Pond Boss Forums INTRO Questions & Observations Bluegill breeding article

I just want to thank Pond Boss and Dave Willis for the recent article on Bluegill breeding site selection. I have two ponds, both muddy, and the bluegill reproduce just fine. But the article indicated that bluegill overwhelmingly prefer pea gravel in 3' of water with quick access to deep water. So I decided to help them out. In my newly enlarged 1A pond I now have large flats that should be around 3 ft deep, close to the original, deeper pond basin. I put three 12'x12' tarps down in three different places (to keep the pea gravel from sinking into the mud) and I am going to cover them about 4" deep in pea gravel. If you decide to do something like that, I recommend puncturing the tarp in several places to help the bubbles escape. It makes the process much easier. Now if I can just get more rain.

Ed :

That was a good article!!! Now we just need to talk Dave into doing a few more articles. Then we will have an entire BG series . How about it Dave are there more to come ? I hope so!!! Ed there is a related article on BG spawning at the first link below. It is by one of the authors Dave cites in his article .The second link is to the PB thread where some of us discussed parts of this a couple of mths, ago. ewest

http://publish.uwo.ca/%7Ebneff/papers/genetic_paternity_analysis.pdf

http://www.pondboss.com/ubb/ultimatebb.php?ubb=get_topic;f=20;t=002154;p=

thanks for the links ewest,

you are right, he has really good info on bluegill. I almost forgot about the article in the previous issue. It is amazing how nature works. I wonder what the triggering mechanisms are for a male to take on female coloration - or even camouflage cocoration. I doubt they have the capacity to make a conscious decision, so it must be encoded in their genetics.

But this last article I could really sink my shovel into, and make constructive changes to my pond.

Hey guys what do you think about putting the pea gravel over lake when the ice is on in the winter? My idea is when the lake warms it will all to to the bottom at the depth that was put on the ice.

This is just speculation as I have not done too much structure placement by ice.

I'm not sure that when you place some structure on ice that the structure will end up in the same place in the pond. When ice melts, doesn't it sometimes break into pieces, and then move as the pieces shrink? And I am not sure if the ice remains level with weight (what you've placed on it) as it thaws; won't it tilt as some point, thus letting the structure slide off?

Just questions here.

Well those are good concerns Sunil but from my experience it pretty much goes straight down when the ice melts - at least in small ponds. Why? Because the added heat from the stone usually causes the area with the pea gravel to melt first.

Thanks for the kind comments, Ed. The Pond Boss crowd is a lot of fun.

Actually, ewest is tracking down scads of information on hybrid bluegills and their genetics. He knows more than me. :-)

I do have another bluegill research project right now, and I'll let the cat out of the bag on a recent thought that I am having. Working with bluegills in Nebraska and South Dakota, am I starting to wonder if they don't primarily have a single spawn. In our NE study, we had one lake one year where they clearly had two spawns. However, most of the other lakes are primarily a single spawn, with a little tail of bluegill fry produced later in the year. This is all pure speculation, and I need to find time to dig into past research reports at other northern locations. However, single-spawning bluegill sure might change the "prey production" thoughts of our management strategies in the north country, couldn't they?

John -- what will keep the gravel from just sinking into the silt on the bottom of the pond?? I'm not certain, but I think it might do so.

We have a virtual BG factory with nothing to spawn on besides sandy clay.
Checked a few days and population ranges from 1 - 10 inches.

Are we just lucky?

George Glazener
N.E. Texas 1/4 and 2 acre ponds

Dr. Dave - I agree with your thoughts for the probablity of a single bluegill spawn in the plant hardiness growing zones of 5 and colder; places such as NY, PA, OH, IN, IL, IA, KS, CO WY AND areas more northern. I think the length of the bgill spawn in these areas is somewhat extended in time compared to say a yellow perch spawning season. I also sometimes see a brief spawn of bgills late in the summer. The late bgill spawns are probably less frequent in the more northern regions with and cooler summers.

