Martin Jaffa
Environmental regulator’s feed cap forgets crucial fact about salmon
AT the beginning of October, the Scottish Salmon Producers Organisation (SSPO) issued a statement rejecting the environmental regulator’s proposal to introduce a feed cap as a way of controlling organic waste. The SSPO has described this new initiative by the Scottish Environment Protection Organisation (Sepa) as ‘lazy regulation’ which, if introduced, would raise significant concerns about fish health and welfare.
This is because feed is of course central to fish health, welfare and growth. The intention of Sepa’s new proposals is to replace the existing biomass controls, which have formed the basis for industry growth for many years.
These new proposals come after repeated criticism of Sepa by a very vocal minority who have their own agenda for trying to control the development of the salmon farming industry.
In my opinion, it does seem that Sepa is trying to show it is flexing its muscles to this minority but without actually achieving anything, and certainly not in relation to the protection of the environment.
The critics continually talk about fish waste as sewage, equating the amount produced as being equivalent to that produced by a small town.
However, fish waste is not the same as human waste and is part of the natural marine ecosystem. After all, there are 3.5 trillion fish in the world’s seas and oceans, all of which defecate straight into the water.
There is a build-up of waste under fish cages, but it is localised. If the footprint of all the cages in Scotland is added together it covers an area the size of two 18-hole golf courses, which is tiny considering there are more than 550 golf courses across all of Scotland.
I have repeatedly asked over the years for the critics to point out where the huge damage they claim that salmon farming does to the environment can be found.
Of course, there has never been an answer as
the environmental disaster they cite is more a figment of their imagination than some real and lasting damage.
All farms I know could be moved if required and the seabed under pens does recover, but critics are not interested in hearing about such recovery.
However, while the SSPO call Sepa’s proposal lazy regulation, I am left wondering how much Sepa actually knows about salmon because nowhere in its consultation document can I find any reference to the fact that salmon are poikilothermic (cold blooded fish).
This is significant for one simple reason and that is the feed requirement of salmon changes with changing temperature.
In a nutshell, the problem with a feed cap is that if the water temperature is warmer than expected, feed consumption will rise, and if feed is limited then the fish will go hungry.
This is not some big industry secret, so it is unclear why Sepa didn’t mention it at all in its consultation document. Industry feed tables include water temperature as part of the feeding regime.
An example of a feed table is given in the Handbook of Salmon Farming, written in 2002 by Selina Stead, now head of the Institute of
Aquaculture, and the late (and sadly missed) Lindsay Laird.
One example is that fish of about 200g in weight are fed 1.55 per cent of their body weight at 4 deg C, rising to 2.60 per cent at 16 deg C.
Larger fish of more than 3kg in weight are fed 0.4 per cent of their body weight at the lower temperature, but double that at the higher temperature.
This clearly makes a significant difference as to the amount of food that the fish should be fed. In these days of changing climate, it will be even less apparent as to how much feed a farm will need each year.
In its consultation document, Sepa suggests that the average quantity of feed used on farms varies from 15kg/tonne of fish at the start of the production cycle down to 7kg/tonne for larger fish. This is some form of acknowledgement that the feed rate changes as the fish grow.
However, the way the feed usage has been expressed does not really relate to the realities of how the fish are fed. This is because smaller fish are unlikely to be stocked at levels where the biomass is calculated in tonnes.
In fact, Sepa illustrates typical variations in mean daily rates graphically, and it has not recorded any feed rates of 15kg/tonne. Even the agency concedes that the mean rate is only 5.5kg/tonne. This is extremely misleading.
I suspect that most people working for Sepa have no recollection that the salmon farming industry has now been operating for nearly 50 years.
During all this time, salmon farms have been releasing organic waste on to the seabed, yet Sepa has not illustrated this need for change with even one example of where the seabed has been irretrievably ruined.
There are probably some regulations that do need to be amended as the salmon farming industry grows, but regulating feed to control waste is not one of them.
“I am left wondering how much Sepa actually knows about salmon”