Red Legs, Yellow Legs, Edible Legs, NOT

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.

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

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.

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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Lagunitas Coho Are Almost Average!

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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Lagunitas Creek Spawner Update

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.

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.

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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Lagunitas Creek Spawner Update

by Eric Ettlinger

The deluge we received earlier in the month (more than ten inches of rain over eight days) raised Lagunitas Creek stream flows to their highest level since 2006. On the downside this may have scoured some early coho redds (and washed the eggs away), but on the upside the high water seems to have cleaned much of the streambed of accumulated fine sediments. In many places the clean gravel looks like a blank canvas on which coho are now creating their redds.

Huge male coho carcass

Before I wax poetic on all the wonderful things the flood did for the creek (you should see the debris jams!), let me get to the fish numbers. In the last two weeks coho were seen spawning throughout the creek, and in numbers not seen in six years. MMWD biologists counted 66 coho redds, including 39 in Lagunitas Creek, 15 in accessible areas of San Geronimo Creek, and 12 in Devil’s Gulch. We also counted 130 live coho and found four carcasses (including the impressive male pictured here). To date we’ve counted 160 live coho and 80 redds, which is above average for mid-December (click here to see chart). This run is shaping up to be a huge improvement over the parent generation, which spawned three years ago. Only 67 coho were seen that entire season. This year’s coho are unlikely to match the runs of their grandparents (2006-07) or great-grandparents (2003-04), but it’s been a long time since a Lagunitas Creek coho run could be described as even “above average.”

Other notable observations from recent surveys included a school of 14 coho holding in a pool in San Geronimo Creek, and possibly the largest coho redd I’ve ever seen, measuring 27’ by 19’. Mid-December is usually the peak period for coho spawning in Lagunitas Creek, with spawning tapering off through January. Typically two-thirds of coho spawn after the peak week, so it’s likely that many more coho have yet to spawn and there will be plenty of opportunities to see them do it.

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Lagunitas Creek Spawner Update

by Eric Ettlinger

Significant storms are bearing down on Northern California at the moment, which limited spawner surveys this week and will likely curtail additional surveys for a while. However, our limited surveys did find some very interesting things.

The storm just before Thanksgiving dropped more than three inches of rain and raised flows in Lagunitas Creek to over 400 cfs. That high water allowed the first coho spawners to migrate throughout Lagunitas and San Geronimo Creeks. Coho were seen spawning upstream of the Leo T. Cronin Fish Viewing Area as well as adjacent to the San Geronimo Golf Course, which are both near the upstream anadromous limits of those two creeks. MMWD biologists observed the highest level of spawning activity for November in eight years, including 30 coho salmon and 14 new redds.

Female chum salmon in Lagunitas Creek

The most interesting observation of the week, however, was of a chum salmon—a rare species for California, and more common in rivers from Oregon to the Arctic Ocean. Aside from a freak run of chum salmon in 2001, we’ve never seen more than a handful of these beautiful fish in Lagunitas Creek in a season, and no chum at all have been seen since 2006. When we first came upon this fish on her redd, we briefly saw blotchy vertical stripes before she darted upstream. When we next saw her a short distance upstream, she had changed her coloration to mostly gray with a dark horizontal stripe. This color changing ability is peculiar to chum salmon, and was fascinating to see. I got a quick photo of her (well, most of her) before she swam away again. It would have been great to see this fish in her full spawning glory, before her tail was worn from digging and fungus began to grow on her back, but hopefully we’ll see more of this species next month and in the years to come.

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The Coho Run Has Begun!

by Eric Ettlinger

The 2012-13 spawning season is off to an auspicious start. We’ve already received 12.5 inches of rain—far above average for this time of year—and with the rains come the salmon. The first coho salmon of the year were seen on Sunday near the Leo T. Cronin Fish Viewing Area. Today we saw two of these fish actively spawning on a fresh redd. Another redd was seen yesterday in Samuel P. Taylor State Park that had characteristics typical of a Chinook (king) salmon redd, including a deep pit and sharp edges. Chinook salmon typically spawn at this time of year but we haven’t seen Chinook spawn in Lagunitas Creek since 2008. We’re excited by the possibility of Chinook spawning, but we need to see a fish before we can conclude that Chinook have actually returned to Lagunitas Creek.

