On this date in 1941: The second application of rotenone on Third Sister Lake

Time was that the humane treatment of animals didn't really extend to fish. As part of a bit of background reading to assess the possibility of conducting an updated fish survey of Third Sister Lake, I found only one article on the topic of fish in this lake, and it was published in 1942.

The very first sentence of the introduction reads:

The complete removal of fish from Third Sister Lake was not carried out for the primary purpose of making a fish population analysis but rather as part of a general investigation on the existing relationship between the fish and fish-food organisms in this lake.

The author continues by clinically describing the process:

The destruction of the fish population was accomplished by means of rotenone (Derris root) which was supplemented by netting-and angling during the 3 weeks previous to poisoning. The actual poisoning process and its effect on the fish and other organisms found in the lakes described by the authors elsewhere in this volume.

The first poisoning operation was carried out on May 6, 1941, before the spawning season and before the aquatic vegetation was extensive enough to hamper the recovery of fish ... Because the first poisoning did not kill all the fish, a second application was made on August 18 and 19 when water temperatures were more favorable. Only a very few adult fish were recovered along with many thousand bluegill and pumpkinseed fry. These were not included in the population total. After that time, however no fish were seen in the lake until June, 1942,when a few long-eared sunfish entered the lake, presumably via the outlet during high water. We believe that the poisoning was 100 per cent effective in the removal of fish in August.

In other words, they poisoned the lake and then collected the fish that floated up to the surface. The first time wasn't good enough to clear the lake, and so they did another application, but didn't include those fish in the survey. Oh, and by the way, no fish were seen until the summer of the following year; likely up-migration from the connecting stream.

We are relatively concerned about the presence of 1,4 dioxane in the groundwater, and the spills and their infiltration into the groundwater is cause for concern throughout the area affected, but it is worth noting that the wonderfully lovely looking Third Sister Lake was - at one point - the site for the deliberate complete and utter destruction of all fish (and all invertebrates, as well) in the lake. Of course, unlike 1,4 dioxane which is a very persistent molecule, rotenone loses almost all of its toxicity within one week.

Still, considering that the methodology is one that we wouldn't think of using today when conducting fish surveys, the 1941 survey did a few things, such as provide a good estimate of total fish biomass in Third Sister Lake as well as providing a date certain from when there were absolutely no fish in the lake.

BTW, rotenone continues to be used for fish collection and as a measure of last resort for fish management. Happily, though, rotenone won't be use in Third Sister Lake at any time soon.

Rain!

Ahhh... rain on the forest: lovely, lovely, lovely.

And it looks like we'll be getting rain throughout today and tonight.

It's not too surprising to say that this is something that the forest really needs.

Summer drought: Comparison of years

Just like the comparison of "winter" this year and previous ones, it's interesting to look at the condition of this year's drought conditions. The front lawn area is where this year's drought is most evident. The brown lawn looks more like something one sees in California than what one would expect in southeastern Michigan.

From Thursday morning (July 25, 2012):


Compare it with July 23, 2011:


September 7, 2010 (couldn't find a photo from the end of July):


July 23, 2009:


And although the lake appears to continue to be nice and blue and stable, it actually has continued to drop quite precipitously (considering that it's a spring fed lake and all). To wit:

On Thursday afternoon (July 25, 2012), you can see the matted bottom starting to show through the algal mat:


whereas two months ago (May 25, 2012) it was a channel deep enough for it to be a usable fish passage:

Buckeyes growing in the forest

Living through this summer of far-hotter-than-normal days in Ann Arbor - home to the University of Michigan Wolverines - and working in environmental and natural resource management, I am thinking about the on-the-ground effects of climate change more than often. (Maybe more than is healthy.)

I hope for rain. I hope for cool winds. I hope for clouds even.

We get heavy sun that heats up asphalt, withers trees, and browns the grass. We get hot gusts of dry wind that buffet you into sweat-stained submission. We get few clouds, and those we get rarely carry rain for us.

