Algae

Algae are always present in our lakes.  The amount of algae is generally dependent upon nutrients, light, temperature, and to some degree predators.  Of these, the only lever we can control is nutrients – we need to reduce nutrients (phosphorus) to reduce algae.  Algae are the base of the lake food web, so if we didn’t have some algae, we wouldn’t have fish. Globally, algae are also an important source of oxygen – it’s estimated that half of the oxygen on earth comes from algae.  Many different kinds of algae exist – green, golden, filamentous, diatoms and more.  When algae are dense in a lake, we call it an algae bloom or algal bloom.  Blue-green algae, although sometimes lumped in with algae, are actually a cyanobacteria – a bacteria that can photosynthesize – quite amazing!

Harmful algal blooms

Some algae can make toxins that can be harmful to humans, and when toxins are present, it is called a harmful algal bloom, or HAB.  HABs are associated with cyanobacteria, but not all cyanobacteria produce toxins, and it is unlikely any produce toxins all the time.  Scientists are trying to find out what makes them “turn on” or “turn off” toxin production.  HABs are happening more often around the world, both in marine and freshwater, perhaps because of global warming.

Three Lakes Council routinely assesses our lake waters during the summer as part of the CSLAP sampling programs.  This feeds the NYHABS website that provides notification of HAB blooms.  We don’t visit every shore, and the CSLAP program is only every two weeks during the summer. So while we will try to notify those on our google group, we may not see every event.  Stay alert for blooms.

What should you do?

If in doubt, stay out.  If you see a scum on the surface of your lake that looks like green paint or any of the blooms shown below, avoid activities that put you in contact with that water.

Pets may ingest algae.  If your pets get in the water, they can ingest the algae when grooming, so rinse them off with clean water.

NYS DEC identifies suspected cyanobacteria blooms by appearance, but that will not tell if toxins are present. Take sensible precautions.  If you see a bloom and you want feedback, contact us at ThreeLakesCouncil@gmail.com

NYS DEC has adopted a visual assessment approach to Harmful Algal Blooms (HABs).  Since sample analysis takes time and is not always conclusive, they now rely only on visual appearance. If a cyanobacteria bloom occurs it can produce toxins. So the DEC  behaves as if it does produce toxins, and tells people to avoid contact with the bloom.

Know what a cyanobacteria bloom looks like. Descriptions of cyanobacteria blooms include streaks on the water surface, spilled paint, and pea green soup.

HABS photographs

Here are photographs that were taken on our lakes to help you identify blooms.

 

 

 

 

 

 

 

 

 

 

 

 

 

Also see the plankton page for more information about the algae and zooplankton in our lakes.

Additional Resources:

Plankton – this page will have links to recent phytoplankton and zooplankton reports

USGS Algae Identification Guide

DEC HAB page and DEC HAB notification page.

EPA page on harmful algal blooms

A 3LC presentation on Goop and Zoop (algae and zooplankton)