Most of Lagunitas Creek is still running high and brown after last night’s rain, but salmon spotting should get easier over the holiday weekend. Happy Thanksgiving!

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Coho Salmon Leave Lagunitas Creek in Record Numbers

by Eric Ettlinger

Every spring MMWD biologists count coho and steelhead smolts as they migrate from Lagunitas Creek to the Pacific Ocean. These smolts have survived despite floods, predators and competition for limited habitat, and their numbers tell us a great deal about conditions in the watershed. This year’s smolt emigration provided us with enormous insights, as well as renewed confidence that the Lagunitas Creek coho population is recovering after two years of very low numbers.

MMWD began monitoring smolts in 2006 using a rotary screw trap. The trap is essentially an aluminum raft with a large, rotating funnel that catches smolts as they’re swept downstream. The funnel has internal baffles so fish going into the funnel can’t come back out. Every morning from late March through May we remove fish from the trap and count, measure and release them back into the creek. We also mark up to twenty fish per day with a small fin clip and release them upstream to estimate how many fish we’re catching, and more importantly, how many we’re missing.

During the peak of the coho emigration in late April the trap was catching nearly 300 coho smolts per day, and it was clear that this emigration would be the largest yet seen. When the trap was removed at the end of May, we had captured over four thousand coho smolts, and we estimated that 8,315 coho had left Lagunitas Creek. Over the years we’ve gathered strong evidence that Lagunitas Creek couldn’t produce more than about 6,000 coho smolts, which it has done in three of the last seven years. How did Lagunitas Creek produce over 8,000 smolts this year?

The answer seems to be an unusually small steelhead population. This year’s steelhead emigration was smaller than average, and in the last seven years whenever steelhead numbers went down, coho smolt numbers went up (click here for graph). Steelhead seem to be able to outcompete coho for habitats that provide protection from high flows, shelter from predators and good feeding opportunities through the winter. Steelhead generally live in the creek for two years before migrating to the ocean (compared to one year for coho), and these second-year steelhead are larger and can likely dominate the best habitats. We couldn’t simply reduce our steelhead population to benefit coho, since both species are federally protected. We need to enhance habitats in Lagunitas Creek in ways that benefit coho more than they benefit steelhead. This may be the most important insight gained from counting smolts seven days a week, two months out of the year, for the last seven years.

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Spawner Update: Coho Make a Comeback and Steelhead Follow Suit

by Eric Ettlinger

Coho salmon appear to have completed their spawning run for the 2011-12 season. Only two live fish (both males) were observed last week. MMWD biologists will be conducting spawner surveys again this week in sections of creek that haven’t been surveyed recently, so a few more coho redds may still be found. For now our season totals stand at 130 coho redds and 340 live coho. Most spawning occurred in the main stem of Lagunitas Creek, but 23 redds were seen in San Geronimo Creek and 11 were seen in another tributary, Devil’s Gulch. National Park Service biologists reported seeing coho spawning in another Lagunitas tributary, Cheda Creek, for the first time in four years. Three redds were also seen in small tributaries to San Geronimo Creek. This year’s coho run was smaller than average, but five times larger than the parent generation of three years ago. This is a very hopeful sign that Central California Coast coho are making a comeback after three years of abysmal spawning runs.

Male steelhead

Steelhead are also spawning in larger numbers than have been seen in recent years. Steelhead spawning generally peaks in February and continues into April, and to date we’ve counted 60 steelhead redds and 93 live steelhead. Half of the steelhead redds have been seen in San Geronimo Creek. As with coho, this year’s steelhead are unusually large (see photo), which is an indication that they found plenty of food in the ocean.

Even without the final tallies, it’s not too early to start speculating about why coho and steelhead numbers are up. Of the 2,100 or so coho smolts (adolescent fish) that migrated to the ocean in 2010, approximately 12 percent returned. The rate of coho marine survival in the previous four years ranged between two and five percent. Improving ocean productivity is likely the primary factor that allowed salmon to grow larger and survive at a higher rate. Another potential factor contributing to the coho comeback is the Giacomini Wetlands restoration. In 2008 the National Park Service restored over 500 acres of tidal marsh at the mouth of Lagunitas Creek, providing additional rearing habitat for young salmonids on their way to the ocean. This season’s coho were only the second cohort to have access to this new habitat. Coho numbers from other California streams will hopefully be reported soon, and we should then be able to tease apart which factors improved regionally and which improvements were specific to Lagunitas Creek.

