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Posts Tagged ‘salmon’

by Eric Ettlinger

Coho smolt

Coho smolt

Salmon in California have evolved to follow the seasonal rhythms of wet and dry periods as they migrate between their natal streams and the ocean, and then back again. The fall rains that swell Lagunitas Creek and herald the return of adult salmon to Marin County also encourage young coho salmon to begin their downstream journey to the ocean. In normal years, winter is the time when many of these young salmon migrate from headwater tributaries down to lower Lagunitas Creek, where they transform into silver smolts in preparation for the ocean phase of their life cycle. These smolts wait in the lower creek until April and May before entering the ocean, just in time to take advantage of the spring plankton bloom.

2013 and 2014 have not been normal years, however. Fall rains were infrequent and light, and January was the driest on record. The drought caused a significant delay in salmon spawning and resulted in a much smaller coho run than expected. The extended dry period did, ironically, seem to benefit the young salmon preparing to emigrate to the ocean. Many coho fry were unable to migrate downstream until the rain finally arrived in February, which meant that they weren’t packed together in lower Lagunitas Creek. The habitat in the lower creek can’t support very many young salmon through the winter, which appears to be one of the principal factors limiting the size of the entire coho salmon population. This year, salmon fry spent the winter spread throughout the watershed, and likely spent little time crowded in the lower watershed.

The result was the largest emigration of salmon smolts yet seen in Lagunitas Creek. Biologists with the Watershed Stewards Project, the Marin Municipal Water District, the National Park Service, and the Salmon Protection and Watershed Network counted coho smolts every day between late March and early June as they migrated past traps on Lagunitas, Olema, and San Geronimo Creeks. In typical years the lower watershed doesn’t appear to be able to support more than approximately 11,000 juvenile coho salmon through the winter. This year nearly 20,000 coho smolts emigrated to the ocean.

smolt chart

Click the image above to view full-size chart

What does this mean for the future of coho salmon in Marin County? In the short term, if food is abundant in the ocean we could see 2,000 adult coho return to Lagunitas Creek in 2015 (the most in more than half a century). On the other hand, this year’s smolts were fairly small and may not survive well. Over the longer term, while we can’t recreate this year and prevent coho from migrating to the lower watershed, we can provide more habitat there. A grant currently being considered by the California Department of Fish and Wildlife would fund the construction of five projects in lower Lagunitas Creek to expand side channels and floodplains for coho salmon winter habitat. Hopefully this grant will be funded and the projects will achieve their goals. As with the seasonal migrations of salmon, we’ll just have to wait and see.

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by Eric Ettlinger

Coho season is wrapping up, and thankfully it’s ending with more of a bang than a whimper. In late January, at the typical end of the coho spawning season, the San Francisco Chronicle ran the headline “Crisis for the coho” with a couple of pictures showing the extremely dry conditions in the Lagunitas Creek watershed. As if on cue, the rain started falling a few days later and coho spawning took off. Since then spawning activity has subsided and in the last week we’ve seen what are likely the last few coho of the season. Our preliminary watershed totals are 433 coho and 203 redds, which is roughly double the size of the coho run three years ago.

Steelhead (pictured) have also been spawning in impressive numbers. In the last three weeks MMWD biologists have seen 153 steelhead and 126 redds. Steelhead are likely to continue spawning through at least April, and at this pace we’re looking at a very good year for steelhead. Rain is forecast to return late next week, which should bring up another wave of steelhead spawners.

steelhead female and small male

Steelhead female and small male

steelhead male

Steelhead male

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by Eric Ettlinger

Female coho

Female coho (photo by Rosa Albanese)

It’s been an exciting couple of weeks in the Lagunitas Creek watershed. In my last update I described how coho salmon spawning had unexpectedly jumped up (so to speak) following a tiny bit of wet weather on January 30. Another small rain event followed that survey, coinciding with an increase in water releases by MMWD, and more spawning ensued. Over three long and wet days last week MMWD biologists surveyed most of Lagunitas Creek, and finished the uppermost section of creek this morning. In total we counted 118 coho salmon and 56 new coho redds. We also counted 118 salmon during the previous week, but it’s difficult to say how much of this coincidence was due to counting the same fish twice. To date we’ve seen 349 coho and 161 coho redds. This is an increase over three years ago, but still far less than the large coho run we were expecting.

The other big news was, of course, the enormous amount of rain we received. Since Friday the Kent Lake rain gauge has recorded over 11 inches of rain, while the gauge at the top of Mount Tamalpais recorded over 21 inches! This has helped our water supply situation and has finally allowed salmon to swim into the tributaries. Flows are still too high and turbid to conduct surveys, but later this week we’ll be investigating how many salmon survived both drought and flood to return to these creeks at last.

