Visual Representations of Invasive Species Impacts

This map charts the various invasive species control methods currently utilized on Sea Lamprey in Lake Champlain, and where each method is practiced.

(New York State Dept. of Environmental Conservation, www.dec.ny.gov/animals/7240.html) 

 

 The graph above represents the total number of new species introduced to Lake Champlain by decades. There is a high number of introduced species most recently, in the 2000s, but the number is a drastic reduction from the peak in the 1990s.

(kanat.jsc.vsc.edu/student/lightfk/default.htm)

  

 The annual budget allocation dedicated to controlling water chestnut populations in Lake Champlain given to the Watershed Management Division by the VT Dept. of Environmental Conservation is shown above. 

(www.vtwaterquality.org/wqd_mgtplan/stressor_AIS.htm)

The graph above shows the rate of sea lamprey wounds on the native fish species, Lake Trout and Atlantic Salmon, in terms of woulds per 100 fish. Overall, it seems as though the peak of sea lamprey attacks occurred during 2003 till 2006, with lowest rates in 2010 for salmon and 2011 for lake trout.

(New York State Dept. of Environmental Conservation, www.dec.ny.gov/animals/7240.html)

Vermont Wildlife Action Plan

 Vermont's Wildlife Action Plan is an all inclusive management plan created by the Fish and Wildlife Department in 2005.  It was developed to harness Vermont's conservation ideals by addressing pressing problems and engaging new methods in conservation.  This plan identifies 22 categories of problems that effect species and their habitats, including invasive species.  Chapter 4 of this document put forth many management options to conserve the native fish species of Vermont's waters.  Invasive species, one of the factors that may affect their, is mentioned along with habitat degradation (fragmentation and alteration) as well as climate change.  The state has put forth ideas to monitor native species to better understand the effects of invasives, and has put great emphasis on sea lamprey and the effectiveness of the sea lamprey control system. A final strategy, one that I fully agree with and support, institutes better measures to control the introduction and spread of non-natives.  This includes cooperation between in-state and interstate agencies.

http://www.wildlifeactionplans.org/pdfs/action_plans/vt_action_plan.pdf
- Specifically Appendix K: pg 1070-1080, Chapter 4: pg 15-19


Kart, J., R. Regan, S.R. Darling, C. Alexander, K. Cox, M. Ferguson, S. Parren, K. Royar, B.
Popp, editors. 2005. Vermont's Wildlife Action Plan. Vermont Fish & Wildlife Department.
Waterbury, Vermont. www.vtfishandwildlife.com

Another Professional Documentation Summary

Published by the Water Quality Division of the Vermont Department of Environmental Conservation, the publication, A Key to Common Vermont Aquatic Plant Species, is an exercise designed to familiarize readers with thirty-eight of the most common aquatic plant species found in Vermont. This list is comprised of both native and invasive species, with invasive species labeled as so. The main objective of this key is to increase plant identification knowledge and skill of the public, but to also locate possible invasive species attacks to the Vermont watershed. The key's introduction includes instructions should the reader correctly identify an invasive plant:

[Invasive] species threaten the natural biodiversity and water quality of Vermont’s water systems. If you believe you have identified an aquatic invasive species, notify the Vermont Department of Environmental Conservation immediately. If you have questions or would like the identity of a plant confirmed, you are encouraged to send a plant sample to the Lakes and Ponds Section. Wrap the plant in damp paper towels, seal it in a plastic bag, and label it with the location where it was collected. Mail it along with your telephone number, e-mail address, and home address to:

Lakes and Ponds Section
Water Quality Division
Department of Environmental Conservation
103 South Main Street, 10 North
Waterbury, VT 05671

Additionally, the key continues to explain that there are invasive species that are not currently in Vermont, but are of great concern should they enter Vermont water bodies, and lists them for the reader, i.e.fanwort, anacharis, hydrilla, parrot feather (vtwaterquality.org, 2010).
.

Personally, I believe that the agenda of this publication is extremely purposeful in that it increases public awareness of an invasive species problem and goes so far to offer clear, concise instructions on what to do when one finds an invasive plant. As an environmental science student and member of the Rubenstein community, it is hard to believe that some are completely unaware of any sort of problems to the Lake, let alone the profound repercussions of non-native plant species on the lake's ecosystem. So, it is important to keep the general public knowledgeable, encourage them take action, and most importantly, impart them with the skills necessary to better their community and the environment.

