It is well known that blue-green algae (cyanobacteria) releases toxins over its life cycle however most of the work has focused on the cyanobacteria that live in the water column (planktonic). A recently published journal paper, in Water Research, looked at a number of filamentous benthic (sediment dwelling) cyanobacteria including Anabaena (benthic form), Limnothrix, Lyngbya, and Pseudoanabaena to see if they also produce toxins.
Benthic algal samples were taken from 3 different Australian drinking water reservoirs. A number of tests were carried out to assess the toxin production of the algae. The research showed that benthic cyanobacteria can produce toxins; like their planktonic counterparts. Some of the algae collected from the reservoirs were found to produce toxins (hepatotoxin) which can damage the liver.
This study highlights the importance of including inputs from the benthic environment when designing water quality monitoring programs, particularly in drinking water reservoirs. When all elements of the aquatic system are considered, there is a better understanding of how to treat the water body for improved water quality. In this situation, Phoslock can be used to bind the food source (phosphate) before benthic algae grows and proliferates in the reservoir. Phoslock can be used as a management tool to inhibit the growth of benthic cyanobacteria in reservoirs and the release of harmful toxins in the water.
More information on this research can be found at: http://www.sciencedirect.com/science/article/pii/S0043135417306462?dgcid=raven_sd_aip_email