Jump to content


Bluebreast Migration


  • Please log in to reply
35 replies to this topic

#1 Guest_farmertodd_*

Guest_farmertodd_*
  • Guests

Posted 01 December 2009 - 08:28 AM

I thought I'd stop hijacking John's great orangefin thread :)

So Lance and Blake, what is the progression of presence on these bluebreast riffles you're observing? Are they there in the spring and leave once the flows cease? If you have a wet summer, do they stay / come back?

I ask, because this might make a really nice florescent elastomer study for a, ahem, masters student that ties in with a lot of the research I'm already doing. ;) Their relative rareness and conservation status make it quite fundable and actually a better population to look at (like who'd want to sort through all the millions that are in Paint Creek here in Ohio lol).

Todd

#2 Guest_natureman187_*

Guest_natureman187_*
  • Guests

Posted 01 December 2009 - 12:24 PM

I spent a bit of time over there toying around this past year. I was seriously considering something along those lines if I don't migrate myself ;-)

We had a significantly wet summer along with a blowout spring which for whatever reason left the Vermilion covered in a silt film and quite turbid when water levels finally receded during very late summer. It was easy to get more than enough dominant bluebreast males for viewing pleasures at any riffle with larger cobble throughout the spring during high discharge even going at it solo. Large specimens were completely absent from these same riffles after water levels became stable in the later part of the year.

I was a bit disappointed after not being able to find these fish late. In my opinion, previous efforts throughout the duration of last year never yielded change in distribution away from that niche enough to make mental note. I will say unlike last year, the cobble was a bit impacted in the riffles but not so much adjacent downstream in the deeper runs. Perhaps the niche changed slightly due to an uproar of moving sediments? I initially assumed these bluebreasts were utilizing the non impacted cobble in the slower deeper water making them capable of easily avoiding capture.

Todd, with your thoughts on migration, could they have completely hightailed it to other locations?


- Lance Merry

#3 Guest_blakemarkwell_*

Guest_blakemarkwell_*
  • Guests

Posted 01 December 2009 - 03:22 PM

They are definitely migrating. Now, what is driving the migration? That is left unknown. The only variable I have to work with is a rapid increase of siltation. The flow really doesn't correlate with what I have observed. I have caught them by the bucket full in the summer when there is little flow and have also caught them in abundance when the flow is at a dangerous level. I will have to pay more attention to it next spring and summer.

I'm with Lance in that I will be migration too, not that soon though as I gotta wait for the girlfriend to get done with college. So until then I will be taking many more classes to make me a more diverse Biologist and an even poorer student. ;)

Blake

#4 Guest_fundulus_*

Guest_fundulus_*
  • Guests

Posted 01 December 2009 - 05:25 PM

Could the migration be driven by shifting availability of macroinvertebrates? We've been doing monthly driftnet collections on the new moon in the upper Paint Rock River system in 'bama since July, and the various arthropod Orders change dramatically in relative and absolute abundance. Last month we found an explosion of Collembola like we haven't seen before.

#5 Guest_farmertodd_*

Guest_farmertodd_*
  • Guests

Posted 01 December 2009 - 08:09 PM

Contributions to abundance at the local scale, in my experience, are two part:

Part 1 is connectivity of habitats... If they have good connectivity of habitat in the stream, they'll be able to move around a lot better, and may be why you see the huge populations in the Till Plain streams of Ohio, for example, since they're one long riffle with some pools interspersed among them. However, on a old river like some of the streams like the Kentucky or Licking Rivers, riffles in big stream orders can be amazingly far apart, and this may begin to explain the extirpation or absence of maculatum in those systems. In the Ohio River drainages, I would hypothesize camurum is the most tolerant, followed by tippecanoe and then maculatum, and I have data to support this at the scale of the State of Ohio, but I need to flush some more things out before I can publish it.

Part 2 is more theoretical... If we think about this in terms of their ecological niche, these species may be considered specialists. What makes them a specialist? That comes down to the difference between the functional niche (all places they could occur) vs the realized niche (where they occur). For a species like a johnny darter, the functional niche is enormous (can occur on riffles in big rivers, lakes, tiny headwaters), but they may be limited at the local scale to a very thin piece of the pie and only have a small realized niche. However, with our friend maculatum, the functional niche and realized niche are a much much much more close an approximation of each other - either the habitat is there, or they're not there (and sometimes this goes back to factor 1).