I'm just speculating, but I wouldn't be surprised if the liklihood of a supplemental spawn might jump a little when Wr's are good. If an adult fish can expend a little energy toward spawning without damaging it's own individual chances of surviving the winter, then this might give the species a better chance at propogating, in particular a year with poor spring recruitment.

If bluegill populations work like some other animals that have been studied, then in years with low numbers of spring YOY survival, the breeding size adult fish would have less competition for invertebrates, thereby increasing Wr's. This would in turn encourage a late summer/fall spawn to supplement the depressed YOY numbers.

It's a virtual certainty that late summer/fall recruits would have a lower winter survival rate than their spring counterparts. Good evidence to support this thinking has been collected by studying walleye winter survival. There is a "cutoff" size that does quite well in winter survival, with those individuals below this size and Wr doing much more poorly in following spring samplings.

I don't have to worry about ice at my location, and I am glad that I don't have to worry about my bluegill possibly only spawning once/yr. I have kind of a forage pond above my main one. It is nothing but clay, 30 degree banks. I stocked it with minnows, bluegill, and about 10 CC, two years ago. We just drained and sained it. Found all 10 fat cats, no minnows and several times the original weight in bluegill of 1-5". The smaller the fish, the higher the quantity. We also found about 6, 6" saucer shaped nests clumped together on a flatter part.

So they do reproduce well in clay. But in my main pond, they will have pressure from predators, so I want to make it as easy on them as possible.

Dave :

Again thanks for your efforts and I know we will all be looking forward to any reports. While I am trying to track down info on several topics and am glad to share, you and Bill know what those studies mean many times better than me. No way , no how, do I know more about those matters than you. After all I have seen quite a few studies that you wrote or co-wrote or were involved in and I am amazed at their diversity of scope and knowledge. That is why you are the teacher and we are begining students. I am thankful that you are helping me and the other forum members understand what they mean!!! ewest

I did read with great interest an outstanding 1985 article underwritten by SDSU titled below . An outstanding study which all forum members should read to get an understanding of the differences between fisheries North and South and some of the "why" reasons. It will help any ponder understand some of the parts to the puzzle and how they fit together.

Latitudinal Growth Effects on Predator-Prey
Interactions between Largemouth Bass
and Bluegills in Ponds

TIMOTHY MODDE AND CHARLES G. SEALET
Department of Wildlife and Fisheries Sciences
South Dakota State University
Brookings, South Dakota 57007

George -- good point on the spawning substrate, and one which I hope was sufficiently emphasized in my last Pond Boss article. Bluegills DON'T need gravel for successful spawning. What was cool in that study I discussed was that they selected ONLY gravel sites when the gravel was available. Certainly, do NOT read anything more into it. :-)

Say, lots of forum traffic for a holiday! Happy Thanksgiving everyone.

I love this sight it lets me bounce my ideas off of other people. As for as the gravel on the ice is concerned I never thought of it floating off but I think it would warm up faster with the gravel on the top and settle to the bottom. It is a gamble. As far as the silt on the bottom I figure that some will sink into it but it might be another alternative of having a little different bottom for fish to spawn in.

Another idea my son in law used to drive a tri axle dump truck called the Rock Shooter. What it did was it had a conveyor belt on the back and was able to shoot rocks up to 70 feet. He told me of one time taking a load of sand to a lake and shooting it in to it so the guy could have a sandy bottom in it. Just another thought.

I also think a large percentage of the northern late bgill spawns are due to slow or late maturing females. I hope research sheds some more light on this topic.

When I originally heard of BG spawning multiple times each year, I envisioned the same fish spawning over and over. But, if I now understand the situation more clearly, it is more the case of some of the BG spawning during the first time window (full moon? I'm still unsure how much of that "spawn during the full moon" legend is fact and how much is Farmer's Almanac quality CW.) and others spawning later (due to later maturation, poor RW/condition early in the season, being beat out for nesting sites early on, etc.). So it's kind of a "rolling spawn," where some BG may spawn more than once but much of the "multiple"ness comes from different BG being out of synchronization for one reason or another.

