Tuesday, June 23, 2015

Chena Slough Restoral - Part 3

Local officials held a meeting last week with one day's notice. I missed the notice, but 25 other people showed up and listened to an herbicide salesman tell how he could, for $600,000, over three years, apply the herbicide Fluridone to a 10 mile stretch of flowing water and eradicate what appears to be the most eradication-resistant aquatic plant species on Earth.

I only learned of the plan when I read the headlines June 18th, 2015: 

Chena Lake herbicide proposal draws no opposition

Oh, really?

Reading on, I learned it was not just Chena Lake, as the headline implied, but Chena Slough as well. The Chena Slough runs alongside my property. I use the water to irrigate my garden, my chickens drink the water, my bees drink the water. The moose in my freezer drank the water. My drinking water well is drilled about 100 feet from the edge of the slough.

Part 3...The Elodea Wars

Elodea is considered to be quite troublesome in most of its natural range. It can compromise slow moving waterways and lakes, impacting travel and fisheries. Elodea spreads mainly from broken pieces of stem which float away and take root. Elodea is easily spread from water to water by boaters and floatplanes that unwittingly carry Elodea fragments. Elodea is also spread by waterfowl that eat it, breaking off pieces that float away or carrying it with them as they fly. Moose, muskrats and beavers may also cause Elodea to spread as they use the plant for food.

Mama Moose eats Elodea while twin calves play nearby (photo by author, Chena Slough)

Too Little, Too Late?

Elodea was first discovered in the Chena Slough in 2009, and discussed widely since 2010 (Etcheverry, 2011). The Elodea Working Group was soon formed. The working group has five subcommittees (Steering, Control, Survey, Research, and Outreach). They have a website, http://www.fairbanksweeds.org/elodea-working-group.php and a Facebook page that 15 people "like."

The website seems to have not been updated since 2011 or 2012, and contains lots of incorrect information. for instance:

Elodea has only been found twice in Alaska: in Eyak Lake near Cordova about thirty years ago and in the Chena Slough/Chena River system in 2009-2010.  It has not been reported from anywhere else in the state before or since.  The closest known population is found approximately 1000 miles southeast of Fairbanks.

As we know from Part 2, Elodea has been documented in at least four lakes in south central Alaska. Other tidbits found on their website are misleading or just plain wrong, such as:

In 2010 Elodea nuttallii was discovered growing in the Fairbanks area in Chena Slough. Elodea has the potential to impact Alaska’s freshwater resources by directly competing with native flora. The impacts include:
  • degraded fish habitat and displacement of native plants,
  • alteration of freshwater habitats, including decreased water flow and increased sedimentation,
  • endanger safe float plane operation,
  • impediment to boat travel and reduce other recreational opportunities, and
  • reduction in property values in impacted areas.

As we also know, the species found in the Chena Slough is not E. nuttallii, but a hybrid species. The Chena Slough is not used for float planes. Boat travel is limited to about 1/2 a mile of the 20+ mile-long slough. Property values have not decreased because of Elodea, and native plants and fish still live in the slough.

If this was such an impending disaster, why did they wait five years to start discussing an action plan? One worthy of Napalm.

If this had been a true emergency, the State of Alaska should have declared it as such. They should have immediately placed barricades at culverts and outlets to catch fragments and began intensive eradication until every stem was gone. Instead, they did nothing. They made a few infographics, and set up a few "slough days" where volunteers pulled weeds.

Chena Lake seems to have gotten a bit more effort. They had a suction dredge, divers, and tried a few non-chemical methods to clear the Elodea. The conclusion of these efforts:

Multiple attempts to remove the species, including hand weeding and dredging, have failed. A total of 238 man hours managed to remove only 0.59 acres of Elodea, and questions remain as to whether the whole root system was removed.