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by Eric Ettlinger

coho salmon pair

Coho salmon pair in Lagunitas Creek, January 31, 2014

Finally some good news from Lagunitas Creek! Last Friday MMWD biologists conducted surveys to get a baseline salmon count ahead of a three-day increase in stream flows. This was the last “Upstream Migration Flow” of the season, and we wanted to document how many salmon spawned in response to the extra water. We were blown away to see significant numbers of salmon spawning throughout the creek before the flow even started. Apparently the 0.07″ of rain we received on Thursday was enough to encourage coho to finally spawn. In total we observed 118 live coho and 45 new coho redds. So far this season we’ve documented 252 coho and 103 coho redds. On Friday we also saw seven spawning steelhead and seven new steelhead redds. Finally, during a partial survey of Walker Creek (the next salmon stream north of Lagunitas Creek), we found the first coho redd and coho carcass of the season.

The Upstream Migration Flow coincided with 0.8″ of rain on Sunday, and we’ll be documenting the salmon response in Lagunitas and Walker Creeks for the rest of the week. By next week we should have a pretty good idea how many salmon survived the last few months and finally spawned.

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by Eric Ettlinger

Salmon spawning in Lagunitas Creek has remained muted, despite water releases  from Kent Lake. On January 1-3 MMWD released approximately 29 million gallons of water to increase flows in Lagunitas Creek from 20 cubic feet per second (cfs) to 35 cfs. This “upstream migration flow” is intended to allow salmon to swim upstream through shallow areas and spawn, although it’s unusual for spawning activity to increase significantly when these releases don’t coincide with rain. We found 12 new coho redds following the flow, which was an increase from the previous week, but similar to the low counts in December (see chart). We also found a redd that was likely built by a steelhead, which was the first evidence of steelhead in the creek this season. This past week we surveyed all of Lagunitas Creek, nearly down to Point Reyes Station, and found ten new coho redds.

To date we’ve observed 57 coho redds in Lagunitas Creek, which is exceptionally low for mid-January. A surge in spawning is still possible; back in 2001 we counted 96 coho redds in the second-to-last week of January. With no rain in the forecast that’s probably too much to hope for, but hopefully the forecast is wrong and rain is on its way.

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by Eric Ettlinger

January has arrived and both rainfall and coho salmon numbers remain far below normal in the Lagunitas Creek watershed (see chart). In the last two weeks MMWD biologists counted 15 new redds in the main stem of Lagunitas Creek. On Tuesday a school of 35 adult coho were seen in the “Swimming Hole,” a deep pool in Samuel P. Taylor State Park. That brings the season total to just shy of 100 coho (some of these were likely counted multiple times), which is far below the 400 fish typically seen by early January.

Yesterday MMWD began releasing extra water to provide an “upstream migration flow” for coho salmon. Salmon generally prefer storm runoff for migrating upstream, but on occasion we’ve seen coho increase their spawning activity in response to these water releases. If the extra water doesn’t encourage a surge in coho spawning, there is some light rain in the forecast for late next week that might do the trick. We’ve seen spawning activity spike as late as the last week of January, but hopefully we won’t have to wait that long.

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by Eric Ettlinger

Another week without rain and very few salmon are spawning in Lagunitas Creek. MMWD biologists documented 24 coho salmon and seven new coho redds this past week. We also saw three Chinook salmon and identified what appeared to be five new Chinook redds. The total counts are similar to what we saw the week before, but far below average for the third week of December, which should be peak spawning time. In fact, excluding the population crash of 2008-09, the 22 coho redds seen so far this season are the fewest seen for this date in the last 17 years. Back in 2004-05, the great-grandparents of this year’s coho had constructed nearly 200 redds by this date (see chart).

Looking on the bright side, Lagunitas Creek is faring better than many coastal streams that continue to be closed by sand bars due to the record-breaking dry spell we’re experiencing. Water releases by MMWD have allowed some salmon to migrate as far upstream as Peters Dam, and more water will be released in January to facilitate additional spawning. In about a third of years, coho spawning peaks in January and this appears to be one of those years. All we can do is hope that rain returns soon.

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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 1 of work partyby Erin Tracy, Watershed Stewards Project Member

The Americorps California Conservation Corps Watershed Stewards Project in partnership with Marin Municipal Water District hosted a volunteer Lagunitas Creek habitat enhancement on Saturday, November 23,  and it was a huge success!  Following a large woody debris installation to improve coho salmon habitat in the creek, the disturbed bank was in need of some rehabilitation.  Thirty motivated volunteers spent their Saturday planting the creek bank with native trees, shrubs and ground covers.  Re-vegetating this bank will not only reduce erosion and excess sediment flow into the creek but will also provide shade and cooler water temperatures that salmon need to thrive.