The publication can be found at the following link:
A Key to Common Vermont Aquatic Plant Species

Works Cited

vtwaterquality.org. In (2010). Vermont Department of Environmental Conservation. Retrieved from http://www.anr.state.vt.us/dec/waterq/lakes/docs/lp_KeyToComAquaticPlants.pdf

Professional Documentation: Aquatic Invasive Species Guide

The primary documentation that I chose to look at was a document put forth by the Lake Champlain Basin Program.  It is an informational guide to inform the public on the different invasive species of the basin, and educate the public on how to prevent the spread of invasive species.  It overviews how to clean your boat to prevent the spread of invasives, as well as how to identify different invasive species.  It covers all fish, mollusks, crustaceans, and plants that are invasive to the area, as well as certain species that are not yet invasive, though potentially could be in the future.  The guide is very helpful since it provides in depth descriptions and clear pictures to help identify the various invasive species. The guide can be found here as a PDF file:
http://www.lcbp.org/PDFs/LCB_AIS_Guide.pdf

Eurasian water milfoil (Myriophyllum spicatum)

Eurasian water milfoil (Myriophyllum spicatum)

Eurasian water milfoil is an aquatic plant native to Europe, Asia, and Parts of Africa. Introduction to North America is believed to have occurred in the early 1900's. The source of introduction is unknown, but the aquarium trade is suspect as well as United States Department of Agriculture.

 It was first discovered in Lake Champlain in 1962 in St. Albans Bay. By 1976, several thousand acres were estimated to be infested in Lake Champlain, and is the most abundant plant species in 11 of lake's wetlands. At least 40 other bodies of water have been infested in Vermont, and new ones become infested every year. 

Milfoil usually forms very dense patches, reducing light penetration and light availability for native plant species and altering fish and wildlife habitat. It also is a nuisance for boat motors, fishing, and swimming activities. Since 1982, Vermont has spent over $4.1 million dollars on Eurasian water milfoil control.

Marsden, E, and m Hauser. "Exotic species in Lake Champlain." Journal of Great Lakes Research. 35.2 (2009): 250-265. Web. 15 Apr. 2012.

Water Chestnuts - "They're Not Talking About Chinese Food"

(Alfred Cofrancesco, U.S. Army Corps of Engineers, at www.forestryimages.org)

(http://www.iisgcp.org/EXOTICSP/waterchestnut.htm)

Originating from European, African, and Asian waters, Trapa natans, commonly called the water chestnut, began to invade the American northeast around the 1870s. Some of its offenses include the clogging of waterways and ponds, as well as significantly altering native aquatic habitats, one of which includes the mighty and already infested, Lake Champlain.

Water chestnuts inhabit shallow areas of freshwater lakes and ponds as well as slow-moving streams and rivers, upon which, the formation of impenetrable mats of floating vegetation begins. They also favor nutrient-rich waters with a pH range of 6.7 to 8.2. The Burlington bay area of Lake Champlain fluctuates around a pH of 8, making it a great medium for water chestnut habitation. To put the severity of Trapa invasion into perspective, the author of this article lists species distribution history throughout the Northeast, and immediately proceeds this by singling out Lake Champlain. Of all the aquatic bodies listed, the Charles River, the Hudson River-Mohawk River drainage basin, and even Lake Ontario, Lake Champlain was the only one mentioned to be a "major infestation of more than 300 acres... throughout some 55 miles... between New York and Vermont" (O'Neill, 2006). 

(Alfred Cofrancesco, U.S. Army Corps of Engineers, www.forestryimages.org)

Water chestnut populations are mainly kept in check by parasitism provided by native insect species. Devoid of such insects, Lake Champlain currently has no natural predation defenses against and remains susceptible to such invasive attacks.

