Aquatic Invasive Questions Answered

last update: May 12, 2016

Aquatic Invasive Questions Answered

Associate Provost for Academic Innovation, Professor of Biology and Env. Sci., Director, Center for Aquatic Research, Keuka College

1. First two pictures taken Tues. 9/8. Could see large areas of these clusters long distance out.  Last picture taken at 2 pm 9/10 after heavy rains during yesterday's storm. My husband noticed these different sizes this summer. These are the first I had seen.
Do you know what these are? (Sorry - the site only allowed one photo.)


Dear KLA Member,

The KLA Office forwarded your question and pictures about the green clusters in the lake.  The pictures were great (I wish more people would send pictures as this helps a lot!).  The pictures show clumps of filamentous green algae.  These clumps are not unusual for Keuka Lake, and they are not dangerous/harmful. 

While it sounds it a bit odd to say "green algae" (aren't all types of algae green?), there are actually hundreds of different types of algae: green ,red, brown, blue green, etc.  Green algae is very common and non-harmful.  I also used the word "filamentous."  Algae species in Keuka Lake (or any lake, for that matter) can be planktonic or filamentous.  Planktonic algae is tiny (microscopic) and is suspended in the water.  You cannot see the individual algal cells, but when they are plentiful enough you can certainly see the green, soupy color to the water.  Filamentous algae, by contrast, forms long strings and branches that are easily visible.  These can appear as strings, clumps, etc.  So, what you are seeing is a filamentous, green algae.  At any one point Keuka Lake will have many, many different types and species of algae; this is perfectly normal and healthy for the lake.  These species will change over the course of the season depending upon a number of different factors.  It's really a very dynamic system.

You noted that you are seeing more of this.  Good observations!  Most likely we are seeing an increase due to the warmer weather and the time if the season -- late summer.  Both of these factors favor the formation of this kind of algae.

What we are NOT seeing a lot of (at least not yet) is another kind of algae called "blue green algae."  It is a good thing that we are not seeing a lot of this type; many of the other Finger Lakes are not so lucky this summer.  Blue green algae is technically "cyanobacteria," but the old name "blue green algae" still sticks around and is used.  There are many different species of this type, and most are perfectly safe.  However, there is a set of cyanobacteria that can cause problems for the lake health and the people that swim, boat, and drink from the lake.  It is this kind of cyanobacteria that has been in the news recently.  Fortunately, Keuka Lake has very low levels of this type, but we are always watching! 

I am sorry; I am sure I provided a bit too much information for you, but I am so happy when people ask great questions like you did!  Please feel free to ask any follow up questions (or even send more pictures).  I hope the end of the summer season finds you well!

2. KLA Folks:

Below is an email from your counterparts on Canandaigua, that lesser lake to the northwest of here.
Serious questions, though: Do we have blue green algae at Keuka?  If no, is there something we should be doing to prevent us from getting it?
Ditto for Quagga Mussels.
Thank you! KLA Member

Blue Green Algae and Lake Foam Update
September 15, 2015 Watershed Council Program Manager Update:

