MENIFEE (CBSLA.com) — Authorities continued testing the water in Menifee Lake Friday after thousands of dead fish have been seen floating since last weekend.

Menifee city officials first heard reports Saturday of floating fish at the lake, which is located on private property about a half-mile east of the 215 Freeway.

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Since Menifee Lake is not on public land, state and local agencies do not regulate or manage the waters, according to KCAL 9’s Tom Wait.

According to a state official, one possible theory is that chlorine leaked into the lake after a nearby pool was acid-washed and re-chlorinated.

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Seasonal algae blooms that produce a deadly neurotoxin have been blamed by officials for similar “fish kills” in Agoura Hills and Redondo Beach.

A representative with the Menifee Lakes Master Association, which owns the property, said they are testing the waters for deadly chemicals, but so far, the results are inconclusive.

Resident Lisa Quick said it’s not just fish that have died – birds have been victims as well.

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“The baby ducks that have just been born…it’s just been really hard to watch and hard to see,” Quick said.