Probably not for salinity, but certainly for other dissolved minerals. Salmon and trout supposedly find their way from the sea to a particular stream my tasting the exact mineral composition of the waters they were born in. It's pretty mind boggling really.Do fish have hydrometers that precise too?
Someone needs to write a pinned topic on how to use these things. As you say, there are tricks to remember.When I use a hydrometer, the trickiest thing I find was to remember to wash it immediately before and after using it.
Cheers, Neale
My dad is a keen angler and frequently travels to Ireland where he fishes for sea trout, brown trout, pike, salmon etc. He really couldn't give 2 hoots about fishkeeping, but he said it was an amazing sight to see fish returning into the lough from where they originated. They have a bridge over the mouth of the lough and you can actually see the fish returning through the comparitively small gap (small when you consider the size of the ocean).
There is also a place in england (it might be many places, I remember this from an attenborough wildlife show some years ago) where eels and elvers travel only when there is a full moon up across an "eel stairway" or something similar, much like how salmon have particular sections of rivers dedicated to their free travel. Can anyone shed any light on this, or am I simply confused?
Sorry for the thread hijack!