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by Eric Ettlinger

Coho salmon are currently spawning throughout Lagunitas Creek, albeit in below-average numbers. We observed 21 coho salmon and 11 new redds this week (see table of MMWD salmonid observations so far this season). The most upstream of these fish were two coho on a redd upstream of the Leo T. Cronin Fish Viewing Area, about as far upstream as salmon can go in the creek. These fish likely migrated upstream following the small storm we received last week. We expect coho spawning activity to increase slowly but remain below average while the dry weather continues.

Chinook salmon observations have declined over the last few weeks, with only one Chinook and one Chinook redd observed this week. We may see another pulse of Chinook if/when the rain returns. The extended weather forecast is for dry conditions to continue for the next two weeks.

coho redd

Coho redd

I’ve included a photo of one of the coho redds we observed this week. The contrast between the light-colored redd and the dark, undisturbed streambed, plus the extraordinarily clear water, make this redd unusually easy to identify. Upwards of 2,000 salmon eggs are likely buried in the upper right portion of this redd.

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Photo of Chinook salmon in Lagunitas Creek

Chinook salmon in Lagunitas Creek. Photo by Madeline Cooper, a member of the Watershed Stewards project.

by Eric Ettlinger

Salmon spawning season has returned to Lagunitas Creek, and so has one of its more sporadic and uncommon visitors. Chinook salmon, commonly known as king salmon, have been seen spawning in the creek for the first time in five years! The first sign of Chinook this season was a redd discovered on October 24, which would be exceptionally early for our resident coho salmon to spawn (a redd is a gravel nest where salmon lay their eggs). Their presence was confirmed on November 13 when three Chinook spawners were seen on that very same redd. Since then MMWD biologists have documented a total of seven Chinook salmon in Lagunitas Creek, which is the most seen since 2006. These salmon probably weren’t born in Lagunitas Creek but may have gotten lost as they tried to migrate back to their natal streams in the Central Valley.

One of the most perplexing aspects of our Chinook observations this season has been the presence of very small salmon (less than a foot long) sharing redds with very large Chinook. These small fish behave like “jacks,” which are small but sexually mature salmon that return to spawn a year earlier than full-sized salmon. The adult male salmon chase the jacks like they were competitors, but we’ve never seen jacks this small. We’ve only seen two so far, but ruled out trout or other fish species as candidates. A little research turned up a Chinook life history variant called the “mini-jack,” which migrate as fry to estuaries for only a couple of months before swimming back upstream to spawn. If these little fish are indeed mini-jacks, then Chinook salmon must have spawned in Lagunitas Creek last year without being observed. We did find a few redds in October and November last year that looked like Chinook redds, but without seeing the fish we couldn’t assume that Chinook had returned. Now it looks like the King may have returned a year ago.

To date we haven’t seen any coho salmon in Lagunitas Creek, but that’s not unusual. The first coho tend to show up in late November after heavy rains increase stream flows. Last week’s rain hardly increased flows, so the coho may be waiting a little longer to migrate upstream. Rain or no rain, we’ll probably start seeing coho within the next couple of weeks. Once the rain really starts falling, we’re expecting more coho salmon to return to Lagunitas Creek than we’ve seen in at least seven years.

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by Eric Ettlinger

Long before sub-prime mortgages became a household term, coho salmon were suffering through their own housing crisis. For more than a century, dam construction has blocked salmon from returning to the birthplaces of their ancestors. In Marin County, dams and urbanization have eliminated most of the habitat for salmon, and much of the remaining habitat is highly degraded. Some of the best remaining habitat is in Lagunitas Creek, which runs through Water District, State Park, and federal land. But even here the creek bears the scars of logging, hydrologic manipulation, and land management practices that included removing logs from the channel. These logs, which once included massive old-growth redwoods that could remain stable for decades, provided deep water, protection from predators, refuge from floods, and even insects for food. Without these log houses, young salmon are essentially living on the streets, vulnerable to predators, the weather, and hunger.