Dr. Dave & BC (et. al.):

Could Northern waters where a single BG spawn predominates be due to local conditions (available nesting geography, BG population demographics, population structure of other species, water temperature vs. time of year, etc.) which limit or focus the BG spawning activity to a single time window? (The longer I make that question, the more it sounds like "Could the increased luminosity experienced in early morning be due to the sun coming up over the horizon?" so maybe the answer is obviously yes.)

In regards to Theo's two paragraphs:

First paragraph: Fully agree.

Second paragraph: Completely agree.

Theo -- probably much truth in what you said, especially about the rolling spawn. Back when I worked in Kansas, I spent quite a bit of time on gizzard shad. People told me beforehand that they had two distinct spawns. After working more closely on them, they clearly had an extended spawn and definitely not two separate spawns. The term rolling spawn is a good one. The shad in better condition (higher Wr) spawned first, those in lower condition first had to increase Wr and then they spawned, by then the first fish had ripened their second clutch of eggs and spawned, etc. So, I really like your term.

One key to this is that in some fish species, individual fish have the capability to spawn more than once. If I take the ovaries from a female bluegill or gizzard shad just prior to the spawning period, they have different sizes of eggs in their ovaries. There is a large size of eggs just about to be spawned, a second clutch of smaller eggs that can be ripened for a later spawn, and then some tiny eggs that generally are believed to be for the next year. If I take eggs from a walleye or northern pike just before the spawn, all the eggs are a single size. Single spawners, clearly!

Why is it that when we hunt pheasants on opening day we'll sometimes see a rooster that's clearly about eight to ten weeks old? Same reason, I'd suspect, that bluegill produce a "rolling spawn". (BTW, I'm going to use that term as if I came up with it. ) Species don't reproduce because it's a particular time of year. They reproduce because for thousands of generations that particular reproductive strategy has worked to push DNA forward in time. For bluegill, and equally for pheasants, certain environmental influences such as climate and available forage make it advantageous to take a second or third go at it. If this strategy has worked before for a particular species, then it becomes part of the hardwiring.
It would also stand to reason that the further north you go, the more stress it would be on the individual to attempt a late spawn. The energy expended in the attempt might decrease the odds of surviving the long winter ahead.

Very interesting.

I have been gathering info on the single spawn idea and forwarding to Dave.

This is one area where I think there are big differences as well as some similarities in northern vs southern ponds in a " rolling latitudinal effect"

I have no doubt of there being multi-spawns in the south based on observations and published material including fisheries manuals by the biologists of a number of states. Even the Neff article quote below from the longhair post showes that there were at least a few multi-spawners in his studies which occured in Ont. Canada. I do think that Dave is on to something in northern ponds based on other studies including the Neff ones and that there is likely one longer rolling spawn in many northern ponds. I also think that even in the south there are some rolling spawn elements with late maturing or small or poorer conditioned fish and while there are multi-spawns all do not spawn at the same time or the same # of times.

Theo I use to be very skeptical about moon phase matters and still am in many areas but not wrt BG/RE spawn. I have observed it to much in our ponds and had to many fisheries biologists confirm it in this area. From 10 years of observation notes the first spawn BG/RES (overlaping) of the year is the first full moon (usualy March)after the water temps get high enough. There are then ebbs and flows in BG spawning with max spawn activity on the full moon in May (or early June depending on what time of mth they fall) If you come back to observe 10 days after the full moon there is very little activity in comparison. There is an obvious ebb and flow but no 100% point (where all are spawning or not or are on or off the beds). As the full moons of Mar.-Aug. ( ? Sept. late spawners) approaches BG spawning maxs. then declines. Same for entire spawn - it starts slow in March - maxs in May/June and wanes through Aug/Sept. However in the studies I have read from northern ponds I have never seen this type of activity (multi-spawns or full moon) discussed or refered to or mentioned and my guess is it does not happen in northern waters or scientists of this caliber would have noted it. ewest

Neff study ppg 283.

