it’s quite distinct. Blue wildrye provides excellent habitat for birds, mammals and waterfowl, can be used to stabilize streambanks, and is very tolerant to fire. Early in the season it provides forage and the seed is an excellent summertime food source for native mammals and birds [USDA Blue Wildrye (Elymus glaucus) Plant Guide].

California Oatgrass (Danthonia californica)

Danthonia as the genus that represents a variety of native oats, and when you tune your eye you’ll notice slight variation within the group along with some similarities. Their inflorescence (arrangement of the flowers on a plant) is composed of 3-5 spikelets and it is a pretty distinct recipe once you start to recognize it. They have relatively short peduncles (stalks that hold the flower or seed), only about 1-2 feet above the ground and their most distinctive feature are their “hairy arm pits.” Danthonia tends to have very hairy leaves and sometimes particularly long hairs right where the leaf separates from the stalk. Danthonia also looks to me like a little field of tiny stars, as they stand in such a distinct pattern along the ground.

Purple Needlegrass (Stipa pulchra) (Nassella pulchra)

Lastly, Stipa pulchra, recently renamed to Nassella pulchra and commonly known as Purple Needlegrass is a grass that I – personally as a plant person – have heard a lot about throughout the state. Purple needle grass is the most widespread native grass in California and was named the “state grass” in 2004. In my experience I’ve have never seen it doing quite as well as the populations you can find here in Trinity County. This plant has long awns similar to rip gut brome but is soft to the touch while brome is typically quite coarse and harsh to the touch.

Purple needlegrass is drought tolerant and produces a lot of seed which helps to suppress non-native grass species. This grass supports native oak habitats and provides nursery habitat for caterpillars and butterflies of California.

Getting to know grasses is a process of revisiting them frequently to see the way that they change through the year. Touching and observing their basal leaves versus their flowering stalks can help you get to know the ways that they are similar and different from each other. To me, the jovial angle that each grass holds its seed is an expression of its personality and projects attitude. As the seeds mature, usually the stems of the grass start to grow heavy, and once the seeds are dispersed, they’ll spring back up again.

Grasses are a huge part of the plants that we see in our daily lives. Their role creating tiny holes for insects to live in and deep roots which hold our soils together are foundational to a healthy landscape. It’s easy to overlook the niche of grasses when we all spend much of our time trying to weed whack them down. I encourage you to try to take that extra moment to see if you can identify if a grass is native or non-native, bunchgrass or annual grass. These little details are small pieces of history that we used to know in times long past.

References

Bromus carinatus
Native American Ethnobotanical Database: Brome
https://ucanr.edu/sites/default/files/2016-03/235849.pdf
Blue Wildrye (Elymus glaucus) Plant Guide
Nassella pulchra – Wikipedia
iNaturalist see individual links for details for each species

Simone Groves, Riparian Ecologist, Hoopa Valley Tribal Fisheries

Simone is first generation California transplant of scottish descent raised in the unceded territories of the Raymatush in the rural west peninsula of the SF Bay where farmers, farm workers and hippies form the heart of the small town. She graduated in 2016 from Humboldt State University with a BS in Botany and has worked in the outskirts of rural Humboldt county on Natural Resource and Land management since 2013. She is passionate about plants and their interactions with dynamic systems as a mechanism for relearning our human-landscape interdependence.

Bats of the Trinity River

Posted on June 9, 2025June 10, 2025 by Kiana Abel

Wait, bats? Of the river? Yes! A river is more than its bed and banks, it is also intricately tied to the valleys, canyons, and forests through which it flows. Many North American bats are tightly associated with proximity to both forest cover and water (e.g. Dixon 2012), and the bats of the Trinity River watershed follow suit. In fact, some of our bats do almost all of their foraging over and near water, which in a dry, mountainous landscape like ours, means over the Trinity River and its tributaries.

*Bats fly into a Texas sunset. [US Fish and Wildlife Service]*

Bats are the second largest order of mammals in the world, with >1,400 species on every continent except Antarctica, though a majority of those species are in the hyper-diverse tropics. The Klamath Mountains, through which the Trinity River flows, are home to at least 18 species (Reiss, Kauffman, and Feldman 2022). Some of these are year-round residents and are known to hibernate locally, whereas others migrate to warmer climates during the winter. All of our local bat species echolocate, meaning they essentially “yell” in very high frequency sound and then listen for the echoes (the same concept as sonar), which helps them navigate and feed in a dark world.

While the incredible worldwide diversity of bats includes many unique feeding styles such as nectar-feeding flower pollinators, fruit eaters, and (a bat fan favorite) bats that fish for food like the super cool fish-eating myotis, all of the bats in the Trinity watershed eat invertebrates like insects and spiders. That said, there’s a remarkable range of ways that they do that. Let’s take a look at a few of the species that call the Trinity River watershed home.

Myotis species

*A little brown bat. [USFWS/Ann Froschauer]*

Of the bats discussed here, the five or more small, brown, round-eared species of Myotis in our area are perhaps the closest to what people think of when they think of a “bat”. Their appearance exemplifies the German word for bat, Fledermaus or “flutter mouse”, though bats are much more closely related to deer, whales, and carnivores than to rodents.

Yuma myotis (Myotis yumanensis) are among the most frequently encountered species in the region and are “aerial insectivores”, meaning they forage on flying insects. They can be found flying along forest edges but most commonly over slow-moving water, typically only a couple feet above the river. This is because while they will also take things like moths and beetles, they are strongly predisposed to hunting emerging aquatic insects like caddisflies and midges. They make low, repeated passes over water smooth enough for their echolocation to detect the disturbance of insects on the waters’ surface. In areas where few large trees are found, they will form maternity roosts in buildings; these are where large groups of females gather together to raise their pups until they are old enough to disperse. However, in areas of the West including parts of the Trinity River where there are healthy riparian areas with large, old trees, they will roost in things like hollowed-out old cottonwood trees. This is one of the reasons that the Trinity River Restoration Program attempts to avoid impacts to mature riparian forests when building our restoration projects.

*Myotis yumanensis (Yuma myotis) (11362476624) – Yuma myotis – Wikipedia]*

Another Myotis worthy of note is the little brown bat (Myotis lucifugus). While they are less abundant than Yuma myotis in the Trinity River region (Pierson and Rainey 2007), they are strongly predisposed to roosting in buildings and thus relatively commonly encountered. They are noteworthy in that, while fairly generalist in their feeding habits, they eat disproportionately large numbers of mosquitoes, making them allies of their human neighbors (Wray et al 2018). They have quite a large range, extending from the subarctic to the southern US, and through the late 2000s were among the most common bats on in North America. However, they are now classified as endangered by the International Union for Conservation of Nature because of the catastrophic impacts of an introduced disease called white-nose syndrome; it is estimated that the eastern and midwestern populations of the species have declined by 90% since 2010.

