PHARMAQ’S annual knowledge transfer event, Pharmaqademy, saw a record number of delegates gather at the Kingmills hotel in Inverness at the beginning of November. The two-day conference, directed by Pharmaq sales manager Chris Mitchell, opened with the company’s Elise Hjelle updating the audience on the progress of Smoltvision in RAS aquaculture.
Smoltvision is an analytical tool which provides an insight into the progression of smoltification, the physiological process by which young salmon in freshwater transform themselves for the marine part of their lifecycle.
This molecular tool uses RT-qPCR (quantitative reverse transcription polymerase chain reaction) to measure the expression of freshwater and saltwater ATPase, as well as a co-factor in the gills of smolts, prior to transfer.
Typically, farmers will supply 20 freshwater smolt samples to Pharmaq Analytiq to assess the ‘readiness’ of the population for transfer to seawater. The co-factor’s expression gives an insight into overall gill health, which can provide an enhanced understanding of the stocks’ status.
The data collected over the years has given the company an excellent view of the physiology of smolting salmon. Fish living in freshwater, especially in RAS aquaculture, can undergo multiple smoltification events, followed by a reversal of the process if the fish are not transferred to saltwater.
A range of environmental cues can trigger an unplanned smoltification, the most common of which is salt exposure, sometimes used to induce the event.
However, Hjelle indicated that transferring fish to a lighter tank can also trigger early smoltification. Unplanned smoltifications make it more difficult for farmers to synchronise the process across the population.
Julia Tandberg, one of the R&D scientists at Pharmaq, then gave an update on the occurrence of new variants of Moritella viscosa, the causative agent of winter sores in farmed salmon, cod and lumpfish in Norway and Scotland.
Handling or injuries can increase the risk of infection that can lead to the development of ulcers. The prevalence of this disease in both Norway and Scotland has led to the rapid increase in the uptake of vaccines for Moritella, with 90 per cent of farmed salmon now using them in Norway.
However, surveillance of Moritella has indicated that about 90 per cent of isolates collected are new variants and Tandberg postulated that vaccination may have rapidly selected for them. Phylogenetic trees from Moritella isolates formed three groups and ELISA (enzyme linked immunosorbent assay) cross-reactivity testing showed that some variants can be controlled by currently available vaccines, while others cannot.
Although the group had not investigated so many Scottish isolates, the presence of new variants has
“The low inclusion rates of marine material in diets were suggested as a possible risk factor in deformity”
been confirmed here, but not to the same extent as in Norway. In Scotland, approximately 75 per cent of fish are vaccinated against Moritella.
Tandberg asked Scottish producers at the conference to send samples so she could better characterise the bug in Scotland.
Two speakers, Bernt Martinsen, Zoetis’ group sales director, and Ane Sandtrø, senior manager, Outcomes Research, Zoetis International Operations at Pharmaq, then focused on vaccines and associated risk factors that can lead to deformed vertebrae in salmon.
Pharmaq offers a vaccine against pancreas disease (PD),ALPHA JECT micro 1 PD, which can be delivered to pre-smolts alongside other vaccines.
But as with other commercial PD vaccines, the vaccine may be a risk factor for some newly described vertebral deformities, which appear to be significantly more common in Norway than in Scotland.
Use of functional feeds has been proposed as a risk factor associated with vertebral deformity and results from clinical field studies indicate a connection here. However, other studies have been inconclusive.
Following the presentations, discussions turned to potential nutritional aspects associated with deformity.The low inclusion rates of marine material in diets were suggested as a possible risk factor, which might explain the current difference in observed deformity levels between Norway and Scotland.
The final talk on the first day was given by Claudia Tschesche, Pharmaq’s sponsored PhD student at the University of Stirling. She presented an update on her work on resistance in sea lice to deltamethrin, a synthetic pyrethroid which Pharmaq markets as AMX, a bath treatment for this parasite.
In insects, knock-down resistance (kdr) to deltamethrin has been described as a mutation which disrupts the molecules’ ability to bind to the target site in voltage gated sodium channels.
