Category Archives: Water Quality

2024 Clary Lake Watershed Survey: Volunteers Needed!

Our Watershed Steering Committee has begun planning the 2024 Watershed Survey, with the assistance of DEP Staff. This is not our first watershed survey, the picture at left is the actual Clary Lake watershed map developed for the 2001 watershed survey. While the watershed itself hasn’t changed in 22 years, a lot of land development has occurred in those intervening years. It is way past time to take this important step in protecting and preserving Clary Lake and its water quality.

The purpose of a watershed survey is to identify sources of non-point source pollution- areas where soil erosion is taking place within the watershed such as along shorelines, gravel driveways, camp roads, road side ditches, dysfunctional culverts, etc. Runoff from rainstorms and snowmelt can result in soil erosion and sedimentation which makes its way into the lake, bringing with it sediment and nutrients, the most damaging of which is Phosphorus. If you’ve been paying attention over the years, you’ll know that Phosphorus is the primary cause of algal blooms and If we want to keep our lake free of blooms (see picture at the top of this post), we need to reduce the amount of Phosphorus entering the lake. A watershed survey is the first step in doing that.

Once we’ve completed a watershed survey and have developed a Watershed Plan, we become eligible for Nonpoint Source Water Pollution Control Grants. DEP administers Nonpoint Source (NPS) grants to help communities make progress restoring or protecting waters named as NPS Priority Watersheds (Nonpoint Source Priority Watersheds List). While Clary Lake is not listed as an “Impaired” lake, it IS on the list of Threatened Lakes, making it eligible for 319 funds- a dubious distinction but an important one! Grants for projects are funded with monies provided to DEP by the U.S. Environmental Protection Agency under Section 319(h) or Section 604(b) of the Clean Water Act.

Volunteers Needed!

We’re going to need roughly 15 volunteers to help with the actual field work of the survey. The plan is to divide the watershed into 4 roughly equal sized sectors and assign each sector to a survey team consisting of 3-4 volunteers and a Technical Specialist who will oversee and guide the survey fieldwork. It is anticipated that the actual field work will take approximately one day to complete. It will obviously be a long day! Food and refreshments will be provided.

The survey is to take place on Saturday May 4th (rain date, Sunday May 5th). Volunteers will need to attend a Zoom training session held a week or two before the survey. The training will be offered several times to accommodate varying schedules. To volunteer to help with the watershed survey field work or to volunteer in any other capacity on this important project, please email watershed@clarylake.org or call George Fergusson @ 207-242-2256. If you have any questions at all about the survey or why we’re doing it, please do not hesitate to contact us!

Total Phosphorus In Clary Lake

[November 2023] I’ve been working on this article about Total Phosphorus levels in Clary Lake for some time, another in our continuing education series, based on the premise that informed people make better Lake Stewards! The better we all understand lake science the better able we will be to protect and preserve our cherished natural resource. This article on Phosphorus in Clary Lake will be posted under Programs.

Total Phosphorus In Clary Lake

Phosphorus (P) is an element on the Periodic chart and it exists in nature in rocks and soil in various forms. P is crucial to all life forms and in small amounts it is a good thing, but as you’ve all learned by now, too much P can cause excessive algae growth resulting in harmful algal blooms. Consequently, an important part of our Water Quality Monitoring program is collecting data on the Total Phosphorus (TP) load in Clary Lake, and studying how it varies over time (TP is a measure of ALL the phosphorus found in a sample whether it is dissolved or in particulate form). We take 3 water samples for TP testing every season, and our 3rd and final TP test result for 2023 is back so this seems like good time to dig into this important topic. On September 22nd we took a 7 meter core water sample; it came back showing 0.017 mg/L of TP. I was actually expecting a higher figure in the mid to upper 20s and I’m glad I was wrong, but clearly it was high enough to fuel a moderate month-long algal bloom this fall with sightings of dead green algae collecting along the shore as early as late September and as recently as the end of October. The blessing if there is one is that it didn’t happen during the summer! Last year we had generally higher TP readings and a much more severe algal bloom that started around September 1st and didn’t burn itself out until late November. Other factors do contribute to produce algal blooms, but the presence of Phosphorus (P) in our lake is the single biggest cause. When we say algal blooms, we’re mainly talking about excessive growth of blue-green algae, more commonly known as Cyanobacteria. We’ll cover Cyanobacteria in depth at another time. Continue reading →

