he world population is growing rapidly. In fact, the United Nations estimates it will reach 11.2 billion by 2100, with approximately 83 million people being added to the world's population every year.
Feeding over 11 billion people is a huge concern, as it will put enormous strain on the earth's ability to produce enough food. An answer to the future global food challenge may be through the use of sustainable fish farming.
The UN's Food and Agriculture Organisation reports that the average amount of fish eaten per-capita globally has more than doubled from 9kg in 1961 to 20.2kg in 2015. Of course, there are well-publicised cases of overfishing.
However, much of this growth has been from aquaculture. In 2016, 46.8 percent of the fish we ate came from aquaculture, a rapid growth from just 25.7 percent in 2000. This data includes finfish, crustaceans and molluscs.
Aquaculture is the fastest growing food production sector in the world and is considered a practical and sustainable method to produce food and bridge the gap between supply and demand.
However, aquaculture faces many challenges and one of the biggest is combating disease. For example, infectious disease is currently the single most devastating problem in shrimp culture and presents on-going threats to other aquaculture sectors. In addition, there is increasing concern over the consequences of newly emerging diseases in aquaculture.
As with any form of farming, growing large amounts of food in a small space increases the incidence of infection and disease, which can spread extremely rapidly through a stock of 90,000 fish confined to a pen.
For this reason, fish farms are looking for modern innovative methods to ensure that fish are kept healthy. Better disease control, feed and nutrition help to minimise losses and produce a high-quality product. If fish farming is the answer to a sustainable food source, rapid disease and parasite diagnosis, together with improved health management, will be key to increasing stock levels.
Large farms continuously monitor water, but there is no substitute for visually inspecting the fish, and early detection of small parasites requires a microscope. As part of a good health management plan, routine parasite and disease screening should be completed regularly.
Microscopes are the most important tool for disease diagnosis. However, analysing and monitoring disease with traditional compound microscopes is very difficult. They are heavy, cumbersome and problematic to transport.
Many fish farms are located in remote environments where it is impractical to use compound microscopes. There is usually no way of sharing images for records or a second expert opinion.
Through exploring advancing technology, a new generation of portable digital microscopes has been designed to capture and share images and videos of parasites and other fish pathology instantly from a standard mobile phone. This new technology can be used to monitor 'in-the-field', therefore enhancing rapid detection to help diagnose disease instantly, which is vital for effective control.
The image quality of the new equipment is now close to that of a compound laboratory microscope, but the device is small enough to fit inside a jacket pocket. This new class of high-resolution, portable microscope dramatically improves the speed of diagnosis and, therefore, the productivity in aquaculture environments.
It is now possible to sample, diagnose, and treat serious health conditions within a few minutes. Site staff can even get a second expert opinion in the time it takes to send and receive an email.
The importance of rapid diagnosis can be understood by looking at Gyrodactylus salaris, or salmon fluke, a microscopic parasite that feeds on the flesh and mucus of salmon and other freshwater fishes.
It has caused mortalities of up to 98 percent in wild Atlantic salmon populations in Norway. Some stocks have been lost completely or destroyed by adding pesticides to infected rivers, killing parasites and fish, though this treatment is no longer common.
Gyrodactylus salaris is so serious that it is classified as a listed disease in Europe that must be reported to the authorities. Although the UK is currently recognised as being free from the disease, evidence exists to suggest that our Atlantic salmon populations are highly susceptible to both infection and mortality.
This is a perfect example of why rapid detection is vital in the removal of infected fish and the fight against these contagious diseases if we are to increase stock numbers.
Advancements in digital microscopes have been enabled through the use of high-quality, low-cost components designed for mobile phones to make highly compact, robust instruments. Originally these devices were low-cost, low-resolution, USB-connected devices, with limited application in the aquaculture market.
However, more recent microscopes are extremely compact and use a wireless connection to deliver 1-micron resolution images to a standard mobile phone. These innovative products feature a robust stage and transmitted and incident illumination just like a compound microscope, but importantly they have the technology to instantly share high-resolution images and videos for immediate feedback.
'When examined side-by-side with pictures taken with my US $10,000 microscope/camera set-up in our laboratory, the images stood up pretty well – for 10 times less money,'commented Dr Rod Getchell, a member of the Aquatic Animal Health Programme at the Cornell University College of Veterinary Medicine, New York, USA.
'I think this instrument has value for our fish farming friends in the field who do not want to deal with a traditional microscope.'
Bill Manci, President of Fisheries Technology Associates, Colorado, USA has also experienced the benefit of the new generation of portable high-resolution microscopes.
A specialist since 1982 in fisheries management, characterisation and evaluation of wild fisheries, and technical and economic feasibility analysis of fish farming and aquaculture facilities, he said, 'Without a doubt, the portability and ruggedness of these units and the high quality of the images are the innovations that truly wowed me. For me, this was one of those moments when you say to yourself, 'How did I ever get along without this device?''
If aquaculture is the future of sustainable food and to continue its remarkable contribution to feeding the growing population of the world, fish farms need new tools, processes, technology and innovation to succeed.
Productivity and sustainability rely heavily on the ability to detect fast-moving diseases instantly, in remote locations. Referring samples to a laboratory back at base is time-consuming and will result in significant stock losses and further spread of disease.
Tools need to be implemented that can work proactively to ensure fish stock is healthy. Instruments like microscopes, which must be portable, accurate and provide instant sharing technology, are needed to make accurate diagnoses and should become a standard tool within an effective health management plan.
ioLight Secures Backing from Innovate UK to Enhance its Portable Microscope
Most recently, ioLight won a substantial grant from Innovate UK, the UK's innovation agency, to further enhance its digital high-resolution portable microscope. The funding will be used to explore a number of exciting new features to increase user experience even more. Andrew Monk, Co-founder ofioLight said: 'Thanks to the Innovate UK grant we can accelerate the ioLight microscope into another dimension by developing new features. For example, we will be looking to design an X Y stage to make it even easier to count cells. All of the new proposed features can potentially have a huge impact on diagnosing disease and parasites in the developing world.
'Traditional compound microscopes are difficult to transport and use in remote environments and usually have no way of sharing images for a second expert opinion or records. By advancing the ioLight microscope further, it will help to improve the speed of diagnosis, therefore aiding in the fight to reduce disease in humans, animals and within the aquaculture industry.'
Andrew concluded: 'This is a really exciting time for ioLight. Our objective now is to create the next generation of portable digital microscope which will provide even faster, more reliable, diagnoses far from the lab thanks to its outstanding high-resolution images and ease of use.'