2020 Cynobacteria Testing in Lake Garfield
Lakes, ponds, and other bodies of water have microscopic organisms living in the water. Some of these organisms can be toxic in large quantities to humans, pets, and local wildlife. A particular group of potentially toxic organisms are called cyanobacteria. Cyanobacteria are aquatic bacteria that obtain their energy through photosynthesis (a process of obtaining energy using sunlight). Cyanobacteria are more commonly called “blue-green algae”. There are many different species of cyanobacteria, but not all of them produce toxins. When optimal conditions are in place, the cyanobacteria can grow in large blooms which could be toxic to the body of water. Optimal conditions include warmer temperatures, abundant sunlight, more intense rainfall, pollution from human activities and plentiful nutrients such as nitrogen and phosphorus.
Last summer, samples were taken by the guidelines of the EPA and its Cyanobacteria Monitoring Collaborative Program on Lake Garfield and Lake Buel. The samples were frozen and sent for analysis to the EPA and the data was added to the regional data of the EPA program. Each sample before it was frozen was analyzed for phycocyanin (blue-green pigment emitted by cyanobacteria). Last summer’s testing also gave an idea of what genus’s are in the lake and at what time of the year. We have a base line data set to compare this summer’s results too. At the end of the summer, the data was presented at the LAPA West Symposium and later at Westfield State University Conference. (See Poster Below for all last summer’s data or view a downloadable PDF).
For summer 2020, the plan is to conduct cell counts to provide a quantitative reading on the genus’s present in the lake along with the phycocyanin readings and samples being sent to the EPA. Testing will be conducted every two weeks until August where it will be once a week because it is the optimal time of the year for blooms. The states threshold for unsafe levels for recreational use of the lake are 70,000 cells/mL of cyanobacteria. Every citizen can participate in the monitoring by watching the lake for any sign of blooms (anything abnormal on the surface and/or water column) and letting us know so we can test it.
June 22, 2020
On June 22, 2020, a sample was taken at the Big Bowl. The phycocyanin levels were at 0.10 parts per billion which is extremely low. The cell counts were 23 cells/mL of Dolichospermum, 180 cells/mL of Aphanizomenon, and 146 cells/mL of Microcystis. All three have the potential for being toxic. For a total of 349 cells/mL which is not anywhere close to the states recommended threshold for closure at 70,000 cells/mL.
Compared to this time last summer the phycocyanin levels are much less as there was a reading of 25.38 parts per billion. However, it was raining at the time of sampling and we had a lot more rainfall in June 2019 then we have had this June. Of a bit of concern is that the lakes water temperature is a lot warmer at this time than last year. We are seeing temperatures that we saw in August of 2019.
As part of the monitoring efforts, we are going to start measuring dissolved oxygen levels using a specialized sensor and water transparency or turbidity using a Secchi disk.
July 6, 2020
On July 6, 2020, a sample was taken at the Big Bowl. The phycocyanin levels were at 0.10 parts per billion which is extremely low. The phycocyanin levels were at 0.10 parts per billion which is extremely low. The cell counts were 216 cells/mL of Microcystis, 60 cells/mL of Aphanizomenon, and 20 cells/mL of Dolichospermum for a total of 296 cells/mL.
Compared to last year the results are the same as last year and that the cyanobacteria levels are low.
New to the sampling procedure is testing the temperature and dissolved oxygen (mg/l) from 1 to 25 feet. The oxygen steadily increased to 15 feet deep then decreased by half at 20 feet. Then dropped below 1 mg/l. The secchi depth was 12.5 feet meaning the water was pretty clear. In the next sampling, a sample will be taken at 15 feet for a cell count as the dissolved oxygen is higher than at the surface.
Figure 1. Estimated lake stratification.
July 20, 2020
On July 20, 2020, two samples were taken one at the surface in the big bowl and the other at 15 feet in the big bowl. The phycocyanin levels were at 0.10 parts per billion which is extremely low from both samples. The cell counts were 390 cells/mL of Microcystis, 146 cells/mL of Aphanizomenon, and 212 cells/mL of Dolichospermum for a total of 748 cells/mL at the surface. The cell counts at 15 feet were 106 cells/mL of Microcystis, 892 cells/mL of Aphanizomenon, and 504 cells/mL of Dolichospermum for a total of 1,502 cells/mL from the sample at 15 feet. The cell count at the surface has increased from two weeks ago.
