Take Action for Little Fish

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Maybe you have seen this going around about the Little Fish our big fish eat?  Pew has been pushing this around for a while, and you know what, they are spot on.  As fishermen, sport and commercial, we fight over allocation, we fight over hatchery releases, and we all are overwhelmed with the issues of habitat.  All this has to do with what is going down on land.  There is something we can do that is pretty simple and gets us ahead of the curve on a major issue in our oceans.  The increase harvest of Forage fish.

Forage fish are the herring, anchovies, sardines, dace, smelt, squid etc. that eat phytoplankton turning it into protein for the big stuff, like seals, salmon, steelhead and birds.  This increase in harvest in a volatile ocean, see the sardine issue, turns commercial fishermen to seek out new species to target for harvest often to feed fish farms.  Of all these little fish, only anchovies, market squid, Pacific herring, and sardines are regulated on the West Coast in the L48.  What Pew is suggesting, along with Trout Unlimited, Association of Northwest Steelheaders, Wild Steelhead Coalition and a slew of others, is they actually manage for the majority of species on an eco-system level.  This is the proposal from the Pacific Fisheries Management Council that fish folks are supporting.

These fish feed Steelhead and salmon, making them strong so they can swim to places as near to the ocean as Siletz, Oregon or as far as Salmon, Idaho, healthy fish are strong spawners and fight hard as well.  The other thing these little fish do is create massive bait balls at the mouths of some of our biggest rivers, like the Columbia. This provides incredible cover for outgoing smolt who run a gauntlet of birds, seals, and predator fish as they enter the ocean.

So take a minute and Take Action – Tell the Pacific Fisheries Management Council the time is now to protect unmanaged Forage Fish – Deadline for Comments is March 30th.

Head over to http://www.tu.org/take-action and find the link titled “West Coast TU Members: Urge Fishery Managers to Protect Our Forage Fish”

What’s up with the steelhead stalkers?

The crew of the research vessel Chasina gets ready to drop an acoustic telemetry receiver 300 feet down into Puget Sound. The device will record tagged steelhead as they swim out of their spawning rivers. Credit: Ashley Ahearn

OPB radio recently provided a look into the research conducted by Megan Moore (NWFSC – NOAA) and colleagues on an early marine survival project. If you didn’t catch the program, it describes the sources and locations of steelhead smolt mortality upon leaving their natal river. The researchers are tagging wild and hatchery smolts, then tracking their movements (and survival) through Hood Canal in Washington to study where mortality is occurring and if differences between hatchery and wild fish are present.

Their most recent steelhead stalker project had the following 4 objectives:

  1. Get a baseline survival estimate for two wild populations;
  2. determine if conservation hatchery smolts had similar survival rates compared to wild smolts;
  3. evaluate if wild and conservation hatchery smolts from the same population have similar behavioral traits, and;
  4. locate hot spots of mortality during smolt migration.

The study was repeated over three years (2008-2010). Wild smolts were captured from two Hood Canal rivers and tagged with VEMCO acoustic tags. These tags emit an active signal (think along the lines of sonar) that is picked up by receivers positioned in migration corridors. Each tag has a unique ID code so individual fish can be tracked through their path of migration. The conservation hatchery fish were offspring of wild spawners and collected as recently fertilized embryos from the river (no artificial spawning involved).

Two different hatcheries were used to rear the fish. One hatchery (Duckabush population), was low-density with circular tanks and the second (Skokomish population), was higher-density (within conservation program guidelines) using raceways for rearing. The same tags were implanted in the hatchery fish and wild fish so there wasn’t a difference in tag effects.

To track the fish, four lines of receivers were deployed during the study. The first was at the river mouth of each river smolts were tagged in. The second was at the Hood Canal bridge, a third was made across Admiralty Inlet and the final array was spanning the Juan De Fuca Strait.

Program MARK, using a Cormack Jolly Seber survival model, was used to determine if any of the following five factors influenced survival;

  1. population (river differences);
  2. rearing type (hatchery vs wild);
  3. hatchery (differences between two hatcheries used);
  4. Skokomish (combined Duckabush wild and hatchery vs Skokomish hatchery), and;
  5. Duckabush (combined Skokomish wild and hatchery vs Duckabush).

Three covariates (length, condition factor and release date) were included in all models as well. If you want more details on the analysis check out the pdf (I dare you…).

For survival probabilities of each population in each section of the migration click here. Wild fish had the highest survival probability, but the Duckabush hatchery smolts were not statistically different from wild fish. The Skokomish hatchery fish had lower survival in every migration segment except from the Hood Canal bridge to Admiralty Inlet. The Hood Canal bridge to Admiralty Inlet segment was the area of highest mortality for all populations. Release date has a slight positive effect on survival, meaning hatchery fish released later in the season had a slightly higher probability of survival. There were no differences between wild and hatchery populations in freshwater or saltwater migration behavior.

Let’s put this one in perspective. Some hatchery fish had indistinguishable survival rates from wild fish…score one for the conservation hatchery program! The other hatchery population (the Skokomish) had lower survival probabilities, but they were raised at higher densities in a raceway environment. Potentially higher-rearing density, or something unique to the raceway, had an effect on post-release survival.

