The Environment Agency said the low oxygen level in Pittville Lake could be algal bloom or sediment stirred up by rain, or both.
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For the second year running, Sandbanks has been identified as Britain's most expensive seaside location.
Warning of thunderstorms across the Bank Holiday weekend. In between some brighter, even sunny conditions though.
Heavy thundery showers are on the way for the South West across the Bank Holiday with some brighter sometimes sunny spells in between.