Cyanos Activity May 8, 2018
Water is clean for recreation.
Disclaimer: The information presented below reflects conditions throughout the lake and may differ from conditions on specific shorelines. For information regarding beach closings please contact the Torrington Area Health District or local town officials.
Two cyanobacteria genera, Woronichinia spp. and Coelosphaerium spp., were
detected in the concentrated plankton net tow-samples. Woronichinia spp. was
also detected in the whole water samples at the Center Lake Site in very low
concentrations of approximately 177cells/mL. As observed on April 22nd, the
May 8th phytoplankton flora in the whole water sample from the North Bay Site
was largely comprised of golden algae (Chrysophyta) and diatoms (Bacillariophyta)
at 74 and 21% of the pelagic community, respectively. At the Center
Lake Site, golden algae constituted nearly 92% of the flora and Uroglenopsis
spp. comprised almost all of that at 7,300cells/mL.
Secchi transparency was measured at 2.81m and 2.48m at the North Bay and
Center Lake Sites, respectively. One of the additional sites where profile and
Secchi data were also collected yielded a value of 3.34m. Passing cumulus
clouds could have contributed to the variability of Secchi transparencies measured
on May 8th.
Surface water temperatures more than doubled since April 22nd. Surface water
temperatures ranged from 15.8 to 16.7°C. The water column began to show
signs of stratification. On April 22nd differences in temperatures from top to
bottom at all four sites was <1°C. On May 8th temperature differences from top
to bottom ranged from 2.5 to 4.6°C with sites of greater total depth exhibiting
the biggest differences in temperature from top to bottom.
Oxygen profiles revealed biologically sufficient levels (>5mg/L) at all depths and
sites. Unlike that observed on April 22nd when oxygen levels from top to bottom
were within 1mg/L of each other, oxygen levels at the bottom on May 8th
were 1 to 2mg/L less than that measured at the surface.
Similar to the April 22nd observation, specific conductance of the surface waters
(1m depth) at the North Bay Site on May 8th was slightly different compared to
that of the surface waters at other sites. At the North Bay Site specific conductance
was measured at 192µS/cm while at the other sites exhibited values between
185 and 187µS/cm.
Data is collected and analyzed by Aquatic Ecosystem Research, who is contracted by Bantam Lake Protective Association.
