Clear Lake, located in California, is one of the key monitored lakes in North America, where harmful algal blooms are a serious issue. In order to better understand the reasons for the massive growth of algae in the lake, researchers from the University of Southern California in Los Angeles and the Southern California Coastal Water Research Institute (SCCWRP) have chosen products from the Thermo YSI brand, which can monitor lakes and capture data on water depth, quality, and temperature, providing high-resolution algal bloom data for researchers.

Although algae are the origin of green life on Earth, releasing about 50% of the oxygen in the atmosphere, when these algae grow uncontrollably, they can form harmful algal blooms, posing a serious threat to surface water quality. Harmful algal blooms have a wide range of effects, from affecting the taste and odor of drinking water to producing toxins that may cause illness in animals and humans.

There are many types of algae that can produce toxins, and each type of algae can adapt to different environmental conditions with strong vitality. The causes of harmful algal blooms include excessive nutrients in water, especially nitrogen and phosphorus. In addition, the temperature rise caused by climate change also provides conditions for the growth of algae that produce toxins.

Encountering numerous challenges in studying harmful algal blooms in Lake Clearwater

Clearwater Lake is one of the largest freshwater lakes in California, with an area of 27.4 square kilometers. It has a history of approximately 2.5 million years and is also one of the oldest lakes in North America. Harmful algal blooms are one of the most concerning issues for the Clearwater community, as 18 drinking water companies use the lake as a water source to supply water to over 40000 residents.

Scientists know that the appearance of harmful algal blooms here may be the result of temperature and eutrophication, where nutrient rich fertilizers flow into the lake, causing excessive growth of plants and algae. Researchers want to have a deeper understanding of algal blooms, but unfortunately, the data provided by discrete samples is limited, and Lake Clearwater is composed of three forks with different characteristics, making the situation quite complex.

Although discrete samples provide important information about the lake at specific locations and times, researchers still need to understand the physical structure of the lake and the impact of changes in water depth (water column) on algal blooms.

Using innovative technologies to conduct new research

A recent research project conducted at Lake Clearwater aims to address some of these challenges using Thermo Fisher's YSI technology. One key objective is to link new data on water column and environmental parameters with other data collected from discrete water samples.

The researcher of the project, Dr. David Caron from the University of Southern California, wrote, "If we can connect these different pieces of information through space and time, we can obtain first-hand information about the species succession and nutrient interactions of plankton in Lake Clearwater

The area of Lake Krier is so large that it is not easy to connect all the data of the lake, but it is crucial for understanding the biological processes that cause algal blooms and toxins. The study also aims to assist researchers in determining where to collect discrete samples, a process that incurs significant costs.

Researchers collaborated with Selemer to use the YSI integrated solution to map harmful algal blooms in lakes, resulting in high-resolution maps of water quality, flow, and depth. Simultaneously utilizing YSI's EXO platform, it is an intelligent and field applied water quality monitoring system.

Research on Lake Water from Two Different Scales

The researchers conducted this study to monitor lakes from two distinct spatial scales. The first scale is taken along the main axis of the three forks of Lake Clearer to grasp the overall characteristics of the lake water. The second scale is to conduct high-resolution mapping of a portion of Xiahucha Bay, with the aim of gaining a detailed understanding of the distribution of blue-green algae (cyanobacteria) and their toxins.

Equipping during the research processYSI EXO1 detectorEquipped with sensors for measuring conductivity/temperature, total algae count, dissolved oxygen, and pH value. When the spacecraft moves vertically at different depths, the measurement data obtained can be used to construct a 2D water column map.

I have gained a brand new understanding of Lake Clearwater

The solution provided by YSI, a brand under Thermo Fisher, has given researchers a better understanding of the water column structure of the lake, enabling them to propose testable hypotheses about the factors leading to harmful algal blooms in the lake.

The data obtained throughout the entire lake also provides important information on where and how to utilize limited resources to select sampling points. The subsequent task is to add these data to the dataset in order to further understand the relationship between water quality and the algal blooms in Lake Clearwater.