Monday, March 29, 2010
Wednesday, March 17, 2010
The Pacific smelt, officially known as the eulachon, is a small anadromous fish, barely 9 inches, which historically ranged from northern California to the Bering Sea in Alaska. They return to the freshwater in masses to spawn, usually at night. Most adults die shortly after spawning. They are important to Native American tribes, the ocean and freshwater food chains, as well as both commercial and recreational fishers.
Sadly, the numbers are at a historical low right now and the National Oceanic and Atmopheric Administration (NOAA) says that the fish is at “moderate risk of extinction”. On Tuesday, NOAA listed the Pacific smelt as “threatened” under the Endangered Species Act. You can read more about that here.
“This evening we were visited by Comowool the Clatsop Chief and 12 men women and children of his nation . . . The Chief and his party had brought for sail a Sea Otter skin, some hats, stergeon and a species of small fish which now begin to run, and are taken in great quantities in the Columbia R. about 40 miles above us by means of skimming or scooping nets . . . I find them best when cooked in Indian stile, which is by roasting a number of them together on a wooden spit without any previous preparation whatever. They are so fat they require no additional sauce, and I think them superior to any fish I ever taste, even more delicate and luscious than the white fish of the lakes which hae heretofore formed my standaart of excellence among the fishes.”
From the Journals of Captain Meriwether Lewis and William Clark (February 25, 1806)
Photo of drawing reproduced from the Journals of Lewis and Clark (Illustration by Meriwether Lewis from American Philosophical Society)
Tuesday, March 16, 2010
Lampreys are pretty cool creatures. They are really old (as a species). They barely even count as a fish since they don’t have bones (they have cartilage) and have a very simple spine (called a notochord). The only fish close to the same age are hagfish, which are also odd looking creatures of the deep ocean. Lamprey have probably been around for the last 360 million years and changed very little in that time!
Even though they have been around for a long time we know much less about their biology and ecology than we do for other fishes. The conventional assumption is that Pacific lampreys use mainstem river habitats (Columbia or Willamette Rivers) mainly as a migration corridor. Adults return from the sea and migrate upriver to tributary streams (much like salmon) to spawn and die. Juveniles migrate downriver to the sea after spending a time period in the tributary streams. In the sea they begin their parasitic part of their life. Nobody really thinks they use the mainstem areas as a place to live – although no one has ever really thoroughly looked.
We used quite a contraption – a deepwater electrofisher – to collect lamprey ammocoetes from deepwater habitat in the Lower Willamette River from Willamette Falls downstream to the confluence with the Columbia River. Ammocoetes are the blind larval stage that burrow into the sediment and filter feed detritus and organic material. Our contraption is basically an electrified suction dredge. The “bell” is lowered to the bottom with a winch and the pump is turned on. Then the electricity is turned on and any ammocoetes that are in the sediments are stunned and sucked up and filtered through a basket. No, we don’t get any other crazy things from the bottom - like bones or sunken treasure. Most of the time we just got little bits of mussel shells and twigs. The video at the bottom shows the device in action.
Sure enough – the lamprey larvae were down there! We found both Pacific lamprey and western brook lamprey (a native non-parasitic freshwater lamprey) in water up to 53 feet deep! We even found them right in downtown Portland. We found them in shallow water and we found them in deep water. At this point we really couldn’t identify a pattern to where they may occur. We also found a wide range in sizes from less than 20 mm to over 140 mm meaning that they are likely a variety of ages. They weren’t really there in high numbers but they were there consistently enough to start thinking that they might be using these habitats to live and grow. Although we are not sure if the larvae migrated there or were “swept” downriver by strong currents it is conceivable that they are using the mainstem sediments as areas to feed and grow. Interestingly we did not find any larvae in the Multnomah Channel even though we thought this may be a good area for them – and we looked at over 60 sample sites! They may be in the channel but probably just in really low numbers.
It is encouraging and exciting to find lamprey in these areas but it also poses a whole host of concerns regarding lamprey welfare. Issues like channel dredging, contaminants, and flow alteration are examples of things that need to be studied further to understand their effect on the larval lamprey. We plan to keep looking in more areas for the lamprey larvae. We are going to look in the Columbia River at various locations downriver toward the estuary. We also want to look below and above some of the mainstem dams like up in Bonneville Pool. Also, it may be interesting to look at areas before and after channel dredging occurs to evaluate the potential impact of this activity. Stay tuned for future lamprey updates.
Wednesday, March 10, 2010
One of the most gratifying aspects of the work and culture at CRFPO is working with students. Long-term (a.k.a old) employees, such as myself, get to share their experience and passion with students. In turn, these students share and develop their passions with us, as well as rekindle the passion we sometimes forget about. The U.S. Fish and Wildlife has a program called STEP (Student Temporary Employment Program). Each year we try and hire a number of Biological Science Technicians through the STEP program. This program (and these students) help us get important work done and helps students get invaluable practical experience as their resumes begin to take form.
