Wolf River Sturgeon Update and Wolf River Cam Wednesday 27 April 2011 4-28-2011
gengberg April 28th, 2011
Wolf River Sturgeon Update Wednesday 27 April 2011
A little warmer weather today and a few glimpses of the sun this afternoon made a lot of difference with pushing the lake sturgeon along their path towards ramping up their spawning activity today.
We tagged fish most of the day again along the Sturgeon Trail on County Highway X west of New London, and then at Pfeifer Park in New London on the Embarrass River. The fish were coming in most of the day at these two sites, as well as at about 4 or 5 other sites on the system in the New London and Shiocton areas. Water temperatures went down from highs reached on Monday due to the cold rain yesterday, but the higher temps we saw on Monday were enough to get fish going at a number of sites. 
Despite seeing more fish, we did not collect any eggs today for our restoration projects since we only captured a few females and most of these fish were not yet ovulating or ready release any eggs - we’ll take eggs at Shawano this weekend hopefully. A female will come into a spawning site a few hours before she is finally ready to ovulate and begin releasing her eggs. The males aren’t overly interested in her at this time, although they know she is there and will hang around her hoping to be one of the first males to be in the best position to begin spawning with her once she does begin to ovulate. They will hang with her for quite some time, unless there are other females also in the area that are more attractive because they have already begun ovulating and releasing eggs. Once a female begins to ovulate she will blast out about 1000 eggs every 90 seconds or so until she is empty - 8 to 10 hours after she started releasing eggs. At this point she is pretty much exhausted and may hang around the spawning site for perhaps an hour or two or so before she leaves the sites and begins drifting back down towards the Upriver lakes and/or Lake Winnebago. The males will continue to hang on the spawning site for days or weeks to continue spawning with other females. So - lake sturgeon are polyandrous (one female spawning with numerous males) and polygynous (one male spawning with numerous females) - Mother Nature’s way of ensuring genetic diversity in the stock.One of the real surprises of the day was capturing a very old and very large male lake sturgeon. 
This fish was 70 inches long, and while we have captured males longer than this, we never captured a male as heavy as this one. We did not weigh the fish (we generally don’t weigh fish we capture in the spring since we get enough weights during spearing season), but we estimated this fish weighed about 150 pounds! This was a massive fish. Continue Reading »
