This summer has been full of learning opportunities, interesting times in Portland, and making great connections with others. Working at a cubicle was by no means my first choice this summer but looking back I couldn’t have asked for a better internship! My aspirations to help salmon and steelhead populations could not be better achieved than to assess the impacts that climate change will have on them. Research on salmon and steelhead has reached new heights in the last decade thanks to technological advancements such as PIT tag technology (used in some pets), genetics, and modeling.
To start, not a lot has been understood about the life history of salmon and steelhead until we were able to track and monitor their migrations. PIT tags and acoustic tags have helped researchers track where in the ocean these fish go to feed and undergo metamorphosis. Although we have been able to establish migratory routes for many of these fish one thing that we need to better understand is the diversity of life histories that exist with these species. Some anadromous fish spend only a year in the ‘salt’ (as anglers say) while others spend two to five years in the salt. As you can imagine this results in huge differences in the size and fecundity of the fish. Because salmon are semelparous, meaning they put all their energy into one large reproductive event, size does matter. Bigger fish produce more eggs and therefore have higher fitness than smaller fish. One concern for salmonids in the ocean is that the longer the fish spends time in the ocean the more likely it is to be caught by fishing boats, prey, or die due to pathogens and disease. Currently research is being conducted to better understand alternative life cycles of salmonids and what can be done to increase their chances of recovery in the Pacific Northwest.
Another fascinating and fairly new technology is genetic analysis. One interesting finding is that some parents contribute more to the next generation more than others. A hypothetical example is if two all star athletes produce offspring compared to if two people with poor health produce offspring. The all star offspring are more likely to survive and pass on their genes to the following generation. This is important because if we remove the all stars through fishing we may reduce the fitness of subsequent generations. These kinds of studies are being conducted throughout the range of salmonids to analyze the effects of hatchery fish breeding with wild fish.
Lastly, models have come a far way by having a better understanding of what assumptions must be put into the model. As we learn more about the ecology of salmonids models can be improved to better represent the reality of population cycles. One difficulty that remains in modeling is taking into account genetic interactions with hatchery fish as well as how does a one year salt fish breeding with a three year salt fish effect fitness. These small details are hard to account for in models and often time little is known about these interactions to begin with.
My work will play a role in addressing the impacts of projects that affect salmonids in light of the struggles they face with climate change. I am looking forward to seeing my work applied in the NEPA process as well as continuing to work with salmon and steelhead in the future. Thank you Sea Grant for helping me follow my passions!