With Malaysia aiming to double its exports of aquaculture products by 2017, SIRIM’s solar hatchery and aquaculture solutions could not have entered commercial readiness at a better time




The aquaculture industry is fairly new in Malaysia. But, with an annual growth rate of 15 per cent, it is expanding rapidly. Indeed, the country is already the fifth-largest producer of fish and seafood through aquaculture in ASE AN, producing around 380,000 tonnes of aquaculture products annually. Almost 80 per cent (300,000 tonnes) of this output is exported to lucrative overseas markets like Europe, the United States, China, Japan and Singapore. The sector hopes to raise production to 800,000 tonnes per year and to double annual exports to 600,000 tonnes.

The impetus behind all this rapid growth has been Malaysia’s National Agricultural Policy, which allows aquaculture farmers to breed freshwater aquatic species such as fish and prawns in relatively small bodies of water. But concentrating so many aquatic animals in one pond at one time can be very risky: keeping these watery habitats stable is a constant challenge, and farmers have to be ever-vigilant or risk losing everything due to fish kill.

A fish kill can wipe out your whole harvest overnight, often without warning. One day you have 10,000 fish in your pond worth RM200,000; the next day, you have nothing.

The hatchery industry faces similar production challenges. Tasked with supplying the local aquaculture industry with the fish and shrimp larvae it needs to breed aquaculture produce, the industry is highly susceptible to disease outbreaks.

SIRIM has spent the past few years working on self-sustaining solar solutions to help hatcheries and aquaculture farmers prevent fish kill and increase the productivity of their ponds. The two products that have resulted from these efforts – the Solaerator™ and the Green Aquaculture System – form a complete aeration and water condition monitoring system that can be installed anywhere.


How to kill a fish

Fish kills can occur for many reasons, the most common of which is low dissolved oxygen (DO) levels. Fish populations rely on the photosynthesis process of aquatic vegetation to turn dissolved carbon dioxide into oxygen, but this process only happens during the day when there is sunlight. At night, these same plants respire and start consuming oxygen instead. DO levels can drop drastically when this happens, especially between the hours of 4 am and 7 am. If the amount of DO produced the previous day is not enough to sustain the pond habitat through the night, panic ensues.

When you see your harvest struggling near the water’s surface, you know you have a fish kill on your hands. Anything that can swim will head towards the top of the pond, where DO levels sustain the longest. And when DO levels drop there, they will start to ‘gasp’ at the surface. This poses a problem for fish farmers. In order to make a farm economically viable, it is necessary to cram as many fish as one can into a single pond.

However, the more fish you have, the more fish waste there is to manage, most of which tends to sink to the bottom of the pond where it blocks out the sunlight and limits the ability of plant life to photosynthesise during the day. The decomposition of fish waste also consumes dissolved oxygen, further starving the pond’s aquatic life of this precious gas.

The end result is a pond that is no longer able to sustain dissolved oxygen levels for its entire habitat. 


An intelligent system

The only way to ensure an aquaculture harvest does not go belly up is to ensure that the pond is properly aerated, especially at night. The best aeration systems use paddle wheels to stir the water’s surface as well as diffusers to pump air directly into the bottom of the pond. You also need a highly efficient system for measuring and monitoring the environmental conditions of each fish pond so that you can ensure that the water’s acidity and ammonia levels do not get out of hand.

Unfortunately, all these things require electricity. If the power outage happens during the day when the aquatic vegetation is still producing oxygen, a pond can go without paddle wheels and diffusers for a few hours. But if it happens at night, it only takes a few minutes before the crop starts dying.

This is where SIRIM has innovated a self-sustaining hatchery and aquaculture solutions that do not need to be ‘plugged in’. The Green Aquaculture System is a floating, solar-powered device that monitors all the factors that can impact a pond’s health: temperature, ammonia, pH and salinity, and, of course, dissolved oxygen. When any of these readings hit dangerously high or low levels, the controller sends out a text message alert to a predetermined mobile phone number.

By running on solar power, the Green Aquaculture System is also independent from any external power source or failure. When paired with the Solaerator, this solution can save fish farms thousands of ringgit in electricity bills.

The Solaerator pumps compressed air into the bottom of a pond using a non-clogging diffuser, increasing oxygen levels and reducing water stratification, which is a major cause of poor water quality. During the day, it runs on solar power; during the night, it runs on batteries. Fully charged, the battery can keep the system pumping for up to two days.

If used with the Green Aquaculture System, however, the Solaerator system can be configured to only turn on when it is told to do so. Both systems can also be applied to small and medium-sized hatcheries. 

The Solaerator therefore should not be considered a substitute for conventional aeration systems, especially for large farms but is best applied when used to complement conventional aeration systems.


Big savings

The Solaerator can save the average aquaculture farm about two-thirds in aeration electricity bills, while the Green Aquaculture System all but eliminates the need for foreign labour to manually monitor water conditions around the clock. Together, the aquaculture solutions significantly reduce the manpower and energy costs of aquaculture farming while reducing the risk of human error.

The Solaerator is currently available in two versions: one with two diffusers, and one with four. The smaller, two-diffuser version is ideal for smallholders and independent aquaculture farmers, while the bigger version is best suited to larger enterprises with multiple ponds or large lakes.

SIRIM’s test site is at the Fisheries Research Institute (FRI) in Gelang Patah is a 2,500 m3 lake that survives quite comfortably on two large Solaerators.

A rural farmer’s best friend

SIRIM first installed its first Solaerator for a rural fish farming community in Simunjan, Sarawak. The Solaerator is especially suited to rural aquaculture farms with no access to electricity at all. Here, commercial aquaculture is a touch-and-go affair at best, with farmers depending entirely on Mother Nature to see their harvest through. The result is an extremely low survival rate.

Conventional paddle wheels and monitoring systems are useless if the farms don’t have a power source. A self-sufficient aeration system would significantly improve their yield and income. Hatcheries also do best under strong aeration conditions.

SIRIM’s hatchery and aquaculture solutions are designed to be self-sufficient and that’s what makes them special.

Both the Green Aquaculture System and the Solaerator are practically maintenance-free, with the batteries needing replacement only once every three years and the solar panels lasting up to 20 years. All farmers need to do is give the panels a wipe every few months to ensure that accumulated dust does not block the photovoltaic cells from receiving the sun’s radiation.

Its ease of maintenance and relatively pain-free installation also makes the Solaerator an attractive proposition to golf courses, whose water hazards and recreational ponds frequently become polluted – and quite smelly – with fertiliser run-off from the greenway.

Aeration not only helps fish live longer and grow healthier, but it also reduces the accumulation of sludge and the stink of stagnant water. The Solaerator can also be used in golf courses. 


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