24 people working a single 10 hour day is 240 man-hours. This is all the effort that's gone into Elodea removal in five years? The meeting, attended by 25 people, concluded:

"No one likes the idea of dumping chemicals in the water, especially in Alaska. But I feel like it's the only way we're gonna stop this."
- Trish Wurtz, invasive plant program manager at the U.S. Forest Service.

[Author's note: I own 5 acres of property with 550 feet of slough frontage on the Chena Slough. To date, no one from the Elodea Working Group has contacted me to discuss these issues, though I have contacted them several times.]

Elsewhere in Alaska

Elodea was found in 2013 in three remote lakes on the Kenai Peninsula on the Kenai National Wildlife Refuge. Refuge managers worked with state officials and began treating the lakes with two chemicals, Fluridone and Diquat. Apparently this was done with little fanfare and limited public comment (Kenai Weeds, 2015). This infestation was treated as an emergency and the few residents of the lakes apparently provided little opposition to the plan. 

According to several accounts, the Elodea appears to be gone from one of the lakes and "nearly gone" from the other two. The plan calls for three years of chemical applications (Peninsula Clarion, 2015).

In Anchorage, Alaska's largest city, Elodea was discovered last year on Sand Lake. Sand Lake is home to a large fleet of privately owned float planes and is surrounded by high-priced homes. Talk has begun of treating this lake with Fluridone as well, but it's not being so well received by local residents.

Harold Heinze

Harold Heinze is one of the more vocal opponents of using herbicides in Alaska's waters. We should listen. Heinze was once the commissioner of the Division of Natural Resources (DNR), the same agency proposing to use these chemicals. Knowing a bit about how government organizations operate, Heinze has concerns that "the process the state is using to approve the use of Fluridone and the “terribly downplayed” potential human health risks at play," according to a news article in the Alaska Dispatch on June 6, 2015. Heinze wants the permits denied until the health risks are thoroughly assessed. According to Heinze:

There are potentially significant public health issues related to this stuff and it seems to me that that needs to be in the forefront of the process.

Also in this article: 

The Sand Lake Community Council doesn't have an opinion on the plan, its president said Thursday, because nobody briefed them on it (Alaska Dispatch, 2015).

And a quote from a 74 year old float plane pilot and lake resident:

Undoubtedly some dipweed dumped a goldfish bowl with elodea in the lake.  If they don’t do something, it’s just going to be a swamp.  You can tell I'm a little frustrated with the whole thing.  

The Lower 48

In the rest of America and Canada, Elodea is commonplace, and people just live with it. How can this be?

It turns out that a common trait of Elodea is that when it "invades" a new area, it experiences 5-6 years of rapid growth, then stabilizes or decreases. According to the State of Alaska Elodea Management Plan (Morton, et al., 2014):

Where elodea has been introduced outside its native range , elodea has generally responded by a fairly explosive growth period of 5 — 6 years (Sand - Jensen 2000, Mjelde et al. 2012) followed by a declining (Nichols 1994) or sometimes a stable (Mjelde et al. 2012) population. Rapid growth may be initiated in areas where the sediment is iron rich; growth is terminated when iron reserves are depleted (Spicer and Catling 1988) or when the decaying biomass depletes the oxygen and lowers the p H , thereby weakening the carbon fixation and photosynthesis efficiencies of elodea (Lehtonen 2000).

Since Alaska is only on year five of the "invasion," maybe a few more years should be given to see if the Elodea will stabilize.

Range of Elodea in the US and Canada

The European Experience

Elodea canadensis was taken to Ireland as an ornamental aquatic in 1836 and has since spread to nearly every waterway and body of water in Europe. In 1936, Elodea nuttellii was introduced in England, and it, too, has spread far and wide. Unlike Alaska, the two have never hybridized and in the case of E. nuttellii, only female plants exist (ThiƩbaut, 2008).

Throughout Europe, hand-pulling and mechanical removal have proven difficult, expensive, and ineffective. Chemicals are not widely used on Elodea throughout Europe in favor of mechanical and biological methods (Gollasch, 2006). The biologic methods employed have been the introduction of fish, such as carp, that eat Elodea. A fungus (fusarium) has also been used successfully (Zettler, 1972).

