National Oceanic and Atmospheric Administration (NOAA) predicts more harmful blooms in the Pacific Ocean. They have been increasing in size and frequency worldwide, a fact that many experts attribute to global climate change. HABs can cause significant harm to animals, the environment and economies. Higher water temperature and low circulation also contribute. The excess nutrients are emitted by agriculture, industrial pollution, excessive fertilizer use in urban/suburban areas, and associated urban runoff. The two most common nutrients are fixed nitrogen ( nitrates, ammonia, and urea) and phosphate. HABs are induced by eutrophication, which is an overabundance of nutrients in the water.
SECOND EXTINCTION NEUROTOXIC SLIME DRIVERS
In certain locations there are links to particular drivers like nutrients, but HABs have also been occurring since before humans started to affect the environment. It is sometimes unclear what causes specific HABs as their occurrence in some locations appears to be entirely natural, while in others they appear to be a result of human activities. Harmful algal blooms in marine environments are often called "red tides". When these zones cover a large area for an extended period of time, neither fish nor plants are able to survive.
After the bloom dies, the microbes that decompose the dead algae use up more of the oxygen, generating a " dead zone" which can cause fish die-offs. Blooms can last from a few days to many months. HABs are sometimes defined as only those algal blooms that produce toxins, and sometimes as any algal bloom that can result in severely lower oxygen levels in natural waters, killing organisms in marine or fresh waters. These kinds of algae can cause harmful algal blooms.Ī harmful algal bloom ( HAB) (or excessive algae growth) is an algal bloom that causes negative impacts to other organisms by production of natural algae-produced toxins, mechanical damage to other organisms, or by other means. Cyanobacteria (blue-green algae) bloom on Lake Erie (United States) in 2009.
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