It's the largest drought area ever declared, but some people are wondering if this is a forecast of things to come, or even the new normal. However, people from Mississippi River managers to Michigan cherry crop farmers to almost anyone paying attention in much of the country is recognizing that there is a massive drought happening and that weather has gone haywire (unless you happen to be Newton Leroy Gingrich).

And these are just the things that are happening right now. For University of Michigan fans, things could well get much worse.

According to research done in 2007 by Daniel McKenney and colleagues, the Ohio buckeye - which is the state tree of Ohio as well as the mascot to Ohio State University - will be shifting northward over the next 100 years. This means they will be shifting into Michigan, moving from its current distribution and possibly into Michigan (according to the CSIROmk35 A1B prediction model).

This will turn Michigan into the new "Buckeye State", and in Saginaw Forest, there are already many buckeye saplings that have been growing quite happily over the past number of years. Take a walk near the tree-tee-pee and see for yourself. (Here's the Ohio DNR's handy identification page.)

Will this growth get a lot of Michigan (and Michigan State) fans quite angry about the whole thing, and maybe start to think of climate change as something real? Yes, it's a strange way to introduce people to the effects of climate change, but many people have visceral attachments to sports, and for many people this includes university sports (even if they never attended that particular university).

What might make this an even greater blow for University of Michigan fans is that the last known wolverine living in the state died in 2011. With the local extirpation of the wolverine - the UofM mascot - and the encroachment of their largest rival's mascot onto home territory, could there be some sort of climate change education and action that come out of this? True, it was tried back in 2008, when the implications of McKenney's paper became recognized, but maybe the time is ripe again?

While part of this is written as tongue-in-cheek, another part of me is trying to think of ways to get people latched onto simple fact that climate change is not just happening right now, but has been happening for decades already; that the time to act is not tomorrow, but yesterday; and that the fact we haven't done a lot is only going to require us to work all the harder down the line.

Unexpected cool morning

The morning is unexpectedly cool. After reaching 100F in town yesterday, and having an expected low temp of only 75F, I wake up to quite comfortable temperatures. The windows are now open and I'm attempting to pull in as much cool air as possible.

Hopefully, the weather won't get too hot today.

Are vines growing faster?

Walking through Saginaw Forest this summer, I have noticed far more vine growth than I recall there being in previous years. Is this just my imagination? Confirmation bias? Or could it have something to do with the really warm winter that we had? (Too, could it have something to do with the differential rates of growth between vines and trees?)

What we know for sure is that the winter of 2011/2012 was a really warm one and March, May and June have been uncharacteristically warm, as well. There has also been less rainfall than usual.

Now, what I'm guessing at is that, since vines require less resources to maintain themselves and grow compared to trees, it seems possible to me that vines have been able to quickly take advantage of the warm spring and start their growth while also being able to continue growing during these more parched months. However, this is just a guess on my part.

What I know is that there are a lot of trees with vines growing on them; the vines themselves are very dense, and there's a lot of poison ivy, too. This radically warm winter, spring, and summer seem to correspond with the basic message of a 2006 paper by Mohan et al. Their abstract reads, in part:

Contact with poison ivy (Toxicodendron radicans) is one of the most widely reported ailments at poison centers in the United States, and this plant has been introduced throughout the world, where it occurs with other allergenic members of the cashew family (Anacardiaceae). ... Rising CO2 is potentially responsible for the increased vine abundance that is inhibiting forest regeneration and increasing tree mortality around the world. In this 6-year study at the Duke University Free-Air CO2 Enrichment experiment, we show that elevated atmospheric CO2 in an intact forest ecosystem increases photosynthesis, water use efficiency, growth, and population biomass of poison ivy. The CO2 growth stimulation exceeds that of most other woody species.
So, poison ivy is expected to be more abundant and a greater lover of the high CO2 future than trees. And this is likely also a cause for the increase vine abundance in general.