( Vermont Department of Natural Resources)

 These attacks introduced various physical, ecological ,and economic impacts that were previously absent. Firstly, the dense mats of vegetation prove to be a hazard to recreational lake users as the sharp, spiny nuts can puncture swimmers. Mat density also severely limited light penetration for other species. This, along with the plant's decomposition, creates a trophic cascade since reduced oxygen levels and increased fish kill resembles the effects of eutrophication. So, water chestnuts can severely and easily out-compete native aquatic species, and deteriorate the biodiversity of the entire habitat. Moreover, the species provides little to no nutritional or habitat value to other fish or waterfowl species.


It is possible to control the spread of a water chestnut invasion, but is easiest to do so in the early stages; thus, early detection and rapid response are key to preventing infestations. Small, early populations can be easily hand-pulled, while larger populations require the more costly use of mechanical harvesters or aquatic herbicides. Even so, these solutions are merely temporary, as new mats of chestnuts will once again grow back next season from the bed of the waterbody. It is estimated that a treatment of 10 years would be needed in order to completely eradicate such an invasion. The article goes on to mention that New York and Vermont alone have spent $4.3 million dollars from 1982-2001 on water chestnut control measures on Lake Champlain (O'Neill, 2006).

( The Nature Conservancy, www.nature.org/aboutus/careers/index.htm)

(Vermont Department of Natural Resources)

References
O'Neill, C. R. (2006, February). Sea grant new york. Retrieved from http://www.waterchestnut.org/Assets/PDF/wcfactsheet.pdf

Interview with UVM's own Ellen Marsden

Ellen received her doctorate in Fisheries in 1988 from Cornell University, before coming to UVM in 1996 as an Assistant Professor in the School of Natural Resources.  Her interests include restoration of native species, specifically lake trout, and impending effects of introduced exotic species.  She has done extensive work on the movements of sea lamprey in response to pheromones is Lake Champlain, as well as the effect of zebra mussels on soft sediment fauna and benthic predators.  Some selected publications that may be of interest to our readers include:

Marsden, J. E., and M. Hauser. 2009. Exotic species in Lake Champlain. J. Great Lakes Res. 35:250-265.

Madenjian, C. P., B. D. Chipman, and J. E. Marsden. 2008. Estimate of lethality of sea lamprey attacks in Lake Champlain: implications for fisheries management. Can. J. Fish. Aquat. Sci. 65:535-542.

Q:  What do you believe to be the top three invasive species present in Lake Champlain
A:  Zebra mussels are clearly the first, followed closely by alewife.  As for the third, it is a toss-up between the aquatic plants milfoil and chestnut.

Q:  There has been recent debate on whether or not sea lamprey are a native species.  What is your view?
A:  First off there is genetic data that says they are native, but I believe this is not compelling, and it is easier to say that they are not native, than they are.  There is no record of sea lamprey in the records of Jesuit priests, who were incredible naturalists and took very detailed notes.  We know that there are, and were, silver lamprey in Lake Champlain, but there are no records of people seeing these organisms either.  One would think that if someone were to notice these grotesque creatures, that they would take note.  The reason sea lamprey have become such a nuisance is that we have created the perfect habitat for them; an incredibly silty environment, and the removal of their larval predator, the eel.

Q:  Do you believe there are any invasives that are helpful to Lake Champlain
A:  No matter what you do exotics will eat something, usually native, causing a some sort of negative effect.  But if this food source were plentiful, for example a brook silverside, than we can look past this.  We used to think that round gobies had no effect, but we now know that they displace the native sculpin and eat lake trout eggs.  When evaluating what is "good" or "bad", we must consider through what lens we are viewing.  Anything that humans like will be deemed good, for example white perch.  These fish do compete with natives, but there is no noticeable decline in such populations.  They also may shift fishing pressure away from the natives, and people love to catch these fish.

Q:  Could there be a time when Lake Champlain is completely invaded?
A:  Even though a system may seem wrecked or out of whack, there is still no such thing as completely invaded.  Whether the outcome is good or bad for us, the system will make adjustments to the changes.  This could take 2-3 years to occur.  Natives could indeed play a smaller role in the future, but still contribute to the system.