Today's 80 + degree F temperatures along with sunny calm conditions have provided the right conditions for increased algae levels on the lake.  Visual inspections along the shoreline and out in the middle of the lake from the boat this afternoon has documented widespread streaking of algae with isolated higher concentrations both out in the middle of the lake and along the shoreline.  Therefore the algae bloom advisory is still active.  Multiple secchi disk measurements were completed to document lake clarity.  Overall clarity has increased from an average of 3-3.5 meters last week to 4-4.5 meters today.  This is encouraging information, however the algae seem to be concentrating in the top few feet of the water column, which is where we have the most contact with the water.  Please continue to use caution and the visual indicators before entering the water.  The weather this week will probably create the right conditions for continued algal growth.
     As many of you have noticed, we are also seeing substantial white foam on the lake over the last 10 days. The foaming of surface waters on lakes is not a new phenomenon. It is a natural process that has been going on for a long time in many different parts of the world.  Foam is created when the surface tension of water (attraction of surface molecules to each other) is reduced and the air is mixed in, forming bubbles.  When organisms, such as algae, plants, fish and/or zebra mussels die and decompose they release cellular products (surfactant) into the water, which reduces the surface tension.  When the wind blows, the waves on the lake agitate this surface agent, thus transforming it into sudsy white foam.   Currents and boats also mix air with the organic compounds present in the lake to produce foam.  The foam will frequently form parallel streaks in the open water, caused by wind-induced surface currents.  It will also collect in large quantities on windward shores, coves, or in eddies.   This is especially true on the east shore of Canandaigua Lake.
    Over the past years Skaneateles Lake, Cayuga Lake, Keuka Lake and Oneida Lake have also experienced foam.  We have also had substantial foam on the lake in September of 2001 and then again in 2006.  We have periodically seen foam in recent years as well.  In 2002, the Watershed Council worked with Dr. Greg Boyer, a leading researcher from the State College of Environmental Science and Forestry in Syracuse, to collect and analyze foam samples from Canandaigua Lake.  The purpose of the research (included Dr. Bruce Gilman of FLCC, and Webster Persall of DEC) was to try to scientifically link the production of foam to its source.  Samples were analyzed for organic matter, lipids, protein, carbon, carbohydrates, fatty acids and nitrogen.  The chemical testing on the foam however could not definitively pinpoint the source of the foam, but did show a mixture of plant and animal organic matter.  Results did rule out any man-made sources.  We are going to reach out to Dr. Boyer to see if he can analyze this year's foam.
    There are two main theories we are investigating.  We are going to try to determine if there has been a die off of Quagga Mussels that cumulatively excreted large amounts of surfactants (organic matter) into the water creating the foam.  The second theory is that ecosystem changes wrought by Quagga Mussels, such as an increase in blue-green algae, may also be a contributing source.  In 2001/2002, we documented a temporary Zebra Mussel die-off through age-classification of Zebra Mussels in the Lake.  Analysis performed by Finger Lakes Community College showed that the overwhelming population of living Zebra Mussels collected in eight different lake locations was less than six months old.  We are going to try to do the same analysis for Quagga Mussels which have largely replaced Zebra Mussels in the lake.  Those who live on the shoreline can help us by investigating your shoreline for empty Mussel shells.  Please let us know what you find!
    We hope to have Dr. Greg Boyer out for a presentation sometime this fall to discuss the substantial increase in Blue Green algae on Canandaigua Lake and what his research is documenting across New York State.  We will keep you posted!

Canandaigua Lake Watershed Association

Dr. Tim Sellers response:

Hi KLA Member,

I'm Tim Sellers, the science advisor for the Keuka Lake Association.  The KLA Office forwarded your note to me. I hope I can provide a little clarity on your great questions!

Yes, Canandaigua and some other Finger Lakes have been experiencing some severe issues with a type of naturally occurring algae called "blue green algae" (technically, this is called "cyanobacteria").  Does Keuka Lake have cyanobacteria?  Yes, we do.  However, our levels are still very low so they are not causing any problems or concerns.  The KLA tests for the presence and concentration of cyanobacteria throughout the year (April - November). 

I've written a few different article about this.  For example, see this link below.  My short article appears on page 6. 

We continue to watch for the particularly nasty varieties of blue green algae, and -- so far -- we continue to have very low levels.  This is directly related to our water quality, specifically to the low amounts of phosphorus that comes into the lake.  This is a very good thing, and a result of good watershed practices.

Do we have quagga mussels? Yep!  The zebra mussel and its cousin the quagga mussel are both present in Keuka Lake.  At this point, there are more quagga mussels than zebra mussels (approximately 70% Q - 30% Z).  Most people would be hard pressed to tell the difference between the two just by picking them up; they look almost identical, and they do the same "job."  I often refer to the quagga mussel as a "zebra mussel PLUS."  The quaggas are a little bigger and do their jobs a little better.  There are a few KLA articles that talks about these guys in Keuka Lake (page 5):    -- Page 5   -- Page 9

There is actually a very interesting, although somewhat complicated, interaction between certain types of cyanobacteria and quagga mussels that does not have a happy ending, and we are watching to see if this story line unfolds in Keuka Lake.  Thankfully, this book has been opened -- yet.

So, yes, Keuka Lake has cyanobacteria and we have quagga mussels.  But, the cyanobacteria in Keuka Lake, unlike Canandaigua and other FL lakes, remains at a very low level and means Keuka Lake is still in great shape. But we are keeping our eyes open!

Please let me know if you have any other questions. I hope this helped a bit!

To Preserve and Protect Keuka Lake