OK, first -- don't eat a fish that you find dead.
Weather conditions and a bad season for golden algae have caused fish to die off in several ponds across the Phoenix area this winter.
Several 12 News viewers have reported seeing alarming numbers of fish dead at Tempe Town Lake. The cold is to blame in this case. Almost all of the dead fish are tilapia, which can't stand water temperatures below 55 degrees for extended periods of time.
This die-off of tilapia happens every winter, according to Arizona Game and Fish community fishing program specialist Joann Hill. Tilapia are native to Africa and thrive in warm temperatures.
Golden algae is hitting community fishing ponds particularly hard this season. The algae can emit toxins that attack fishes' gills, suffocating them. Meanwhile, the water is still safe for humans and pets to drink, Hill said.
Golden algae isn't a death sentence for all of a lake's fish. It can be present while not emitting toxins. It can affect some areas of a pond and not others. It can be treated with an algaecide.
Veterans Oasis Lake in Chandler was hit early in the season, which typically lasts from November to May. Golden algae blooms in winter months when other algae types aren't blooming as much.
Cortez Lake in Phoenix and Riverview Lake in Mesa were also confirmed to have golden algae in November.
Desert Breeze Lake in Chandler was just treated after a fish die-off due to golden algae. It was not stocked with fish the week of Jan. 11. Hill says recent tests for golden algae show treatments have worked. Stocking will continue after more testing.
Alvord Lake at Cesar Chavez Park in Phoenix is in the middle of a fish die off due to golden algae. The park staff, the city and Arizona Game and Fish are working to treat the lake.
Hill said golden algae has been particularly bad this season. It has been a warm and dry winter, even by Arizona's standards, and that could have caused the big bloom.
So what should you do if you see dead fish? A few dead fish aren't cause for concern to officials, but get someone's attention if you see several dead fish an area. You can talk to that park's staff if you can find them, or you can communicate with the city or Arizona Game and Fish.
Just remember -- it is still safe to catch fish in Phoenix-area lakes. Make sure you have your fishing license!