*Little brown bat (Myotis lucifugus) in a historic building. [Mike Dixon, Bureau of Reclamation]*

Pallid bat

In contrast to the myotis bats described, pallid bats (Antrozous pallidus) are quite large, with a wingspan of up to 16 inches. Beyond their large size, they also have enormous ears that can be a third of their body length. This is because rather than catching insects on the wing, they are gleaners, meaning they hunt prey on structures or, in their case, the ground. They are still capable of echolocation, but their over-large ears also allow them to listen for the sounds of their prey and target them that way. They are particularly fond of scorpions, of all things. Their inconsistent use of echolocation and ground-hunting behavior also means they tend to hunt in more arid or open areas, but they still stay relatively close to water. They frequently roost in trees in northern California (Baker et al. 2008) but can also be loyal users of strategically located buildings as night roosts. Night roosts are places that bats hang out for a variety of reasons including rest, digestion, picking apart large prey items, and various social interactions including information sharing (Ormsby et al. 2007). For several years, I have observed congregations of 5-20 pallid bats in the same corner under my eaves almost every night when overnight lows temperatures exceed 45^oF. I appreciate them keeping the front of my house scorpion-free!

One fun fact about the pallid bat is that it is officially the state bat of California!

*Pallid bats (Antrozous pallidus) have frequently used this night roost on a cabin next to the East Branch of East Weaver Creek. [Mike Dixon, Bureau of Reclamation]*

Hoary bat

Hoary bats (Lasiurus cinereus) are striking in appearance. Rather than the shades of brown with which bats are often portrayed, the hoary bat has dark fir with brightly frosted tips and a yellowish face. Also unlike many bats of the temperature regions, it doesn’t hibernate – rather, it spends its summers from the northern U.S. (including northern California) well into Canada, and then in the fall migrates sometimes over 2,000 km south to a winter range that extends from the Southwest into Central America (Cryan et al 2004).

Rather than flying low over the water or ground or on the edges of forest, the hoary bat is a high-flying moth specialist that makes long passes over open water or the top of the forest canopy, sometimes flying almost 25 miles in a night of hunting. The coevolution of bats and moths has been a subject of long study, as there is evidence that echolocation by moth-hunting bats drove the evolution of ears and evasive behaviors in moths, which in turn changed how moth-specialist bats echolocate (Ter Hofstede and Ratcliffe 2016).

Hoary bats are more solitary than most of our bats and tend to roost individually by hanging from tree branches like dead leaves, but they can form large aggregations around landmarks during their long southward migrations. This means that after they leave our Klamath Mountains, they are often recorded in what would seem to be pretty unusual places for a bat – they have been observed swarming ships at sea and commonly recorded over the Farallon Islands 30 miles off the coast of San Francisco. These long, sometimes over-water migrations also presumably led to one of the more unlikely events in the history of bats – the colonization of the Hawaiian Islands over 1.3 million years ago by hoary bats from what is now the west coast of the U.S. In this single founder event, wayward bats established the most isolated bat population in the world, which has since diverged significantly into its own species, the critically endangered Hawaiian hoary bat (Lasiurus semotus).

Bats and people

I have already mentioned how a couple of our native bats benefit people by controlling pests, and that topic has been the subject of many publications. Suffice it to say, bats are very important to the ecology of the Trinity River watershed and provide services to its people here and throughout the world, but they can also be inconvenient and, occasionally, dangerous to people. Here are a few suggestions for living with bats.

First and foremost – while bats don’t “carry” rabies (it is also deadly to them), the abnormal behavior of rabid bats is what often brings them into contact with people. NEVER pick up a bat that you encounter. It is unlikely that it has rabies, but the consequences of contracting rabies are so serious that it is not worth the risk. If you encounter a bat in your house, shoo it out but do not handle if it all avoidable – you’d be surprised how thick of a glove a bat can bite through!
If you have the space for it, embrace an untidy yard. Long grass provides a home for large insects like crickets that are preyed upon by our gleaning bats. Leaving fall leaves until the following spring allows many types of caterpillars and beetle grubs to use them as winter cover, providing food for our aerial insectivores the following summer. Trees with loose bark cavities or large are used by many species for roosting and can be left as habitat where they do not cause a hazard.
Many species like to use buildings for day or night roosts or for hibernation. Sometimes this isn’t a huge deal – I already mentioned that I appreciate the night roost above a seldom-used door at my house, and even use their guano as a garden amendment. However, in confined spaces like the walls and attics of buildings, the guano can become smelly and damage walls, and bats roosting in those places sometimes find their way into parts of those buildings with people (not a good thing, as already discussed). Many pest control companies have experience with excluding bats in a humane way (essentially letting them fly out but not back in). If you need bats evicted from your home, try to wait until late summer when the pups have fledged, so as not to separate foraging mothers from their flightless pups.
If you’d like to encourage bats to use your property, you can build or buy prefabricated bat houses. The trick in a climate like that of the Trinity watershed with sometimes intensely hot days and cool nights is to find the right sun exposure. Nursing mothers and pups want a spot that will gather and retain heat into the evening but will not get so hot during the day as to be uninhabitable. There’s an element of trial and error (and luck) to getting bats to move in, but it’s a great way to provide wildlife habitat and help keep your bugs down. For more resources on gardening and bat houses, this is a great place to start: Bat Gardens & Houses – Bat Conservation International.

References

Baker, Michael D., Michael J. Lacki, Greg A. Falxa, P. Lee Droppelman, Ryan A. Slack, and Scott A. Slankard “Habitat Use of Pallid Bats in Coniferous Forests of Northern California,” Northwest Science 82(4), 269-275, (1 September 2008).

Dixon, Michael D. “Relationship between land cover and insectivorous bat activity in an urban landscape.” Urban Ecosystems 15 (2012): 683-695.

Ormsbee, Patricia C., James D. Kiser, and Stuart I. Perlmeter. 2007. Importance of night roosts to the ecology of bats in Michael J. Lacki, John P. Hayes, and Allen Kurta, eds. Bats in Forests – Conservation and Management. The John Hopkins University Press: pp 129-151.

Pierson, Elizabeth D. and William E. Rainey. 2007. Bat distribution in the forested region of Northwestern California. Report for California Department of Fish & Game, Contract #FG-5123-WM.

Reiss, Karen, Michael Kauffman, and Chris Feldman. Mammals in Michael Kauffman and Justin Garwood, eds. (2022). The Klamath Mountains – A Natural History. Backcountry Press. Pp. 428-430.

Ter Hofstede, Hannah M., and John M. Ratcliffe. “Evolutionary escalation: the bat–moth arms race.” Journal of Experimental Biology 219.11 (2016): 1589-1602.

Wray, Amy K.; Michelle A. Jusino, Mark T. Banik, Jonathan M. Palmer, Heather Kaarakka, Paul White, Daniel L. Lindner, Claudio Gratton, and M. Zachariah Peery, (2018). “Incidence and taxonomic richness of mosquitoes in the diets of little brown and big brown bats”. Journal of Mammalogy. 99 (3): 668–674.

