CASTAIC (CBSLA.com) — Authorities reopened Pyramid Lake to swimmers Tuesday, but visitors were warned that the toxic algae that forced a swimming ban last week is still present in parts of the lake.

The latest samples showed a decline in microcystin toxin levels, according to the Department of Water Resources, which still urged people to use caution when entering the water. The algae bloom was first discovered late last month at the reservoir near Castaic, about 60 miles from downtown Los Angeles.

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State officials urged visitors to:

— avoid swimming or wading near algae or scum;
— keep children away from algae in the water or on shore;
— avoid drinking lake water or using it for cooking;
— keep pets away from the water and any scum on the shoreline;
— avoid eating shellfish from the water; and
— throw away the guts of any fish that are caught in the water, and thoroughly clean fillets with tap or bottled water before cooking.

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State officials also urged parents to warn their children not to swallow any lake water.

Exposure to the toxins in high amounts can lead to symptoms such as skin rashes, irritation to the eyes, nose, mouth or throat, headaches and gastrointestinal discomfort. Dogs can also become sick from drinking or licking lake water from their fur.

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