October 2023 Water Level Chart Archived

I have archived the October 2023 water level chart (above, and at left). Rainfall for the month once again exceeded normal (a common refrain this year!) keeping the lake level higher than intended, at one point coming within almost an inch of the HWM with water flowing over the dam- unusual in October. By the end of the month however the lake was back down to 3/4 of a foot below the HWM which is about normal for this date. All told we received 5.36 inches of rain (normal is 4.45 inches) bringing us to 49.6 inches for the year, fully 13.6 inches above normal! Even if rainfall remains normal or below normal for the rest of the year, 2023 will still go down in the record book as an exceedingly wet year. We’ve seen greater-than-average rainfall in 7 of the first 10 months of 2023, and normally the wettest month of the year, November, is about to start. Continue reading →

Fall 2023 Clary Lake Algal Bloom

While it doesn’t appear quite as severe as last fall (at least not yet), this fall’s cyanobacteria algal bloom is gathering steam. This is not wholly unexpected: our last lake transparency reading was only 2.7 meters (8.8 feet) and there was quite a bit of green algae in suspension (see 2023 Water Quality Monitoring Season Comes to a Close) so I’m not really surprised to see this. The picture at left was sent to me yesterday afternoon by Danny Bell. Quite a shot! Apparently the aquatic growth helped keep the algae from drifting off. I went down to my shoreline and found only a thin greenish sheen of algae on the surface- nothing to compare with what Danny was seeing. The blue-green bacteria dies and floats to the surface where it’s moved around by wind and currents and in some places you’ll see quite a bit of green and in others much less or even none. Last year the bloom continued into early December. Hopefully this one will burn itself out soon. I will be sending a sample into DEP for testing.

This picture was sent to my wife this morning by Fran Marsh who was understandably concerned.

Please send me your observations and pictures!

Blue-Green Algae Finally Makes an Appearance

The lake has gone through its Fall Turnover meaning the temperature stratification that was a summertime feature of the lake has broken down and the lake water has mixed pretty much from top to bottom. The high winds from the remnants of Hurricane Lee last a week ago Saturday certainly helped with the mixing! Kelsie French and I were out doing our biweekly water quality monitoring last Friday and the water temperature at the surface (21.5°C) was only 2.5°C warmer than the water 8m (26ft) down. Two weeks ago the temperature difference from top to bottom was 7.8°C.

That turnover resulted in Phosphorus-rich water at the bottom of the lake mixing with the upper sunlit layers, giving a shot of nutrients to the cyanobacteria living there. A week later, they’re beginning to die off and float to the surface resulting in that telltale green scum on the water surface. The picture at left was sent to me by Jack Holland. Yesterday morning the green stuff was fairly evident over much of the lake surface (featured image, above), thanks to the lack of wind. It quickly dissipated when the wind picked up.

While no algae bloom is a good thing, as blooms go this one is pretty mild and it was expected. Hopefully it won’t get much worse. Last fall you may recall we experienced a much worse bloom, way more intense and widespread that went on for 3 months, extending all the way through November. It is likely all the rain we had this summer and the resulting flushing action that kept our water quality so high for so long.

The Cyanobacteria in Clary Lake is Alive and Well

As nice as as our lake water has been this summer, and it has been nice, there is nonetheless cyanobacteria alive and well living in it. Runoff from all the rain we’ve received has washed sediment into the lake which is the primary source of phosphorus and phosphorus as you know by now is good for algae, bad for lakes. In the featured image above, taken by Jack Holland on the morning of August 10th, the telltale green scum comprised of dead blue-green algae is evident, but not terribly alarming compared to what we’ve seen before, even as recently as the first of June this year. After Jack sent me his picture, I went down to my shoreline and took the picture at left. The telltale green sheen is so faint and ephemeral as to be easily overlooked. But it’s there. If this is as bad as it gets this year we’ll be very lucky. Continue reading →

24 July 2023: Midsummer Water Quality Update

Clary Lake Transparency

Kelsie French and I got out on the lake on Sunday for our biweekly water quality data collection and the results are worth sharing. We had a secchi disk reading (a measure of lake transparency) of 4.18 meters (13.71 feet) which while not unheard of, is actually quite good, especially this time of year, considering all the rain we’ve received this summer. Rain means runoff and runoff means sediment and sediment means Phosphorus and Phosphorus means algae… Two weeks ago it was 3.80 meters (12.46 feet). I didn’t expect to see it improve, but it did! You can see today’s reading on the far right just above the 4 meter line on the above chart. We’re definitely trending in the right direction! You can see a subset of the data we collect back to 2012 on our Clary Lake Water Monitoring Data page.

