invasive species research Susq

[nymphingmaniac]

Biology professor awarded $105,461 grant toward invasive fish research

Looking at the effects of flatheads. Some have discussed this here and it might be of interest



https://news.psu.edu/story/627860/2020/08/07/research/biology-professor-awarded-105461-grant-toward-invasive-fish

 

[lycoflyfisher]

This will be great research, I think that at some point evidence will exist to show the presence of flathead catfish has a significant impact on native fish species.

 

[bigjohn58]

lycoflyfisher wrote:
This will be great research, I think that at some point evidence will exist to show the presence of flathead catfish has a significant impact on native fish species.

Depends on what you call native species. I'd say have a huge impact on current species. Smallies are not native to the Susquehanna. Actually a lot of native species are no longer current in the Susquehanna.

 

[Dave_W]

Thanks for the heads-up on this. Please keep us informed.

Schall seems like an up and coming biologist and I'm delighted to see grant money coming through for young scholars focusing on invasive species, the impact of flatheads in the Susky watershed, etc.

In particular, the focus on flatheads' diet should reveal some important data. Over time, we may also be able to get a better picture of how that diet changes. For example, if early studies of flatheads in a certain river section reveal sunfish to be a high prey species... will their prevalence in flatties' stomach's decline in proportion over time? What other species may increase?

Another topic we need data on is the role of flatties in tributaries. We can expect they will go up the Juniata, but what about smaller trips, say lower Penns Creek, and how far up? How does this compare with channel cats? Will only smaller flatties colonize these tribs and what does their diet look like? There's likely studies of this from the flatheads' native range, but the results in the Susky watershed may prove dramatically different

So many questions, so little time... but at least there is some funding available.

 

[lycoflyfisher]

bigjohn58 wrote:

lycoflyfisher wrote:
This will be great research, I think that at some point evidence will exist to show the presence of flathead catfish has a significant impact on native fish species.

Depends on what you call native species. I'd say have a huge impact on current species. Smallies are not native to the Susquehanna. Actually a lot of native species are no longer current in the Susquehanna.

Hence why I used the term "native" and did not list smallmouth or generalize gamefish.....


Much of the native populations are already displaced or in much lower densities than historical estimates. Flatheads are a major challenge to the operation of fish lifts to provide for shad migration on the Schuylkill and Susquehanna. Dave brings up some good questions on the sunfish populations as well, many of which are native to the drainage.

 

[bigjohn58]

lycoflyfisher wrote:

bigjohn58 wrote:

lycoflyfisher wrote:
This will be great research, I think that at some point evidence will exist to show the presence of flathead catfish has a significant impact on native fish species.

Depends on what you call native species. I'd say have a huge impact on current species. Smallies are not native to the Susquehanna. Actually a lot of native species are no longer current in the Susquehanna.

Hence why I used the term "native" and did not list smallmouth or generalize gamefish.....


Much of the native populations are already displaced or in much lower densities than historical estimates. Flatheads are a major challenge to the operation of fish lifts to provide for shad migration on the Schuylkill and Susquehanna. Dave brings up some good questions on the sunfish populations as well, many of which are native to the drainage.

I'll say this...I bet it will be one very interesting study that's long overdue.

 

[larkmark]

If the study finds the invasive Flatheads are damaging native fish what do you think should be done about it? Or is the study just sort of for fun?

 

[Mike]

Lark, always a good question if you are trying to separate pure research from applied research. Without thinking deeply about possible results and their application, a simple hypothetical application of such research, depending upon the results, COULD be to be to further weigh species introductions against opening stream corridors with respect to dam removal projects on tribs. The problem with such considerations, however, is the wild card of anglers introducing unwanted species upstream from barriers anyway.

Please note that I only thought about this because you asked and because I had any underlying knowledge of where such research was headed.

 

[troutbert]

The people doing the studies are different than those who will be making management decisions.

A university researcher HOPES that someone will use the information they find for some practical applied purpose.

But they don't really have control over that.

 

[bigjohn58]

troutbert wrote:
The people doing the studies are different than those who will be making management decisions.

A university researcher HOPES that someone will use the information they find for some practical applied purpose.

But they don't really have control over that.

I would feel this would make the study less bias and maybe a little more trustworthy. When someone wants a real study done they always bring in an outside source.

The study though will not hit on the rockbass problem. Rockbass are so rare on the West Branch and they used to be the most common fish in the river. The West Branch Susquehanna doesn't have the flatheads or not yet anyways and the rockbass disappeared 10 years ago or more.

Wonder how long until til they will need a snakehead study...

 

[Mike]

There is no mention of the West Branch. The study description says Susquehanna R.

 

[Mike]

What kind of bias would be anticipated when doing gut analyses? Either the fish ate a particular organism or it didn’t.

 

[bigjohn58]

Mike wrote:
There is no mention of the West Branch. The study description says Susquehanna R.

I'm well aware of that. I'm just saying if they claim the flatheads ate all the rockbass in the main branch Susquehanna then I'm not believing any of that study.

 

[lycoflyfisher]

Its pretty hard to make up stomach contents.... if rock bass populations are already as low as many anglers believe, even on the main river, then they would likely not be found in stomach contents of flatheads that are being sampled now. Megan Schall has been involved in many large research projects throughout her educational career several focusing on smallmouth that you may find interesting.

https://www.researchgate.net/scientific-contributions/2127875732-Megan-K-Schall