woody debris structures Lagunitas Creek

Log structures constructed in Lagunitas Creek in 2013

Starting in 1999, the Marin Municipal Water District began collecting logs from Kent Lake and using them to build log structures for juvenile coho salmon. The first structures were fairly simple: one to three cut logs, held in place with boulders and cables, and often protruding a short distance into the creek. Over time we learned that structures that collect sticks and small logs also tend to create the deepest pools with the most fish. We now build larger, more elaborate structures and arrange them in groups to transform simple, straight channels into complex meanders. In September, using funding provided by the California Department of Fish and Wildlife, we completed four new structures in a straight, shallow section of Lagunitas Creek. By next summer the creek will hopefully be meandering between complex debris jams housing hundreds of juvenile coho salmon.

snorkeling salmon survey

MMWD’s AmeriCorps interns counting juvenile salmon

So how do we know that these log homes are actually benefitting salmon? We monitor them extensively, measuring water depths, observing them during winter storms, and snorkeling around them to count the juvenile salmon using them through the summer. The results have been encouraging. Coho numbers at enhancement sites quadrupled within two years of construction. In the last 15 years the summer survival rate of juvenile coho throughout Lagunitas Creek has increased by approximately six times. While we can’t prove that the log structures are responsible for the increase in coho survival, the evidence suggests that providing more homes has made Lagunitas Creek a safer neighborhood for coho salmon.

large woody debris vs salmon survival

Summer survival of juvenile coho has increased as more log structures have been built. The New Year’s Eve Flood of 2005 took a toll on both structures and salmon. (Click chart to view.)

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by Eric Ettlinger

This post is the sixth in a year-long series celebrating the 40th anniversary of the Endangered Species Act. Read the previous post here.

In our monthly series celebrating the 40th anniversary of the Endangered Species Act, we’ve so far covered the mighty bald eagle, fascinating frogs, and beautiful but exceptionally rare flowering plants—all found on the Mt. Tamalpais Watershed. It now falls on me to introduce the most diminutive and charisma-challenged local endangered species that you will likely never see. Measuring less than 2.5 inches long, with a translucent body and a unicorn-like barb, please give it up for the California freshwater shrimp (Syncaris pacifica)!

California freshwater shrimp

California freshwater shrimp (Syncaris pacifica)

These little shrimp (that’s somewhat redundant, isn’t it?) are found in slow water habitats throughout lower Lagunitas Creek, downstream of MMWD’s watershed lands. There they feed on detritus—the bits of organic matter that wash downstream and collect on aquatic plants and roots that extend into the water from bank vegetation. Their translucent bodies and subtle movements make them nearly impossible to be seen by native fish species, but non-native fish such as bass are highly efficient hunters and aren’t as easily fooled. Luckily the shrimp have a last-ditch defense. When eaten, they can jab their sharp spine into the roof of the fish’s mouth and hopefully encourage the fish to spit them out. Shrimp are occasionally found with a broken rostral spine, which may be evidence of a close escape.

About 3,000 species of shrimp exist worldwide, including roughly 650 freshwater species. North America hosts only 17 freshwater species, including the California freshwater shrimp. A sister species, the Pasadena freshwater shrimp, lived in southern California before going extinct in the 1930s. That shrimp was the only other member of the Syncaris genus and the only freshwater shrimp to go extinct in recent times. The closest remaining relatives in North America are two species of cave shrimp in Kentucky and Alabama.

The risk of becoming the next shrimp to go extinct becomes clear when one realizes that the global distribution of Syncaris pacifica is limited to about 20 streams in Marin, Sonoma and Napa Counties, and all but one of these streams (Lagunitas Creek) are on private land. Channelized creeks, banks hardened with riprap, cattle grazing, water diversions, pesticides and non-native fish are all threats to its continued existence. Lagunitas Creek, however, remains a shrimp stronghold, where these threats are greatly reduced. Shrimp habitat is well protected on federal and State Park land, non-native fish are uncommon, and the creek has more water in the summer than it did historically, due to releases of water by MMWD. Surveys in recent years have found above-average numbers of shrimp in Lagunitas Creek. In other creeks, private landowners and community groups are working to protect and restore shrimp habitat. So while very few people are fortunate enough to see one of these unique animals, many people are working for their continued survival.

