This blog post analyzes the impact of ballast water on marine ecosystems, explores problems caused by the introduction of invasive species, and examines ballast water treatment systems (BWTS) designed to address these issues.
Ms. K, a Korean woman who enjoys eating Chilean grapes—edible with skin and high in sugar content—orders them without fail every day. She maintains her health by eating fresh, sweet Chilean grapes for breakfast each morning. She has never considered how far these grapes travel or the processes they undergo to reach her, but she is simply satisfied that they always arrive fresh.
At the Chilean grape factory receiving the order, the grapes are loaded into a container ship bound for Korea. These grapes are carefully packaged and meticulously managed to maintain freshness during their long voyage to Ms. K’s table. Countless people collaborate throughout this process, striving to preserve the grapes’ top quality until the moment they reach Ms. K.
A container ship arrives at Busan Port after crossing half the globe. But the fish living in the waters off Busan are horrified. They’ve never seen these foreign fish before—Chilean fish have suddenly appeared in vast numbers. For the fish of Busan’s coastal waters, this situation is like a completely unknown new world suddenly appearing. The moment they encounter these unfamiliar Chilean fish, the ecosystem loses its delicate balance, and signs of change begin to appear.
Did you know that ordering Chilean grapes might also bring Chilean fish? While this fact may seem unfamiliar to many, it actually happens every day. How did these fish end up in Korea? Before explaining why, readers must first understand what ballast water is. For a ship to float and move on the sea, the depth to which it is submerged in seawater must be maintained appropriately. To achieve this, the ship loads a certain amount of seawater inside. Specifically, seawater is repeatedly loaded into designated spaces (tanks) within the ship and then discharged to maintain the ship’s balance. This seawater used for maintaining balance is called ballast water.
Container ships carrying grapes from Chile also inevitably depart loaded with this ballast water, i.e., seawater. However, this seawater contains diverse Chilean species. Not only fish, but also small plankton and microscopic marine organisms are transported along with it. These organisms are typically very small creatures that people rarely notice, yet their migration routes are global. At Busan Port, the container ship discharges the ballast water used for its long voyage and takes on new ballast water. It is during this process that Chilean fish appear before Korean fish in the waters off Busan. Consequently, the ecosystem off Busan faces a new challenge.
UK shipping analyst Clarksons forecasts global container cargo volume for 2024 at 208 million TEUs. You may be unfamiliar with the unit TEU. TEU stands for Twenty-foot Equivalent Unit, representing a single container measuring 20 feet in length, 8 feet in height, and 8 feet in width. While this is just one container, it reminds us that millions of containers departing from ports worldwide are transported in the same manner. This illustrates the immense volume of cargo carried globally via container ships. During this transport process, an equally staggering number of fish are also being carried worldwide via ballast water. It’s no longer surprising to find fish originating from Chile discovered in Busan, or conversely, Korean marine life found on other continents.
This scattering of fish across the globe causes devastating damage to marine ecosystems. This mirrors the threat posed by invasive species like the bullfrog and bluegill to Korea’s native ecosystems. The discovery of North American jellyfish in Europe’s North Sea, the colonization of the Great Lakes by European mussels, and the presence of Mediterranean crabs in Australia or South America are all attributable to ballast water. If this continues, biodiversity will disappear, disruption to native ecosystems will worsen, and chaos in marine ecosystems will accelerate. This could lead to a rapid decline in marine resources in specific regions or even threaten native species with complete extinction. Ultimately, these problems directly impact people’s lives. Changes in marine ecosystems can negatively affect fisheries, tourism, and the broader marine economy.
The solution to these problems is the keyword of this blog post: BWTS (Ballast Water Treatment System). The fundamental concept of this treatment system is to prevent or eliminate the entry of biological species present in ballast water using physical and chemical methods, thereby maintaining clean ballast water. It primarily utilizes filters and sterilizing agents such as ultraviolet light and ozone. The International Maritime Organization (IMO) adopted the ‘Ballast Water Management Convention’ in 2004, mandating that all ships with ballast tank capacities exceeding 5,000 cubic meters must be equipped with a BWTS starting in 2016. The introduction of this system is expected to protect marine ecosystems and support the sustainable development of the shipping industry.
Installing one BWTS on a single ship costs approximately 10 to 15 billion won. Installing them on all 68,190 international container ships worldwide would require a staggering 80 trillion won. Despite this enormous cost, it is viewed as an essential long-term investment for protecting the marine ecosystem and ensuring sustainable shipping. To capture this massive market, all shipbuilders are actively working to accelerate new technology development and build efficient systems. This technological advancement will ultimately contribute to achieving two goals: protecting the marine environment and fostering economic growth.