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Spawner Update: Great News for Lagunitas Creek Coho Salmon

by Eric Ettlinger

The long-awaited storm that began January 19 dropped ten inches of rain over parts of the Lagunitas Creek watershed. The exceptionally dry ground absorbed a lot of that, but couldn’t absorb it all, and streams rose quickly. Adult coho salmon swam and jumped into many of the local streams, including into at least one headwater stream where they haven’t been seen in years. By late last week stream flows had declined enough for MMWD biologists to conduct spawner surveys and document the unusually late peak in coho spawning. We counted 35 new coho redds and 104 adult coho salmon. This brings the preliminary season total to 103 redds and 377 coho observations. The live fish count is likely an overestimate due to counting the same fish over multiple weeks, but the redd count is a more accurate measure of the size of the run. To date we’ve counted four times more redds than were built by the previous generation of coho salmon three years ago! We don’t expect these numbers to go much higher since late January is typically the very end of the coho spawning season. However, last week’s murky water may have prevented us from seeing every redd and we may find a few more when we survey again later this week.

A striking aspect of this season’s coho run has been the very high proportion of coho jacks. Jacks are small, two-year-old male salmon that return from the ocean one year earlier than most adult coho. More than half of the spawners seen last week were jacks, which is significant since the vast majority of their siblings are still out in the ocean. Lots of jacks this year suggests that far more coho will return to Lagunitas Creek next year.

Coho salmon in Dog Creek (photo by Carl Sanders)

One last bit of good news was the observation of coho spawning on MMWD property at the mouth of a small tributary to Lagunitas Creek called Dog Creek. Dog Creek used to flow through a cylindrical metal culvert that was too small to handle large floods and also impeded the natural movement of gravels to Lagunitas Creek. MMWD crews replaced the cylindrical culvert with an open-bottomed arch, and the creek quickly built a gravel delta at its confluence with Lagunitas Creek. Last week a pair of coho became the first salmon to spawn in this new habitat.

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Smile, Lion, You’re on Candid Camera!

by Eric Ettlinger

MMWD biologists like to keep track of things on the Mt. Tamalpais Watershed. We know how many fish are in the creeks (more or less), when rare plants are blooming, where owls are nesting, and we are always trying to understand how the water district’s operations might affect these species. Our most recent effort to catalog the abundance of life on the watershed involves a few carefully placed cameras that “catch” wildlife walking by.

Remote cameras—also called game cameras, trail cameras or camera traps—have become increasingly important for wildlife conservation in the last couple of decades. They’re being used to monitor rare species around the world, and occasionally discover new or long-lost species, such as the recent discovery of a Persian leopard in Afghanistan. MMWD’s camera trapping effort began with an attempt to find another such long-lost species that we suspect may have returned: the Pacific fisher. This large member of the weasel family was last seen in Marin County in 1913, and the closest current population is in Mendocino County. In 2010, Andrea Williams, MMWD’s Vegetation Ecologist, saw an animal on Mt. Tamalpais that fit the description of a fisher. The animal was larger than a raccoon, dark, low to the ground, and had a bushy tail. With the help of a local wildlife researcher, Virginia Fifield, we deployed remote cameras near the observation site and in suitable habitat elsewhere on the mountain. Despite nearly a year of looking, we never captured a photograph of the mystery animal.

The effort was not wasted, however, because the cameras captured an abundance of other wildlife using the roads and trails of the Mt. Tamalpais Watershed. We decided to shift our research towards investigating how these species move across the landscape, which we hypothesized was not simply random. Natural and manmade features such as ridgelines and reservoirs funnel wide-ranging species into “wildlife corridors,” where they would be more likely to encounter our cameras. We therefore strategically placed our cameras in a few of these potential corridors to see what species were traversing the watershed through them.

The videos are already telling us which corridors are wildlife freeways and which are only backroads. A camera on a ridgeline has captured a parade of deer and coyotes, as well as a mountain lion and a bobcat. Wildlife traffic along a nearby valley road has been much lighter. We plan to move the cameras to other potential corridors and over time try to develop a picture of what species are moving across the landscape and where they’re all going.

Check out these videos:

Mountain lion
Coyote pair with large pups
Bobcat

Note: This study has been authorized by MMWD. Placing personal cameras on water district property is prohibited.

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