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by Eric Ettlinger

This post is the second in a year-long series celebrating the 40th anniversary of the Endangered Species Act. Read last month’s post here.

Peoples’ interest in frogs can be viewed as something of a leg obsession. The most obvious example is our insatiable appetite for frogs’ legs. During the California Gold Rush, populations of native red-legged frogs (Rana draytonii) were decimated by over-harvesting, leading to the importation of bullfrogs (Rana catesbeiana) from the eastern United States to help satisfy demand. These voracious predators (bullfrogs, not people) quickly spread to anywhere year-round fresh water could be found, and they continue to eat their way through native frog populations to this day.

Our obsession with frogs’ legs is not limited to cuisine, however, and extends to the very names we’ve given them. Here in Marin County we have three native frog species: the northern Pacific treefrog (Pseudacris regilla), the California red-legged frog, and the foothill yellow-legged frog (Rana boylii). We also have California toads (Anaxyrus boreas halophilus), which aren’t technically frogs, and since they don’t fit into this essay’s theme on leg obsessions, they will not be mentioned further.

Of our real frogs, two of the three are named for their legs, which gives the impression that there’s something quite distinctive about those springy appendages. On the contrary, the red and yellow coloration for which these frogs are named is generally confined to the undersides of their legs, which few can see.

Naming these frogs for their legs fails to capture what’s truly fascinating about them. The red-legged frog is most famous for being the central character in Mark Twain’s “The Celebrated Jumping Frog of Calaveras County.” Given such celebrity, wouldn’t a more fitting name be something like “Twain’s jumping frog?”

Female FYLF on cliff at Little Carson Falls. Photo by docent Peter Barto.

Female FYLF on cliff at Little Carson Falls. Photo by docent Peter Barto.

Foothill yellow-legged frogs (FYLFs) don’t have a claim to fame but can perform feats like climbing slick bedrock cliffs and clinging to rocks at the bottom of waterfalls. “Clingy frog” is more apropos and interesting, and doesn’t require an acronym.

In recent years both of these frogs have  taken on new, more ominous, labels. California red-legged frogs have been listed as a federally threatened species, and FYLFs are listed as a “species of special concern.” The reasons for their declines include predation by non-native bullfrogs, crayfish, and fish; habitat loss; pesticides; and the modification of river flows. Their plight is a small part of an unfolding global amphibian crisis, which may result in the largest extinction event since the age of dinosaurs. A significant cause of the crisis is the global spread of a deadly Chytrid fungus, although FYLFs appear resistant to Chytrid infection and the role it plays in red-legged frog declines is unknown.

Red-Legged Frog in Lagunitas Creek

Red-Legged Frog in Lagunitas Creek

In the last decade, a single red-legged frog was seen on the Marin Municipal Water District’s watershed lands. That individual likely dispersed over a ridge from Point Reyes National Seashore, where a relatively large population uses managed stock ponds (artificial ponds for cattle) for breeding.

FYLF populations on MMWD watershed lands appear to include roughly 30 breeding pairs, which breed in only two locations. One of these breeding sites is Little Carson Falls, a popular hiking destination near Pine Mountain. On warm spring days when the falls are flowing, hikers and their dogs have been known to wade in the water and inadvertently dislodge fragile egg masses clinging to the rocks. Fortunately for the frogs, volunteer “Frog Docents” also hike out to the falls, educate visitors about the plight of the frogs, and collect data for the biologists monitoring the population.

Foothill Yellow-Legged Frog at Little Carson Falls. Photo by docent Matthew Sykes.

