Research round-up from our top institutions
Transformation of aquaculture has been made possible by advances in control of ‘new’ diseases
It s now exactly 50 years since I first started to work on fish pathology. In 1965 there was a spate of diseased wild salmon presented for diagnosis at the University of Glasgow set School. No one knew anything about them, so as the most junior pathologist, I was assigned the task of post-morteming them and reporting to the aggrieved river proprietors.
That was the start of the UDN outbreak which lasted only for a few years but changed the way we deal with fish diseases in the UK forever. It led directly to the se ng up of the fish disease teams in Aberdeen and Weymouth, and also to my being given the chance to set up the fore-runner of the Institute of A uaculture, the A uatic Pathobiology Unit, funded by the Nu eld Foundation.
Over the ensuing half a century, the world of a uaculture has been transformed from a minor contributor to human nutrition to, in the case of both Scotland and Norway, for example, the largest food producing industry, and worth far more than the value of cattle and sheep production combined.
None of this would have been possible without the contribution of the scientists and veterinarians who have discovered, diagnosed and controlled the plethora of new diseases that have arisen in the course of development of intensive salmonid and shrimp production and, further afield, in the great contribution that tropical a uaculture is now making to feeding the developing world.
The situation is not now all rosy, however. saccines have made great contributions to the viability of many production systems, resulting in minimal use of antibiotics nowadays. Better understanding of biosecurity and also international movement regulations have limited the risk of viral epidemics such as the ISA outbreaks that virtually destroyed the Chilean industry.
But parasites, especially the copepods, continue to present a challenge in many areas. New work on vaccines even for these is starting to look promising but it will be a long haul I fear.
One area which has been particularly exciting, though, has been the prospect of genetic selection for disease resistance. The work on development of salmon resistant to IPN which our Landcatch team did with the Roslin Institute was recently stated by a very senior scientist at an international animal breeding conference to be ....generally regarded as possibly the most successful example of genetic control of disease resistance in any livestock species . Praise indeed.
The success of these techni ues provides hope for many of the other serious pathogens. Just before I finally retired last year, we were able to announce, in conjunction with a consortium of Sco sh universities, that work we were carrying out at the Machrihanish Marine Laboratory was showing that it was possible to produce genetic resistance to sea lice as well
In many ways that is the Holy Grail of fish pathology, with implications for other parasitic diseases and other fish species as well. The scientific papers are now published and the commercial exploitation is beginning both in Scotland and Norway. While there will still be a role for the wrasse and the lice treatments, for some time to come, I am sure lice control will become much easier and such treatments will be much less fre uent in the near future, to the benefit of all concerned.
So the future is bright for the industry and I believe also glowing for the fish veterinarians and their scientific colleagues. There is now a large World A uatic seterinary Medicine Association (WAsMA). In Scotland, in Norway and indeed throughout Europe, there are significant groups of scientists working on previously intractable problems.
When we add this to the large e ort in the Americas, Asia and of course Australasia, the di erence from 50 years ago, when we were, I guess, less than ten veterinarians in the whole world working on fish, is stark.
As the following pages will demonstrate, there are still di cult problems, but also lots of hope both for the welfare of the fish and the environment and for the financial benefits that result, o en in economically challenged regions, from ade uate management of diseases in fish stocks.