Snipe, were there any efforts made to estimate standing weights of the community members? It would be really interesting to understand what percentage of the standing crop is represented by each species in that lake.
Though LMB standing crops vary widely as a percentage of total standing crop, they seem to average between 14% and 16% of the total standing weight when many samples (from different lakes/ponds) are taken. Swingle noted that the most ponds meeting his definition of balanced had F rations (prey weight over predator weight) of 3 to 4 (which equates to 20% to 25% of the total standing crop) for the LMB/BG combination. But its not just that percentage, how many mouths comprise that percentage is also important.
The paper on the survey of 42 ponds is an amalgamation of 42 anecdotes where each one represents a unique natural system. In other words, no individual pond is representative of anything typical. There is one pond of these samples which (I think) skewed heavily the association of LMB standing weight with presence of OSS. It was pond 29 which was 21 years of age at the time of survey. It's standing crop was 650 lbs of which there were 320 lbs of LMB, 108 lbs of crappie, 71 lbs of "Other sunfishes", 146 lbs of "Course fishes", and 5 lbs of BG.
Course fishes and Other sunfishes are where individual species are not counted but lumped together. In the paper they explain which fish are lumped into these categories. RES, LES, GSF, & OSS are the other sunfishes. It is very interesting to note how "not prevelant" BG were in this pond. 5 lbs of 650 lbs gives the BG proportion less than 1% of the standing weight. This despite BG having an average of proportion of 39% of the standing weight of all ponds considered. My hunch is that this pond's "other sunfishes" were comprised mostly of the maximum noted OSS standing weight of 64 lbs/acre where the remaining 7 lbs could have been RES, GSF, and/or LES. I thinks this is a reasonable inference given that OSS were associated with above average standing weight and because BG tend to outnumber (RES, GSF, and LES and most any other water I have experience with. It isn't known whether the OSS were introduced to this pond simultaneously with BG and other sunfish, introduced first, or invaded the pond in high water events. I think the latter is definitely a possibility and if this is so then I think this suggests that OSS are particularly robust survivors for such a small fish. So this keeps with the thoughts of the biologist's hypothesis that OSS are impacting BG recruitment. It would also seem to suggest that OSS are capable of impacting recruitment of other sunfishes like RES, GSF, and LES.
Now I would mention that of all the ponds surveyed this pond ranked 3rd in At. This metric is the proportion of the standing weight of that is of harvestable size. This value for this pond was 76%. This is all the more remarkable when we consider that OSS never reach their definition of harvestable size and that a population of 64 lbs of OSS represents almost 10% of the standing weight. More than 65% of the standing weight was comprised in the predators LMB, and Crappie. Substantial proportion of the crappie must have been harvestable. So from the perspective of an LMB/Crappie pond ... the addition of OSS may be beneficial. This provides an anecdote of at least one possible eventual outcome of such a combination's interaction.
Last edited by jpsdad; 06/27/22 05:57 PM.