Mike Dixon is the Executive Director of the Trinity River Restoration Program and a northern California native. He fell in love with the Trinity River and Klamath Mountains while assigned to his first duty station at Coast Guard Air Station Humboldt Bay. He received a Ph.D. in Conservation Biology from the University of Minnesota, Twin Cities, where his dissertation focused on the landscape ecology and population genetics of bats. He lives on a small, perennial tributary of the Trinity River near Weaverville.

Photo: The [much younger] author with a little brown bat in Voyageurs National Park

Animal Spotlight – Northwestern Pond Turtle

Posted on May 14, 2025May 15, 2025 by Kiana Abel

The northwestern pond turtle (Actinemys marmorata) has lived in the waters of the Trinity River for thousands of years. This species has undergone several taxonomic revisions since first being first described in 1841 (1, 2, 3). It was originally considered a single species with the southwestern pond turtle (Actinemys pallida) and called ‘Emys marmorata’. Then both species were renamed ‘Clemmys marmorata’. The northwestern and southwestern groups were more recently split into two species based on genetic and physical differences between them. So, you may read our local turtles described with different common and scientific names depending on when the document was published (3). But no matter when it was published, there is only one native freshwater turtle known to the Klamath Mountains and the current name is “northwestern pond turtle” (Actinemys marmorata).

Photo: A female northwestern pond turtle. [Don Ashton]

Actinemys marmorata
actin = ray or beam // emys = turtle // marmorata = marbled

As its common name suggests, the northwestern pond turtle is known to inhabit ponds and lakes, but within the Klamath Mountain ecosystem they are commonly associated with riverine habitats. Northwestern pond turtles are poikilothermic, meaning that they regulate their temperature by basking in the sun when they are cold, and seek cool water or shade when they are too warm. They distribute in sunny, slow water reaches with boulder lined pools that, importantly, have connectivity to broad floodplain habitat (5, p. 353).

A male Northwestern Pond Turtle in underwater refugia on the Southfork Trinity River. [Don Ashton]

The northwestern pond turtle has an acute sense of sight and low-frequency hearing, and while they are often seen basking in the sun above water, they will quickly retreat when they feel threatened (5). Reader, a river enthusiast we surmise, we are sure you’ve witnessed the sound of a plopping western pond turtle off a river log – but did you see them?

Male turtles are known to migrate from river to upland areas to overwinter in riparian shrubs or leaf litter. This trait is not ubiquitous among all turtles as some choose to stay close to their summer habitat by overwintering in banks near the river or pond. Local herpetologist Don Ashton of McBain Associates/Riverbend Sciences has spent decades studying turtles in the Trinity River and said, “Turtles are very smart animals, they tend to migrate close to the high water line (think 100 year floodplain) but over time we have found that in comparison with North Fork Trinity River populations, turtles on the mainstem are found more frequently hibernating and nesting in lower elevation areas, likely due to adaptation of minimized flooding by Trinity and Lewiston Dams.”

In addition to migration for hibernation and summering, female turtles migrate twice for nesting. When they are ready to lay their eggs, they fill their bladders and set off on a slow but steady journey to upland areas to dig their nests. Once in a satisfactory location, the female turtle wets the ground with her urine to help soften it for digging. Once her eggs are laid, she will journey back to her summer habitat.

A Northwestern pond turtle nest, predated. Egg fragments and plug are identified. [Don Ashton]

Migration to upland areas for nesting or hibernation can often lead to chance encounters with humans or their vehicles. If you happen to cross paths with a turtle, Ashton advises to leave them to their journey, “they are not lost” Ashton declares. However, if their location poses a risk of vehicular homicide, and you feel compelled to move them, point them in the direction of their path. That is unless the turtle happens to urinate while being handled, then, Ashton suggests, they should be pointed back toward a water source.

These ancient creatures are small to medium in size, growing up to 8 inches long. Interestingly, Trinity River turtles have been documented as even smaller than their regional counterparts. Some herpetologists surmise this could be due to temperature suppression caused by elevated dam releases causing cold water releases in the latter spring and summer months (6). Watch Don Ashton’s 2024 Trinity River Restoration Program Science Symposium presentation on the subject below.

Don Ashton, Senior Aquatic Herpetologist/Ecologist for McBain Associates/Applied River Sciences presents, “Frogs and Turtles informing flow management and river restoration.” at the 2024 Trinity River Restoration Program Science Symposium.

Their dark brown or olive-colored shells often feature fine, lighter markings that give them a marbled look as reflected in their species name, marmorata. Their low profile and coloring help them blend in with riverbanks, keeping them safe from predators like raccoons, skunks, and birds of prey. The male northwestern pond turtle can be identified with a pointier snout and lighter pale cream coloring under its neck. If you encounter a turtle with hints of red near the ear it is likely a non-invasive red-eared slider, make note of where you are and if possible, provide photo documentation to the Trinity River Restoration Program or the California Department of Fish and Wildlife. Documentation of these instances can help in protecting our native turtle populations.

A female northwestern pond turtle on the Southfork Trinity River. [Garth Hodgson, Don Ashton]

Unlike many reptiles, northwestern pond turtles grow slowly. They start out about the size of a quarter. Females don’t start laying eggs until they’re between 8-10 years old (3, 7, 8). They lay between 3 and 13 eggs, which incubate through the summer. In some parts of Northern California, hatchlings stay in the nest through winter, emerging the following spring. In the photo you can see a comparison of a female turtle at 55 years old with a newly hatched turtle. Ashton, in the background mentioned that the elder at age 55 was carrying 9 eggs at the time of that photo (2018) which suggests their lifespan may be quite long. Ashton mentioned, “it is certainly possible that there are turtles living in the mainstem that have lived there since before the dam was placed.”

Photo: A female, marked and recaptured and aged at 55 years old in comparison with a hatchling. Held by Bruce Bury and Don Ashton smiles from the back in 2018. [Jamie Bettaso]

The northwestern pond turtle has been studied locally for over 50 years due to the diligence of herpetologist Bruce Bury, now retired from USGS, who monitored northwestern pond turtles starting in 1968 while earning his Ph.D. at UC Berkeley. He marked turtles with an identifying notch in a tributary of the South Fork Trinity River, allowing for scientists to track longevity on the only native species known in the Klamath Range (5, p. 354). Although Bury has documented turtles over 50 years old, northwestern pond turtle longevity is still being studied today.

The northwestern pond turtle is commonly seen in the Trinity River, but its population has been declining throughout its west coast range. This decline is so severe that in 2023 the U.S. Fish and Wildlife Service proposed to list the northwestern pond turtle as a “Threatened” species (8, 11). Habitat loss, hydrologic alterations and invasive species are a few human caused threats to northwestern pond turtles. The state of California also recognizes the northwestern pond turtle as a species of “special concern”. As such, handling these turtles requires permitting and are considered illegal to keep as pets.