In the salmon louse, however, the target site is unknown, although emerging evidence suggests that mutations in the mitochondrial genome may play a role.
Tschesche is currently examining possible markers in the mitochondrial genome which predict for resistance and, in doing so, gain a better understanding of the mechanism. Last year, she presented evidence showing that deltamethrin resistance is maternally inherited in sea lice and closely linked to four mitochondrial single nucleotide polymorphisms (SNPs) that are protein modifying.
Furthermore, a Norwegian study has shown that two of these mutations are located on the surface of these proteins, providing the possibility that deltamethrin may bind at these sites to exert a toxic effect.
Her experiments lend further weight to this hyphothesis. By exposing deltamethrin resistant lice to the insecticide etofenprox, she found that these lice were fully susceptible to this compound. Had their resistance to deltamethrin been mediated through kdr mutations, then this should also have protected them against etofenprox – no such protection was observed and by extension kdr is not the mechanism of protection in lice that are resistant to deltamethrin.
The second day of presentations was opened by Jamie Brannan, vice president of Zoetis UK, Pharmaq’s parent company. He gave a high-level perspective of Zoetis’ innovation offering in the rapidly changing animal health market place. Zoetis operates globally, with annual revenues of $5.8 billion; of its 10,000 staff, 1,100 are involved in research and development.
The company has identified three key global drivers of growth: rising population, a growing middle class, and a rise in pet ‘medicalisation’ and protein consumption (12 per cent meat and 30 per cent fish) by 2026.
He explained that Zoetis’ mission statement is to provide a ‘continuum of care’ to farm and companion animals.The tools and services provided aim to predict and forecast animal health, prevent any disturbances to health, as well as offer a range of treatment options if it is compromised.
Lucy Williamson, an independent human nutritionist, said the aim of her nutrition services is to provide simple evidence based advice. Her talk focused on fish consumption from the omega-3 perspective, but also as a source of iodine, vitamin D and selenium.
One aspect of human nutrition which is of concern, she said, is the current trend towards vegetarianism and veganism, particularly in children who are still growing rapidly.
Williamson said that surveys of the population indicated that most people do not consume the two recommended portions of oily fish each week, and that consumption of long-chain omega-3 fatty acids was too low.A lack of awareness about cooking fish was often cited as a cause of this.
Although vegetable oils do contain omega-3, it is in the form of ALA which must then be converted into EPA and DHA, the same beneficial oils found in oily fish.This process requires enzymes which share the omega-6 metabolic pathway; because there tends to be far more omega-6 in our diet naturally, the omega-3 pathway is disadvantaged.
Eating fish allows us to benefit from a direct source of EPA and DHA, crucial to our long-term health.The omega-6 to omega-3 ratio in the UK diet is estimated to be about 10:1, a long way from the 2:1 recommended by WHO or even the 6:1 which has often been used as a realistic target!
Continuing the theme of nutrition, but from the perspective of the fish, Chloe Phan Van Phi from Innova Feed, a French company leading the way in the manufacture of insect derived products, outlined the company’s use of agricultural by-products to produce an insect protein meal, an insect oil and a rich organic fertiliser as by-product from the ‘frass’ (what’s left after a production cycle).
Innova Feed is working closely with Cargill to investigate the use of these materials in salmon diets.
The company will open the world’s largest insect rearing plant in 2020, capable of producing 15,000 tonnes of insects each year.The factory will be co-located with a Tereos operated starch and sweeteners mill and Kogeban, a biomass turbine.
This will allow Innova Feed to exploit excess heat and by-products from the mill, as well as capture so-called ‘fatal’ energy from the turbine normally dissipated into the atmosphere, leading to a reduction in carbon emissions of 35,000 tonnes each year.
Other initiatives to develop the market include working with chefs and fish mongers to spread the concept of rearing fish using insects and observing how this is received by the consumer.As part of this process a new label has been developed, ‘Poisson nourri à l’insecte’,‘fish fed with insects’, to support the new sector’s laudable ambitions to contribute to a more circular economy.
