Service Learning: Chum Salmon Hatchery

Chum Salmon Hatchery

Total Hours: ~10 (just for this quarter been a part of this project for more than a year now)

Organizer: Thomas Murphy (tmurphy@email.edcc.edu)

Sponsors: Privately owned fish hatchery by Jack

                My assigned duties at the fish hatchery are to help everyone maintain the fish hatchery and keep the salmon eggs and the following alevins and fry alive and healthy. When we first got the eggs we had to fertilize them before putting them in the water which you can see in the first video below; because I was a longtime volunteer the high school students got to prep the first batch of eggs and I prepped the second batch of eggs a few weeks later. The second video below you will see us put the salmon eggs into their designated trays where they will stay until a couple of weeks after they hatch. During this time, volunteers were assigned a day during the week and the hatchery was checked multiple times to make sure the water is flowing properly and cleaning the screens that cover the eggs of any algae along with cleaning out some of the bad eggs. After the salmon hatched, we move them into larger tanks that will have additional air pumps to keep the water well oxygenated and we also begin to feed them as they lose their yolk-sacs. While in the bigger tanks we continue to check on them but, more often as the filters must stay clean; if not the water will overflow along with the salmon fry. Feedings will also increase as they grow and eventually we will have the need for not only daily checks but, multiple checks each day as the algae bloom in the spring from the water supply can get pretty thick.

Video 1: Prepping the Salmon Eggs

Video 2: Placing the Salmon Eggs into their trays

                The role of science in society is extremely important as without the help of the various people involved in this fish hatchery, it would have been shut down as the private owner is on the cusp of retiring. Not only that but, it is well known that we as a society only enable the over fishing of our waters and having people involved to minimize their impact or contribute to improving the situation is very important. Without these efforts, the time we have fishing with family members and the cultural bonds surrounding such activities will not last much longer. The worst part however, is the environmental impact it could have; nature’s ability to be self-sustainable is a team effort, everything has a part to play and when a part is missing, just like a machine it will no longer properly function. The salmon raised at this fish hatchery also have a special release destination; a restored stream that was once in ruin due to a construction project. However, the city of Mulkiteo purchased the land and with the help of EDCC over time the stream and the surrounding area has been restored; returning the salmon to the stream is a part of the restoration effort.

                The part of this service learning even that probably has a direct connection to the class was prepping the salmon eggs. Mixing the sperm and egg together showed the external fertilization process that salmon undergo when they spawn. While ours was in a more controlled environment and not in moving water and under gravel; seeing the alevin salmon weeks later after prepping was really great to see. How this service learning connects to biology as a whole I really like the idea of trophic cascades. Trophic Cascade is “an ecological phenomenon triggered by the addition or removal of top predators and involving reciprocal changes in the relative populations of predator and prey through a food chain, which often results in dramatic changes in ecosystem structure and nutrient cycling” (Britannica). When it comes to salmon they play an important role for the nutrients cycling as they die after spawning providing nutrients to the surrounding soils, scavenger type animals and of course predators such as coyotes, bears and river otters. While Bears are not prevalent in the Mulkiteo area, not all salmon released will return to the same stream, sometimes salmon can spawn in a new stream establishing a spawning population there. Of course, another predator would be us, from bonding with family and friends on a fishing trip to the salmon industry that is huge and employs a lot of people. The loss of salmon would be a huge loss and would have a huge impact on both the local cultures and environments that are their home. Their absence could affect the health of not only those that prey on them but, it can affect the health of the streams as even the plants and trees on the banks of these streams rely on some of the nutrients that will seep into the soils as they decompose after they die from spawning. Salmon is an important part of the team in the Pacific Northwest and it is very important to keep them on our roster for both the health of our environments and the unique culture is brings to our region.

Additional Media:

Video 3: Salmon Alevin after hatching

Second Batch of eggs we received mid January

Alevin Salmon after hatching

Questions:

1)      During salmon monitoring to see how many returned; a lot of invasive nightshade plants with poisonous berries were growing on the side of the streams and in some parts lots of those plants and berries ended up in the stream.  Would this contribute to why the stream we observed showed a low count of salmon?

2)      Could we use eDNA to keep track of populations we released and see if they returned to the same stream we released them in?

3)      The opposite of nightshade plants, I wonder what native plants have a direct influence over the health of the salmon or the success of making it to the ocean?

4)      The hatchery has no lights in the tanks and they are in a greenhouse under a shelf, I wonder if the lesser amount of light has any effect on their growth? Or maybe does the size of the tank have any effect?

References:

Britannica. "Trophic Cascade." September 28. 2010. https://www.britannica.com/science/trophic-cascade