The Trinity River Restoration Program has been involved in research to identify and address some of these threats. A graduate student from Cal Poly Humboldt, Leah Sloan, determined that non-native bullfrogs (Lithobates catesbeianus) eat young northwestern pond turtle hatchlings to the detriment of their populations along the Trinity River (10). Bullfrogs prefer off-channel ponds, which are perfect areas for northwestern pond turtles to grow. Bullfrogs require perennial ponds to reproduce because their tadpoles take longer than one year to grow (and the mainstem Trinity River is too cold and swift to support bullfrogs year-round), so ponds that normally dry out won’t support bullfrogs permanently. Seasonal drying isn’t much of a concern to turtles because they can simply walk to the river when their home dries up. This is one recommendation for the Program to consider when rehabilitating a site.

A trail camera captures a female northwestern pond turtle basking on a log. [Don Ashton]

Today, turtle researchers and wildlife managers are still learning more about turtle behaviors and how to change management to better serve the northwestern pond turtle in the Trinity River region. From size and aging to nesting sites and travel patterns, each discovery helps build a clearer picture of what these turtles need to thrive.

References

Scientific and Common Names of the Reptiles and Amphibians of North America – Explained © Ellin Beltz
Holland DC. 1994. The Western Pond Turtle: Habitat and History.
Bury, R.B., Welsh, H.H., Germano, D.J., and Ashton, D.T. (eds). 2012. Western Pond Turtle: Biology, Sampling Techniques, Inventory and Monitoring, Conservation, and Management. Society for Northwestern Vertebrate Biology, Northwest Fauna, Number 7. 128 pp.
Shaffer H.B., Scott, P.A., 2019. Assessment for the Western Pond Turtle. Prepared for the US Fish and Wildlife Service by University of California, Los Angeles.
Kauffmann, M. Garwood, J. The Klamath Mountains: a Natural History. 2022. p. 353-354.
Ashton, Don & Bettaso, Jamie & Welsh, Hartwell. (2015). Changes across a Decade in Size, Growth, and Body Condition of Western Pond Turtle (Actinemys marmorata) Populations on Free-flowing and Regulated Forks of the Trinity River in Northwest California. Copeia. volume 103. 621-633. 10.1643/CP-15-253.
California Herps – Northwestern Pond Turtle – Actinemys marmorata
Wikipedia – Western Pond Turtle
https://www.fws.gov/press-release/2023-09/us-fish-and-wildlife-service-proposes-federal-protections-both-species
Sloan L, Marks S. 2012. Summary of Management Implications for the Project on Western Pond Turtles (Actinemys marmorata) in Lentic Habitats Along the Trinity River, California. Report to the U.S. Bureau of Reclamation, Trinity River Restoration Program, from Humboldt State University, Department of Biological Sciences, Arcata, CA. Available: https://www.trrp.net/library/document?id=1819.
Endangered and Threatened Species: Status with Section 4(d) Rule for the Northwestern Pond Turtle and Southwestern Pond Turtle. Posted by the Fish and Wildlife Service. Apr 4, 2024.

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Trinity River Watershed Monitoring

Posted on February 14, 2025February 14, 2025 by Kiana Abel

California Department of Fish and Wildlife Steelhead Report Card Dashboard

The California Department of Fish and Wildlife (CDFW) tracks steelhead angler effort and success through a reporting program. This reporting program consists of a mandatory report card that all steelhead anglers need to have in their possession while fishing. Anglers record each day that they fish, where they fish, how many fish they catch, and whether those fish are from a hatchery (determined by the lack of an adipose fin, which is removed by hatchery staff before the fish is released), or were spawned in the wild (determined by the presence of an adipose fin).

Each year, anglers are required to send these report cards back to CDFW, either physically or by entering the information online.

After many years of collecting data, CDFW recently released a compilation of raw summary data for the period of 2012-2023 (linked here). The data set can be sorted by area (the Trinity River is one of 20 river systems or regions), season, or month, and shows the numbers of fishing trips, the number of hatchery steelhead caught, and the number of wild steelhead caught.

The Klamath River and tributaries (except the Trinity River) stands out as an exceptional fishery. The Trinity River is not too far behind it among the 20 steelhead fisheries in the state.

It’s important to understand that while the raw data is informative, it is only a starting point toward understanding the fisheries. For example, in many systems, including the Trinity, hatchery production has changed substantially over the time period that the dashboard shows. Some hatcheries have reduced steelhead production by as much as 40%, which has an obvious bearing on the average number of steelhead caught per trip. Conversely, this data set covers two of the most severe droughts that Northern California has ever experienced. Droughts can leave the smaller tributary streams, which are usually off-limits to fishing because steelhead prefer to spawn in smaller streams, too dry for fish to migrate into. So, they remain in the mainstem river where people can catch them more readily than in normal or wetter years when they would have migrated into their spawning streams earlier. Tribal harvest methods, too, have changed in this time period and are much more selective for hatchery steelhead (identified by their lack of an adipose fin) over wild steelhead.

Still, this dashboard can be very useful for planning where and when to go on a steelhead fishing trip. And steelhead anglers should be happy to see the data that they carefully record and report is going to good use!

Return to the February Newsletter

The Language of Sediment

Posted on February 12, 2025April 29, 2025 by Kiana Abel

Rivers are dynamic ecosystems shaped by multiple interacting and overlapping physical and biological processes. A fundamental aspect of a river’s ecology is sediment, which is the foundational underpinnings of habitats, influence for water quality, and support for wildlife. In this article, we explore terminology and features of Trinity River sediments, the building blocks of our river system.

What is Sediment?

Although it might seem obvious, all sizes of rocks fit into the larger family of sediments. Sediments are inorganic particulates that can be transported by water, wind, or ice and deposited and perhaps stored for long periods of time in a particular location. In rivers, sediment is further classified according to its diameter and composition:

Clay (Particles smaller than 0.002 mm): Clay transports while suspended in the water column and when deposited can store nutrients aiding the growth of biology when organics chemically bind to individual clay particles.
Silt (Particles 0.002 mm to 0.063 mm): Silt also transports suspended in the water column and can affect light penetration and aquatic plant growth, just as clay particles do. Clays and silts that cloud the water also provide cover for fish, which use the cloudy water as protection from predators and tend to survive at higher rates when available intermittently.
Sand (Particles 0.063 mm to 2 mm): Sand provides a medium for plants to establish and grow. This sediment type provides rearing habitat for juvenile lamprey when located in deposits below large rocks or trees, and acts as a filter to benefit water quality when deposited between gravel particles.
Gravel (Particles 2 mm to 64 mm): Ranging from the size of a small blueberry to a large kiwi, gravel offers essential spawning grounds for fish and invertebrates.
Cobble (Particles 64 mm to 128 mm): About the size of an orange, cobbles are the framework for bar deposits in river systems. When settled they form a surface that is difficult to mobilize from and creates roughness that encourages small particles to deposit on top of them. While waters flow over through and under these habitat formations the sediments caught provide a diversity of flow in depth and velocity which species depend on in streams.
Boulders (Rocks larger than 128 mm): These create physical barriers in rivers that help form log jams, leading to diverse flow patterns and detailed habitats for a range of organisms.

