|
|
Member
Posts: 2680
Location: Essexville, MI./Saginaw Bay. | Recently the Great Lakes region has begun a turn around trend and is experiencing an increase in water levels. Of course this may be temporary and nowhere near does it recuperate the amount of water we've lost over the last 12 to 15 years from the Great Lakes. I know from both experience and historic records, that back in the 70's and 80's, those high water level amounts were at historic Core of Engineers high water datum highs. But I really don't know rather those historic highs or the present water levels now were or are more the norm for the Great Lakes. I do know that a lot of things changed all at once as those levels changed and fluctuated in the last 20 years. Being on the water many times a year myself during these times both hunting and fishing, I always noticed the sometime subtle and often more severe changes and how they effected the ecosystem on the Lake and along the lakes shore lines.
My question is, what harmful or helpful factors if any, do you think these low waters levels played when combined with the aquatic invasive invaders. The recent water level fluctuations seemed to have started and continued to drop almost equally in step with the invasives introductions, as year after year more invasive's were added one on top the other to our great Lakes ecosystem. Coincidence or not, almost all the recent threatening changes to our fishery and it's food web have been proven to of had something or in some cases everything to do with these invasive's. With an ecosystem being all connected in one way or another, has the DNR ever studied rather water fluctuation trends made things worse when combined with these invasives?
Dan.
Good questions Dan.
My understanding is that Lakes Michigan and Huron are back to 'normal' or more specifically long term average. One single water level isn't the norm rather a periodic fluctuation within certain levels is the norm. Of course there are annual seasonal fluctuations but im talking fluctuations that range from highs and lows that last about every 16 years. It's a fairly predictable 16 year cycle from lows to highs and research says it's due to weather patterns that in turn are driven by sun spots on the sun (I kid you not). The sun exhibits a 16 year cycle of spots or storms that affect weather on earth. So what we are emerging from (many believe) is a normal low point in the cycle. If history is correct, we are headed for high water levels.
What was maybe different this time in the water cycle is that we fell to a new record low. Many believe (myself included) that we are seeing the effects of climate change (global warming) making usual weather patterns more extreme. Climate change models say MI is becoming warmer such that our average temp will be 6-12 degrees warmer by the end of the century. Dosent sound like much but that means the lower peninsula will have a climate about like Ohios in the next 15 years and like Arkansas by the end of the century. Interestingly the same climate models forecast that while we'll be dryer in the summer we'll be wetter in the winter and spring. Generally everyone believes the lakes will drop (estimates are 4 - 26 feet). The wide range is because there are conflicting forces at work.. Warmer means little or no ice cover and that means more evaporation and the dryer summers will mean more seasonal losses but the wetter winters and spring will compensate some (but nobody is sure how much).
Anytime we have extreme conditions we are more vulnerable to more invasions by exotic species and more pronounced effects from the invasives we already have so the recent record low water levels didn't help matters but I don't think they were a direct contributor or cause. The big food web change in Lake Huron was almost entirely an ecological phenomenon with no exact ties to habitat change (in my opinion). | |
| | |
Member
Posts: 2680
Location: Essexville, MI./Saginaw Bay. | I've been informed that some changes to the walleye limits criterion are in the works for Saginaw Bay. Those changes will be announced when finalized and invite the publics opinion on them within the next 3 to 5 weeks according to my DNR buddy. With repeated trawl results showing the predator/prey relationship out of balance and favoring the predators, this change rather temporary or not, needs addressing now. | |
| |
|
Recent/Revealing Q & A with my DNR buddy.