I am doing a science project on what is affecting the difference between two local creeks' fish populations.
I noticed yesterday that there was a watersnake in the creek with a very small population of fish. I came to the conclusion that the snake was a Diamondback water snake. From what I have researched, it is said to feed on fish, amphibians, and other aquatic life. Can this snake be enough to cause a noticable decrease in the sunfish and bass population in this creek.

Would depend on the size/depth of the creek/pond and the ambundance of each of the various species of food sources you mentioned. Shallower water lends itself to more predation than deeper water from non-aquatic species of predators. You have to take into account other predators that consume the same food sources, ie commorants (sp). They can gobble up more fish than a snake per day/week/month especially if there is a large group of them. Rarely do I see 1 or 2 of them, they are usually in larger groups.

They certainly do come it groups, like this one I found at Lavon-


I can't imagine a snake eating as much as other predators like the cormorant that Scott pointed out.

If it's a creek I would say the hawks, owls, racoons and maybe otters will put a dent on a shallow creek. If there's no deep water near by, any fish will be a stat waiting to happen. Water Turkeys can put a dent on a creek, but not as likely if the creek has a canopy over it. The other critters do just fine canopy or no canopy. Snakes get a smaller slice of the fish pie than all the others I mentioned IME.

That's a breeding ball of snakes. The smaller males are trying their hardest to be the first to get to that larger female. As stated above regular populations of snakes won't hurt the fish population,everything has a role to play in an ecosystem. When certain predators become too abundant that's when things get out of order. Commorants can do more damage in a short time to a localized fish population than probably any other predator. Pollution could be another thing to look at. Water temp with lower water levels, invasive species like golden algae, and zebra mussels.

Thanks for the help. The creek is very polluted. I also noticed a street runoff storm drain deposite pipe up stream. After a few water quality tests, they showed the creek had low dissolved oxygen levels. I believe that the pollution has contributed to that.

That's probably it, good work, make your findings known to the right people to see if something can be do. We all should try to protect our precious resources. I applaud your hard work.

Remember also that this time of year that a snake's metabolism will be a lot slower, or should be, because of ambient temperature. They won't eat as much as coons, owls, hawks, etc. as mentioned above. Keep up the good work!

That would be a mating ball of them you photo'd, mdobs.

[quote=mdobs]They certainly do come it groups, like this one I found at Lavon-


I can't imagine a snake eating as much as other predators like the cormorant that Scott pointed out. [/quote

Interesting thoughts. Good luck on your research.