Sources of Sediment in River Systems

Fine sediments entering the confluence of the North Fork and the East Fork North Fork after rain dropped on the the Monument Fire scar in July 2023.

Sediment can enter river systems through multiple processes, each contributing to the overall sediment dynamics and ecology of the river. Key sources of sediment include:

Erosion: As water flows over land soil and rock can move with it. Depending on the landscape and the soil content these sediments can be delivered to rivers, especially during heavy rainfall or rapid snowmelt.
Runoff: Rain and melting snow can wash fine sediments from forests, fields, urban areas, roads, and construction sites into nearby streams and rivers.
Bank Collapse: Riverbanks can be eroded by the current of flowing water, particularly in areas with high flow velocities, resulting in banks collapsing directly into the water.
Tributary Inputs: Creeks can contribute sediment as they flow into larger rivers, contributing sediments from their own drainage basins.
Human Activities: Construction, mining, and land clearing can disturb soil and rock, increasing sediment loads in nearby rivers. Deforestation can also enhance erosion rates when tree roots are damaged or destroyed, leading to hillslope failures into streams.
Natural Events: Floods, landslides, wildfires and volcanic eruptions can rapidly introduce large amounts of sediment into river systems, altering habitats and turbidity.
Aquatic Organisms: Organisms can influence sediment storage by building dams (beavers) or webs between gravels to capture food and fines (net-spinning caddisfly). Organisms can also mobilize sediment when building nests (salmon) or grazing for food, such as crayfish winnowing fine sediments from amongst gravels.

Pool and Riffle Dynamics

MinuteEarth – Why do Rivers Curve?

When the slope of a river is greater than 2 percent, water moves quickly over rocks and other obstacles creating rumbling mountain streams. Moving downstream as the valley walls open and slope decreases a pool and riffle river system will form. The creation of alternating river bends is based on physical obstacles along the river’s path and water velocity which will form deep (pools) and shallow (riffles). The dynamic plays a crucial role in the movement and storage of sediment as the river runs its course to the ocean. A few key terms:

Pools: Pools are deep areas of the river that form over time with flow velocity that scours (or digs) small unstable sediments from the area. Pools offer dynamic habitat during different times of the year that include a varied temperature column in the summer months when waters slow within the river. In winter, during high flows, pools are areas where faster water occurs. The increase in speed in pools relative to their companion riffles is what is responsible for pools scouring to depths found in summer.
Riffles: During lower flows that occur in late spring through fall, faster currents are found in riffles because the water surface is steeper on them. Riffles are nursery areas for macroinvertebrates and help oxygenate the water and benefit species that thrive in turbulent conditions. High flows in winter that scour pools deposit sediments from the scour on riffles downstream, and in this way a pool-riffle sequence of habitats is formed and maintained on alluvial rivers.

Salmon and Sediment Interaction

Salmon are a keystone species in freshwater ecosystems, and their interaction with sediment is crucial for their lifecycle. During spawning, female salmon seek out gravel beds on riffles and near the streams banks to lay their eggs. These gravel beds, composed of appropriately sized sediment, are essential because they provide the necessary water flow to provide oxygen to fertilized eggs, ensuring their development to the fry stage.

Additionally, the composition and stability of sediment in spawning areas can influence the quality of habitat available for juvenile salmon. Fine sediments, often stirred up during high flow events, can cover spawning habitats, suffocating eggs and reducing the overall success of salmon populations when fines are overly present.

However, Trinity River geomorphologists are learning that too few fines also pose survival risks to salmon. When spaces between gravels where eggs are spawned are left open, turbulence is created through flow within the salmon nest and can jiggle eggs causing abrasion to the egg membrane, leading to mortality. Too few fines can also cause surface flows in a river to be conveyed entirely through a bar, sieving off the juvenile salmon onto dry bar surfaces for predation by birds.

Join us Feb. 26 for Science on Tap featuring Dr. Todd Buxton for “Fine Sediment in the Trinity River: History, effects, and current Impacts”

Maintaining a balanced sediment regime within pool and riffle systems is essential not only for river ecology but also for the conservation of salmon, whose life cycles are intricately tied to the health of their sediment-rich habitats. As we learn more about these systems, it becomes increasingly important to recognize how sediment influences river health and ecology, guiding conservation efforts to ensure the survival of these vital ecosystems.

We invite you to join us Wednesday, Feb. 26 for Science on Tap! Dr. Todd Buxton will dive into Trinity River Fine Sediment, history, effects and current impacts. The event is held at the Trinity County Brewing Company and starts at 6pm.

Return to the Feb. Newsletter

Bug of the Month: Baetid mayflies

Posted on January 16, 2025April 29, 2025 by Kiana Abel

Bug of the month: Baetid mayflies

genus Baetidae

Mayflies from the family Baetidae are this month’s ‘bug of the month’. Commonly known as blue winged olives by fly fishermen, Baetid mayflies are small (<10mm) and can be extremely prolific. In addition, they grow rapidly and can have multiple generations within a year (known as multivoltine). This means that you can see adult Baetid mayflies during most of the year although they are especially apparent during the winter in early spring when few other bugs are hatching.

Photo Credit: TroutNut.com

Baetid mayflies are exceptionally adept at colonizing new habitat. They are extremely good swimmers (for a bug) and are known for undertaking what is known as behavioral drift. Behavioral drift is a strategy where macroinvertebrates enter the flow of the river voluntarily to seek out new habitat. Short life cycles, excellent swimming ability, and the propensity to undertake behavioral drift allow them to settle new habitat like when high flows inundate floodplains.

They are often the first to colonize a new area due to their swimming skills and their preference for shallow, slow water. These newly formed areas grow algae very well which is the primary food source for Baetid mayflies. They can often exploit newly formed habitat within a few weeks and live their entire life cycle within 12 weeks before other bugs get a chance to settle in an area. Seasonal inundation of floodplains are extremely important to Baetid mayflies success. Juvenile salmon have evolved to depend on the seasonal inundation of floodplains because of the presence of Baetid mayflies, which they eat for food.

Chris Laskodi, M.S., Fish Ecologist – Yurok Tribal Fisheries Department

Chris serves as the fish biologist/ecologist for the Trinity River Restoration Program in the program’s Science branch. Chris has worked on the Trinity River since 2015, previously serving as a fish biologist for the Yurok Tribe and a fisheries technician for the US Fish & Wildlife Service. Chris holds a B.S. in Wildlife, Fish and Conservation Biology from the University of California, Davis and a M.S. in Aquaculture/Fisheries from the University of Arkansas at Pine Bluff. In his free time, Chris enjoys taking friends and family fishing on one of the many watercraft available to him.

