Can someone explain Algae Bloom to me? What is it and what benefits does it have?

Thanks.

Ron

Algae bloom is produced by microscopic sized algae that reproduce abundantly to a point it starts to impart color to the water; usu a green tint, but not always. Clear water has low numbers of microalgae usu. due to low nutrients. Excessive algae reproduction "bloom" is usually caused by overabundant nutrients in the water. These microalgae are able to stay suspended up in the water column and are called PHYTOPLANKTON. These algae are the next step larger than bacteria.

Hundreds of different types or species of microalgae can produce a bloom. Many of the types respond to specific or different nutrient levels and environmental conditions. These algae can be single cells or single cells grouped together to form a colony which are sometimes visible with your unaided eye when the water is examined closely or it is put in a clear glass container.

These microalgae contain oils, proteins, starches & vitamins and are food to tiny animals who also live up in the water column. These suspended animals are called ZOOPLANKTON. Most of these animals collect the phytoplankton by straining the algae out of the water. Some of the smallest zooplankton (protozoans) capture microalgae & bacteria one at a time. Zooplankton are eaten by all newly hatched fish. When the fish grow larger they start feeding on larger food items. Some fish live on zooplankton most of their lives. Adult bgill have the ability at times to graze extensively on larger sized zooplankton. Paddlefish and gizzard shad live primarily on zooplankton.

Obviously the more nutrients a pond has the more phytoplnakton it grows, which in turn feeds more zooplankton, which in turn feeds more fish. This whole process is termed production.

A secondary benefit of an algae bloom is it can tint the water and shade or filter out surface light so it does not reach the bottom and does not allow rooted plant growth.

An algae bloom can become so abundant that it consumes all the nutrients from the water column and all the algae starves and dies. When all the algae dies at once it starts to decay and the decay from bacteria can consume enough oxygen from the water to cause fish to suffocate (fish kill). Fish kills can also occur by other means.

Bill,

Thanks for your detailed explanation of algae bloom. It sounds like I need some algae but a bloom our excessive algae could be detrimental to the pond.

How do I prevent or control the excessive algae? Would aeration help?

Ron

Overabundant algae blooms or blooms caused by problematic, noxious or toxic species of algae can be bad. Not all blooms are bad if your GOAL is high pond productivity and abundant fish biomass. Many of the readers here fertilize ponds to produce algae blooms. Algae blooms are diffciult or tricky to properly manage on a continual, long term basis.

Excessive algae or blooms is best controlled by nutrient reduction or control. Nutrient control is key to this problem. Reduce the food for the algae and it does not grow very abundantly.

Aeration can help with certain types of nutrient production from decay within a stratified pond. Outside / external nutrient sources have to be controlled on the watershed.

A few, but by no means all, bacterial additions or microb/ enzyme suppliments have bacterial strains that consume nutrients faster than algae. These have helped control blooms or mild phytoplankton outbreaks for some pondowners.

I personally use native vegetation (emergant & submerged) with "controls" to consume nutrients and compete with planktonic algae.

Alternatively use algaecides.