Foothill Yellow-Legged Frog at Little Carson Falls. Photo by docent Matthew Sykes.

Now in its sixth year, the Frog Docent Program is looking for volunteers to help conserve these rare frogs. If you’d like to help save this species from possible extinction by becoming a 2013 frog docent,  call our Volunteer Program at (415) 945 -1128 or e-mail volunteerprogram@marinwater.org.

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by Eric Ettlinger

Coho salmon numbers in Lagunitas Creek have been so low in recent years that even a run-of-the-mill run would be welcome news. Well, I’m pleased to report that our current count of coho redds (nests) is just shy of a 17-year average.  In the last two weeks, MMWD biologists observed what may be the last few coho redds of the season, bringing the watershed total to 239. This is only eight redds shy of average and makes this the largest coho salmon run seen in the watershed in six years (see chart). What makes this even sweeter is that it was so unexpected. In 2011 we documented a relatively small number of coho smolts migrating from Lagunitas Creek to the ocean. Typically, only 2-5 percent of these fish would survive to return to their natal stream and start the cycle again. As things now stand, an astonishing 10.3 percent of those fish have returned. Excluding Olema Creek, where coho have returned at a fairly typical rate (4 percent), the rest of the watershed has seen nearly 13 percent of its coho return!

According to the Northwest Fisheries Science Center, ocean conditions were very good for coho salmon in 2012. Physical conditions improved and plankton were abundant, including the copepods and fish larvae that make up coho salmon’s preferred prey. Looking forward, they predict that these favorable conditions will continue through 2013, which would be very good for Lagunitas Creek coho. If the coho currently in the ocean are surviving at a rate similar to what we just observed, we could see over a thousand coho salmon return in the fall. A record-breaking run isn’t out of the question.

Not to be forgotten, steelhead are currently spawning in small numbers (see chart). To date we’ve seen 15 steelhead and 38 redds, and spawning activity is likely to remain subdued while the dry weather continues. Once the rain returns, however, we’ll find out if ocean conditions have been as good to steelhead as they have been to coho.

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by Eric Ettlinger

The holiday season is a tough time to keep up with regular spawner updates, and a lot has been happening in Lagunitas Creek over the last three weeks. Right after my previous update (12/17/12) we were hit by the second large storm of the season, which dropped over seven inches of rain. Stream flows peaked at 1,900 cubic feet per second and within a week Kent Lake began spilling. Flows have remained too high since then to conduct surveys in the main stem of Lagunitas Creek.

A pair of coho salmon spawn in Lagunitas Creek.

A pair of coho salmon spawn in Lagunitas Creek.

On December 27, the day before Kent Lake started to spill, MMWD biologists conducted a survey in the ½-mile reach between the Leo T. Cronin Fish Viewing Area and Peters Dam. They observed 28 coho and 12 new redds. Folks who visited the Fish Viewing Area around that time were lucky enough to witness the best salmon viewing in the last few years.

To date we’ve counted 320 live coho and 170 coho redds, which are the highest counts for early January since 2006. More than half of the redds found so far have been in San Geronimo Creek and Devil’s Gulch, where we’ve documented 49 and 42 coho redds, respectively. By the end of this week we’ll be able to once again survey the main stem of Lagunitas Creek, where we expect to find quite a few more coho redds.

MMWD fisheries intern Ariana Chiapella of the AmeriCorps Watershed Stewards Project prepares to collect tissue samples from a spent female coho salmon.

MMWD fisheries intern Ariana Chiapella of the AmeriCorps Watershed Stewards Project prepares to collect tissue samples from a spent female coho salmon.

The timing of spawning this season has been consistent with historical trends (see chart), so within the next three or four weeks coho spawning should essentially be over. But as coho decline, steelhead spawning will ramp up. We observed live steelhead for the first time last week in San Geronimo Creek. Steelhead spawning typically peaks in mid-February and continues through April. This year we’re expecting an above-average steelhead run to return to the Lagunitas Creek Watershed.

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