Return to the January Newsletter

Featured Article: The Language of Flow

Posted on November 15, 2024April 29, 2025 by Kiana Abel

Rivers are vital parts of our ecosystems, and they behave differently depending on the climate they flow through. In a Mediterranean climate, which is characterized by hot, dry summers and variable, wet winters, river flow can be particularly interesting. Let’s explore some important terms and concepts related to river flow that is represented in our unique climate and system.

What is River Flow?

At its most basic, river flow, or discharge, is the volume of water that moves through a river over a specific period of time. On the Trinity River, flow is typically measured in cubic feet per second (CFS). Currently flow rates are measured in a few locations above and below Trinity and Lewiston Dams. Discharge on the Trinity River at Lewiston has been measured daily since 1911, when Model T’s were just rolling off of the assembly line!

There are very few rivers in California that experience full natural flow. Most Northern California rivers are managed through dams that generate power, create water diversions, or hold back water for later use. Dams block upstream deposits of water, wood and sediment and when managed narrowly have caused significant harm to riverine ecology downstream.

Understanding river flow both pre-dam and post-dam helps river ecologists to compare current management with the pre-dam natural conditions that species and their ecology developed within. This strategy aims to deepen understanding of the natural environment to provide favorable conditions for plants, wildlife, and people that depend on the river.

Why is River Flow Important?

The Trinity River’s flow is crucial for many reasons:

Ecosystems: Flow influences the types of plants and animals that live in and around the river.
Water Supply: The Trinity River provides drinking water, supports economic development, supplies irrigation for agriculture and generates power for millions of Californians.
Recreation: The Trinity River supports activities like fishing, boating, hiking, gold panning, wildlife viewing and swimming.

Key Terms Related to River Flow: Managed vs Natural

Natural Seasonal Flow: Although highly variable from year to year, undammed rivers in a Mediterranean climate, tend to exhibit seasonal patterns. During the rainy winter months, flow rates typically increase due to precipitation, the size and magnitude of that increase depends on seasonal patterns and the frequency of storm events. In the spring, snow in the mountains melts adding flow to the Trinity River and its watershed. Conversely, in summer, flow rates tend to slowly decrease as the dry season progresses.

Natural Base Flow: This is the normal level of water flow in a river during dry periods. It usually comes from groundwater and keeps the river flowing even when there hasn’t been rain for a while. In a Mediterranean climate, base flow can be low during the summer months due less water in the system and high evaporation rates. Baseflows are important for cold-blooded aquatic species like foothill yellow legged frogs who utilize slow water for rearing and then populate riverside riparian areas as adults.

Hydrograph: A graph that illustrates how the flow of water in a river changes over time. It shows time on the horizontal axis and the flow rate, usually measured in cubic feet per second, on the vertical axis. As the line on the graph rises, it indicates an increase in river flow (like after rain), and when it falls, it represents a decrease (such as during dry periods). Hydrographs are important for managing water resources, studying weather patterns as well and ensuring that environmental flow needs are met in regulated river systems.

Natural Surface Runoff: After it rains, water flows over the land and enters rivers. This is known as surface runoff. Winter rains in the Trinity watershed typically lead the tributaries and the Trinity River (below Douglas City) to a spike in flow. However, the impact is highly dependent on the water year, ground saturation and snow accumulation. Surface runoff provides additional wood, leaf litter and sediment to rivers which are the building blocks for healthy habitat creation in the Trinity system.

Over-bank floods: When there is a lot of rain in a short period, rivers can overflow their banks, causing over-bank floods. On the Trinity River over-bank floods are more likely to occur during the wet season and provide important ecological functions, including to Trinity River fish. These flows improve soil quality, provide prime growing grounds for aquatic insects and other fish food and help to reset the form of the river’s main channel through scour.

Environmental Flow: Is a management term that identifies the quantity and timing of water needed to sustain the health of river ecosystems, particularly downstream from a dam. Managing environmental flow is important for maintaining habitat for Trinity River salmonids and other wildlife that depend on the river. Within the environmental flows framework there are many methods for implementation. Since 2004, the Trinity River Restoration Program’s method for environmental flows were based on functional implementation of three periods, a summer baseflow (450 CFS), a fall/winter baseflow (300 CFS), and a spring snowmelt mimic hydrograph. Since 2016 local scientists have advocated to adapt this method by adding variable flows to the wet-season months (December – April) for the benefit of growing healthier juvenile salmonids.

Recommended Periods within the Environmental Flow Timeline for Water Year 2025

1. December 15 – February 15 – Synchronized Storm Pulse

A dam release synchronized to a natural storm event. The release is triggered by a CNRFC forecast for the Trinity River above North Fork that rises to 4500 CFS or more. Once initiated, the release would be triggered even if the forecast is reduced. The primary purpose is to reduce redd smothering by preventing fine sediment accumulation from tributaries, to maximize the synchrony between tributaries and the mainstem of the river, as well as recondition the streambed and align the ecology for salmon food production.

2. February 16 – April 15 – Wet Season Flood

Depending on forecast water year type in the California Department of Water Resources February B120 forecast and whether a synchronized flow has occurred, the Program may schedule flows above baseflow in the Feb. 15 to Apr. 15 timeframe. Depending on the March B120 forecast, the schedule may be adjusted as of March 15. The primary purpose of this is to inundate floodplains for aquatic food production and habitat for juvenile salmonids at the right time of year – similar to natural wet season flooding.

3. April 16 – Variable – Snowmelt Peak and Recession

The spring snowmelt peak and recession are an important annual migratory cue for both adult and juvenile chinook. The Program has implemented a spring snow-melt mimic release annually since 2004. CDWR April B120 forecast determines total volume of restoration flow releases. Water that has not been released for Storm Pulse Flows or Wet Season Flooding is scheduled for release during the Snowmelt Peak and Recession period. This schedule encompasses many purposes for river ecology and the salmonid life cycle.

4. Managed Base Flow

Baseflows released from Lewiston Dam to the Trinity River are currently managed at 450 CFS through the summer, shifting to 300 CFS on Oct 15 through the subsequent spring. This management strategy is a relic from the 1999 Flow Study and was put in place with the mindset that increasing baseflow in the summertime could help with river temperature management for migrating adult spring chinook. Flows reduce in the fall because temperature objectives are no longer needed. In addition, water managers leaned on water savings during the fall through the wet season so that accumulation in the system could be understood prior to use for diversions or river ecology. Fish biologists hypothesize that if current summer and fall management were adapted to a more natural hydrograph it may serve Trinity River salmonids and other wildlife better.

