The Traditional Fisherman's Forum

We've had some cool days and even some rain lately. When I checked this morning everything was back to normal.

Buller wrote: ↑Sat Feb 03, 2018 9:42 am Interesting Shaun - I'd have thought that rain would have oxygenated the water

I took this from a E.A. paper...

Thunderstorms present particular problems for fisheries during
hot summer conditions. In fisheries where prolific algal blooms
are present, the combination of lower atmospheric pressure
associated with thunderstorms and the sudden influx of cooler
rainwater can cause the suspended algae to sink to the bed.
Now deprived of sunlight, the algae stop photosynthesising and
may begin to die, thereby causing rapid proliferation in the
number of bacteria and swift deoxygenation.
Moreover, because warmer water will rise above colder water,
there may also be an “over-turning” of the water column
during or following thunderstorms. This can release anoxic
organic matter previously trapped in the bottom sediment,
often causing the water to become dark brown or black and to
deoxygenate rapidly. This release of sediment may also
stimulate additional de-oxygenation through increased
bacterial activity.
Additional hazards of thunderstorms are the rapid influx of
surface water from surrounding areas that may contain
materials and substances promoting deoxygenation, and the
discharge of combined sewer overflows.

Wow! Really interesting. Thanks Shaun