We heard news a few months back that the atmospheric concentration of CO2 has increased past 400ppm, which doesn't correspond to the elevated CO2 chambers of Motan et al's study, but as the Motan paper discusses previous studies on increased CO2 and vine growth:

With an increase in CO2 concentration and a corresponding increase in photosynthesis, vines can allocate more photosynthate to additional photosynthetic tissue, because of a low allocation to support tissue relative to other woody growth forms (13, 14, 18, 19). Increasing abundance of woody vines is causing increased tree mortality and reduced tree regeneration in forests around the globe (18, 20�23), potentially resulting in shifts in community composition that may impact carbon cycling and biodiversity (23). Although it is unclear how elevated CO2 will affect the growth of vines in forest environments, the contemporary increase in woody vine abundance may be the result of rising atmospheric CO2 concentrations (19, 23).

The Motan et al paper doesn't discuss the impacts of warmer winters, springs, and summers on poison ivy growth (nor on the growth of other vine species). However, I am going to guess that a large part of the vine growth this year is likely due to the ever increasing CO2 levels and have been exacerbated this year by the unnaturally warm seasons.

Warming temperatures leading to additional lake complications?

This past winter, Third Sister Lake didn't get a complete freeze, and it was possible, as the spring approached, to see algae growing in some of the ice. In March, while we were experiencing temperatures normally part of June weather, I wrote about some of the possible impacts that such weather might bring if they become the norm. I also wrote about some of the possible impacts to Third Sister Lake that such warming might bring.

Well, add to all that one more impact brought on by warming: decreased lake turnover. In a new paper out in the journal Climate Change, Swiss scientists have shown how increased warming in Swiss lakes have decreased lake turnover, and this has brought about increased levels of Burgundy blood algae.

The paper's abstract states:

Anthropogenic-induced changes in nutrient ratios have increased the susceptibility of large temperate lakes to several effects of rising air temperatures and the resulting heating of water bodies¹. First, warming leads to stronger thermal stratification, thus impeding natural complete water turnover (holomixis), which compensates for oxygen deficits in the deep zones^{2, 3}. Second, increased water temperatures and nutrient concentrations can directly favour the growth of harmful algae^{4, 5, 6}. Thus, lake-restoration programmes have focused on reducing nutrients to limit toxic algal blooms⁷. Here we present evidence that the ubiquitous^{8, 9, 10} harmful cyanobacterium Planktothrix rubescens has become the dominant species in a large lake during the past four decades, although the phosphorus content of the ecosystem decreased fivefold. However, the nitrogen input was not diminished concomitantly, favouring this non-N₂-fixing cyanobacterium owing to increased N:P ratios¹⁰. P. rubescens contains gas vesicles that allow for buoyancy to accumulate within the depth of optimal irradiance¹¹. As the toxic cyanobacterium has low consumption by predators¹², water turnover represents the main mechanism of seasonal population control. Thus, unidirectional lake-restoration measures¹³ in parallel with recurrent absence of holomixis owing to lake warming may lead to similar undesired effects that have formerly emerged from fertilization.

This type of impact is problematic for Third Sister Lake, not because of Planktothrix (or because of other cyanobacteria, at least to my knowledge), but because Third Sister Lake is already a lake that doesn't completely turn over. From a 2001 paper by Bridgeman et al., the finding of lake stability (i.e., the resistance to turnover) in Third Sister Lake was that:

Salt-laden water entering Third Sister Lake [during the winter] from [the business lots to the southeast] could eventually lead to the formation of a chemocline. Large vertical gradients of salinity may potentially prolong stratification or altogether prevent mixing. ... If Third Sister Lake follows a similar pattern [to First and Second Sister Lakes], the contribution of a chloride gradient to stability would reach a maximum in March or April ... and the lake ... will remain [thermally stratified] until mid-November.

The paper also reported that - due to forest growth from 1904 - Third Sister Lake didn't fully turn over in the spring (i.e., following ice-out), even back in 1986. The authors of the 2001 paper concluded that:

Given that the lake is now more sheltered [than in earlier decades] and may require about 60% more wind energy to overcome a chlorine gradient, complete spring mixing, which was a common event at least into the 1940s and occurred occasionally until the early 1980s, is now probably rare.

And it's likely to remain rare if increased temperatures become the norm. (That is, unless a significant number of trees fall down, thus increasing the lake's wind exposure.)