Community Manager's Report

I have had many comments and questions concerning the activity on our lake over the past few weeks, so I am going to review what has taken place.

Since Thanksgiving, we have had two golden algae blooms. We caught both very early and treated the lake quickly. There was a fish loss and we worked diligently through the holidays to remove the dead fish.

We were not alone with these blooms. During this same time period, twenty-five other lakes in the metropolitan Phoenix area reported fish kills attributed to golden algae.

I want to share some information about golden algae from the Texas Parks and Wildlife Department where the first golden algae fish kill was reported in 1985. The Lakes had its first outbreak of golden algae in 2005. It is believed that every state in the western US has some occurrence of golden algae today.

What is golden algae?

Golden algae (Prymnesium parvum) is a microscopic, single-celled species of algae. It occurs worldwide and can live in a wide range of water temperatures and salinities. It has a complex life cycle and can form resting cysts at the bottom of a lake which can later bloom when conditions are favorable: cool water and minimal competition from other algae species. When the algae grows and the cysts burst, they give off a toxin that is harmful to fish.

How does it harm fish?

Some organisms have protective layers to prevent the attack of golden algae toxins, but the exposed cells on fish gills and fins are not so protected. Toxins attack the outside layer of cells, then the next layer is affected, and so on. Soon the gills are so badly damaged that they are unable to function. Fish behave as if there is not enough oxygen in the water. They swim at the top of the water surface or rest on the bottom in edges and shallow areas until they die.

What triggers toxic blooms?

The dynamics of bloom formation still aren't well understood. Golden algae can live in a water body for months, even years, without causing a fish kill. Scientists suspect that a number of factors — temperature, water chemistry — combine to give golden algae an advantage over other plankton species and lead to a population explosion.

Can fish kills be predicted?

Golden algae cells are quite small, but they can be viewed with a microscope. When biologists examine water samples, they look for two indicators: the number of golden algae cells in a given volume of water, and the percentage of golden algae in comparison to other microorganisms. However, cell counts don't always correlate with toxicity, and a fish kill may not result even when golden algae becomes dominant.

Does it affect other animals?

Golden algae toxins appear to have no lethal effect on non-gill breathing organisms.

We have monthly testing for the health of our lake by our water consultant, Dr. Rick Amalfi from Aquatic Consultants, Inc. His company not only takes care of our lake but the majority of the lakes in the Phoenix area, including Tempe Town Lake.

If you would like to learn more about golden algae and the health of our lake, plan on attending our next regularly scheduled board meeting on Wednesday, January 24 at 7 PM in the Lakes Beach and Tennis Club. Dr. Amalfi will be present to discuss golden algae and take questions.

I hope to see you at the meeting.

As always, if you have any questions or concerns, please feel free to call me at 480-838-1023.

Christine

Community Manager's Report

Christine Baldanza

January 2018