I can show this with rocks (Wentworth scale), depth and flow, which you saw the collection of this data on the Licking, Lance. This is from 2200 observations of darters including the species "No Fish", as absences are just as informative as presences.

Attached File  nonigrum.jpg   764.78KB   8 downloads

Distances along those axes represent the strength of the interactions on those measurements. Notice how the size of substrates corresponds with depth and flow.

And I can also generate some pretty interesting histograms that suggest some of this also dynamic, esp if the abiotic factor they're responding to is flow and it ceases, and they're intolerant of sand and silt and it's increasing (which is roughly correlated with flow).

Attached File  sand.jpg   39.36KB   3 downloads

The two circles are all statistically significant from each other at the 0.05 alpha, and then there's nigrum lol. These tolerances of sand may explain some northward migration and perhaps some of the long segments of the Tippecanoe River where Nothonotus are absent. Flabellare, of course, was able to resolve that issue by living in riffle crests in millimeters of water where sand is always washed away.

It's pretty slick stuff. I need to get the CCA axes to be fixed so I can look at different rivers to look for niche shifts for caeruleum, blennioides and zonale. My hypothesis is that caeruleum will shift around to the cobble axes in the absence of the Nothos, zonale will shift to gravel and blennioides will stay about put... And they'll have much weaker interactions on those axes. I'll be submitting this for publication after Christmas, so hopefully we'll have the whole story together shortly.

We're also starting to work on this in the Great White North where it's basically caeruleum, blennioides, flabellare, and nigrum, all four have been known to live in wave zones in bigger lakes, for example, and have been extirpated in some places by round gobies (extreme edges of functional niches, or were the gobies really just big meanies? ;)). Again, I expect the same pattern, weak associations etc.

So back to your question and more straight forward speculation... My guess is that under the heavy flows, they were able to live within their tolerances for local velocity and rock type at your site, and didn't use the Wabash or downstream riffles until much later when the rains backed off. Under normal flow regimes, the habitat would have become much more marginal for camurum during the summer months, and they would get out of there and move downstream. That is not to say that some prime real estate in the camurum world isn't available... There might be that anomaly that the king of the riffle can stay on, and you would check that off in your head as a "hit", or "presence". But I guarantee if you were writing down lengths and sex at each sample, you'd see it change under normal conditions, and wouldn't see much of a change under this past summer's extreme conditions.

Now on to Bruce's point... Yes, food stuff is probably a correlate of rocks, and vice versa. Next undergrad I get is going to do a review of all that old skool lit that documented life history, and we'll pull it into the present and see if we can't tie it to rocks. I'm using rocks because they're much more simple to quantify, and I'm explaining away a lot of the variation using these somewhat expulsive methods, so why get precise? :)

Todd

#6 Guest_natureman187_*

Guest_natureman187_*
  • Guests

Posted 01 December 2009 - 09:01 PM

Impressive stuff as always. Blows my mind how beautiful that correlated. You are right, one or two pigs would satisfy 'visually pleased'. Would be neat to have funding for something of such here. I have an inkling it would fit in with your work perfectly :cool:

I love how drastic maculatum is out there. That's a straight shooter after my eyes got opened in the Green.

Looking forward to the entire read once it's done. Are these figures updated since the last I saw?

Edited by natureman187, 01 December 2009 - 09:17 PM.


#7 Guest_fundulus_*

Guest_fundulus_*
  • Guests

Posted 01 December 2009 - 09:05 PM

That's a comprehensive work-up breaking down the abiotic environment to a manageable number of variables. We became interested in drift inverts in one riffle/pool system to see if we could relate invert presence to what we find in the guts of telescope and scarlet shiners, who have their own environmental partitioning between, respectively, high flow and lower flow stretches of this system. I'm still not sure how I would precisely compare the fundamental vs. realized niches of telescopes and scarlets. But looking at 8 sympatric(?) species of darters certainly is easier with a methodology like CCA. You done good.

