There are more Aquaculture Service boats in operation and they are getting more sophisticated as the industry develops around the world.
Here is a new one that just crossed the Atlantic to work in B.C, Canada:
Source:
I believe there was a class of 4 or 5 of these but this was the only one that came across the pond to BC
The Aqua Tromøy is a mid-size Live Fish Carrier that can also be used to remove lice and other parasites from the fish, using fresh water.
Having Diesel/Electric propulsion allow the 4 generators to be used to power Reversed Osmosis (RO) to produce up to 6000 Cbm./day of fresh water when not steaming:
https://www.dessaqua.com/aqua-maly-1/aqua-maly-3ry67-76lcr-fz7c5-8g24n-9zsat-ssgw7-ajaan-bydy7-p5mjt
The Coastal Server use a Skarmik 1.5 mechanical de-licing system and cover a wide range of other tasks around fish farms.
PS> The design has already proven it’s seaworthiness:
UPDATE:
Mowi MAY reduce their fleet of chartered vessels operating in B.C. soon:
Two new Aquaculture vessel on order in Turkey:
These will not only carry live fish from the fish farm to processing plant, but slaughter and bleed the fish while doing so:
The Norwegian flagged fish carrier AQUA VIKING spotted Aug 14 at Lochinver in the North West of Scotland. Based in Kristiansund, she is 1409 tons dwt with an IMO of 9777254. She has recently called at Scalloway, Lerwick and the Kyle of Lochalsh
Photo: Simon Wergan, Milton Point Pictures.(c)
5 small service boats were ordered in Jul. 2020:
Designed by Solstrand Trading for FSV Group. Hulls are built in Poland, towed to Norway and outfitted by Sletta Verft A/S.
These multi-purpose service vessels will serve fish farms long the entire Norwegian coast and beyond.
First of these, “Muliti Vision” handed over 24. April 2021:
The second, Multi Ocean followed 25. Oct. 2021:
They may be small but packed with equipment and comfortable for the crew to live and work on:
All Photos: Sletta Verft A/S
The third in the series, “Multi Electric” was delivered 02. March, 2023:
A larger version of multi-purpose service vessel with Hybrid power are already in operation for FSV Group:
Service vessel Moen Astor seen in Ålesund today:
Here seen at the building yard Moen Marine AS:
This is a workboat of type NabCat 1499, similar to this one:
I have been up to the Cambell river several times to inspect fish farm vessels and have always been impressed with the quality of workmanship of vessels constructed in Poland.
No the ones i inspected had discharge hoses to feed pellet food to the penned in salmon and bottom doors mid ships that would flood the fish holds usually 2 holds. once flooded they would vacuum the fish out of the pen run them down a fluted slide that would sort them in size then drop them into the holds. there were packed so tight for the short run back to the pier that they would have to aerate the holds to keep them from dying. once along side the pier they would vacuum them out through a clear plastic pipe that ran along the pier to the processing plant. you could see the fish wiz buy through the pipe.
the propulsion was diesel electric. there was an electric motor that sat at the top of a narrow vertical passageway the belt drove a variable pitched prop.
they had nice joinery in the accommodations space but was essentially a day boat due to the close proximity to the pens.
Do you have name of the vessel(s) used in BC?
Sounds like the function is similar to this one. Bringing live fish from the pens in Storfjord to slaughter and processing in Ålesund:
Or the newer variant where the fish is killed and blead out on board while under way to the processing plant:
It was a long time ago. It was more of a Baltic trader design
House and machinery all aft. 3 fish holds forward. Family own boat. Two brothers and an Eskimo engineer 
The pens were out in the straights. They were as big as an American football field
Looks like fish farming service industries are getting the attention of the big boy in Wallstreet:
The fleet of vessels involved:
https://froygruppen.no/flate/
I hope GS isn’t planning to run this fleet from Wallstreet. (Nor milk it for values and run away)
The Norwegian fishfarm support vessel PATRIOT moored at the Nieuwediepkade in Den Helder. Photo: Wim Albers ©
Summary
Name PATRIOT
DWT Summer 3,079 MTs
Build Date 01/01/2006
IMO Number 9350795
Flag 
NORWAY
Ship Type Fish Farm Support Vessel
Gear Gearless
LOA/Beam/Draft 73.6 m / 16 m / 9.99 m
Source: PATRIOT – Fish Farm Support Vessel, IMO 9350795, Flag NORWAY