Repeat spawning

To ascertain if repeat spawners showed consistency in their nest
position, in the years 1988–1990, 1993 and 2002 a total of 901
parentals were tagged using Floy brand T-tags inserted into the
muscle directly below the dorsal fin on the left side of the body.
The study site was monitored for the duration of the spawning
season and the nest position of repeat spawners was recorded. In
most cases in which males spawned a second time in a breeding
season they were not remeasured. Thus, while we had repeat
measures of nest position, we did not have a second estimate of egg
score, male length, condition or ear tab area.

pg. 384

Of the 901 tagged males, 119 (13%) nested a second
time during a single breeding season (Table 3). Seven of
115 males (6%) that nested colonially in their first
breeding attempt switched to nest solitarily in their second
breeding attempt, and none of the 4 males (0%) that
nested solitarily in their first breeding attempt switched to
nest colonially.

Neff link

http://publish.uwo.ca/%7Ebneff/papers/Solitary_nesting_in_bluegill.pdf

Longhair link

http://www.pondboss.com/ubb/ultimatebb.php?ubb=get_topic;f=20;t=002154;p=1

PS : Bruce may well be right that a large part of the difference may be genetic differences developing over a long periods of drift/mutation/selection. If so I wonder if the north-south continuum of ranges of difference occurs from and based on the latitudinal seperation.

Now, let's carry this bluegill spawning discussion one step further. Even a "small" second spawn by bluegills could be darn important to largemouth bass in northern waters. The largemouths also spawn later up here than down south, and those age-0 bass really do better if they have a source of fish prey. So, even a small amount of later spawning by bluegills might provide the small size of prey fish that the little bass need. We've got a couple of small public impoundments (75 acres sort of waters) that look like they should be good largemouth bass habitat, but bass density is low. I wonder if their offspring need a better food supply during their first summer.

What a thought!!!! Is it possible that BG could over time change genetically --learn/adapt/mutate/drift so they have one earlier spawn before or at the same time as LMB so as to starve off the LMB offspring by not providing enough BG forage at the right time to sustain the YOY LMB fry. It would only take the BG moving up their spawn a couple weeks. The ultimate survival adaptation -- starve out one of your primary predators by having your offspring early so they will be to big to eat by the hungery hoard. That would lead to many stunted BG over time and defeat the adaptation plus the larger older male BG spawn first anyway and don't need that adaptation to pass on their genes. But they (larger males) would not need to move their spawn up much, it would be the smaller BG spawners ( who are the most in # ) who would be pressed to move up their spawn to meet the genetic challange of fitness to pass on their genes. The Successful passing on of a populations ( or part of a populations) genes is a powerful driving force for adaptation.

Neff pg 384 "It has been proposed that brood predation may be the
driving force behind the evolution of coloniality in
bluegill (Dominey 1981; Gross and MacMillian 1981)."

Wow there is a lot to think about. Thanks Dr. Dave for pushing the learning curve. Do you think we may have an answer soon or is it the more we learn the more unanswered questions we have to figure out. ewest

I'm glad this progressed to the number of spawns. I have been thinking(uh oh), if some of the several spawns in southern ponds could be impeded, especially in light of first spawns being of the fittest, could we have a better overall pond quality by sabataging some spawns?
Could this be done by timely lowering of water and introducing colder water; not enough to stress the entire community, but to decrease nesting activity? Has this been researched; does it sound feasible?(small pond)

Ewest, I see you are on forum this AM, what do you think about my previous post?

Back to the pea gravel post. I'm starting to dig out my 5 acre pond and designing the bottom. I want to have some spawning areas and like the use of a tarp to keep the pea gravel from sinking into the clay.

But now I'm reading that bluegill will spawn with or without the pea gravel. What about the bass? Will they use the pea gravel? Would it be better to have seveal smaller spawning ares or one big one? What is the best size for a spawning area?

Thanks,
Eddie