Compared to last year the results are the same as last year and that the cyanobacteria levels are low.
New to the sampling procedure is testing the temperature and dissolved oxygen (mg/l) from 1 to 25 feet. The oxygen steadily increased to 15 feet deep then decreased by half at 20 feet. Then dropped below 1 mg/l. The secchi depth was 12.3 feet meaning the water was pretty clear.
Figure 1. Estimated Lake Stratification
August 3, 2020
On August 3, 2020, two samples were taken one at the surface in the big bowl and the other at 15 feet in the big bowl. The phycocyanin levels were at 0.10 parts per billion which is extremely low for the surface sample and 13.54 parts per billion for the 15-foot sample. The cell counts were 346 cells/mL of Microcystis at the surface. The cell counts at 15 feet was 1,432 cells/mL of Microcystis and 284 cells/mL of Dolichospermum for a total of 1,716 cells/mL. The cell counts have increased from two weeks ago. However, this sample was taken before the tropical storm and I have found in the other lakes tested after the storm that the cell counts have gone down after the storm. I suspect the same case of Lake Buel. I will be going out either Wednesday or Friday to collect samples.
Compared to last year the results are the same as last year and that the cyanobacteria levels are low.
New to the sampling procedure is testing the temperature and dissolved oxygen (mg/l) from 1 to 25 feet. The oxygen steadily increased to 15 feet deep then decreased by half at 20 feet. Then dropped below 1 mg/l. I took a sample at 15 feet because the dissolved oxygen levels are increased and is a good indication that cyanobacteria are in the area as they can photosynthesize. The secchi depth was 11.2 feet meaning the water was pretty clear.
Figure 1. Estimated Lake Stratification
August 12, 2020
On August 12, 2020, two samples were taken one at the surface in the big bowl and the other at approximately 4.5 meters in the big bowl. The phycocyanin levels were at 0.10 parts per billion for both samples which is extremely low. This has decreased from the sample taken on the August 3rd. The cell counts were 110 cells/mL of Microcystis, 70 cells/mL of Dolichospermum, and 110 cells/mL of Limnoraphis at the surface for a total of 290 cells/mL. The cell counts at 4.5 meters was 60 cells/mL of Limnoraphis and 780 cells/mL of Dolichospermum for a total of 840 cells/mL. The cell counts have decreased from a week ago.
Compared to last year the results are the same as last year and that the cyanobacteria levels are low.
New to the sampling procedure is testing the temperature and dissolved oxygen (mg/l) from 0.30 to 10.7 meters. The oxygen steadily increased to 4.5 meters deep then decreased by half at 6 meters. Then dropped below 1 mg/l. I took a sample at 4.5 meters because the dissolved oxygen levels are increased and is a good indication that cyanobacteria are in the area as they can photosynthesize. The secchi depth was 11.4 feet or 3.5 meters meaning the water was pretty clear.
Figure 1. Estimated Lake Stratification
August 19, 2020
On August 19, 2020, two samples were taken one at the surface in the big bowl and the other at approximately 4.5 meters in the big bowl. The phycocyanin levels were at 0.10 parts per billion for the surface sample which is extremely low. However, at 4.5 meters the phycocyanin levels were 11.41 cells/mL. This has increased from the sample taken on the August 12th. The cell counts were 480 cells/mL of Microcystis, 56 cells/mL of Dolichospermum, and 210 cells/mL of Aphanizomenon at the surface for a total of 746 cells/mL. The cell counts at 4.5 meters was 1,300 cells/mL of Microcystis, 768 cells/mL of Dolichospermum, and 780 cells/mL of Aphanizomenon for a total of 3,848 cells/mL. The cell counts have increased from a week ago and Limnoraphis has disappeared while Aphanizomenon has reappeared.
Compared to last year the results are the same as last year and that the cyanobacteria levels are low at the surface.
