Over the past few weeks of fish seining I have observed a wide variety of fish species ranging from salmon and flounder to gunnels and pipefish. Most fish we catch are juvenile and under 1 ft in length. Of all of the species I expected to encounter during my work this summer, a sturgeon was not even on my radar. It was to my surprise last week when we found one in the bag of our net. I was intrigued by this amazing creature and couldn’t help but read up on these fish in my free time.
Oregon is home to two different species of sturgeon: the green sturgeon and the white sturgeon. While white sturgeons’ populations are healthy enough for commercial and recreational fishing, the green sturgeon are a protected species.
Green sturgeon are seldom collected with seine nets in South Slough. In fact, the last green sturgeon collected by SSNERR was during a similar monitoring program in 1986. Coming across one of these dinosaur like fish was quite the treat. Their bodies have changed little over the last 200 million years and are lined with rows of bony plates. The green sturgeon’s are especially pointed and sharp. These fish also have barbels on the underside of their snout that they use to navigate along riverbeds and find their prey.
Unfortunately, certain characteristics of sturgeon put them at risk of extinction. First off, females full of eggs have historically been over-harvested to provide markets with caviar. The average lifespan of a sturgeon is 50-60 and sexual maturity is not reached until around age 15. This heightens the risk of a population collapse do to over-fishing. If all of this wasn’t enough, most of these fish are anadromous, meaning they feed in coastal waters and spawn in freshwater. As rivers are dammed, anadromous fish lose critical spawning habitat and populations most often decline.
As my understanding of Oregon’s coastal fish species grows, so does my appreciation for the work South Slough conducts to protect these species. I am excited to come into the lab each day, because I know the data we collect will be used to manage and conserve estuarine ecosystems. I’m grateful to be a part of such work and I look forward to future unexpected catches.
I love the life history lesson about sturgeon! I caught one of these guys once in the Columbia River and was also astounded by their dinosaur-esque physique. I had no idea that they lived for so long though! It’s great to see that you’re understanding the bigger picture of your influential work at SSNERR.