Why is algae monitoring important?
Due to the increase in atmospheric carbon dioxide (CO2) and its effect on climate change, the occurrences and durations of nuisance algae growth and Harmful Algae Blooms (HAB) are expected to increase during the coming years. Algae that was once limited in distribution to tropical and subtropical environments are now moving further northward. This movement can cause shifts in local North American water bodies, causing disruptions in lake and marine ecosystems by affecting trophic food webs, and can pose public health related problems due to toxin production. The need for expanding local, state and national algae monitoring programs along with accessing acute bloom events is therefore becoming a necessity.
Algae, a vital group of bacteria and plants in aquatic ecosystems, are an important component of biological monitoring programs for evaluating water quality. They are suited to water quality assessment because of their nutrient needs, rapid reproduction rate, and very short life cycle.
Algae are valuable indicators of ecosystem conditions because they respond quickly both in species composition and densities to a wide range of water conditions due to changes in water chemistry.
However, when N:P ratios are high, chlorophytes (green algae and flagellates), along with diatoms, are often the dominant genera. In the various Palmer genus indices, groups of green algae and diatom genera are separated into categories that reflect different trophic conditions. These categories include clean water algae, nuisance algae that can clog the screens of intake pipes from drinking water reservoirs, and algae that affect the water’s taste and odor. Another group of algae is associated with municipal sewage treatment plants and is present in large densities in sewage stabilization ponds (lagoons).
Microscopic algae are common in marine coastal waters, fjords and bays. Being primary producers, they are a vital part of the marine food web. But when their populations increase quickly they form blooms that can change the color of the water, commonly referred to as red tides. Often these bloom situations are associated with toxin producing genera that can kill fish, shellfish, marine mammals and birds. Toxin producing blooms may directly cause illness in humans when contaminated shellfish are eaten or indirectly by breathing aerosolized toxins during recreational beach activities. As a consequence, bloom events adversely affect commercial and recreational fishing, tourism, and valued habitats, creating a significant impact on local economies and the livelihood of residents.
Blooms of non-toxic marine algae can also impact the health of marine ecosystems. Spine forming diatoms can clog the gills of fish resulting in respiratory failure and interfere with zooplankton feeding mechanisms. Dense blooms of algae can significantly reduce the light penetration in the water column impacting the survival of marine plants that depend on the sunlight for photosynthesis. Also decomposing algal cells which sink to the bottom of water bodies and are consumed by bacteria can contribute to anoxic conditions resulting in benthic dead zones and the loss of marine life.
NAL also offers various services for monitoring algae in marine environments. See our Analytical Services.