On the downside, dissolved oxygen (DO) was only 1.1 mg/l at 4 meters which is damned low for such a shallow depth; 2 weeks ago it was 5.4 mg/l at 4 meters and 2.5 mg/l at 5 meters. Today it rapidly fell off from 4 meters and at 7 meters and below we found NO oxygen at all. Under these severely anaerobic conditions, Phosphorus which is normally stored in bottom sediments can reenter the water column. As long as it stays near the bottom, it’s not a problem but in the fall when the lake turns over, this Phosphorus rich water will mix with the upper layers where algae live, and this can spur out of control algae growth. This is why most severe algae blooms occur in the fall. The bloom we had last fall was in part due to this phenomena. There were other extenuating circumstances.

We also took the first of 3 core water samples we’ll take this season for Phosphorus testing. We’ll take another in mid-August and a 3rd in mid-September.

Right now, the water quality in Clary Lake is very good but that may change this fall. Time will tell.

Maine Lakes & Lake Stewards of Maine Annual Conference

LSM’s Annual Conference this year will be a joint conference with Maine Lakes.
Location: China Lake Conference Center
Date: June 17, 2023. There are discounts for early registration, LSM Water Quality monitors and Invasive Plant Patrollers, and Maine Lakes’ LakeSmart volunteers.

Please have a look at the conference webpage to register and to learn more about the programming, workshops, sponsors, door prizes, and silent auction items that will be at this all-day, engaging, and inspiring day. Information will be added in the coming weeks as the schedule of speakers and activities are finalized.

November 2022 Water Level Chart Archived

November 2022

I have archived the November water level chart (at left). Our plan at the beginning of the month had been to start dropping the lake to it’s early winter level around 14”-16” below the HWM. November is actually the month with the highest rainfall with an average of 4.58 inches but the first 10 days of the month were rain-free and we really didn’t know what to expect for the rest of the month so we didn’t take any drastic management actions, preferring to let the lake find it’s own happy level. Then the rains started first with a 1.85” rain event on the 11th followed by several more rain storms over the next 5 or 6 days which brought the lake level back up to the top of the dam by the 18th. On the 23rd we pulled the last two stop logs out of the weir and the lake level started dropping again, but two more large rain events towards the end of the month (1 inch on 27th and 1.34 inches on the 30th) brought us to 5.53 inches for the month and despite having opened the gate ¾ of a foot, the lake level rose back up to the top of the dam. We ended the month with a full lake and a full inch above November’s average rainfall. This brings us to 44.29 inches for the year to date, 3.67 inches more than average. Needless to say, the drought is over for this year. Continue reading →

27 September 2022: Cyanobacteria in Clary Lake

Clary Lake is experiencing an algal bloom this fall and today I was met with an unpleasant, but sadly not unexpected site when I walked down to my dock with a cup of coffee, to savor the morning. Dead blue-green algae (cyanobacteria) slowly swirling around my dock like green smoke. We’ve seen reduced lake transparency due to algae growth since late-August, and it’s only gotten worse. I’ve been expecting to see something like this on my shoreline for a while now. I posted about our declining water quality back on September 5th (Clary Water Quality Declining). This current “bloom” covered an area of about 200′ by 600′. Our last official secchi disk measurement taken on September 3rd was 2.38m (7.8 feet). I’ve taken a few additional secchi disk readings since then and they’ve all been in the 2.2m range. After seeing this mess around my dock I went out with my secchi disk and found the transparency to be 2.30m. Back on September 4th a small patch of green was spotted over at the State Boat launch, and I saw just a hint of it, a few wispy tendrils, yesterday when I was out fishing. Here’s a short video I took this morning to show you what it looked like as I headed out in my boat: Continue reading →

05 September 2022: Clary Water Quality Declining :(

You might have noticed that Clary’s water has been getting cloudy. Sadly, it’s not just your imagination! Last Saturday afternoon Kelsie French and I went out for our twice-monthly water quality monitoring session and we recorded a secchi disk reading (a measure of water transparency) of 2.38m (7.8 feet), down from 3.15m (10.33 feet) two weeks earlier. The next day, Dave Knight who was on CBI duty at the State boat launch, took the picture at left and sent it to me. I was not surprised. What the picture shows is dead blue/green algae (cyanobacteria) which floats to the surface where it’s pushed around by wind and waves. Eventually it sinks to the bottom and decomposes. Less than an hour after he took this picture, the green stuff was gone. Technically, an algae bloom is defined as a secchi disk reading of 2m or less, though in my opinion, anything below 3 meters (9.8 feet) puts you in bloom territory and we’ve been there for a few weeks now. A little dead blue/green algae washes up every year and it’s nothing to be too concerned about, but this year we’re likely to see a good deal more than usual in the next few weeks. In other words, our water transparency is likely to deteriorate further before it starts to clear up later this fall. We’ll be taking another water sample for Phosphorus testing in two weeks and will be monitoring lake transparency weekly until this algae growth winds down. Keep an eye on our Water Quality Data page. Continue reading →

