Doggy Doodah: Page 84 of the latest issue of Trout & Salmon magazine consists mainly of a picture of anti-salmon farming campaigner Corin Smith sitting on the pack of a pickup with his arm cradling his dog Monty. I am exactly not sure what breed of dog Monty is, but he is a fair size and I’m sure he has a healthy appetite after a good workout along the banks of salmon rivers near his home.
Of course, any larger dog with a healthy appetite does also leaves their mark on the environment, even if that ‘mark’ is picked up and taken home. Live Science reports that America’s 83 million pet dogs produce some 10.6 million tonnes of poop every year. Thus, at the same poop rate, the UK’s nine million dogs would produce about 1.15 million tonnes of waste.
Live Science say that whilst dog poop is not an environmental problem as big as climate change, the risk from poop can be more than just a mess on your shoe. Dogs can be home to lots of viruses, bacteria and parasites, including harmful pathogens like e coli and salmonella. A single gram of poop can apparently contain 23 million bacteria. Studies by the US Geographical Survey have found that 20-30% of bacteria in water from urban watersheds comes from dog poop. The US Environmental Protection Agency have indicated that just two to three days of waste from 100 dogs can contribute enough bacteria, nitrogen and phosphorus to close 20 miles of a bay watershed to swimming and more importantly to harvesting shellfish.
In the UK, its only a couple of years since the Daily Telegraph reported that the animal charity ‘Buglife’ had discovered significantly high levels of the chemical imidacloprid in rivers and streams in the Scottish Cairngorm mountains, the River Ouse in Bedfordshire and the River Ancholme in Lincolnshire. The chemical is commonly used to treat arthropod parasites and is listed in 68 registered veterinary products designed to kill fleas in dogs and other small animals.
Three rivers, the Thame in Manchester, Wye Beck in Leeds and Somerhill Stream in Kent, were so polluted that they exceeded safe limits. The only source of the imidacloprid that could be identified was from pet dogs. Buglife said that they were devastated by the extent of the damage to British rivers caused by these neonicotinid insecticides, They say that once the chemical has been applied to pet dogs, it can end up in storm drains and water courses during rain showers or when the animal or its bedding is washed. The chemical then enters the sewage system and then into water courses. Alternatively, the chemical can enter water courses directly if the animal is allowed to swim in open water.
Of course, I am sure that Mr Smith is an extremely responsible owner and takes Monty’s poop home to be disposed of in the most environmentally friendly way possible Equally, being such a guardian of Scotland’s rivers, I am sure Mr Smith would never allow Monty to enter any open body of water, not just because the risk of depositing chemicals, but also to minimise the risk of upsetting the natural local fauna.
I must apologise for being distracted by the picture of Mr Smith’s handsome dog and my comments about the 1.15 million tonnes of dog poop, when really I wanted to discuss the 35,000 tonnes of waste that Mr Smith says is generated by salmon farms each year. He usually compares salmon waste with that from humans and describes it as sewage. Mr Smith has written a commentary after someone left a post on his Facebook page suggesting that it would be better to compare the poop from salmon farms to that from cattle. Unfortunately, many of his facts and statements are simply incorrect, possibly because he doesn’t appear to have a science background or simply because he is trying to paint a picture of salmon farming that actually doesn’t exist. Many of the errors he makes could be easily rectified if Mr Smith would be willing to learn about the industry from those who are directly involved in the industry but when asked in the seven page Trout & Salmon magazine interview why he won’t, his response was that talking to the salmon farming industry is strategically naïve and he would become tarnished by association. Instead, his views are tarnished by a lack of knowledge (I have decided not to comment on Mr Smith’s long interview because another commentary has been posted at https://medium.com/@talksalmon/muddied-waters-and-a-maze-of-duplicity-55aa0d79637e which is well worth a read).
The post on Mr Smith’s Facebook page suggested that the waste from salmon farms was nothing compared to that of cattle. There are 1.8 million cattle in Scotland, each producing nearly 30kg of waste a day so there is clearly a lot of waste produced. Actual data is somewhat confusing because some figures includes bedding and others include liquid. As a guide, an article in the Guardian newspaper suggest that all the cows in the UK produce about 36 million tonnes of waste a year.
However, Mr Smith dismisses the comparison. Whilst he is happy to compare human waste to salmon farming, he is not so willing to do so for cattle. He says that Scottish cattle are a perfect example of a circular farming system. The cattle live outside eating grass and then pooping their waste onto the ground where it acts as a fertiliser to grow more grass. He adds that cattle have always been in the ecosystem and have been doing this for tens of thousands of years. This is unlikely since cattle were only domesticated 10,500 years ago and it is thought that they didn’t arrive in Britain until around 4,000 BCE.
Mr Smith admits that cattle can cause a problem when they are intensively farmed. However, even outdoor cattle can cause problems when they are brought inside at certain times of the year. Mr Smith says that the disposal of slurry is regulated and uncontrolled emission of slurry into water bodies is not permitted. Interestingly, the environmental campaigner, George Monbiot tweeted this week that farmers are currently spreading excess slurry onto fields just before heavy rain so it is quickly washed off the land, thus allowed more to be spread.
Mr Smith concludes that this is why you don’t see floating chicken farms on freshwater lochs. This makes no sense at all since firstly the discussion is about beef not chickens and secondly, cattle graze on grass not on water. It seems Mr Smith is a bit confused about this aspect of modern agriculture.
