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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Spawner Update: Weekend Rains a Welcome Event for Coho

by Eric Ettlinger

Coho salmon jumping in San Geronimo Creek (courtesy of Virginia Fifield)

Good news! High flows this weekend allowed coho salmon to migrate into the tributaries to Lagunitas Creek for the first time since Thanksgiving! Observers saw at least 20 adult salmonids (mostly coho plus some steelhead) jumping through the “Inkwells” on San Geronimo Creek. I’ve included a photo of a particularly fat coho salmon jumping there, courtesy of Virginia Fifield. We’ll conduct spawner surveys once stream flows recede a bit and I’ll post an update on what we find.

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Spawner Update: Dry Spell Finally Over

by Eric Ettlinger

The long dry spell is finally over and we’re expecting heavy rains tonight. This should provide the migration flows that the remaining coho salmon have been waiting for. I’m keeping my fingers crossed that coho will migrate into San Geronimo Creek and Devil’s Gulch and spawn. Tomorrow may be the last, best chance to see salmon spawning this season.

For the local readers, I would appreciate hearing if coho or steelhead are seen jumping through the Inkwells (at the mouth of San Geronimo Creek) or into Devil’s Gulch. We’ll be conducting spawner surveys next week and I’ll post an update on what we find.

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Coho Spawners Are Here but Waiting for Some Rain…

by Eric Ettlinger

School of coho salmon in Samuel P. Taylor State Park

November was a surprisingly good month for coho spawning in the Lagunitas Creek watershed, but we haven’t had any significant rain since Thanksgiving and spawning activity has slowed. Only three new coho redds were seen last week and only one was seen this week. This is typically the peak time for coho spawning, and we’re expecting to see a lot of it once we get some rain. We haven’t seen much redd construction lately but this week we observed 27 coho, mostly holding in pools and waiting for some rain.

Douglas-fir log

In one small pool adjacent to the Samuel P. Taylor campground we saw 22 coho spawners. It’s been a long time since we’ve seen that many spawners in one place. Their choice in pools was less than ideal, unfortunately, since it was also where State Park staff were planning to drop a large Douglas-fir. The 100-foot tree was diseased and dangerous, and park staff collaborated with MMWD to drop it into Lagunitas Creek for fish habitat. But just as the cutting got started we saw the large school of coho beneath the tree and quickly decided to fell the tree away from them. It’s a little ironic that a tree intended to provide a home for next year’s juvenile coho could have killed some of their parents. State Park and MMWD staff are now discussing how to push the large log into the creek, in a spawner-free location.

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Spawner Update: A Good Week for Coho, and What a Smelly Carcass Can Tell Us

by Eric Ettlinger

This has been another very good week for Lagunitas Creek coho salmon (and for the biologists who count them). We spent the last four days surveying all of the spawning reaches of Lagunitas Creek, plus the tributaries San Geronimo Creek and Devil’s Gulch, and found signs of spawning activity in every stream reach we surveyed. We saw 15 live coho and 23 new redds, which brings the season total to 26 salmon and 26 redds. We haven’t seen this many redds in November in ten years. It’s been the kind of week that makes handling a spawned-out, smelly salmon carcass a joyous experience (see photo).

Speaking of salmon carcasses, it may look like we handle them just for fun and photo opportunities, but we’re actually collecting important data on every carcass we find. We collect genetic material that tells us how Lagunitas Creek coho relate to other coho in the region (they’re pretty unique!). We also collect tiny bones called otoliths from within the salmon’s head that provide a record of the fish’s entire life. These two millimeter long bones tell us when the fish hatched, how old it was when it migrated to the ocean, how long it spent in the ocean, and how fast it grew at each stage of its life. It’s like a flight data recorder. A study being conducted at UC Berkeley is using the otoliths we collect to investigate where in the watershed these salmon hatched, which may indicate survival differences for fish growing up in different parts of the watershed. Understanding which fish have higher survival rates (and why) could indicate what habitat characteristics improve survival and even how habitat should be enhanced. So it turns out that these dead, smelly fish can tell us a lot about how to save them.