Lake Water Quality Monitoring Resumes for 2022

Clary Transparency

Kelsie French and I resumed our water quality monitoring efforts for 2022 on Saturday May 14th, a little later than originally planned due to circumstances which all seemingly conspired to keep us off the lake. We’re back in the saddle now however and plan to visit Clary’s deepest spot to collect data every couple of weeks this season. Continue reading →

September 2021 Water Quality Update

Total Phosphorus Chart

The Total Phosphorus test results from our 8/6/2021 core water sample came back the other day at 0.035 mg/liter, the highest TP value we’ve ever recorded. This is ominous. The next highest value we recorded was 0.034 mg/liter in July 2007 (see chart at left). I don’t remember the particular circumstances surrounding that reading, but there was another high TP reading of 0.032 mg/l more recently, in July 2015 that I do remember. It coincided with a secchi disk reading of only 1.95 meters indicating an algae bloom was in progress (secchi disk readings of 2 meters and below indicate a bloom in progress). You can see this 1.95 meter data point on the chart showing Clary transparency below. In this particular case, extreme low water conditions were a major contributing factor to poor water quality!! I expected a high TP value this time because of the 9″ of rain received in July. Rain means runoff and runoff means soil erosion and sedimentation which is the primary source of Phosphorus in lakes, but still, I was surprised to see such a high number. High phosphorus levels are not good for water quality! We really need to update our Watershed Survey!

Despite the high phosphorus level, we haven’t seen a significant algae bloom yet this summer and we may not, though I did notice a few wisps of dead cyanobacteria along the shoreline back in August, and water transparency is currently holding up nicely: at our last the water monitoring session on Sunday September 5th, Kelsie French and I had secchi disk readings of 3.55 and 3.45 meters respectively which is about average, and better than expected considering the level of phosphorus in the water. Transparency could deteriorate quickly however and we’re going to keep a close eye on it; we will take our 3rd and final water sample for Phosphorus testing during our next water quality monitoring session in a couple of weeks. Continue reading →

12 August 2021: Damariscotta Lake Blooms

Damariscotta Lake has been experiencing considerable cyanobacteria growth in recent years, a troubling condition that affects many lakes in Maine. Some lakes are big enough for these types of events to impact only certain areas, though they can be lake-wide. This particular algal bloom in Damariscotta is in the Mills area. So far this summer I’ve noticed only slightly elevated levels of blue-green algae (cyanobacteria) in Clary as evidenced by faint wisps of dead algae on the water surface and slightly reduced transparency in early August. This is most likely the result of runoff from heavy rains in July. A small amount of algae growth is expected, and is more or less normal. Clary Lake however is by no means immune to severe algae blooms, defined as a transparency of 2 meters or less and while we haven’t experienced a severe bloom since 2014 (see chart at left), it can and will under the right condition happen again. It behooves us to be vigilant and minimize soil erosion on our properties to stop the introduction of sediment and phosphorus into our lake.

Algae Bloom at Damariscotta Mills Potentially Harmful

The Midcoast Conservancy staffer Patricia Nease who is monitoring the Damariscotta Lake bloom spoke at our recent Annual Meeting about the Invasive Plant Patrol program on Damariscotta Lake and things we should consider when starting up an IPP program on Clary Lake.

23 May 2021: Relax, It’s Tree Pollen!

Tree Pollen on Clary Lake

While this looks similar to the end stage of an intense algae bloom, it’s really only plant pollen. One telling difference is the color: this stuff is decidedly yellow whereas dead cyanobacteria is bright green. I suspect it’s pollen from White Pine though I’m not sure. In any case, it’s a natural phenomena and there is no reason to believe pollen has an impact on water quality though for a short time it can impact lake water transparency. While it looks ugly, it is of a short duration and will eventually disperse into the water column and sink. Another difference between pollen and algal blooms is the timing: pollen events happen in the Spring whereas algae blooms are typically a mid-to-late Summer and early Fall phenomena. Here are a couple of pictures of cyanobacteria on my shoreline taken in October of 2013. The color is decidedly different:

The more you know!

