07.jul.27 Cowlitz Beach Seine with Tina and Russel · 27 July 2007, 11:11 by Julie Loyd
Friday was a day of sun and hazy sun, a breath of a breeze, with a high around 71º. Low tide was at 10:32, high at 18:38.
This image was taken from the dock and shows what are probably herring, and a barn swallow.
Present (some briefly, some from 2 – 8:00): Donna A, Fred A, Winnie A, Russel Barsh, Anthony B, Eliza-Jane B, DeeDee D, Laurie G, David L, Julie L, Madrone Murphy, Ann-Gwen O, Glen R, Tina Wyllie-Echeverria
The purpose of the session was to test the new net that Russel had made for us, to learn gastric lavage, and eventually to correlate what juvenile salmon eat with the plankton present in the water they’re swimming in.
RESULTS
First seine was at 14:45 at the first big alder from the dock towards Disney, at N 48º 41’ 162”, W 123º 02’ 187”. In the net were a kelp crab and several shore crabs, a 126mm lined perch, 3 shiner perches (with yellow parr marks) at 110, 115, and 115mm, and a 58mm sharpnose sculpin.
We also caught twelve juvenile chinook! Their lengths and stomach contents (if sampled) were as follows:
93 mm, wild, big crab larvae (probably, this was a visual, not a microscope inspection)
72 mm, wild, 1mm black things
106mm, hatchery, a 60mm sandlance!
82mm, wild, mysid shrimp (probably)
77mm, wild, 1mm black things
80mm, wild, mysid shrimp and black things
71mm, wild, 8 black things
76mm, wild, 2 large green blobs and 2 black things. This one had a parasitical copepod in its gills
73mm, wild, not lavaged
74mm
72mm
69mm
Second seine was at 16:25 at Frances’ Cove. In the net were a copoius amount of shredded seaweed such as eelgrass, ulva, and brown algae; a kelp crab, a big red rock crab, a lion’s mane jelly, and two staghorn sculpins at 65 and 74mm. There were three chinooks:
90mm, wild,
113mm, wild, had a gill parasite
116mm, wild, a 64mm sandlance
Third seine was at 17:25, also at France’s Cove. In the net were 2 redrock crabs, 2 small dungeness crabs, a 31mm flatfish, two English soles at 74 and 100mm, four staghorn sculpins at 60, 62, 74, and 85mm, a ginormous cabezon at 240mm, a coho at 82mm, and two chinooks:
78mm
112mm
TECHNIQUES
Net tow: We bowlined a long rope to the net’s bridle rings and tied one end off to a beach anchor such as a piece of driftwood. We’d loaded the net accordion-style on a tarp in the boat, and went straight out, paying out first line, then net. Then, a right angle turn, paying out the line at the other end of the net, and back to shore about 50 yards from the other end. Immediately, people grabbed each line and began walking towards each other, hauling in as they did; minimum was two people per end and two in the boat, or six total. The idea was for the people to meet as quickly as possible, and then pull the net in, keeping the two net ends even. In the shallows, it’s important to flip the bridle bars so that the lead line at the bottom of the net is inside the pouchy area, and to start hauling at the lead line much more quickly than at the float line. This creates a noticeable bag in the net. We mistakenly tried to keep the lead line along the bottom, but by the time the net is in the shallows, it’s caught what it’s going to catch, and it’s more important to keep the lead line off the bottom so that nothing spills out.
Once the net was beached, we started flipping the net contents from the wings towards the center, removing larger pieces of seaweed and leaves as we went. When things were concentrated, people sorted through, throwing seaweed and crabs (after counting them) back into the water and carefully scooping up the fish and putting them in buckets. A kitchen sieve is useful. There should be a separate bucket for the predatory fish such as the larger sculpins. On our last tow, one of the crabs snatched at a salmon and broke its back. It was a shocking lesson in the crab’s speed and our need for even greater speed and care.
Gastric lavage and genetic sampling: Although Tina and Russel can do this alone, we found that four people are optimal, one single-gloved person to watch the fish, one gloved person to collect the data, one to handle samples, and one to record.
Fish watcher: The anesthesia is a powder. If you dampen halfway up the last knuckle of your pinkie, dip it in the powder, and then stir it into about 2 gallons of seawater and fish, that usually is about the right amount, although with one such bucketful we had to triple the dose. 