Bug of the Month: October Caddisflies

Posted on November 12, 2024April 29, 2025 by Kiana Abel

October Caddisflies genus Dicosmoecus

Dicosmoecus (dee-co-smee-cus) caddisflies are better known by the common name ‘October caddisflies’. These caddisflies are notable for there extremely large size (1-2 inches), their concentrated emergence window (October), and their abundance especially in streams containing anadromous fish. These characteristics make it one of the most important hatches to not only fly-fishermen, but to wildlife such as birds as well.

Dicosmoecus like other caddisflies have three life stages: larvae, pupae, and adult. Larvae build cases out of small rocks which serves as protection and their housing. They drag these cases around while foraging for food, mostly algae and detritus. Dicosmoecus are especially notable by the large distances they can cover (up to 25 meters per day) to forage (Resh et al. 2011).

They continually grow and have to build new cases as the old ones become too small. After molting five times (called instars), they attach their cases to the underside of rocks and began to pupate. After about a month of pupating, they cut a hole in their case and swim to the surface before shedding their exoskeleton one more time and becoming adults.

Caddisflies, unlike mayflies, will live for several weeks while they seek out a mate. You will often see them active at dusk and just after sunset. Keep a look out for the large moth-like bugs during sunset for the next few weeks.

References

Resh, V.H., M. Hannaford, J. Jackson, G.A. Lamberti, and P.K. Mendez. 2011. The biology of the limnephilid caddisfly Dicosmoecus gilvipes (Hagen) in Northern California and Oregon (USA) streams. Zoosymposia 5:413-419.

Images courtesy of Red’s Fly Shop and Troutnut.com

Chris Laskodi, M.S., Fish Ecologist – Yurok Tribal Fisheries Department

Chris serves as the fish biologist/ecologist for the TRRP in the program’s Science branch. Chris has worked on the Trinity River since 2015, previously serving as a fish biologist for the Yurok Tribe and a fisheries technician for the US Fish & Wildlife Service. Chris holds a B.S. in Wildlife, Fish and Conservation Biology from the University of California, Davis and a M.S. in Aquaculture/Fisheries from the University of Arkansas at Pine Bluff. In his free time, Chris enjoys taking friends and family fishing on one of the many watercraft available to him.

Featured Article: Flow Variability, the pulse of a river system

Posted on October 16, 2024April 29, 2025 by Kiana Abel

Prior to construction of dams on the Trinity River, flow and river temperatures were synchronized throughout the watershed with seasonal ecology. Storms and snow melt floods regularly altered the stream channel, transporting sediments, wood and rocks. Seasonally predictable disturbance helped maintain a healthy streambed and riparian forest. Disturbance was followed by growth, with wetted areas providing consistent habitat for insects, fish and frogs alike. Even though each year provided different conditions, there was predictability with which aquatic and riverine species, like salmon, evolved to exploit.

Since the foundational 1999 Trinity River Flow Evaluation Report, more than 20 years of scientific research within the Trinity River Basin and from rivers across the world have improved outcomes for Trinity River salmonids. This wealth of new and improved knowledge has made scientists within the Program increasingly aware that changes to flow management have the potential to increase the strength and resiliency of juvenile salmonids produced in the Trinity River.

One important revelation is that elevated releases that continue through late spring and into the summer have kept water too cold for optimal juvenile salmon growth. Larger fish have a better chance of survival in the ocean, so improved flow management that can provide better temperatures for growth is likely to improve survival and subsequent adult returns. Further, Program scientists have found that the majority of young Chinook Salmon have already left the restoration reach by the time elevated spring releases provide access to restored habitats created by the Program over the last 18 years, including floodplains and side channels.

Many studies have shown that when floodplains and side channels get wet at the right time of year when juvenile salmon can use them, then they can take advantage of all the extra food that those habitats create. When fish can access important habitat, increase their food consumption, and have the right temperatures for growth, they can grow faster, get bigger, and survive better.

Recommendations for Change

Changes to Trinity River flow management to partially mimic the seasonality of natural flow were approved by the Trinity Management Council this past September. Program partners in our Flow Workgroup technical advisory committee developed a collaborative proposal that met ecological objectives and accommodated recreational considerations requested by Trinity County. The proposal also needed to adhere to existing environmental regulations. Following the affirmative Trinity Management Council vote in September, the recommendation is now awaiting approval by the U.S. Department of the Interior.

Water Year 2025 environmental flow management is designed to partially mimic natural seasonality so that river ecology can build around flow as it did prior to dams. These managed flows do not strictly follow the natural ecology of the watershed, but rather they represent management that strikes a balance between ecological needs, water availability, and other management and infrastructure constraints. Scientists hypothesize that adding pulse flows, increasing flow in winter, and decreasing flow in the spring and summer could be beneficial to Trinity River salmonids. However, there is no recommendation for this water year to reduce minimum baseflows in summer or fall.

First Recommended Change: Synchronized Storm Pulse

The first recommended sequential change is the two-month Synchronized Storm Pulse period (December 15-February 15) where there may be one peak flow of 6,500 cubic feet per second released from Lewiston Dam timed to match a natural storm event. This synchronized flow would consist of a rapid flow increase release held for a short period then reduced to 750 cubic feet per second. A synchronized storm pulse would only be triggered if the river is predicted to be at least 4,500 cubic feet per second near the North Fork Trinity River. No synchronized release would occur if the river is not predicted to reach that level between December 15 and February 15.

Winter storm pulses provide many ecological benefits, primarily by causing streambed disturbance. Sediments ranging in size from sand to large gravel are displaced and moved downstream, and wood in the channel can be moved or cause erosion in the channel that increases habitat diversity. Fine sediments rich in nutrients are also washed onto upland riparian areas that are typically dry. As waters recede, nutrients remain to help develop a healthy riparian community of plants and animals. For salmon, the disturbance from big powerful storms provides opportunity for small, soft-bodied bugs to proliferate, which are an excellent food source for small juvenile salmonids as they emerge from the gravel.

graph — Pre-dam Trinity River flows at Lewiston (colored lines), and a typical normal water year flow release after 2000 (black line).

Since 1960’s, with very few exceptions, typical winter flow releases from Lewiston Dam have remained under 300 cubic feet per second. When big storms pass through, tributaries deliver trees, nutrients, and all sizes of sediment, which enter the Trinity River where flows are artificially low due to limited dam releases. Often there is not enough flow in the Trinity River to move these deliveries from tributaries, so they settle out quickly. Where Deadwood Creek enters the Trinity River, large fine sediment deposits from the 2018 Carr fire have immediately settled into slow waters in recent years resulting in two negative effects. First, the tributary delta has formed unnaturally, and second fine sediments have smothered and suffocated salmon and steelhead eggs in the gravel.

Second Recommended Change: Wet-Season Flood

The second recommended change is the two-month (February 16 – April 15) Wet-Season Flood period, during which dam releases would be elevated above the typical 300 cfs baseflow with some variability. The amount of water released during this period depends on seasonal snow and rain accumulation and a conservative forecast of inflow to Trinity Reservoir from the California Department of Water Resources (90% B120).