Q:  Do you know of any control methods for the infestation of zebra mussels?
A:  When it comes down to it, there is nothing really.  Some organisms may be realizing they are edible, such as crayfish, drum and carp.  Their population growth seems to be leveling off, as the are over their carrying capacity and beginning to compete with themselves.  The only real control we can do is in fixed situations such as intake pipes.  We have employed toxic surfaces and robots to scour the insides of the pipe, put this is very hard to get at.  Chlorine may be used, but it is detrimental to other species.  The biggest thing to do is prevention.  There are bans in the importation of baits and aquatic plants curb any new introductions into Lake Champlain.  Management has ceased the stocking of any new exotics, only the continuation or currently stocked brown and rainbow trout. Boat hauling has become closely monitored especially because the Champlain Canal is the main source of invasives.  Our only salvation to this problem would be to eliminate all boat traffic.  And of course there is always education!

Sea Lamprey: Invasive or Native?

In the summer of 2009 my dad and I went on a fishing trip in Lake Champlain. We hired Rich Greeno who was a family friend to take us down rigger fishing for many of the deepwater fish species in Lake Champlain including Landlocked Salmon and Lake Trout. In the  hours that we spent fishing on the lake we pulled up 22 Lake Trout varying in size from 12-25 inches in length. It was on this marvelous day of fishing however that I realized the extent of the Sea Lamprey problem in Lake Champlain.  Out of the 22 fish we caught 4 of them had living Lamprey attached to them, and 12 of the remaining 18 had scars that were caused by Sea Lamprey at one point in their life. Only 6 of the 22 fish caught had no evidence of Sea Lampreys. 

Populations of sea lampreys were first identified in Lake Champlain in 1929. It was thought that the Sea Lamprey were an invasive species that came into Lake Champlain through the Hudson/Champlain Canal in the 1800’s. However recent genetic studies have indicated that the sea lamprey may actually be a native species in Lake Champlain.

            University of Vermont Associate Professor Ellen Marsden recently presented information that could help prove that Sea Lamprey are in fact a native species to the Lake Champlain Ecosystem.

(http://www.mychamplain.net/forum/lake-champlain-sea-lamprey-control-alternatives-workgroup-meeting)

Dr. Marsden discusses genetic research that seems to support the idea that Sea Lamprey are a native species to Lake Champlain. For this to be true Sea Lamprey, Lake Trout, and Salmon populations would have coexisted in lake Champlain for thousands of years. This should have led to evolutionary traits in Salmon and Lake Trout to combat the Lamprey, leaving the question of why the sudden increase in reports? This is due to the fact that the Lake Champlain strains of salmon and lake trout are lost forever.

             The negative impact on Lake Champlain's fishery and ecosystem as a result of Sea Lamprey may be able to be explained by two factors. The first factor is the major change in human use of the Lake Champlain watershed. This may have resulted in an increased habitat for larval lamprey. The other factor is that the strain of Atlantic salmon being stocked in Lake Champlain currently did not evolve in the presence of lamprey and therefore may be more susceptible to sea lamprey damage. This does not hold true for the current Lake Trout strain that is being stocked. Studies have shown that the new strain now being stocked is exhibiting a greater tolerance to the Sea Lamprey.

            As the debate rages on as to whether this nuisance species of lamprey is invasive one thing has become clear. Invasive or not Sea Lamprey populations need to be controlled in order to keep healthy Lake Trout and Salmon populations in Lake Champlain.

(http://www.dec.ny.gov/animals/6998.html)

"Sea Lamprey Experts." - NYS Dept. of Environmental Conservation. Web. 02 Apr. 2012. <http://www.dec.ny.gov/animals/7236.html>.

"Sea Lamprey." - NYS Dept. of Environmental Conservation. Web. 02 Apr. 2012. <http://www.dec.ny.gov/animals/6998.html>.

Invasive Species Arrivals by Year

(http://www.lcbp.org/nuissum3.htm)

Invasive Species Threats

Lake Champlain has roughly only half as many invasive species in comparison to the Hudson and St. Lawrence Rivers. The Great Lakes on the other had have almost four times more invasive species then Lake Champlain. This is causing major concern in the Lake Champlain basin because of the fact that Lake Champlain is connected to all of these invasive species plagued water entities. Opening Lake Champlain up to a variety of new species with unknown consequences.