The salmon, which are normally quite perky, slow down and then lie on their sides, panting. If they don’t get to this stage, add another fingertipfull. You have to keep watching them to make sure they’re still breathing. Revive a fish that’s breathing too slowly by swishing it through fresh seawater. Balance this against the knowledge that they lose scales easily and you don’t want to touch them any more than absolutely necessary, and never with bare hands. You need to keep an eye on the fish handler, and make sure they don’t keep the fish out of the water for too long. Once the data collector is done, have them put the fish in fresh water until it’s fully revived. Make sure the water is changed every five or ten minutes so each new fish has plenty of oxygen. Ten minutes should be enough to fully revive a fish, and then you can let it swim out of the bucket into the bay.
We are allowed one accidental fatality per hundred fish sampled. Our rate was higher. To prevent that in the future, we hope that increased skill and speed on the part of the data collector, more attention to water oxygen on the part of the fish watcher, and better netting techniques will help. In case a fish does die, preserve it in alcohol so it can be dissected.
Data collector: To handle chinook, you must wear latex gloves and have a permit. There’s a half-cylinder ruler; gently slide the fish in nose-first and measure from nose to the vee of the tail fork. This one would be 71mm. 
Return to the water so it can breathe a bit.
Then, holding the fish belly-out and nose away (not like in the picture), clip a little 1mm square chunk off the anal fin. 
This fin grows back, in laboratory conditions. It sticks to the scissors, poke it into the sample jar and slide it off. Return the fish to the water so it can breathe a bit.
To do gastric lavage, you need a syringe filled with seawater with the stomach tube and a filter cup. Hold the fish in your subdominant hand leaving your thumb and index finger free. You may have to open its mouth by gently squeezing at its jaw hinge, but usually we didn’t need to since the fish were gasping helpfully. Holding a short length of the syringe tube in your dominant hand, gently poke it straight in to the mouth. If it goes out the gills, try again. Guide it in until there’s slight resistance, then pull back maybe a centimeter. Now you can use the thumb and forefinger of the fish-holding hand to steady the tube. 
Hold the fish upside down over the filter cup (which is being held by the sample person) and depress the syringe gently but firmly. Water and then stomach contents will flow out, mostly into the cup but also over your gloved fingers (which you later rinse into the filter cup). It’s very important to hold the fish upside down for this step so it doesn’t bloat to death. You’re done. Put the fish in fresh water promptly.
Sample handler: You’re responsible for making sure everything is labeled and stored properly. The Juvenile Salmon Record Sheet is pre-numbered. For each chinook, you’ll need a fin sample tube and a gastric sample tube. The fin sample tube has a conical bottom, and is called an Epi, Epindorph, or microcentrifuge tube. Wash it. Write the number preceded by an “f” on this tube and fill it halfway with ethyl alcohol. When the data collector has a fin stuck to their scissors, have them dunk it into the tube, scraping against the side if necessary. Snap the lid on and store it. Wash the scissors in alcohol when the data collector is done.
The gastric sample tube is cylindrical and has a screw lid stored in a separate baggie. Write the fish number preceded by a “g” on this tube. Find the filter cup and hold it under the fish when the data collector pumps the fish stomach out. Use fresh water to sluice off their hands into the cup. Now you want to transfer the filter cup contents into a little glass beaker using the alcohol squirter. This operation is made fiddly by the facts that you don’t want to damage the stomach gunk, and that you want to use the bare minimum of alchohol. Squirt wisely! Once everything has been transfered to the beaker, pour it into the gastric sample tube. This is easier said than done. If there’s too much alcohol in the beaker, you can suck out a bit (not any sample, though!) with the squeezer and throw it away. Pour, possibly squirting down the sides or even gently scraping.
Two of our fish had swallowed sand lance that were half their own length. They come pre-bent for your squashing convenience. If you shove, you can barely cram them into the tubes. Cover with alcohol. Screw the lid on and store. Wash out filter cup and beaker.
Recorder: Fill out the Juvenile Salmon Sample Record Sheet, recording date, 24 hour time, and whatever it asks for. Record everything that wasn’t a salmon, with lengths of fish. Record the salmon lengths and making sure the sample handler is using the right number to label the tubes with. Under “markings”, record whether the fish had an adipose fin (“wild”) or not. Include as many notes as possible such as gill parasites or humorous stomach contents (that would be the sand lance). Maybe you’ll be labeling tubes instead of the sample handler doing it.
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