02 May 2021: Water Quality Monitoring Resumes for 2021!

46 Years of Secchi Disk Measurements

Kelsie French and I got out on the lake today to start Water Quality Monitoring for the 2021 season, a spring ritual that has been taking place on Clary Lake since 1975. All the data we collect is periodically sent to the Lake Stewards of Maine (formerly the Volunteer Lake Monitor Program) where it is checked for validity and accuracy. My father Stuart Fergusson was the first person to submit secchi disk readings for Clary Lake in 1975. David Hodsdon started accompanying him at about the same time and according to DEP’s Linda Bacon, David took over completely in 1991. For many years David worked solo until Jack Holland joined him around 2001. I got involved in 2013 and Kelsie French, our newest water quality monitor, started in 2018. After 44 years on the lake, David retired after completing the 2019 season and Jack Holland has taken a hiatus from water level monitoring. We hope he resumes sometime soon! Becoming a water quality monitor requires certification by the Lake Stewards of Maine, and periodic recertification. Continue reading →

2020 Water Quality Monitoring Wrap Up

Dead Cyanobacteria

We’re nearing the end of our water quality monitoring season. We’ve conducted 8 water quality monitoring sessions this year (a few less than normal because we got a late start) and will conduct one more session this coming week before calling it quits for the year. Many thanks to my associate Kelsie French for her help this year.

Yesterday afternoon when I walked down to my dock I spotted this dead algae washed up on my shoreline. Fifteen minutes after I took the picture, the green scum was gone. Remnants of an small algae bloom, it’s nothing to be alarmed about and there’s a very good explanation for what it is and why this occurred. Continue reading →

02 January 2020: The Winter 2019 Water Column Issue Is Out

The Winter 2019 Lake Stewards of Maine’s periodical “The Water Column” arrived in our mailbox today. As usual, it’s full of interesting information about the state of lake water quality monitoring in Maine, invasive plant problems around the State, and other issues impacting lakes in Maine.

Last year’s Winter 2018-2019 issue of The Water Column was all about the impact of climate change on Maine lakes, and this winter’s issue continues their coverage of climate change with an interesting article on ice-in and ice-out trends. The Lake Stewards of Maine does a great job of publicizing their activities. The Clary Lake Association has been conducting water quality monitoring on Clary Lake in association with the Lake Stewards of Maine (formerly the Volunteer Lake Monitor Program or VLMP) since 1975 and is a long time supporting member of their organization.

https://www.lakestewardsofmaine.org/mediaresources/the-water-column/

Here’s a link to the full document:

The Water Column Winter 2019

15 October 2019: CLA’s Water Quality Monitoring Team Wraps Up Another Season

We’ve wrapped up another season of water quality monitoring on Clary Lake and took this selfie to celebrate. For David Hodsdon, this completes his 44th year of water quality monitoring (he started in 1975!). For Kelsie French it is her second, and for me, my sixth. Jack Holland also helps out when he can. I think he’s been doing it for close to 20 years. We’ve got a good team doing good work.

Clary’s water quality this past summer was better than what we’ve come to expect in recent years despite a mid-summer high Phosphorus reading of 0.028 mg/liter (the 4th highest we’ve ever recorded). That’s considerably higher than we’d like to see it. The high P sample was likely attributable to the 15″ of rainfall we received in April, May, and June as runoff from rainfall is the primary source for Phosphorus. We did see a small burst of cyanobacteria growth no doubt in response to the high P in the lake water, but it dissipated quickly and didn’t raise any real concerns. The results of our last Phosphorus sample (we take 3 samples per season) taken on September 27th) aren’t back from the lab yet. We’re hoping it shows improvement.

Clary Transparency

The average of 13 transparency readings over the summer was 3.6 meters (11.8 feet) which for Clary is Great! Transparency never fell below 3.15 meters (10.3 feet) and got as high as 4.20 meters (13.8 feet) in early May. You can see on the chart of secchi disk readings at left that overall transparency in 2019 easily bucked the historical downward trend we’ve seen during the years of our water level crisis. We expect our newly restored water level regime will result in good water quality going forward, but we’ve got to remain vigilant. Lakes are fragile ecosystems and many issues can affect water quality.

Here’s a link to our water quality monitoring data going back to the beginning of 2012. Historical data is available upon request:

Clary Lake Water Monitoring Data

18 September 2019: Maine Public Radio Program on Algal Blooms

Scott Williams of Lake Stewards of Maine

There is a new Maine Public program on algal blooms and climate change that is well worth watching (or listening to). Here on Clary we have avoided a severe algal bloom this season though we’ve seen them in the past; we did have a mild, short-lived bloom back in early July, no doubt brought on by a spike in phosphorus levels due to heavy rainfall and the resulting runoff in April, May, and June. While Phosphorus levels have remained high this summer, transparency has remained greater than 3 meters all season. We’ve been fortunate. We are most at risk however in September and October as the lake water “turns over” mixing phosphorus at the bottom of the lake into the upper layers of water where it can feed blue-green algae.

Maine Lakes Expected to see More Intense Algal Blooms