Project Overview

lake stratification NexSens CB-450 data buoyAfter algal blooms and other environmental stressors reduced water clarity on Maine’s Highland Lake, the Lakes Environmental Association launched a data buoy to study the water body’s health. The launch was made possible by an anonymous grant to the LEA.

The association tests water quality on many lakes throughout the state, and hoped that the supportive community living around Highland Lake would likely chip in to make its operation a success. After the buoy launched in early 2014, community members added donations to cover additional oxygen sensors for the monitoring platform.

With the new sensors, researchers looked to learn if waters at the bottom of Highland Lake were becoming anoxic, a small piece to the larger stratification puzzle they were trying to solve. If lake stratification was found to break down, especially in the summer, researchers hypothesized that recycled phosphorus might be making its way back to the surface where it could fuel algae growth.

System Description

Highland Lake stratificationA NexSens Technology CB-450 data buoy gave researchers the platform they needed to monitor Highland Lake. Built with durable cross-linked foam and a stainless steel cage, the CB-450 supported various sensors used for studying lake stratification.

PONSEL Optical Dissolved Oxygen Sensors were deployed in a string below the buoy, tracking changes in oxygen levels as well as temperature differences. These combined with a Turner Designs Cyclops-7 Chlorophyll Sensor to take chlorophyll measurements, which can be used as an indicator of lake turnover and aid in the prediction of algae growth.

LI-COR LI-190 and LI-192 PAR sensors revealed the role that photosynthetically active radiation plays underwater as well as above the surface of Highland Lake. And by using a Hydro-Wiper from Zebra-Tech, scientists made sure underwater PAR readings weren’t impacted by biofouling.

All sensor data were logged to a NexSens iSIC data logger installed within the buoy. Equipped with cellular telemetry, the buoy transmitted data wirelessly to project computers running iChart software, allowing researchers to monitor water quality trends in real time. Data collected during the buoy’s first monitoring season have shown that Highland Lake is quick to stratify. But scientists have also learned that the lake’s layers are quick to break down, with temperatures changing earlier in the year than previously thought.

Equipment

NexSens CB-450 Data Buoy

The NexSens CB-450 Data Buoy is designed for deployment in lakes, rivers, coastal waters, harbors, estuaries and other freshwater or marine environments.


LI-COR LI-190 PAR Sensor

The LI-COR LI-190 PAR Sensor accurately measures photosynthetically active radiation (PAR).


LI-COR LI-192 Underwater PAR Sensor

The LI-COR LI-192 Underwater PAR Sensor Quantum sensor accurately measures photosynthetically active radiation (PAR) in freshwater or saltwater environments.


Turner Designs Cyclops-7 Submersible Sensors

The Cyclops-7 submersible sensor is a high performance and compact fluorometer designed for integration into any platform that supplies power and data logging.


PONSEL DIGISENS Optical Dissolved Oxygen Sensor

The PONSEL optical dissolved oxygen sensor uses luminescence to determine dissolved oxygen levels and output data in a digital format.