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Lagunitas Creek Spawner Update: Thankful for Some Fish

by Eric Ettlinger

Expectations for this year’s Lagunitas Creek coho run have been low, if not downright grim, among those of us keeping track of the population. Coho have a fairly rigid three-year life cycle, so fish hatching in one year will typically spawn three years later. This creates a three-year pattern to coho runs, with small runs often being repeated three years later. These multiple generations of coho salmon, separated by three years, are called year classes, and the salmon currently returning to spawn are members of the weakest of the three year classes in Lagunitas Creek.

This year class hit unusually hard times beginning in 2005-06. A flood on New Year’s Eve destroyed nearly all the coho redds (nests) in the creek. In the spring of 2006 a second flood killed many coho fry as they emerged from redds built after the New Year’s Eve flood. When the surviving smolts went to the ocean in 2007, ocean productivity was dismal and less than 2 percent of them survived to spawn in 2009. Those spawners produced only 26 redds (the lowest number on record), which in turn produced the fish that are now returning to spawn.

So keeping this history in mind, last week was a very good week. The moderate rain we received last weekend seems to have encouraged some coho to migrate far into Samuel P. Taylor State Park and spawn. We observed 11 coho salmon and three new redds. We haven’t seen that many fish before Thanksgiving in four years. The Thanksgiving rain will hopefully bring up more salmon. Peak spawning time in Lagunitas Creek is typically mid-December, so we may not have long to wait to see if our expectations were unnecessarily grim.

I’ve included a photo (taken from far away) of coho spawning last week and attached a chart showing the coho year classes in Lagunitas Creek.

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All about the Water

MMWD’s reservoirs continue to stay above average even though rainfall is slightly below average. Here are the latest water supply and demand figures:

Reservoir Levels: As of November 21, the reservoirs contained 61,756 acre-feet,* or 78 percent of capacity. This volume is well above the average for this date of 50,053 acre-feet, or 63 percent of capacity.

Water Use: With several days of warm temperatures over the last 30 days, water production this year was higher than in 2010. The daily average for the last 30 days this year was 21.30 million gallons; for the same period in 2010 it was 18.49 million gallons.

Creek Releases: For the month of October water releases into Lagunitas Creek averaged 3.9 MGD (million gallons per day) and into Walker Creek averaged 3.0 MGD. We release water throughout the year to maintain adequate flows for the fishery per our agreement with the State of California.

Rainfall: As of November 21, we have received 7.29 inches of rain year to date (since July 1). For the same period in 2010 we received 11.00 inches; average is 7.42 inches. Rainfall is measured at Lake Lagunitas.

Rainfall and reservoir figures can be found on the homepage of our website.

*One acre-foot is 325,851 gallons.

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Leo T. Cronin Fish Viewing Area Open for Spawning Season

Leo T. Cronin Fish Viewing Area

Each year during the rainy season, coho salmon and steelhead trout make the difficult journey from the ocean back to Lagunitas and other local creeks to spawn, or lay their eggs, before they die. The Leo T. Cronin Fish Viewing Area next to Lagunitas Creek is now open to the public so visitors can have a firsthand look at this thrilling event.

Last year MMWD completed a number of grant-funded improvements to the viewing area, including resurfacing the parking lot with environmentally friendly permeable concrete that allows rain to percolate into the ground, improving access for people with disabilities, installing new educational signage and restoring habitat along the creek bank.

The viewing area, located on Sir Francis Drake Boulevard just past Shafter Bridge in West Marin, will be open daily, sunrise to sunset, through February. Parking is limited to one hour. If you go, please remain behind the fence, minimize noise and avoid sudden movements so that the fish may spawn undisturbed. The best time to see spawning fish is within a few days following a rainstorm.

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Coho Spawning Season Is Here!

by Eric Ettlinger

Spawner surveys in Lagunitas Creek have found the first coho salmon redd (gravel nest) of the 2011-12 season! The redd was observed downstream of Cheda Creek on November 3, making it the earliest coho redd found in Lagunitas Creek since 2001. Chinook salmon are occasionally seen spawning in early November, but they have been extremely rare in Lagunitas Creek during the last five years and this redd had traits typical of coho salmon redds.

No adult salmon have yet been seen in the creek, but clearly at least two have arrived and spawned. MMWD biologists will be surveying the creek weekly and I’ll provide updates throughout the spawning season.

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