Having dismissed this comparison with cattle farming, Mr Smith is happy to explain why salmon farming is a problem. Firstly, he says it is unnatural. However, everything humans do is unnatural. Mr Smith is happy to cuddle up to his dog Monty, but Monty is not natural but rather the result of forced breeding. Going out into the river to catch fish for entertainment is not natural but a modern affectation of hunter- gathering. Farming game-birds so they can be shot for sport is not natural. The human race has been able to adapt ecosystems and the natural environment to meet its needs. It may not be natural, but it’s life.
Mr Smith continues that even when wild salmon were plentiful, they did not produce any faeces in the inshore environment like salmon farms do. Yet, just because salmon’s life cycle means that they stop feeding on their return does not mean that the marine environment is not full of other fish that poop. In fact, there are about 3.5 trillion fish in the world’s oceans, all of which poop into the water column. This is not a problem because like Mr Smiths circular farming, fish waste is recycled through the aquatic nitrogen cycle.
Of course, salmon farms do contain large numbers of fish in a relatively small area and waste does accumulate under the pens. Mr Smith argues that the ecosystem has no natural ability to cope with that type of ‘pollution’, no matter the quantity. He insists that salmon farm waste doesn’t go anywhere but just builds up in the sea lochs.
There are currently three active salmon farming sites that were first registered as long ago as 1979. This means they now have been producing salmon for 40 years. Following Mr Smith’s argument that the sea bed around a salmon farm cannot cope with the scale of the waste, even a conservative estimate of 10 tonnes a month of waste would mean that the sea bed under these farms has developed a mountain of waste of nearly 5,000 tonnes. I suspect that if Mr Smith were to dive around any of these farms, he would find no such mountain. This is because, just as in the natural environment, the fish waste is continually being recycled.
Mr Smith says that the build-up of waste is what fuels greater numbers of jellyfish, plankton and algal blooms and this leads to greater mortality of the salmon being farmed. He equates this ‘over enrichment’ of the environment to pouring petrol on a fire. He maintains that rearing fish in their own sewage leads to more deaths. For a salmon angler, Mr Smith appears to know very little about salmon. They are extremely intolerant of poor water quality and would not grow and thrive as many do if the environment is as polluted as he claims.
What Mr Smith fails to mention, and it is entirely possible that because of his unwillingness to engage, that he simply doesn’t know, but as a part of their licence, salmon farmers are obliged to monitor the sea bed in each production cycle. This occurs after the peak biomass has been reached with 28 samples taken across 4 set transects. The samples are then sent to SEPA for analysis. This sampling determines whether the farm has satisfactorily met its licence conditions.
Details of past monitoring are easily accessed as is other farm data listed on various agency websites. Unfortunately, Mr Smith doesn’t appear to want to acknowledge this information, preferring instead to produce his own map of Scottish salmon farms, detailing only the information he wants others to see.
Mr Smith then turns his attention to salmon feed. He writes that the content of salmon feed is a closely guarded secret. As I have already pointed out, Mr Smith does not want to speak to people from the salmon farming industry, nor is he willing to accept invitations to visit a salmon farm. This is a shame because if he had he could have had a close look at a bag of salmon feed including the label which lists all the ingredients in a descending order of magnitude. Unlike modern human food labels that give average contents, each run of salmon feed has its own specific list. This is because ingredient usage can change due to variations in nutrients between different batches of raw material. If he doesn’t want to look at a feed label, Mr Smith might be more willing to read Mowi’s 2019 annual report, from which the following graphic is taken. The report also provides other information about the make-up of salmon feeds.
According to Mr Smith some feeds are rich in fish meal whilst others have a higher cereal component. He says that the high fish meal feeds produce waste of around 15% but as high cereal content is harder for the fish to digest, then up to 50% of the feed can end up as poop. This makes no sense since why would farmers give their fish feed that they cannot digest? In fact, many vegetable proteins are hugely more digestible than fishmeal. However, some vegetable proteins do contain higher levels of indigestible fibre, but these are rarely used in fish feed because so much of the ingredient would be required to meet the nutritional profile that it wouldn’t be physically possible to make. All fish feed is produced with the highest possible level of digestibility so as much of the nutrient can be absorbed.
It is worth mentioning here that Mr Smith quotes a figure of 15% digestibility, which he uses to estimate the waste produced by a salmon farm. Mr Smith takes the figure from a paper by Reid et al. in the journal Aquaculture Research. What Mr Smith has not considered, and this information is stated in the paper, is that fish feed contains about 9% moisture. This means that rather than 15% waste, the figure is 13.65%. Using Mr Smith’s figures, the annual waste is actually 32,077 tonnes. If Mr Smith is to make claims about the salmon farming industry, then the figures he uses should be correct.
Mr Smith then turns his attention to the pink colour of salmon flesh. He said this is the result of medicines and colouring that is added to the feed. The definition of a medicine is a preparation for the prevention or treatment of a diseases. I am not sure that pink flesh can be classed as a disease but in Mr Smith’s world, I guess anything is possible. The reality is that nearly all the carotenoids used are produced by fermentation and that the techniques used are no different from those used to make the supplements consumed by the public in their billions every day.
Mr Smith ends his commentary saying that grass reared beef farms are not a problem as such farming is an extension of a natural process. By comparison, salmon farming is unnatural, unregulated, and obviously disposes of all its sewage directly into marine ecosystems.
There are only a certain number of times Mr Smith can repeat such claims without being challenged. I apologise for the length of this commentary, but it is necessary that Mr Smith is now challenged about the facts, even if he doesn’t want to listen.