#8 Guest_farmertodd_*

Guest_farmertodd_*
  • Guests

Posted 02 December 2009 - 03:01 PM

Thanks guys :) Yeah, Bruce, the darters are way more amenable to this analysis. I wouldn't even want to try it with Cyprinids, their partitions are much less intuitive to us.

Lance, new data, this is with all observations. What is very interesting is that nothing changed position... We had this same pattern with only a couple rivers' data, which is what you saw in Sept. But with the extra observations, it allows us to really say something. A lot of the work I'll cite in the paper demonstrated the same thing... Just it was a single river at a time with maybe a couple sites. Which is fine, but they can only say they've quantified what happens in _that_ river. I'd really like to get a whole lot more maculatum data from KY, IN, WV & PA, since I basically did the same things and only quantified spotted habitat in Darby Creek, but that's gonna require some funding, coz I'm tired of giving my research Farmertodd Grants ;)

Something you might also find interesting is a matrix of the tukey studentized t-tests comparing each species on each of the measured axes. Each axis reported were significantly different at the 0.05 alpha.

Attached File  matrix.jpg   182.94KB   6 downloads

You'll notice that camurum & tippecanoe and variatum & flabellare do not separate. Do they live in the same niche space? Any hypotheses? :)

What'll be sweet is when I get some samples with Ulocentra that will probably group as strongly on sand and depth as the Nothonotus did out on cobbles and flow. Would that be ecologic support for taxonomic hypotheses? Maybe, but I'm not qualified to make the determination, so I'll just collect the data and let other people cite it how they want ;) I think I've watched Amanda get thrown in front of the bus enough times to not want to bother with that business lol.

And there's a hundred different ways to run this out... I'm most curious about niche conservation for camurum & bellum and tippecanoe & denoncourti. That is, do these closely related species still live in the same niche space? And how do they relate back to the other sympatric darter species? And I'd also like to figure out what partitions the camurum & tippecanoe pair at the local scale (maybe the contribution of gravel in those site? Is gravel tippecanoe's "cobble"?).

Lots to do!

Todd

Edited by farmertodd, 02 December 2009 - 03:02 PM.


#9 Guest_fundulus_*

Guest_fundulus_*
  • Guests

Posted 02 December 2009 - 04:12 PM

One thought about your species pairs that aren't separated in your tukey table is they might live in the same abiotic environment but preferentially utilize different available foods. I could imagine this to be true especially for tippecanoe and camurum since they're different sizes, with different builds.

Also, as a statistics question, are you going to do some sort of Bonferroni correction for the tukey table to correct for Type II errors if it's based on a series of pairwise tests? Or is such a correction built into this analysis?

#10 Guest_farmertodd_*

Guest_farmertodd_*
  • Guests

Posted 02 December 2009 - 11:29 PM

Thanks for your thoughts Bruce. Perhaps we can run a friendly review by your desk once it's prepared?

Yeah, I think the body sizes explains camurum and tippecanoe. Whether it's food or rocks, I'll probably have to look at that with a finer scale than a seine haul. I think a discharge area accumulator will explain variatum and flabellare once I look at broad regional scales with OEPA data, for example.

Yeah, I ran it with the Bonferroni and not, and there was no difference.

But that's just univariate. I want to start working this more into the multivariate world to get some eigenvalues so I can look at distances. Would also like to run some clustering to see how they group. I think that's all going to tell us more about this than pair wise. The pair wise is just kind of interesting.

Todd

#11 Guest_ashtonmj_*

Guest_ashtonmj_*
  • Guests

Posted 03 December 2009 - 08:18 AM

I'd really love to chime in more, but I'm swamped so I'll just throw something quickly in the mix and hope you guys are still talking in a week or so when I'll be less (yeah right) busy. Instead of a Bonferoni, why not just report the actual p value with some middle ground towards an alternative to null hypothesis testing? I realize you are hypothesis testing to a good extent. By reporting your p-values and 95% CI's and interpreting your data, especially with the aid of a multivariate ordination technique like one you are using, you can not only make a stronger case when something has p=0.049 and is obviously resource segregated, but you can also call out the ecological irrelivance of something that could be p=0.01 and not segregated for whatever reason (large sample size, resource availability, sampling design influence, etc.)? I agree pairwise comparisons provide interesting information, that is often ecological relavent but statistically lost in multivariate techniques and is good supporting evidence. Ever thought of expanding observations and models to a state that has extensive fish data and a small darter assemblage that is made up of several recent invaders/introductions/members to the club?

