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'spawner update'

Feb 24

Lagunitas Coho – The Year in Review

Posted to MMWD Blog: Think Blue Marin on February 24, 2015 at 2:03 PM by Ann Vallee

by Eric Ettlinger, Aquatic Ecologist

The final update on Lagunitas Creek coho for the 2014-15 season is somewhat overdue because of some unusually late spawners. Last week we observed eight fresh coho in Lagunitas Creek, which is exceptionally late for a run that peaked in mid-December. Coho are typically seen spawning in February only when the rainy season is delayed, like last year. Given this year’s early rains the best explanation I have for the extended run is that the parents of these fish may have been late spawners. Back in 2012 the last coho of the season were seen spawning on Valentine’s Day.

So, moving on to the postmortem … The best that can be said about this run is that it wasn’t smaller than the coho run three years ago, which is something. Our preliminary season total is 131 coho redds, or about 65% of average. This does not include spawning in Olema Creek or the tributaries to San Geronimo Creek, which are surveyed by the National Park Service and the Salmon Protection and Watershed Network (SPAWN), respectively. The marine survival rate of these fish was under 4%, which is well below the average of the last eight years.

The picture was brighter for other species. We counted the highest number of Chinook salmon redds (23) in eight years and the highest number of chum salmon (3) in a decade. The steelhead run got off to a late start due to the exceptionally dry January, but is now in full swing. To date we’ve seen 70 steelhead redds, which is approaching average for late February.

 lamprey pair -sm (2)
 Pacific lamprey pair
Finally, we saw the first Pacific lamprey of the season on January 29. We typically see these native, cartilaginous fishes spawning in March, as we’re wrapping up our salmonid spawner surveys. Our AmeriCorps members took this great picture of a pair using their sucker mouths to pull rocks from their redd. Their eggs will hatch into worm-like ammocoetes that will spend as much as seven years filter feeding in the streambed. Then they will migrate to the ocean and find a larger fish to latch on to and parasitize. They aren’t able to navigate back to their natal stream like the salmonids do, but when they’re large enough they’ll let go of their host and follow the scent of juvenile lamprey pheromones to whatever stream they’re close to. Like the salmon, this is a one-way trip and they die after spawning. Lamprey will continue to spawn in Lagunitas Creek through the spring.

Jan 14

The Rain Returned, but the Salmon, Not So Much

Posted to MMWD Blog: Think Blue Marin on January 14, 2015 at 2:11 PM by Ann Vallee

by Eric Ettlinger, Aquatic Ecologist

What started off as an unusually large and early coho run in Lagunitas Creek appears to be coming to a disappointing end. We may see a few fish spawning in the next couple of weeks, but at this point a late surge is unlikely. To date we’ve counted 103 coho redds, which is similar to what we saw three years ago but barely half of average. What’s most disappointing is that in 2013 we observed a robust emigration of coho smolts from the creek. We expected those relatively large fish to pack on some more weight in the restored Giacomini Wetlands and then survive well in the open ocean. It now appears that less than three percent of those fish have returned.

It’s possible that we missed some spawning while 15 inches of rain fell and high stream flows kept us out of Lagunitas Creek in mid-December. If that’s true, we should have found redds, live fish, or even carcasses when we returned to the creek, but we saw few of each. We also surveyed the tributary streams during that period and saw relatively few salmon for that time of year. There’s little option but to conclude that this year’s cohort survived poorly in the ocean.

On January 5 we saw our first steelhead spawner of the season and once the rain returns we should see steelhead numbers ramp up. We’re still seeing a couple of Chinook salmon in the creek, and yesterday had the distinct pleasure of seeing a small mixed school of coho, Chinook, and steelhead holding in a deep pool. It wasn’t much, but we’ll take what we can get.

Dec 15

Spawning Season Half-time

Posted to MMWD Blog: Think Blue Marin on December 15, 2014 at 3:06 PM by Ann Vallee

By Eric Ettlinger, Aquatic Ecologist

The third week of December is typically the mid-point of the coho spawning run on Lagunitas Creek. Spawner survey results before mid-December don’t typically mean much in terms of predicting the season’s coho run, but at this point I can let myself start feeling hopeful or worried about the season total. So with five weeks of surveys behind us, how do I feel about this year’s coho run? In a word, disappointed. To date we’ve seen 51 coho redds, which is somewhat below average, and predicts a season total in the neighborhood of 150 redds. That total would rank in the bottom third of runs over the last 18 years, in a year when abundant rain has allowed coho to spawn wherever and whenever they want, unlike some past years. It may be that this week will mark a sharp upswing in coho spawning activity, but for now things don’t look encouraging.

On a more positive note, we continue to see relatively large numbers of Chinook and chum salmon in the creek. To date we’ve counted 22 Chinook redds, which matches the pace of the big Chinook run of 2004-05, when we saw 125 Chinook and 44 redds. In the case of chum, “relatively large numbers” means three fish, but these few fish continue to be fascinating. Last week we again saw a male chum attempting to spawn with a female Chinook. In this instance the male had taken on the coloration of a female chum, with a solid, dark bar running the length of the fish. We weren’t fooled, however, because he was on a redd with an obviously female Chinook and his pattern of worn scales indicated that he had been fighting, not building a redd. Interestingly, it’s been many years since we’ve seen a chum salmon displaying the bold purple and black stripes of spawning males. Maybe they only dress up like that in the presence of other males.

It looks like rain and high flows will keep us out of the creek for at least the next few days, if not all week. Hopefully coho are surging upstream as I write this.

 Chum salmon
 A cross-dressed chum salmon in Lagunitas Creek