Overfishing, pollution, bottom trawling – we’ve heard of these environmental problems that plague commercial fishing. But does it mean that farmed seafood is the solution to all the fishy problems? Not necessarily. We take a deep dive into aquaculture farms and see if they are truly more sustainable in terms of minimising the impact of fishing on the environment.
Sea-based farms
There are two main types of aquaculture farms – sea-based and land-based farms. True to their name, the sea-based farms in Singapore are found along the coastal and southern waters.
The coastal farms are situated along the Straits of Johor in the north of Singapore and they mostly adopt the open-net cage system. This means the fish are kept in a large netting with sea water flowing freely through it. While this method allows the fish to be kept in its natural habitat, there are some environmental consequences to it.
For one, the open-net cage system results in fish waste, chemicals and parasites entering the sea. You may think that’s “natural” since fish belong to the ocean anyway, but the high concentration of fish waste and chemicals in one specific area is not a natural phenomenon.
Some sea-based farms in other countries are not connected to land at all, so their farm and farmers’ waste are all thrown into the sea as well. Over time, the large amount of waste causes a chemical and nutrient imbalance in the sea, which may even lead to harmful algae blooms. The last time an algae bloom affected fish farms in Singapore was in 2015, when up to 600 tonnes of fish died from it. Thankfully, the sea-based farms in Singapore now dispose of their waste on land, so we’ll hopefully be able to avoid such tragic losses in the future.
That being said, our off-shore fish farms are facing another issue – the fish-rearing capacity at the Straits of Johor is reaching its maximum production levels. According to the SFA, going above the maximum levels may lead to poorer water quality within the farming zones. To mitigate this, the government is targeting to adopt sustainable farming systems in the southern waters. While that is good news, it will take some time for the systems to be set up. To spread out the demand in the meantime, we can take a look at land-based fish farms.
Land-based farms
Land-based fish farms adopt a variety of aquaculture methods, including open pond culture and tank-based systems. While land-based farms are largely thought to be kinder to the ocean, there are some negative environmental impacts too.
Many land-based farms use a closed-containment method, which sees fish grown in a controlled environment such as tanks. This method reduces the exchange of waste, chemicals and diseases between farms and the ocean. In theory, this is great as it means pollution could be reduced. However, farms must take extra care to manage the waste from the tanks instead of simply dumping it into the sewage or back to the ocean.
More farms are adopting modern technology to help with this. For example, at our sister farm Atlas Aquaculture, a recirculatory aquaculture system is used to recycle and reuse the water. The system filters and treats wastewater from tanks before transferring it into a storage tank to be used again. Of course, this is not a perfectly sustainable method, as a large amount of energy is required to keep it constantly going.
At this point, you may be thinking that nothing seems completely sustainable. Well, that is the truth but there are steps we can take to simply be more sustainable! Instead of relying on licences and fancy labels on seafood products, we can do our own research on various farms before making a purchase.
For those who want to take a step further, organise a fun day out by visiting various farms! Whether it’s a coastal farm or land-based farm, it is always good to experience and learn more about the source of our food.
Atlas Aquaculture x Science Centre “I am a Young Sustainability Champion” program
Atlas Aquaculture x National University of Singapore, Ridge View Residential College
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Our sister farm Atlas Aquaculture is offering tours and programmes to the public! If you’re up for some fishy fun on the farm, check out the types of programmes that are available for groups and individuals alike. From sensory tours to craft workshops, there’s something for everyone!
Sea-based farm Image:
