Canadian Science Advisory Secretariat (CSAS)
Research Document 2015/064
National Capital Region
December 2015

Transport and dispersal of sea lice bath therapeutants from salmon farm net-pens
and well-boats

...
The process of conducting a tarpaulin or skirt bath treatment of a net-pen involves several steps. Initially, the outside perimeter of the fish cage net is shallowed to a depth of about 3-4 meters. Next, either a tarpaulin is deployed around and under the net or a skirt is deployed around the net.

Subsequently, the pesticide is pumped into the treatment volume and is assumed to become mixed throughout the enclosed volume by the movements of the fish and the water movement generated by the oxygenation system.

Finally, at the end of the treatment period, the tarpaulin or skirt is removed, the cage net is allowed to drop to its normal depth, and the pesticide begins to leave the cage and advect into the ambient receiving waters.

During the field studies, dye was added to tarped and skirted pens during treatment to allow visualization of the treatment water both within and outside of the treatment volume.

https://waves-vagues.dfo-mpo.gc.ca/Library/362136.pdf

You can also find "cage skirts" permanently ADDED TO a fish cage - so even then the "cage skirt" is not the whole cage.

There is still a primary component used to keep the salmons in - a "cage" and the added "skirt" only used to keep the sea lice out.

https://www.nauticexpo.fr/prod/botngaard/product-196233-5486...
see page 7
https://pdf.nauticexpo.fr/pdf-en/botngaard/perma-skirt-2017/...





--------------------------------------------------
Note added at 20 hrs (2021-01-08 09:24:19 GMT)
--------------------------------------------------

Technical detail: The web designer liked playing with the latest gimmick tools but forgot the main purpose of the whole business - to make the PDFs readable - as you can't zoom in, you have to "print" page by page and then open the separate pages in a PDF reader to be able to read them.