Brown Trout Eggs
The Vibert boxes were pulled last week and the unhatched eggs were counted. Our hatch rate this year was estimated to be 95%+! Excellent job. We also realized that we did not get the 7,500 eggs we usually purchase. The hatchery threw in an extra 2,500 at no cost. That means we had approximately 9,500 brown trout eggs hatch in the LMFR!!! Thanks again to everyone who helped out this year.
Once again, this year saw another planting of Brown Trout eggs in the LMFR. This was an idea floated and started by our good friend Tony Kirk some years ago and then taken up by Roger Turner. After Roger left, the reins were taken up by David Dillow. And once again, he and the volunteers have come though with flying colors!
Every autumn for a number of years now, we have been attempting to supplement our brown trout population and attain some sort of wild population by planting fertilized eggs in what are uncommonly known as Vibert Boxes, named after the man who designed them. The more technically correct term would be Whitlock-Vibert boxes, as Dave Whitlock redesigned the original box into what we use today.
We purchase 7500 eggs from a hatchery up north. They go through a health test first and then all the paperwork is cleared with the ODWC. This is an annual thing so that we don’t introduce anything unwanted into our river. One year we actually chose not to accept the eggs due to an infection of undetermined severity.
Several hundred eggs are then divided out and put into each box that is then buried in the gravel with a marker for retrieval. After sufficient time, we dig the boxes up and count the remaining unhatched eggs. This gives us a “hatch rate”. In the wild, the hatch rate is quite low due to various natural variables. Our hatch rates have been consistently in the 90%+ range.
Now, before you get too excited over all the extra brown trout, the literature to date states that the 3-year survival rate for trout fry is quite low. So we are optimistic when we say that we “think” this results in an extra 500 brown trout – eventually. But we don’t really have a clue on the success of this program. Some things just have to be taken on faith.
Below are some of the photos from this year. Boxes will be removed in about one week and we will know the hatch rate at that time. The volunteers put all of the boxes above the day use area due to ODWC work upstream.
Since the beginning of this program, we have had great support from the White Oak ISD. they show up every year despite the weather conditions. As “payment”, we give them some eggs for their biology lab so the school kids can see and learn about the life cycle of trout hands on. The photos below include a few that show the transport and installation of the eggs into the school aquarium.
Per David Dillow: “Special thanks again to Jim Kelly for being the counter and to Michael Gras for pictures. Thanks to Pat Waters for scouting out the area for us.” If I had a list of all the people that helped, I would type them all out here. But I don’t. So, from me and the LMFRF (and countless fishermen that will never even realize it) – Thank You!