These beneficial floods push water onto floodplains and keeps them wet for months, which essentially converts terrestrial habitat into aquatic habitat just as salmon and steelhead begin to emerge from the gravel and populations increase. This seasonal aquatic habitat grows food for fish and provides slow water habitat for small fish to rest, grow, and escape many aquatic predators.

Oregon Gulch floodplain inundation in March 2024 provided habitat for millions of juvenile salmonids and other aquatic species. Aaron Martin, Yurok Tribal Fisheries Department.

Snow Melt Peak and Recession

The Snowmelt Peak and Recession period has been implemented on the Trinity River for the past 20 years. The action provides important migration cues for adult and juvenile salmonids. Peak flows can provide many of the benefits that winter storm pulse flows provide earlier in the year, resetting the base of the food web and delivering nutrients to riparian areas. Receding flows trigger spring Chinook Salmon returning from the ocean to migrate toward over-summer habitat. Additionally, juvenile salmon and steelhead migrate out of rivers, to the ocean, as habitat availability decreases with dropping flows.

Proposed changes to flow management in 2025 would use the same volume of water that has been available since 2000, so any water released for a synchronized storm pulse or wet season flood would be borrowed from the spring snow melt release. As a result, releases would slow earlier, reducing cold-water impacts to fish growth while providing ecological benefits earlier in the year. Adjustments to flow management that more closely align dam releases with natural ecological processes are intended to also benefit other aquatic and semi-aquatic species, such as Foothill Yellow Legged frogs and Northwestern Pond turtles.

As mentioned, the recommendations presented for water year 2025 are designed to partially mimic natural seasonal processes so that ecological function can develop on the seasonal timeline, as it did for millennia prior to dam construction. Program scientists have long known that these recommended changes are necessary for making progress toward producing stronger healthier Trinity River fish populations.

If changes are approved by the Department of the Interior, the Trinity River Restoration Program will announce details regarding; flow action changes, ways to stay informed and notification timelines as they develop.

Recommended 2025 Water Year Environmental Flow Management Timeline

Ways to stay informed

Join the Trinity Releases email group

Subscribe to Trinity Releases

Follow our Facebook page

Facebook

Join the TRRP newsletter email group

Subscribe to the River Riffle

If you have questions, please contact the Trinity River Restoration Program office at 530/623-1800 or by emailing your question to info@trrp.net.

Return to the October Newsletter

Blue Elderberries (Sambucus nigra ssp. caerulea)

Posted on October 15, 2024April 29, 2025 by Kiana Abel

Blue elderberries, native to California, grow throughout the Northwest and are found here in Trinity and Humboldt Counties. These trees are known for their dainty elderflowers, nutritious elderberries, and hard, hollow wood. Indigenous people have long maintained relationships with elderberries. This food source carries medicinal benefits, famously made into elderberry syrup to promote a healthy immune system and
fight respiratory illnesses.

Photo adapted from Pinnacles National Park, National Park Gallery.

Animals, too, enjoy the berries as they ripen in the summer months. Elderberry trees serve as habitat for native bees and the valley elderberry longhorn beetle, because of the spongy tissue of their twigs. This pithiness also makes the wood uniquely amenable to crafting cultural materials, like arrows and flutes. Tribal practices, like cultural burning, ensure longevity and health of elderberry bushes.

What’s in a name?

Local Indigenous languages all have names for elderberries

Ch’iwhiwh
yúxaas
ta’amo’ ‘wer-nerh
luu-k’vm’

In Hupa, ch’iwhiwh means elderberries. Much like German, Hupa words build description. So ‘elderberries’ translates literally to ‘what one sips through,’ and bears information about how the wood was used.

Yúuxas, in Karuk, means elderberry. Yúuxas ánav means elderberry medicine.

In Yurok, elderberries is ta’amo’ ‘wer-nerh. Ta’amo’ meaning elderberry bush, and nerh a shortened form of nerhpery, berry.

In Tolowa, blue elderberry is luu-k’vm’ and red elderberry is chvn-su’lh.

Indigenous plant names reflect the relationship that group has built with that plant. Some ask, why learn a lesser spoken language? Here is one of the many reasons to do so. Indigenous languages have grown around the environments their speakers lived in, and the needs, wants, and interests of those speakers. So being, they are laden with Traditional Ecological Knowledge (TEK). The vocabulary regarding elderberries, for every Indigenous language, expresses a unique worldview. When used, the line between generations of elderberry enthusiasts flows complete.

When and How to Pick

Blue elderberries will flower in the late spring. This is a good time to identify the
locations of your nearby trees, as they won’t stick out quite so much once the flowers
fall. Flower heads can be clipped and dried. Elderflowers have a “diaphoretic quality
which lowers fever (LaPena et al.).” “Fresh or dried, the flowers are steeped to make a
potent tea to reduce fever (Karuk Tribe et al.).” It is pertinent to remove all stems, as
only the flowers and berries can be consumed. Berries will ripen later in the summer.
Typically, they ripen earlier inland and later on the coast.

I’m a beginner when it comes to picking elderberries. I’ve learned to only pick them when they’re ripe, when the whole flower head has dark blue or dusty grey berries. Any green berries should not be consumed. Go elderberry picking when there is lots of light and good visibility. To pick berries, it is practical to clip heads of berries and later comb them from their stems. As a general rule, don’t take too many from one tree. Leave some for the birds.

Elderberries can be used in an array of baked goods, syrups, and jams, and can also be dried and eaten. Avoid eating fresh berries as they can cause nausea, easily done as you might find they’re not so sweet.

Works Cited

Karuk Tribe. “Uxraah: Native Edible Berries.” G8L2NativeEdibleBerries_booklet, United States Department of Agriculture, nctcc.org/wp-content/uploads/2017/05/G8L2NativeEdibleBerries_booklet.pdf. Accessed 14 Oct. 2024.
LaPena, Sage, et al. “Indigenous Perspectives on Elderberry Uses – California Elderberries.” University of California Agriculture and Nature Resources, University of California, ucanr.edu/sites/Elderberry/Indigenous/Indigenous_perspectives/. Accessed 14 Oct. 2024.
Lowry, Judith Larner. “Blue Elderberry.” California Foraging, Timber Press, Portland, Oregon, 2014, pp. 57–59.
Unless otherwise noted, all photos were generously provided by Muriel Ammon.

Muriel Ammon

Muriel Ammon (Tsnungwe, Hopi) is a graduate of Dartmouth College and the Southwest Institute of Montessori Studies. Ammon is passionate about Indigenous language revitalization. She has many Hupa language teachers, including her dad, Verdena Parker, and Melodie George-Moore. One of her favorite parts of learning Hupa is connecting to the plants and animals in her backyard.

Other Work

Ammon, Muriel. News from Native California. Picking Elderberries Like Squirrels. September 20, 2024