Found at: http://lcbp.wordpress.com/2009/12/02/what-is-the-%E2%80%9Clatest%E2%80%9D-aquatic-invasive-plant-or-animal-that-appears-to-be-heading-for-lake-champlain/. Accessed on: 29 March 2012

Control of Zebra Mussels

As previously mentioned throughout this blog Zebra mussels (Dreisenna polymorpha) were introduced in to the great lakes in 1986, and eventually Lake Champlain in 1993, through the release of ballast water (Ludyanksiy 1993).  They cause adverse effects to the ecology and health of the lake system including degradation of Lake trout spawning area, competition with small and larval fish for plantonic resources, and the killing of the lakes native mussels.  Not only does this nuisance species affect animals but people as well.  The edges of the Zebra mussel are incredibly sharp and able to easily slice human skin.  Some of our favorite swimming spots have become colonized by these invaders, making them hazardous to our well being.

Some view education as the only way to curb the attack of Zebra mussels, but several studies have tested more radical solutions to the problem. Claudi (1994) conducted experiments involving the establishment of Zebra mussel larvae of objects such as pipes (a common occurrence that can effectively block flow).  He found that by applying copper to the inside surfaces larval settlement could effectively be reduced.  Other studies found that applying molluscacides, such as Cutrine Ultra, to water systems can potentially help decrease the amount of Zebra mussel larva, as this is the most sensitive life stage to changes in chemical balance (Kennedy 2006).

While the introduction of chemicals into our watershed may seem a viable option for Zebra mussel eradication, it does not come easy.  Chemicals often do not target a single species, and have the ability to effect any organism that comes in contact with it.  This should be taken into consideration when discussing the most effective way to curve and eventually remove the Zebra mussel population

Claudi, R., Mackie, G.L. (1994) Practical Manual for Zebra Mussel Monitoring and Control.  Florida: CRC Press

Kennedy, A.J. (2006) Relative Sensitivity of Zebra Mussel (Dreissena polymorpha) Life-stages to Two Copper Sources. Journal of Great Lakes Research 32(3):596-606

Ludyanksiy, M.L., McDonald, D., Macneill, D. (1993) Impact of a Zebra Mussel, A Bivalve invader. Bioscience. 43(8): 533-544

Alewives

 

     Alewives migrate into freshwater from the ocean to spawn, but can stay and survive in freshwater.  They have been a problem in Lake Champlain, after their introduction in 2003, because they compete with native fish species and eat eggs of other fish.  They also provide an insufficient diet for Lake Trout and Atlantic Salmon, causing a decline in native species. Some practices for control used in the Great Lakes, that could also be used in Lake Champlain, would be the introduction of a predator species, such as Chinook salmon and steelhead/rainbow trout.  These fish also provide fun for anglers, as Chinook salmon can become quite large in size.
     One of the larger effects of Alewives on Lake Champlain is its destruction of the zooplankton community.  Since Alewives main food source is the zooplankton, they can cause a drop in zooplankton numbers, which in turn can effect the inner workings of the lake.  By eating large amounts of zooplankton, algal blooms can occur because their are not enough zooplankton to keep algae in check.  Water clarity and and nutrient dynamics of the Lake are then altered from the algal blooms.
     Alewives, as stated before, can cause a large problem when they feed on the eggs of native fish, such as the Lake Trout.  Feeding on the eggs can be a bigger problem than food competition, and can cause mass mortality in native fish.  In a study of Lake Ontario, Alewives were found to cause a 100% mortality in Lake Trout fry in near-shore regions where Alewives were common.  If Alewives are not controlled and monitored, Lake Trout in Lake Champlain may see the same fate.
Looking at the map to the left, one can see the red areas around the Lake Champlain basin, showing that Alewives have been introduced to our area.  On the map one can see how they are native to coastal areas since they only come into freshwater to spawn, but now they have made it far upstream and become invasive in areas including Lake Champlain.
Map from: http://www.greatlakesfisherman.com/gallery/files/1/alewiferange.gif

"Vermont Lakes and Ponds- Alewife." Vermont Dept. of Environmental Conservation. N.p.

,Nov. 2011.Web. 11 Apr. 2012. <http://www.anr.state.vt.us/dec/waterq/lakes/htm/ans

/lp_alewife.htm>.