How can ballast water be dangerous to the marine environment

Studies have shown that invasive aquatic species are among the top four greatest threats to the oceans around the world, which ballast water directly contributes to. Aquatic species are supposed to exist in a single area. When these species are collected in ballast water, they are taken from one port to another, which means that they will be discharged from the ballast tank into a new environment that is not made to accommodate the species.

At first, these organisms may simply be known as non-native species. The introduction of invasive species to different environments can pose problems to both freshwater and marine ecosystems. As an example of how harmful invasive species can be, studies have shown that the introduction of invasive mollusks within the U.

Species like the round goby have created problems with aquatic ecosystems in the Scandinavian ecosystem. The Chinese mitten crab is currently an invasive species throughout much of the Baltic Sea, which has caused a reduction in native species like crayfish. Under the International Maritime Organization, every ship that moves through international waters is required to meet water treatment standards for ballast water. While the U. You will also be helping the environment and biodiversity significantly when you manage your ballast water.

The water is taken in along the coastal waters at the start of the voyage, and is adjusted along the way as cargo is loaded and unloaded.

The issue with this water, however, is that it can contain organisms that are not native to the environment in which they are released. If this nonnative species begins to out-compete the native species, it is then deemed invasive. Invasive species are particularly dangerous in water systems as they can easily spread to other water sources, affecting the ecosystem, as well as human resources, health, economy, and the maritime industry. There are many instances where ballast water has been directly linked with invasive species, but two of the most prominent cases center on zebra mussels and Asian Shore Crabs.

Zebra mussels are native to Eastern Europe, but were brought to the Baltic Sea and American Great Lakes areas by ballast water on ships. These mussels are highly invasive as they can attach to any hard surface, thus displacing native mollusks and blocking irrigation and water intake pumps. These invasives illustrate both the negative impacts of ballast water on the marine environment as well as their negative economic impact on coastal or water based communities. When ships need ballast, water is easily pumped into ballast tanks from the sea or the inland waters where the ship is located, which adds weight to the bottom and sides of the vessel.

Ballast water is pumped out into the ocean when it is no longer needed when the weight of the ship needs to be lightened — for example, when the ship is taking on cargo. Ballast water can be disposed of on land while ships are at berth; however, this practice is not common as it is costly and requires specialized equipment and complex processes. Ballast water is crucial for the safe operation of ships.

It is used to adjust the distribution and overall weight of the vessel to keep the ship floating upright and in a safe, stable condition. Ballast is used to compensate for different cargo loads that a ship may carry at different times, including changes in weight during loading and unloading. A commercial ship ballasting and de-ballasting to balance its cargo load.

Ballasting — the process by which a commercial vessel pumps water in or out its ballast tanks while in transit or at a port — is essential for safety, especially if the ship is carrying a heavy load in one hold and a lighter load in another, or empty and facing rough seas. When ballast water is pumped into a ship, sediment and microscopic organisms are also transferred into the ballast tanks.

These organisms include bacteria, microbes, small invertebrates, eggs, cysts, and larvae of various species. When the ballast water is discharged, the organisms are released into the local marine environment. Without their natural predators and given the right conditions these foreign species will not only survive but can also flourish, becoming invasive and threatening and even eliminating resident populations. Since its arrival in the late s due to ship ballast water discharge, this freshwater mussel, native to the Black and Caspian Seas in Europe, has caused significant environmental damages, including disrupting the local food chain.

Zebra mussels can also attach to and suffocate native mussels, causing them to die. Over the years, zebra mussels have continued to spread in Canadian waters and have been found in Quebec St. Lawrence River and Manitoba Lake Winnipeg. This invader has also cost billions of dollars for cleaning and repairs to underwater infrastructure, for example clearing clogged outflow pipes and clusters on pilings.

On the economic front, the impact of invasive species is considerable. Under the Convention, all ships in international traffic are required to manage their ballast water and sediments to a certain standard, according to a ship-specific ballast water management plan. All ships have to carry a ballast water record book and an international ballast water management certificate. The ballast water management standards are being phased in over a period of time.

New ships must meet the ballast water treatment standard. Existing ships should exchange ballast water mid-ocean but they will need to meet the ballast water treatment standard by the date of a specified renewal survey.

Eventually, most ships will need to install an on-board ballast water treatment system. Click here to read more about the requirements. The BWM Convention requires that ballast water management systems used, to comply with the Convention, must be approved by the Administration taking into account the Guidelines for approval of ballast water management systems G8.