In 2009, the Conservation Team at CRFPO was fortunate enough to hire three STEP technicians, Kim, Michaela and Brian. These students worked on various projects for the C-Team. Their experiences (okay, job responsibilities) included work with bull trout that are listed under the Endangered Species Act and with Pacific Lamprey (although not listed under ESA, a species of concern). They were able to work in areas that ranged from the mainstem of the Willamette River (yes, they had to drive a boat on the river) to remote wilderness areas in NE Oregon (yes, they had to camp). They got to network (work side by side) with federal, state, tribal and city biologists. Among other things, they learned how to electrofish, operate big boats, identify larval lamprey, and put PIT (Passive Integrated Transponder) tags into fish. Like all of us, they had good days and bad days “on the job”. Fortunately the good days far outweighed the bad days. How do I know? Well … Kim was a second-timer (would you come back for more if you hated it?); Michaela is hoping to be a second-timer; and Brian never left!
The work that these students completed was incredibly valuable to the species we are trying to help conserve. I get to use results of their work every day. More importantly, the passion they expressed for the work and the gratitude they expressed for the opportunity was infectious. They are the future. And the future is bright!
Submitted by Tim Whitesel, Conservation Assessment Team
Wednesday, March 3, 2010
Did you know that you can also use electricity to put fish to sleep? It is an extremely effective method of putting a fish into a state of narcosis – electronarcosis. You use constant DC voltage… the same type of power found in your car battery. In fact, we hook up a power supply to a car battery! We just put the fish in a cooler full of water with aluminum electrodes on each end that are hooked up to the power supply, turn up the power to around 40 volts, but only about 0.1 amp, and the fish “falls asleep”. What is really happening is that the electrical field is inhibiting any communication between the brain and the rest of the fish’s body, resulting in a completely relaxed fish presumably feeling no pain.
Why would you want to do this? As fish biologists, we handle fish all the time to identify them, measure them, tag them, collect tissue samples from them, or for any number of other reasons. Some of the activities can result in elevated stress levels from all of the handling. So, we use anesthetics to relax the fish, reducing stress and decreasing related impacts such as changes in behavior, growth, or reproductive potential. Historically, one of the most common anesthetics has been a chemical called MS-222. It has a really long name and all kinds of research associated with it… Google it! Most notably, it is one of the few chemical anesthetics approved by the Food and Drug Administration for use on fish that could potentially be harvested for consumption. But, since it has some nasty side effects (such as being a possible carcinogen), if it is used on fish that could potentially be harvested for consumption, those fish must be held for 21 days prior to release to ensure the chemical is out of the fish’s system. This requirement presents problems with adult salmon and steelhead in the Pacific Northwest. Because these fish could potentially be harvested, biologists can’t use MS-222 on them. The alternative has been using no anesthetic on them, probably increasing handling stress in the fish, with unknown consequences.
We finally have a solution to this problem… ELECTRONARCOSIS!
Using this approach, biologists can now release the fish immediately after being anesthetized… literally. With MS-222 or other chemical anesthetics, it takes a while (sometimes 15-30 minutes) for a fish to recover from the anesthetic. With electronarcosis, as soon as you turn the power off, the fish is upright, swimming and ready for release within 10 seconds.
We have been using this on bull trout to surgically implant radio tags (again… a story for another day). Check out the video. When you see my hands go across the screen at the beginning and end, I am turning the power on (beginning) and off (end). There is enough of an electric field to put the fish to sleep, but not bother me the entire time my hands are in the water. These fish go under immediately, are relaxed throughout, are gilling (breathing) regularly, show no signs of pain at any time, and recover from the anesthetic immediately. They would be ready for release if we hadn’t just conducted major surgery on them! So, we hold them for a couple of minutes, and since we have been able to track them subsequent to tagging, we can confirm no delayed mortality.
It is pretty amazing what you can do with technology these days!
In January, I presented “Tryon Creek Restoration Monitoring” at the 8th Annual Urban Ecology and Conservation Symposium. The UERC is a consortium of various agencies interested in sharing urban ecosystem research in the Portland/Vancouver area. I highlighted the history of Tryon Creek and the collaborative movement to improve fish passage conditions at the Highway 43 Culvert. (In August of 2008, the culvert was modified to make entry and passage through the culvert a little easier).
There were 20 presenters and an audience of about four hundred people participating. I learned of the many efforts in our region by various agencies, both public and private. These programs contribute to the health of natural areas and develop ways to integrate the landscape with urban use.
Submitted by Brook Silver.