A mortality “hot spot” was found in the migration pathway. Between Hood Canal bridge and Admiralty Inlet, all smolts had mortality rates up to 15 times higher than any other migration segment. The authors suggested that the subsurface bridge pontoons could be inhibiting the surface-oriented smolts during their migration. And just in the past year Moore, et al. have published another paper on the effects of the bridge on smolt survival. Stay tuned for that article in my next post.


Neil Thompson is a P.h.D. student at Oregon State University studying the drivers of domestication selection in hatchery culture of Pacific salmon and steelhead.  Find out more info on the lab where I work here.

Salmon Use Magnetic Field–Based Internal Maps to Find Their Way

A new study from a team OSU researchers, led by Nathan Putnam, recently published in the February 6th edition of Current Biology finds that steelhead and salmon use magnetic field-based internal maps to find their way back to their natal streams to spawn.

James Gould, an evolutionary biologist at Princeton University who was not involved in the study, wrote in a commentary on the paper that the fish may not have a map like the kind we might imagine, but instead something akin to an Excel spreadsheet, with “lists of magnetic coordinates with the seasonally appropriate directional responses filled in.” That is, the fish may simply perceive the magnetic field at a given location and, like a GPS, have essentially a voice command in its head that tells it where to swim. Putman thinks this is likely the case for the salmon. “If I had to bet, I would say that is probably what’s happening,” he says.

For a writeup of the study, see Scientific American online.  For the full study, click here.

OMSI Science Pub in Corvallis: Cry of the Pacific Lamprey: What This Ancient Fish Is Telling Us About Our Waters

Next Monday, join Carl Scheck of OSU and Jeremy Monroe of Freshwaters Illustrated at Old Wold Deli for OMSI Science Pub. The topic of the evening will be lamprey and what we can learn from these fascinating, ancient fish. 

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Lamprey lack the charisma of Chinook salmon, steelhead or even the sturgeon. With a powerful mouth disc, lamprey latch onto other fish and suck out body fluids. Older than the dinosaurs, these ancient fish have successfully negotiated at least four planetary extinction events. However, they may not survive changes brought about by humans.

Monday, Feb. 10th, 2014

6-8 PM

Old World Deli – 341 2nd St. Corvallis, Oregon

[LINK] to OMSI science pub website

Mushrooms clean dirty Willamette River water

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[LINK] to complete story from KVAL.com

The process used by volunteers with the Ocean Blue Project, an ecological restoration nonprofit, is to place mushroom spawn and a mixture of coffee grounds and straw in burlap bags that mushrooms can grow in, and then place the bags so that water entering storm drains will filter through them.

Oregon Department of Environmental Quality water sampling from 2008 to 2012 showed the presence of pesticides, flame retardants, metals, and chemical ingredients from consumer products in the river. The Oregon Health Authority also has an active mercury advisory warning that children should not eat more than one serving of resident species of fish from the main fork of the Willamette River a month, and that adults should not eat more than four servings. Complete Article [HERE].

Mushrooms are freaking sweet.

Bluebacks to conduct spawn and snorkel surveys on SF Siletz

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Trout Unlimited’s local Corvallis Chapter, The Bluebacks, are undertaking a monitoring effort on the Upper South Fork of the Siletz above the old Valsetz Dam site.  The project will include both spawn surveys for steelhead “redds” and snorkel surveys to determine if juvenile salmon and steelhead are using the SF Siletz and its tributaries as rearing habitat.  The Bluebacks hope to engage the Corvallis community in “citizen science” to collect valuable data on fish populations in the Upper Siletz and provide educational opportunities for community members.

A few years ago, ideas began circulating about rebuilding a dam at the old Valsetz site, to create a reservoir to divert water from the SF Siletz to Polk and Lincoln counties for irrigation and municipal water uses.  Back in 2008, OPB ran a story and an accompanying article that summarizes the proposal pretty well here.  While that effort seems to be on the backburner, the Bluebacks are seeking to collect spawn and juvenile usage data for the Upper South Fork Siletz and some smaller tributaries to better inform any debate around future dam proposals and to gain understanding of native steelhead, Chinook, and trout populations in the Upper Siletz Basin.

Volunteer leaders are being trained in the middle of January, and spawn survey efforts will run from January through the middle of May.  The Bluebacks are seeking volunteers to participate in these spawn surveys, where groups will meet every other weekend at Moonshine State Park and drive to the survey sites.  Surveys will involve walking 1-2 miles of the reaches being monitored, looking for steelhead redds, or nests that spawning steelhead make to lay their eggs in.  The semi-weekly trips will take about a half day and will provide both beginners and experts experience with principles of fish biology and the opportunity to see wild, native steelhead spawning in their natal streams.

If you’d like more information on becoming a volunteer leader, or just participating in a volunteer survey day, contact Chapter Volunteer Coordinator Julie Nist, at bluebackstu@gmail.com, or head over to http://www.bluebacks.org/projects for a full monitoring calendar and more information on volunteer opportunities.

-KS