Is there anyway of getting rid of those birds that keep attacking your bait, like supper soakers or a giant owl on the back of the boat that charter operators could use or is it just something you have to put up with?

Or maybe the charter boat operator could dress as a giant owl or have someone row around dressed as a giant owl.?

Steps wrote: Easest way is any under sized fish, give to them...and recently they have been so hungry and chicks to feed they will with a bit of quiet encouragement take the fish out of your hand... With a good sized undersized snap...25/ 28 cm , it takes them ages to turn and swallow...bit of entertainment, espec for the grandchildren.

Not.

Shags seem to fight for fish we release over the last 6 months and more often than not already know it's easy to wait for us to do exactly that. I have seen them swallow a 30cm+ fish easy and the fish bolted when we let it go but the Shag too smart. The Albatross in the far north do the same thing, friggin steal fish aswell.

What I read is, shags are annoying, and not much you can do, if we have a undersized fish that is near dead then a shag will eat it but not good for us to teach the wildlife that boats mean food, making it more a pest to everyone incl the birds.

Best idea is don't use Bait and Berley lol.

A water gun from The Warehouse will sort your bird issues. The bigger the better lol. And If someone in their boat gets too close too, you can fill it up with Mellow Yellow and spray them too. Again not good to teach the kids that but, I did it as a kid lol who's going to stop them lol.

Water gun is my pick.

Maybe a sprinkler system off the back of the boat would attract the fish and keep the shags away.

Wow this one spiralled out of control pretty quickly Godders. Sounds like you might be talking about Sooty Shearwaters (aka Muttonbirds when they are young), and surprisingly for a bird that happily dives underwater they don't like getting sprayed with water. A deck hose works, as does the contents of a half-filled bucket, but both have pretty limited range. You & IATF suggested a super soaker - perfect - especially if you have kids (aged 6-65) onboard. The worst thing is giving the persistent buggers their first taste - they don't need much food to survive, so those bait & burley scraps are an easy and welcome meal.   

I found the bird action bring the snapper on the bite. maybe they sense the bird action and wait below for falling scraps

Olfart is on to it...
there is more to a day out on the boat than just fishing....its the nature around u.. including the birds.
The petrels/ shear waters whatever they are as I mentioned before , so so reason dont actually take a bait on a line...we dont worry about them
And also as commented, in this thread and others, shags if real hungry will dive down and take released fish.. usually those a bit damaged for whatever reason.....and we have hit a couple on baits... but only off wharfs...
In the REAL world, having a squirt gun does send the shag a LITTLE way from the boat and distract while casting out.. and the practical side is being able to have someone shoot the bird while another is droping the line... doing both is a little awkward.....then ...well on smaller 5/ 6m boats having the squirter ...someone free to grab ...
well those who spend a bit time out can see the practicale side of the picture

If dont have a damaged undersized, or by catch...throw a bit of unsuitable bait out close to a shag... then cast/toss... in opposite direction....
Its no good giving shag tiny by catch...they stay around.. and a waste.....a good sized fish is what sends them away.
And as mentioned, considering one usually gets maybe 1 or 2 off the stern, and not on every trip, and only a couple those maybe full adults .. which is those ones that are of concern...
And make use of those damaged undersized....but there are not enough occasions or even close it it  to 'cater ' for every damaged......and the odd ok undersized for that very persistant hungry shag.
And take into account ever now and then a shag will still get a returned undamaged undersized anyway.. espec on the larger charter boats.....
The concentration numbers to feed a shag  are miniscual... when compared to the total wastage over all... of which huge volumes at a time dumped in number far to great for birds etc to take advantage and simply left to rot on the sea bed....
 
 Sort of like paying off a $100,000 fine at $1 a week

As rec fishers , yeah look after the by catch, handle you fish well... take your rubbish home, take care around other wild life and look after it... not with a one sided , blinkers on approach... but a practical real life, over all balanced approach to the whole environment I think is best.