New to the sampling procedure is testing the temperature and dissolved oxygen (mg/l) from 0.30 to 10.7 meters. The oxygen steadily decreased to 4.5 meters deep then decreased by half at 6 meters. Then dropped below 1 mg/l. The secchi depth was 13.5 feet or 4.1 meters meaning the water was pretty clear and has increased from August 12th. The surface temperature has decreases by 3 degrees Celsius since August 12th.
Figure 1. Estimated Lake Stratification
August 24, 2020
On August 24, 2020, two samples were taken one at the surface in the big bowl and the other at approximately 4.5 meters in the big bowl. The phycocyanin levels were at 0.10 parts per billion for the surface sample which is extremely low. However, at 4.5 meters the phycocyanin levels were 7.48 cells/mL. This has decreased from the sample taken on the August 19th. The cell counts were 40 cells/mL of Microcystis and 120 cells/mL of Aphanizomenon at the surface for a total of 160 cells/mL. The cell counts at 4.5 meters was 1,540 cells/mL of Microcystis, 1,000 cells/mL of Dolichospermum, and 360 cells/mL of Aphanizomenon for a total of 2,900 cells/mL. The cell counts have decreased from a week ago.
Compared to last year the results are the same as last year and that the cyanobacteria levels are low at the surface.
New to the sampling procedure is testing the temperature and dissolved oxygen (mg/l) from 0.30 to 10.7 meters. The oxygen steadily decreased to 4.5 meters deep then decreased at 6 meters. Then dropped below 2 mg/l. The secchi depth was 13.1 feet or 3.9 meters meaning the water was pretty clear and has decreased from August 19th.
Figure 1. Estimated Lake Stratification
September 3, 2020
On September 3, 2020, two samples were taken one at the surface in the big bowl and the other at approximately 4.5 meters in the big bowl. The phycocyanin levels were at 3.88 parts per billion for the surface sample and streams of green was on the surface. However, at 4.5 meters the phycocyanin levels were 0.1 parts per billion. The cell counts were 2,532 cells/mL of Microcystis and 288 cells/mL of Dolichospermum at the surface for a total of 2,820 cells/mL. The cell counts at 4.5 meters was 920 cells/mL of Microcystis, 660 cells/mL of Dolichospermum, and 200 cells/mL of Aphanizomenon for a total of 1,780 cells/mL. The cell counts have decreased from a week ago at 4.5 meters but have increased at the surface.
Compared to last year the results are different this year, the green streams on the surface were not seen last year.
The temperature and dissolved oxygen (mg/l) were collected from 0.30 to 10.7 meters. The oxygen steadily decreased to 5 meters deep. Then dropped below 2 mg/l at 6 meters. The secchi depth was 10.3 feet/3.2 meters meaning the water was pretty clear but has been decreasing in clarity.
Figure 1. Estimated Lake Stratification
September 9, 2020
On September 9, 2020, two samples were taken one at the surface in the big bowl and the other at approximately 4.5 meters in the big bowl. The phycocyanin levels were at 0.1 parts per billion for both samples. The cell counts were 270 cells/mL of Aphanizomenon and 70 cells/mL of Dolichospermum at the surface for a total of 340 cells/mL. The cell counts at 4.5 meters 100 cells/mL of Dolichospermum, and 240 cells/mL of Aphanizomenon for a total of 340 cells/mL. The cell counts have decreased from a week ago at the surface and Microcystis was not present this week.
Compared to last year the results are the same. However, the lake is 2 degrees warmer than last year at this time.
The temperature and dissolved oxygen (mg/l) were collected from 0.30 to 10.7 meters. The oxygen steadily decreased to 5 meters deep. Then dropped below 2 mg/l at 6 meters. According to the data the lake has begun its turnover with the metalimnion or thermocline disappearing. The secchi depth was 11.1 feet/3.4 meters. The secchi depth has increased from last week by almost a foot.
Figure 1. Estimated Lake Stratification
Taxa abrevation as follows:
Doli=dolichospermum
Micro=Microcystis
Apha=amphazamenon
Limn=Limnoraphis
Woro=woronichinia