use adcp within a net pen

Hi,

we want to measure the current velocity and direction within a net pen in a salmon farm. Does anybody knows if is it possible to take such measurements with an ADCP? Is it possible to make it even with the net full of fish?

Thanks in advance,

Gonzalo Olivares

Hi Gonzalo,

Fish will interfere with the velocity measurements made by Nortek instruments. They will typically generate a very strong echo and would be easy to remove from a dataset, but if the population is quite dense you will potentially wind up with very limited data.

A point velocity measurement such as the Nortek Vector could be put into a small cage to exclude salmon from its sample volume and give you more reliable data. It would be difficult to do this with a profiler since it samples a much larger volume.

P.J.

Dear Gonzalo

For scientific experiement looking at the flow field inside the pen, people have used the Vector.  For measurements of the mean flow into (or out of) the pen, people mostly used Aquadopp current profilers. 

It can be quite amazing to watch how the pen stops the current (or forces it to go around).

Best regards, Atle Lohrmann