Cast Net Mesh Size

[chanquetas]

Why do the regulations stipulate a MAXIMUM mesh size?
I would have thought a MINIMUM size would make more sense.

According to the QLD DPI:
Cast nets
These can be no more than 3.7 metres when measured from the point of attachment of the cord or rope to the rest of the net, to the net leadline or bottom of the lowest pocket of the net, whichever is greater. Mesh size must be no greater than 28mm.

Surely if the mesh is say 30mm or 35mm then smaller fish will escape and you are left with the larger ones - harmless. Isnt that the theory behind size limits for other fish?
So in theory you could have a mesh size of 5mm and catch lots of little things (which would be pointless I know).
Can someone explain this?

[agnes_jack]

I think the idea is that too large a mesh size will allow a cast net to be used for gill neting fish such as whiting etc. By having a maximum mesh size, the nets are limited to prawns and small bait fish species, larger fish are not meshed and usually escape.

Regards, Tony

[chanquetas]

Well that makes some sense....thanks Tony