The day started at the Leo T. Cronin Fish Viewing Area parking lot, where volunteers could read interpretive signs about spawning salmon and try to catch a glimpse of one in the creek while waiting for everyone to arrive.  Sipping hot chocolate and tea, we huddled together in the cold morning to talk about our goals for the event.

Photo 2 - planting shrubWith the volunteers, we made our way down to the site and went straight to work planting the potted plants and transplanting sword fern, redwood sorrel, blackberry, and thimbleberry.  At lunch we gathered around the newly installed large woody debris structures and listened to Eric Ettlinger, an aquatic ecologist for MMWD, talk about the role of woody debris as winter habitat for salmon.  Lastly, volunteers helped with trash clean up and brought in woody debris to block off footpaths down to the creek to ensure their planting efforts would remain undisturbed.

At the end of the day a total of 48 plants had transformed the formally barren creek side.  It was an incredibly successful day and we are so thankful our volunteers came out to help the watershed.  We look forward to watching the progress of the plants and seeing this bank returned to the healthy ecosystem it once was.

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by Rosa Albanese, Watershed Stewards Project Member

This is the last in a year-long series celebrating the 40th anniversary of the Endangered Species Act.

Photo of steelhead trout

Steelhead trout in Lagunitas Creek. Photo by MMWD Aquatic Ecologist Eric Ettlinger.

What better way to end this series than with the enigmatic Oncorhynchus mykiss of the salmonidae family. This species exhibits more survival strategies than any other Pacific salmonid species, including flexible habitat preferences, differences in reproductive biology and adaptability in their life cycle types between generations.  Step into any body of fresh water and the fish you would mostly likely encounter is O. mykiss. However, they are still faced with many of the same threats as other salmon and must be carefully managed to ensure their future success.

When referring to O. mykiss one may be talking about rainbow or steelhead trout. What’s the difference? If they never migrate, they are considered rainbow trout. But if they make the great migration to the ocean and back, they are known as steelhead. However, although rare, it has been reported that the offspring of a steelhead may grow up to be a resident rainbow trout and vice versa.  But, basically, steelhead are anadromous (migratory) rainbow trout.

Steelhead also vary in when they migrate. Steelhead have two principal life history patterns: summer and winter runs. Summer steelhead enter streams as immature fish during the receding spring flows and  spend the summer holding up in deep pools, typically near a stream’s headwaters, where they then mature to spawn in winter or spring. Lagunitas Creek, which originates on Mt. Tamalpais and flows west to Tomales Bay, is home to winter-run steelhead. These fish are similar to coho salmon in that they enter the streams from the ocean during winter rains as mature fish. However, steelhead generally spawn later than coho, between January and April. Also, unlike all other salmonid species, they may spawn more than once throughout their lives, which is referred to as iteoparity.

Regardless of life history path, for the first year or two of life steelhead/rainbow trout can be found in cool, clear and fast-moving streams with ample cover and diverse and abundant invertebrate life.  Although highly variable in color and size, adults can generally be identified as a silvery trout with black spots covering their back, dorsal fins and tail and a reddish band along their sides. They can grow to be 45 inches long and weigh close to 50 pounds, but in Lagunitas Creek adult steelhead are typically closer to 30 inches long. These fish have adapted a streamlined body shape that helps them hold their position and swim in fast-moving water, which may be why they are considered by many anglers to put up a good fight and are so highly sought for sport.

Within California, native populations of coastal steelhead have experienced declines similar to those of other local salmonid species. The reasons are complicated but are largely due to competition with humans for habitat, dams and other alterations of landscapes, overfishing and introduction of foreign species as predators and competitors. Due to their diverse life history, management of steelhead is somewhat complicated. Steelhead stocks are placed into groups based on broad geographic distributions, plus run-timing, and many local populations are granted different taxonomic classification. For example, here in Marin County steelhead are classified as part of a Central California population and are federally listed as threatened, while populations further south are listed as endangered. Regardless of the terminology, steelhead are at risk.

There are many important reasons to protect such a unique fish species. Not only are they indicators of stream health, but preserving their wonderfully complicated diversity will allow them to adapt to changing environmental conditions. Steps to the recovery of steelhead and other salmonids start with support for projects that restore watersheds, ensure sustainable stream flows, reduce migratory barriers and minimize competition from non-native species. Protecting California steelhead and other andromous fish ensures that our fresh water and ocean habitats remain intact for future generations and a remarkably diverse species continues to adapt and thrive.

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