Elodea Range in Europe

We can't just do nothing!

Throughout Alaska's Elodea plans, a recurring theme...we can't just sit here and do nothing. On the Kenai Peninsula, they took this to heart. Possibly by watching as Fairbanks forms steering committees an expends untold manhours (238, to be precise), trying to eradicate Elodea, and getting nowhere in 5 years. They saw Elodea, they poisoned Elodia. Questions may be asked at a later time.

Anchorage is taking a more cautious approach, but still they know they cannot just sit there and wait it out. Elodea only gets worse and worse. Forget what it says in the state's management plan about a 5-6 year expansion period followed by stabilization.

Fairbanks is no longer standing by, they are preparing the populous for an application of chemicals, 6 years after Elodea's appearance. Forget the people who live where it grows, this must be done with chemicals, and quickly.

Let's revisit Europe for a moment...according to a French Elodea management plan:

Another solution was to do nothing and to “wait and see”.  A noticeable decline of  E. canadensis in European freshwaters (Simpson 1990) and of  E.  nuttallii  after the peak of  the outburst in Japan’s lake [have been reported] (Nagasaka et al. 2002).  

All eyes should be on Chena Slough, the first real test of the "5-6 year expansion" effect. If the Chena Slough self-corrects, as it appears to be doing, then the battle may be over. The other option is to rapidly extinguish any flame of Elodea the moment we see it, no matter the cost.

In Part 4, we'll take a look at the chemicals that the state proposes using to "treat" the Chena Slough. Believe me, it's no treat!


Alaska Dispatch (2015). Weed killer proposed for invasive plant choking West Anchorage lakes. Retrieved from http://www.adn.com/article/20150606/weed-killer-proposed-invasive-plant-choking-west-anchorage-lakes

Etecheverry, D. (2011). Elodea  management in  Fairbanks. Retrieved from  http://www.uaf.edu/files/ces/cnipm/otherresources/12th-annual/Elodea_Management_in_Fairbanks_A_Review_of_2011_Findings.pdf

Gollasch, S. (2008). Delivering Alien Invasive Species Europe. Retrieved from http://www.europe-aliens.org/pdf/Elodea_canadensis.pdf

Kenai Weeds (2015). KENAI PENINSULA COOPERATIVE WEED MANAGEMENT AREA. Retrieved from http://www.kenaiweeds.org/index.php

Morton et al., (2014). Integrated Pest Management Plan for the Kenai Peninsula. Retrieved from  http://www.fws.gov/uploadedFiles/Integrated_Pest_Management_Plan_for_Eradicating_Elodea_ver4_1.pdf

Peninsula Clarion (2015). Refuge Notebook: Killing Elodea under the ice. Retrieved from http://peninsulaclarion.com/outdoors/2015-06-04/refuge-notebook-killing-elodea-under-the-ice

ThiƩbaut, G., Di Nino, F., Peltre, M. C., & Wagner, P. (2008). Management of Aquatic Exotic Plants: The Case of Elodea Species. In Proceedings of Taal2007: The 12th World Lake Conference (Vol. 1058, p. 1066).

Zettler, F. W., & Freeman, T. E. (1972). Plant pathogens as biocontrols of aquatic weeds. Annual review of Phytopathology, 10(1), 455-470.


  1. I will be interested to read about the chemical. I assume it has a fluorine component, which would compete with iodine (which I've been reading about still).----I think this is a very helpful series. Glad you put it on your blog---- Nothing major, but I still like to know in my own posts, there is inconsistent spelling of Fluridone/Flurodone. ~~TFites

  2. Larsen lives up to expectations with Nick Lisuzzo. He's a natural science expert with the US Forest Service. Lisuzzo says Chena Slough is verifiably a standout amongst the most profitable streams for Arctic Grayling in North America.