A bad summer for water quality in Lake Champlain seems to be getting worse. Over the past week, hot weather, low water levels and a huge bloom of blue green algae have combined to cause a massive fish kill in Missisquoi Bay.

It's not unusual for blue-green algae to appear in Lake Champlain in the summer, particularly when it's hot. But what is unusual is for it to be appearing this early in the year.

After last year's flooding, which sent record amounts of phosphorous into the lake, and a recent streak of hot weather, blue-green algae blooms have appeared in Lake Champlain earlier than normal this year, and have been more widespread.

The town of Williston is reporting high phosphorous levels in Lake Iroquois. But officials say they're challenged in managing blue-green algae blooms because four towns co-manage the lake.

Blue-green algae have spread across a broad swath of Lake Champlain this summer. A tour of the Burlington area by boat shows that the thick blooms seen earlier in the week have been mostly dispersed by the wind and waves.

Health officials are warning there's a high level of toxins on the eastern shores of Missisiquoi Bay at the northern end of Lake Champlain.