I'll throw out two more little discussion nuggets, one you'll probably know Todd from mussel lit...

1) Have we reached our wits end on what we can explain in fish ecoloy by the same simple, descriptive variables we've been using for the past 50 years?

2) Any thought to using NMDS

#12 Guest_ashtonmj_*

Guest_ashtonmj_*
  • Guests

Posted 03 December 2009 - 09:15 AM

I can see you looking at the topic Todd...I know you want to respond...

#13 Guest_JohnO_*

Guest_JohnO_*
  • Guests

Posted 03 December 2009 - 04:44 PM

Here's a thoroughly non scientific observation I noticed this summer.

Went to a particularly productive section of Buck Creek in August to get a couple of bluebreasts and bloodfins. Josh and I had been there in the spring when the water was up, and happened onto a strong riffle that was chock full of big, proud bluebreasts. I took one, and tossed back some real beauties.

Lost that one this summer, so I went back down to grab another. At that riffle, there were no bluebreasts or bloodfins. Bags of these rainbow-ish darters that had very small black spots, but not what I was looking for. Two hours of searching, and nothing.

I finally found them, about a mile upstream, in a little side riffle. It didn't look like much, but the second rustling of rocks came up gold. A couple of nice big bluebreasts, two huge bloodfins, and a big yellow stonecat. I found it curious that the one riffle that had been so productive last spring was empty, and no bluebreasts in the pools above and below that riffle, or anywhere upstream, until I tried that one little riffle off to the side.

Funny note - while I was working my way upstream, a cormorant was trying his hand (beak?) and not having much luck, either. I finally tossed him a fair sized creek chub, which he gratefully devoured.

Did notice last year that the smaller bluebreasts in the Rockcastle were in the riffles in the summer, but moved to the pools just below the riffles on the one winter trip we took there.

#14 Michael Wolfe

Michael Wolfe
  • Board of Directors
  • North Georgia, Oconee River Drainage

Posted 03 December 2009 - 09:21 PM

But that's just univariate. I want to start working this more into the multivariate world to get some eigenvalues so I can look at distances...

Not to thread highjack, but it does my old engineering heart good to hear you advanced degree achademic types talk math... I haven't heard anyone say "eigenvalues" for a long time.

Michael Wolfe
Bachelors of Engineering Science and Mechanics 1985
Georgia Institute of Technology
Either write something worth reading or do something worth writing. - Benjamin Franklin

#15 Guest_ashtonmj_*

Guest_ashtonmj_*
  • Guests

Posted 04 December 2009 - 07:54 AM

Geeze Michael all you had to do was ask and I'd gladly oblige...I probably say it couple times a week around the office this time of year.

#16 Guest_farmertodd_*

Guest_farmertodd_*
  • Guests

Posted 04 December 2009 - 09:17 PM

I can see you looking at the topic Todd...I know you want to respond...


You cheat! :) I do, but I need to have more than 15 minutes to sit down. I'll respond tomorrow, I do really appreciate your feedback Matt!

Todd

#17 Guest_natureman187_*

Guest_natureman187_*
  • Guests

Posted 05 December 2009 - 02:32 AM

Could the migration be driven by shifting availability of macroinvertebrates? We've been doing monthly driftnet collections on the new moon in the upper Paint Rock River system in 'bama since July, and the various arthropod Orders change dramatically in relative and absolute abundance. Last month we found an explosion of Collembola like we haven't seen before.


Bruce are you seeing these shifts driven by seasons or other freerunning forces?

#18 Guest_ashtonmj_*

Guest_ashtonmj_*
  • Guests

Posted 05 December 2009 - 12:19 PM

You cheat! :) I do, but I need to have more than 15 minutes to sit down. I'll respond tomorrow, I do really appreciate your feedback Matt!

Todd


Trust me I enjoy it...Jim basically made me write an alternative thesis that would have ended up being something similar going between the French Broad, Hiwassee, and maybe Little. It was the thesis that could have been...

