Predators are the problem! But what can we do?
It looks like, after nearly 40 years of harping on about the river not producing enough juveniles, new research on the River Dee has finally confirmed what most Ghillies have been talking about for all those years. A large number of salmon Smolts, especially those from the upper part of the river, are being eaten and so have no chance of ever reaching the sea, the same will be the case for salmon parr prior to migration.
For many years we have talked about the fact that we don’t catch the same number of juveniles when fishing with small flies in the summer, and, "visually", there are not the same number of small fish feeding during fly hatches. Anyway, thankfully our observations have now been confirmed, and I’m sure the same will be the case on all rivers with resident populations of fish eating birds, there is now no doubt that a high percentage of juvenile fish of Parr size from the middle and upper reaches will be consumed by those birds. In the case of the Spey, this will be mainly Goosanders, the numbers of which, increased dramatically in the 30year period between 1981 [when they were afforded full protection via the Wildlife and Countryside Act in 1981], and the early 2010s. On other rivers Cormorants will be the worst perpetrators.
The Dee research shows that "potentially" only 30% of smolts produced in the upper river ever reach the estuary, couple this with the fact those birds eat fish, not only at the smolt stage, but as Fry and Parr to, and, in my opinion, you have a major reason as to why fish are not returning. Basically, as we've said all along, they’re not leaving in big enough numbers in the first place. Add to this, predation on the coast as they leave fresh water and I’m sure the main reason for the decline in salmon numbers has been found.
Looking at the timescale for this decline, we find 100% correlation with an increase in numbers of fish eating birds.
The Goosander was first seen in the UK in the 1870s, and did not exist here before. Initially they were seen in very small numbers. I’ve heard it said (but not quantified) that those first birds were actually introduced by man, and in fact, are not indigenous at all. My own observations would certainly point to this being the case, my reason being. Any indigenous Duck will lay between 8 and 14 eggs but will seldom raise more than 4 – 6 to flight, ending at the end of the season with two. However, in the case of this newcomer, the Goosander, 12 eggs laid = 12 chicks to flight. Anyone looking at this alone, should also know, this is not natural, nor is it sustainable, strongly suggesting an introduction rather than natural colonisation!?
Irrespective of whether it was, or was not introduced, what we do know is, their protection began with the protection of birds act in 1954, prior to which those birds were shot in sight by river and gamekeepers. Numbers at this time were so few that they would not impact on the then Healthy population of salmon in our Scottish rivers. However, by the time the were afforded complete protection via the Wildlife and Countryside Act 1981, their numbers were already rising rapidly.
During my youth, based in Peterhead and encouraged by a brilliant teacher, George Dyce, I was a keen bird watcher, egg collector and generally interested in the Countryside. I kept records of any unusual bird, my most interesting nest at the time being a reed-warbler, something not common in the northeast of Scotland in the early 70s. Another was a Goldfinch, it was 1973 and I was ten before I saw one of those. Of all the days I spent on the river, I saw my first Goosander, not on the River Ugie, but in 1975 on the River Deveron. At this time the population must have been small or I'd have noticed. However, by the time I came to work on the Spey in 1985, they could be seen on a daily basis. Turn the clock forward to 1995, after 15 years of complete protection, those birds were now out of control and obviously doing damage to salmon stocks. The great shame is that it’s taken so long for “decision makers” to realise the problem caused by those, and other fish-eating birds.
The main reason for this is, pre1980s, Scientists/Decision Makers, had little or no data to work with, their only relevant information regarding juvenile numbers coming from rivers such as the Esk. Other than this they had little accurate data regarding juveniles in Scotland at this time. In fact, not until the late 1990s, early 2000s, "after the damage had been done by those birds" and to us working on the river, "visually", numbers were already low, did they begin to collect more accurate information. Indeed, 99% of data regarding Juvenile populations in pour rivers comes from this period and later, rendering it useless as a long-term comparison, but very good in the short.
You really would think that it wouldn’t take a brain surgeon to work out, by affording a fishing eating duck (possibly non-indigenous) complete protection, over time, this will have an impact of the fish they eat!? An idiot or complete fool would make this connection. Which is why we know this to be a political rather and practical problem!
So, now armed with the facts, what can we do?
Well, one thing for sure is, the bird/predator lobby is too strong and has much political support to tackle head on. With numbers of wintering birds now exceeding 15,000, To make any difference would require killing those on a grand scale. Not gong to happen!
What do we know? Well, in the case of Smolts, we know they’re being eaten between point A and point B in the river. Can we “protect” them between those points? In the case of Smolts, can we help them during their migration?
If we can put a man on the moon, then surely, with all the information we have, we can protect those valuable fish from those unwelcome avian enemies without breaking the protecting them!!!
Part of the answer to this might be to find a way of shepherding/transferring those smolts to the brackish water. Possibly holding them in tanks/pens/holding units, out of the way of all predators until they’ve adapted to the salt? Then, possibly shipping them some miles offshore before releasing them. Given that we cannot deal with the predator problem, we need to do something, and fast. This could be trialled on a small scale first, just to make sure we’re not doing more harm than good.
https://www.marineinsight.com/types-of-ships/what-are-wellboats/ What about the destruction of Parr in September/October by those large families of birds? Again, the man on the moon scenario springs to mind. If we can’t kill them we need to scare them. How? Someone must have a decent idea?
I have heard it said, feed the predators with hatchery fish. This will give them another source of food, leaving the stronger, more "streetwise" natural Parr and Smolt to migrate safely. However, lessons from the continent with stocking rivers where predations by Cormorants on a grand scale are prevalent, suggest this does nothing but increase the population of the predator. Indeed, my observations of Goosanders on the Spey through the 1980, 90s and early 2000s, would suggest the population had stabilised and the ceiling, with this species anyway, had been reached? However, having not spent as much time on the river during the last ten years, I can't say for sure. Possibly some of the Ghilies could comment?
For this and other reasons, I think large scale stocking with fry is not a good idea in our rivers. We know those will be eaten and serve no other purpose than to feed, thus increase the resident predator population [whatever species that may be]. However, I'm sure hatchery fish do have a role to play but if released into the river [or brackish water] as smolts or pre smolts. This way they have no impact on the natural fish in the river or their potential food.
My feeling is that they could be tagged as part on a wider experiment to ship wild smolts out to the open sea. It's said that as much as 90% of predation on smolts entering the ocean takes place in the first few miles of their journey. Why not actually find this out and at the same time "find out" whether using hatchery fish is, in fact, viable.
Tagging small numbers [a few hundred] wild smolts and a few thousand hatchery smolts before taking them out to sea in a tank might just, at very little cost, provide valuable information. One thing for sure is we should be doing something!
The research on the Dee is continuing, and if found to be conclusive, then my feeling is we must do all we can to afford them protection.
Incredible as it may sound to the laymen, but the future of The Atlantic Salmon, one of Scotland’s most iconic creatures, is in jeopardy, their numbers decimated, and much of this because of a decision to protect this unwelcome, possibly invasive, avian predator which was never seen in this country prior to the 1870s.
How can we get something so wrong and not correct it?