Look to the sea for top farms in the west
It now employs modern technology to farm on a scale unmatched even on land. At Marine Harvest’s four Munster sites, fish husbandry manager Abdon Ryan and about 20 workers oversee the farming of up to 600,000 salmon per site.
Ryan, based in West Cork but a native of Co Wexford, has been working in the fish farming industry since leaving college in 1989. His experience includes working in Connemara, going back to college in Scotland and working for two years in Norway, where he became a qualified commercial diver, and where he gathered much of the expertise that he applies to his job in Ireland.
“Most things that happen to the fish at sea,” is how he describes his area of responsibility. “Basically, their welfare is my remit, health and parasites and water quality.”
Much of his job involves visiting all the sites and being there on the ground to ensure that everything is running smoothly.
“The way it’s set up is that each site, bar one, has a barge, and that barge contains feed in big silos. The capacity of them is 200 tonnes, although we never fill them to more than 100. Through high-pressure air, the feed is sent to the cages, and there’s a spinner in the centre of each cage that distributes the feed around the cage. Below that, we have a camera system. Usually, there’s an operator sitting in a barge looking at the feed leaving the barge, and he also has a screen in front of him where he can flick from one cage to the other, as he’s monitoring the feed response.
“With this system, there’s no wastage whatsoever. He can see straight away if a few pellets pass the camera. You know that the fish aren’t hungry any more, so you move on to the next cage and do the feed there. This keeps wastage to the absolute minimum.”
Ryan describes the feed as “organically derived pellets, like something a dietician would have prepared”. Depending on the size of fish and the temperature, up to 18 tonnes of feed per day can go into a 600,000 fish site. In general, the recommended percentage of body weight feeding per day decreases with the size of the fish, and increases with rising temperature. Unfortunately, the feed now comes from Britain, since the Skretting mill in Westport, Co Mayo closed in 2010.
Although the fish farms can operate remotely for a certain length of time, the normal practice is for the sites to be visited almost daily. “You really need to be there,” says Ryan. “There are only a couple of days in the year when we wouldn’t be out.
“We’re now right up there,” says Ryan of the technology levels used in the Irish fish-farming industry. “We’d be using pretty much the same systems that they use in Norway.
“We started to use cameras in a farm in Killary Harbour where I was site manager back in the late 1990s. Now they’re all colour cameras, and they give a far better view of what’s going on.
“The biggest changes over the years that I’ve been involved,” says Ryan, “are in the cages used, the feeding and the monitoring of the feeding. That side of things is far better. In the past, it was four guys in a boat with scoops and a bag of feed, throwing it in by hand, but these days it’s far more high-tech. You’re able to keep control of it. The whole secret with fish farming is a thing called the FCR, the feed conversion ratio, which is how much food is turned into fish. Without cameras and so on, you don’t know what’s going on.”
Living conditions for the salmon are monitored remotely, with data relating to water salinity, temperature and oxygen levels streaming ashore constantly. On-site cameras transmit colour images of the fish to facilities onshore or to on-site barges.
“We can set the feeding system based on appetite, weight, on the number of fish in each pen, on their behaviour, the water temperature. All those factors will influence the rate of feeding,” says Catherine McManus, technical manager with Marine Harvest, based in Donegal.
The other major advancement in technology, McManus says, is the use of boats that carry live fish, or “well boats”. “This is something that we only started to do three years ago,” says McManus. “We chartered it from Norway, and we were the first in Ireland to use this technology. That’s enabled us to pump live fish into the farms. If we need to send out stocks, it makes life a lot easier. Prior to that, we had to pump them into or move them into a structure that had a net that you could tow behind a boat. That had its own difficulties because you had to tow with the water flow and with the tide, so that you wouldn’t damage the fish. With the live fish carriers, you don’t have to worry about any of that. You can control the oxygen levels and the water flow within the wells, so the fish are quite happy there, irrespective of what’s happening at sea.”
The trend is to take fish farming further and further out to sea, reveals McManus. The company has followed this trend in its farm at Clare Island in Co Mayo, and their site in Ballinskelligs Bay is also quite exposed.
“One of the challenges in siting a salmon farm is getting a place where you have good water flow,” says McManus. “Back in the early 1980s, when fish farming started off in Ireland, the wisdom at the time was that farms should be established in well-sheltered inland areas, away from exposure to the open sea. Over the years, we’ve learned that it’s the opposite, that the fish should ideally be located in areas with good water turnover, good flushing.
“They’re cleaner sites that are environmentally better. It’s also what gives the Irish industry an advantage over competitor countries. These well-flushed sites mean that they’re high-energy sites as well, where the fish are very well exercised. Irish fish tend to be lower in fat content compared to Norwegian fish, for example.”
The demand for leaner fish of the type that Ireland specialises in another factor pushing production further out to sea.
Irish marine technology has come to the forefront in responding to that demand. “You need very robust mooring technology, pen technology and net technology. In Ireland, we’re leading that area because of the exposed nature of the Irish coastline, particularly when you compare it with the situation in Norway. In Norway, they’ve been able to go up long fjords and get some protection from the Atlantic. In Scotland, too, you get a lot of shelter from the Western Isles and the various inlets along its coast. In Ireland, we don’t get that sort of shelter,” McManus says.
Recent hurricane force winds that battered the coastline, particularly in the north-west, caused some damage to facilities, but all of Marine Harvest’s installations survived completely intact.
McManus says: “In Norway and Scotland, the recent severe weather caused damage to our fish farming structures, but in Ireland, we had nothing.
“We’ve spent many years improving the mooring technology and the netting and pens to withstand the waves that we experience off the west coast. In fact, we’ve been able to monitor fish in Ireland when other countries haven’t been able to do it, which has been a boom for us over the past few weeks and even over Christmas. We’ve been able to supply customers that we wouldn’t normally supply, because farmers in other countries couldn’t get out to sea to get the fish.”