Arno Schut from Axentive changed focus with a presentation on the use of Halamid (Chloramin T), as a general purpose disinfectant. In aquaculture, the compound is typically used as an in-water disinfectant rather than for the sterilisation of plant and equipment, as is the case in other types of animal production. Data were presented showing how the compound could be used successfully without any hindrance to biofilter function.
Sterilisation of fish stock rather than fish farms was the theme of Debbie Plouffe’s presentation. She had travelled from the Centre for Aquaculture and Technologies in Canada to talk about gene editing technologies currently under development.
Importantly, she explained that gene editing was
“The current trend towards vegetarianism and veganism is of concern, particularly in children who rapidly” are still growing
not the introduction of new genetic material into an organism but rather the editing of incumbent genes using the CRISPRR/cas9 system on developing fish embryos.
One exciting aspect of these technologies is that breeding programmes can be rapidly accelerated if the desired alterations to genes are understood.
However, Plouffe was keen to emphasise that gene editing is complementary to traditional breeding programmes and not a substitute.
Working with tilapia as a model, the company has deployed the technology to generate sterile fish. These individuals are biologically similar to their parents in all aspects except gonad development and therefore do not encounter the problems sometimes associated with the more traditional method of sterilisation, triploidy.
For now, however, these technologies will remain largely in the Americas, unless accommodating regulatory reform is forthcoming in Europe.
The final topic of Pharmaqademy’s agenda was plastic pollution, with Chris Walkinshaw, a PhD student from Plymouth Marine Laboratory, outlining the scale and impacts of the problem.
He was followed by Catherine Morrison, of Ireland’s Seafood Development Agency (BIM), who introduced the Clean Oceans Initiative’s proposals aimed at managing it.
Walkinshaw’s work examines the impact of plastic pollution within the context of food security. A broad overview showed how microplastics can now be found everywhere in the aquatic environment.
Areas of concern within aquaculture include the adsorption of PCBs, PAHs, dioxins and heavy metals on to microplastics. Harmful species of algae can even be transported across the ocean on plastic particles.
Going forward, he will focus his studies on mussels to analyse the presence and characteristics of microplastics inside these animals, generating data to support the shellfish sector with their risk analyses.
He will also examine fishmeals to quantify the level of plastic pollution in them. He said that the smaller the particle size being searched for, the greater the amount of plastic that would be found.
Morrison informed the audience that simple actions could be deployed to ‘turn off the tap’, to stem the constant flow of plastics into the aquatic environment.
She also explained, the myriad forms that plastic can take, and the complexities associated with recycling the material, especially the separation required due to the varieties of type and density.
She went on to explain how BIM had worked with fisherman in the ‘Fishing for Litter’ scheme. The project provides sacks on the decks of fishing vessels to collect plastic items that are hauled in with the catch.
Approximately 80 per cent of Irish trawlers have signed up to the scheme and are bringing litter ashore. Fish farmers also contribute by organising shore and pier clean-ups in their local areas.
However, the work has not stopped there; recycling the materials is complex and involves sorting and cleaning (salt contamination makes them largely unattractive to recyclers).
Nevertheless, the project cleans and sorts as much as possible and a large mobile shredder has been deployed to help compress and manage the large quantities that are recovered from the sea.
Morrison said that although these types of schemes have additional benefits, specifically to do with satisfying social conscience, more needed to be done to stop the huge quantities of waste being produced in the first place.
Such measures would require a coordinated global effort and involve regulation and extensive modification of supply chains.
The conference, held on November 4-5, finished with lunch and further networking.The author would like to thank Pharmaq for organising such an informative and interesting event, for their hospitality and the chance to try curling!
Above left: Claudia Tschesche and Chris Mitchell Above right: Delegates at this year’s Phamaqademy Opposite: Chloe Phan Van Phi of insect protein pioneer Innova Feed
Above: Zoetis UK vice president Jamie Brannan and Chris Mitchell