NavList:

   

Reply

In New Zealand, we hear this noise almost everywhere, when at rest - at
least in the Northern (ie warmer) part of the country. Its very
noticeable in the marina where I berth my boat - it has quite clear
water (can see down at least three feet in even the worst of conditions)
and lots of both tiny and larger (poss 1 metre?) fish; it is a blind bay
so there is no significant flow. I think that where there is any
significant stream the noise doesn't occur.

We also enjoy occasions of amazing phosphorescence which displays
individual fish down to a couple of metres, which makes me sure that
this noise is not related to the presence of fish. Nor is it related to
the presence of phosphorescence.

Its pretty unnerving to hear such a lot of noise and not know what
causes it. I hesitated to bring up this topic in this list, but now it
on-going I would love to hear of any real diagnosis. Krill seems
possible IF they have some scratching or munching abilities. In my
desperation to conceive of a likely cause I even considered whether
there might be a continuous process of semi-explosive decay of
micro-organisms, which sometimes yields phosphorescence and sometimes
not....

This could well be a retirement project for me if there are as yet no
definitive answers, lets see...

Keith Williams

   

Reply