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Fish die-offs at Tempe Town Lake caused by weather and golden algae

Post Date:01/10/2020 12:10 PM

Every year, Tempe Town Lake experiences fish die-offs due to weather and factors such as golden algae.

Currently, the colder weather and an increase in golden algae are contributing to a die-off of some species of fish in Tempe Town Lake. There is no issue with Tempe Town Lake water quality and this situation does not represent a safety issue for humans or pets. Golden algae affects only animals that breathe with gills.

Tempe Town Lake staff and contractors are working diligently to clean up the fish that have died.

The primary species that have died are shad and tilapia. Many of these fish come to Town Lake through the Indian Bend Wash, as a result of activities in other ponds and lakes that feed Tempe Town Lake when washes flow. Shad are bait fish. They are very small and multiply quickly. Because of their size, they are very sensitive to weather and golden algae. Tilapia are tropical fish and cannot withstand cold weather. Tempe and Arizona Game and Fish do not stock these fish in Tempe Town Lake.

Sport fish species at Tempe Town Lake are not yet affected, but Game and Fish has been made aware of the presence of golden algae so that stocking schedules can be modified if needed. 

Tempe Town Lake is a living ecosystem. The City of Tempe uses the most natural means possible to care for the lake.

Funding for removal of fish and other maintenance at Tempe Town Lake comes from the Community Facilities District, through assessments to residents and businesses located in areas surrounding Town Lake. 

Media contact: Shannon Reed, Public Information Officer, 480-639-9045

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