Along the lines of niche conservation between the paired/related groups I'd be really curious to look at camurm-tippecanoe vs. camurum-dennocourti. We've had this dicussion before at least once, but is there niche 'bullying' going on by rufilineatum where it appears to have recently invaded? Not only would a Ulocentra add something different to the mix, but so would a Doration. Which makes me wonder...

Oh yeah...where was your flow measurement made? Near bottome or 0.6x depth?

#19 Guest_farmertodd_*

Guest_farmertodd_*
  • Guests

Posted 05 December 2009 - 01:03 PM

Okay, the parts I think I understand...

Yes, I'm mentoring an undergrad who is working the same methods in Michigan with blennioides, caeruleum, flabellare and nigrum. We'll also extend this to a couple streams in Ohio, such as the Grand, Blanchard and Honey Creek. I also plan to look at some of the streams where round goby have invaded, but haven't yet displaced anything, even after 7 years of observation. This was, in part, what got this whole idea chucking in my head, as what I found post invasion was that the niche of the natives was just more quantifiable and the goby filled all the space in between.

And, of course, I'd like to take this to the Green, Duck, Little, etc and look at more saturated communities, in addition to the camurum and tippecanoe complexes. The Ohio River drainage was just a good starting point, I thought. It balanced the two extremes well (too much noise, too little noise, it was just right :)).

We're measuring flow 2 cm above bottom at the center of the sample.

With regard to reaching our wits end, I don't think so... There's VERY few studies that have included multiple systems, so all studies are spatially autocorrelated within their own study, or worse, have an n of what? :) Few have addressed scale.

And then there's still this basic assumption from our EPA friends that silt is what crushed and fragmented distributions, yet the crown jewel mussel stream of Canada (Sydenham) is muddy as hell, like "Maumee Muddy". What it has is a heterogeneous geology, no dams and very few municipalities that ever dumped raw sewage in (so I agree in part with the EPA). What they are going to have a much harder time "cleaning up" is homogenization and fragmentation (USACoE territory).

Since they're not interested in studying that, I would like to start by addressing the geology and dams, which I think explain a great deal of the variation, because it is my hypothesis that the lost populations were sinks (maculatum in the Olentangy and upper Green above the lake, for example). The anthropogenic sources were just the nail in the coffin, and happened so because those species were on such little "islands" of habitat that they were easily extirpated. Even with pristine "water quality", it is my feeling we would have still found extirpation occurring, just perhaps more slowly, like as we watch these living dead populations of Unionids, for example.

In short, the other ecologists in the department were quite pleased to see old school ordination to pick apart community. So I don't think this is beating a dead horse :) They're quite good at describing the variation, and since the variation message hasn't made it up the ranks, perhaps we can get some attention looking at the entire community, rather than individual rare species.

Now, I think I understand what you're saying with the CI's. What I am finding in the p values is that with the exception of the two pairs matched, there is at least one factor that those species separate at 0.001. I ran the tukey with correction at 0.01 and only a couple things dropped off, and they were factors that were one of three (like camurum and zonale, for example). So there was something measured in each case besides those two pairs that could reasonably not be attributed to chance. But yeah, the ordination is the real story. And once I start running ordination for each river with more or less community saturation, and chart shifts, that's where the story really comes to life.

What is NMDS? I'm not familiar with that acronym and I doubt it's the nurses organization that Google keeps giving me :)

Did I cover everything? Like I said, I do appreciate your thoughts. I often wonder what things would have been like if you were sitting in the desk next to me :)

Todd

#20 Guest_farmertodd_*

Guest_farmertodd_*
  • Guests

Posted 05 December 2009 - 01:09 PM

Here's a thoroughly non scientific observation I noticed this summer.


Not at all John. It's completely scientific, you made a qualitative assessment, just didn't take it to the next step trying to quantify it. In fact, you're doing much better than a lot of professional ecologists I know... You're actually looking for the questions outside. Many people these days come up with the questions at desks and then go outside to figure out how nature works into their hypotheses. Drives me crazy.

This is exactly what happens for these species... Their community composition is dynamic, the factors upon which they partition the abiotic environment are based in large part on discharge. Another aspect I plan to look at in 2010 is flow dynamics and longitudinal zonation of these species in a couple of the more free-flowing streams that I've already looked at.

Todd




0 user(s) are reading this topic

0 members, 0 guests, 0 anonymous users