HAB Identification
HAB stands for Harmful Algae Bloom. Here are some pictures of cyanobacteria (green blue algae) blooms. These blooms are potentially harmful. If you see an algae bloom on your shoreline that looks like the above photo, avoid contact with the water (including pets) and please report it to EGLE by email at: algaebloom@michigan.gov or by phone at: 800-662-9278. Also, please add your sighting to Eyes on the Lake by clicking HERE.
REGIONAL HEALTH DEPARTMENT ADVISORY REGARDING TOXIC ALGAE BLOOMS ON BLACK LAKE
The following report describes how to respond safely to a bloom.
FACTORS THAT LIKELY CONTRIBUTE TO HABS ON BLACK LAKE
The EGLE report provided below contains a lot of detail that you may like to understand about how we have come to experience HABs on our lake. The report cites the sources for the suggested causes listed below. In summary, the following factors have likely contributed to the problem. As we learn more, we will formulate a broad range of remedial actions.
- The frequency, magnitude, and intensity of HABs is increasing worldwide, and given future climate scenarios coupled with more intensive agricultural practices worldwide, HABs are only expected to get worse. The problem is not unique to Black Lake.
- Following canine deaths from cyanobacteria in several states, there has been intense, nationwide media coverage of the cases. So, there has been increased emphasis on reporting blooms and this has contributed to a rapid rise in reported HABs.
- In general, confirmed cyanobacterial blooms were more prevalent in the southern Lower Peninsula of Michigan, which is the most populated area of the state and contains more agricultural areas. Black Lake is a rare case in the northern Lower Peninsula.
- Whether an algae bloom produces microcystin is dependent on whether the lake possess the toxin-producing genotypes or not. In Michigan, cyanobacterial populations are genetically diverse both between lakes, and within lake populations. We appear to be a bit unlucky.
- Each residential lake dwelling can contribute nutrients to the water body via lawn fertilizer, pet waste, loss of natural shoreline buffers, and poorly performing septic systems
- Zebra mussels contribute to the problem by selectively feeding on "good" algae and leaving a hole in the ecosystem for the "bad" algae.
- Agricultural nutrient runoff has been recognized as a contributing factor to cyanobacteria blooms, Increased dissolved reactive phosphorus loading via field tile drainage pipes has been cited as one of the main causes of cyanobacteria blooms in water bodies that are surrounded by agricultural land use. We don't have heavy agriculture in our watershed, but we do have some.
- Most of the lakes that had confirmed cyanobacteria blooms in the northern Lower Peninsula have dams that elevate the water level. The high lake levels that we experience during the spring thaw are likely a contributor by raising the water water level and causing shoreline erosion and reducing the infiltration capacity of septic drain fields.
- With larger watersheds, more nutrients are likely to flow into the receiving water bodies, thus increasing the chances for cyanobacteria blooms. The ratio of our watershed (350,000 acres) to our lake surface area (10,000) acres is considered very high.
- Shallow lakes coupled with nutrient-rich sediment are prone to nutrient resuspension into the water column as a result of physical disturbances such as wind. Our lake is shallow and has a very shallow shelf around the perimeter that frequently offers calm areas of warm water that is conducive to cyanobacteria growth
EGLE REPORT OF HAB ACTIVITY IN MIGHIGAN FROM 2016-2019
WHAT IS THE BLPS DOING ABOUT THIS PROBLEM
The BLPS believes that a community-wide response is required to respond to our problem with HABs. We have initiated efforts to form a consortium of organization to combine our resources and influence to address the root causes. More information will be forthcoming over the 2020/2021 winter. The response will be a mix of short term and long term measures and will involve a long list of contributors.