Last summer, I touched a fish for the first time since I was a little girl. Not only did I touch it, but I was in charge of getting it off the hook. (!!!) I looked down at the little girl holding her rod and fish, looking up at me expectantly, waiting for me to take it off the hook, just as my dad had done for me when I was a little girl. So, thinking back to my younger days, I thought I could just grab the fish and wriggle it around a little bit and it’d come off the hook. So I grabbed the fish and wriggled it around. I got it off the hook!! Then, to my dismay, it flopped around, in my hand ended up pricking me, and I jumped back and dropped it. (I learned later it was a Rock Bass-a spiny little fellow!) I didn’t know what to do. I started freaking out because I didn’t know how long it could be on the ground flopping around, and I didn’t want to grab it again because THAT HURT MY HAND.
So where was I and why was I “teaching” this little girl how to fish? I was at Stone Laboratory on Lake Erie in Ohio, and this was my summer job. It was apparently assumed the student workers knew what they were doing, but I certainly did not. SO…here I was, with a fish flopping around on the ground, with no idea what to do. I started screaming for another one of the student workers to come over and help. Thankfully, my fellow coworker knew what she was doing: crisis averted.
FAST FORWARD ONE YEAR: Fish are now my friend! And I now think they are really cool.
I have since learned a great deal about not only how to handle fish, but so much more. This summer, I had another job that involved fish. Fish were a part of just about everyday, and I learned to love them. Now, any time I walk by water, and see tiny fish darting around, I want to know what it is!
I’m also taking classes about fish at the Ohio State University, where we learn all sorts of fun stuff about fish. Did you know that freshwater fish comprise 30% of all vertebrate species, even though available freshwater habitat makes up less than 1% of the Earth? Crazy!!
Some other cool stuff we are learning are the major groups of fish, how these fish evolved, the morphology and anatomy, how to ID Ohio fish, morphological and behavioral adaptions, how humans effect fish, and so much more!
So here are some of the coolest things I’ve learned about fish this year, and things I would have loved to know last year:
- There are 181 species of fish just in Ohio! (154 native) Listed below are the species of Ohio.
- Lake Erie contains only ~2% of the water of the Great Lakes, but supports ~50% of the fish diversity of the Great Lakes. Conversely, Lake Superior contains ~50% of the water of the Great Lakes, but only 2% of fish diversity.
- Lake Erie tends to be much more productive (more life!) because of how shallow and far south it is compared to the other lakes, (meaning it stays warmer and more supportive of life). It is also surrounded by more farms and human residential areas (meaning more nutrients are coming off the land into the water) compared to other lakes, like Superior, which is largely surrounded by forest (meaning less nutrients). These nutrients cause the growth of things at the bottom of the food chain, such as algae and phytoplankton, which fish eat!
- Lake Erie is SOOO shallow! At it’s deepest it is only 210 feet. Lake Erie’s western basin (about 1/5 of the lake) is usually less than 25 feet. This is why the lake is so warm and productive! Look below to see how shallow Lake Erie is compared to the other Great Lakes!
- Humans have such a major impact on fish. I never realized how much humans could impact fish and water ecosystems until recently. That new parking lot they’re building down the street? The waterfront apartment building on the river? It affects the fish! But how?
Fish lives in all types of water throughout Ohio. Whether it’s a stream or a pond or a lake, humans have major impacts on fish ecosystems. Impermeable surfaces (parking lots, a sidewalk, a highway, or a building rooftop,) can raise the temperature of streams. When rainwater lands on an impermeable surface, it is warmed by sunlight. Heat is dissipated from the asphalt in the water, which is directed off the surface rather quickly, via a drain or gutter, and is funneled into urban streams, resulting in higher stream temperatures.
When humans build near water, it also decreases shade on the river, increasing river temperature. When trees are taken down, for a better view or for a waterfront apartment building, it opens the water up to direct sunlight, and an increase in stream temperature.
These increases in impervious surface area and reduction of tree buffer zones along streams, as well as other modifications to stream hydrology, impact the conditions in streams. This is known as “urban stream syndrome”. Unnatural spikes in water temperatures are seen in urbanized areas after rainfall. And these water temperature changes can have wide-ranging impacts on fish.
These increases and spikes in stream temperature can have big impacts on the fish that can inhabit the area, as certain fish can only survive within certain temperature ranges. If the temperature spikes too much throughout the day or during rainfall events, it has the potential to stress out the fish, causing issues or even death.
I’m doing research on the stress response of fish to these thermal shifts in streams caused by urbanization, and I am excited to see the results. My lab at Ohio State will be putting fish into tanks and raising and lowering the temperature throughout the day over a period of several weeks, and then testing the stress response of these fish at the end of the treatment. I’m thrilled to be doing work in such a cool field. I think it’s important that we learn how to take care of our aquatic friends as well!
Ironically, the other day while out in a stream doing fieldwork, we found another Rock Bass! (The fish from the beginning of this blog post.) It was the first Rock Bass I had seen since the one that had freaked me out so much last summer. It made me think about what a full circle I had come. It is my hope that you have picked up a thing or two about fish, and hopefully are not as clueless as I was about fish last year! Fish are incredible, and the more I come to learn about them, the more I appreciate what a diverse and amazing species they are.
Sources:
- Lake Erie cross sectional picture:
- Michigan Sea Grant
- Ohio fish species list
- ODNR
- Fish facts:
- Eugene Braig’s and Suzanne Gray’s class lecture slides
- Other fish facts:
- Herb et al. 2008
- Sabouri et al. 2013
- Klein 1979
- Wang & Kanehl 2004
- Walsh et al. 2005