Pond Boss Forums MANAGING AN EXISTING POND Evaluating and adjusting fish populations BG Stunting: North vs South

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http://www.pondboss.com/ubb/ultimatebb.php?ubb=get_topic;f=20;t=002291;p=7#000094

Guys - I have three tidbits to add to this string.

First, let me mention an older study done by Tim Modde, who was mentioned earlier by Ewest. Tim coordinated a study of ponds all across South Dakota. Newly stocked largemouth bass rarely spawned at age 1. In most ponds, LMB reproduction didn't occur until the second year after stocking. The only exceptions were a few of the ponds in the southeastern corner of the state, which has the longest growing season. Assume that LMB and BLG are typically stocked as 1 or 2 inch fingerlings. Then, this tendency for LMB to NOT spawn at age 1 (not big enough yet), while BLG DO spawn at age 1 can lead to unbalanced pond communities. So, we most often stock the BLG a year after the LMB. Seems strange to you southern folks, doesn't it?? We do stock fathead minnows with the LMB fingerlings to get them off to a good start.

So, this thought that bluegills overpopulate more in northern ponds might be at least partially related to stocking regimes used in the past. However, I tend to think it is more of what Bill Cody says. The LMB in these ponds are easily overharvested. I know that in a lot of southern waters, people are relunctant to harvest and eat LMB. Our anglers for the most part will take and eat the LMB. So, a pond with overharvested LMB usually results in BLG overpopulation. When I first started on this forum, I was VERY conservative in my management thoughts, just for that reason! You folks have "loosened" me up a little since then.

Finally, any discussion of latitude and LMB-BLG probably needs to consider the number and amount of bluegill spawns (e.g., prey production). We've been looking a little more closely for the last couple of years, and we're mostly seeing single spawns from our bluegill populations around here. Sometimes, it may be more of the "rolling spawn" that we often discuss on the forum. Even in our work down in north-central Nebraska, it's rare to see two spawns. This HAS to make a different predator-prey relation for LMB and BLG up north, especially the age-0 LMB that don't have plenty of small, late-spawned BLG to eat as happens in southern waters. I'm wondering if that might explain why some "bassy-looking" waters up here don't always have the LMB density that I expect based on that good habitat.

Our main BG spawn is over with just a few BG still on nests. We'll still have a few BG spawn but not many from here on.

On my all male horizontal aeration pond I just had a group of six big males move into a 20 square foot area. They built nests and are jockeying for position. They look like my biggest ones. I don't know why they just chose now to do this.

Bruce -- sounds like the start of your second spawn? Did they build a colony somewhere else earlier??

Norm -- that's what we are seeing in our larval trawling, too. Most of the spawn in synchronized and we get a big peak in larval abundance, but then there is a "tail" that lasts for a while where we still see a few new larvae for a while. Don't forget, one study said that a few percent of bluegill males actually would spawn on a solitary nest instead of in a colony.

I never did see a first spawn. I'm assuming that since it's a new pond that the fish may have still been going through an acclimation process.

Bruce check the calendar --full moon of July. We had this weekend another BG spawn but it was small compared to May and June. I noticed that this spawn was mostly CNBG males (can't tell about the females). The copper nose bars are really visible when spawning. I wonder if they tend to spawn more in warmer water than regular BG ?

Bruce -- keep watching, and maybe we'll get this figured out in our lifetimes.