12/24/2019 | Wastewater | 9 MINUTE READ

How Does Ballast Water Affect the Environment?

boat in water

Ballast water is necessary for the optimal operation of ships. When a ship heads out into the open waters, ballast water provides the ship with stability as well as the capacity to effectively maneuver in the water. It’s also necessary for loading and unloading items and cargo from the ship in question. This water is placed on the ship before it heads out if it has recently unloaded cargo or isn’t currently carrying any cargo. The extra weight provides stability to the ship that allows it to reach its destination without issue.

You can find out more about the importance of ballast water with this environmental evaluation article or via this research article. No matter how much ballast water you use, it’s important that you properly monitor and maintain the water. Without doing so, you could be damaging the surrounding environment by introducing harmful organisms to areas that aren’t able to accommodate them.

The following will take a look at the importance of ballast water to a ship as well as how certain levels can adversely affect the environment.

What is Ballast Water?

ship in the middle of the ocean with mountains

  • Ballast is a substance that can be used to provide stability to a ship while it’s out on the sea.
    • The main substance that acts as a ballast is water, which is taken onto the ship and stored in a large tank. This water is typically discharged upon arrival at the next port in the event that cargo is being taken on.

Ballast water can be easily added to the tank on the ship before it leaves port, which usually occurs once cargo has been unloaded. At this point, water will be taken directly into the ballast tank to make sure that the ship can operate and maneuver safely until it arrives at its next port of call. The water is able to get into the ballast tank simply by opening the necessary valves. Along with making sure that the ship is stable, ballast water also ensures that the rudder and propeller work efficiently. During the voyage, water can be discharged when entering shallow water. Once the ship arrives at the destination port, all of the water should be discharged to make way for the cargo.

Why is it important?

There are many reasons why ballast water is important for the operation of a ship.

  1. For one, it can reduce the stress placed on the hull of the ship while also keeping the ship stable. When a propeller is submerged into the water, the ballast will help the propulsion plant keep its efficiency.
  2. It’s also important to understand that the constant use of fuel by the ship when in operation will cause some weight loss, which can be counteracted by the ballast tanks.

While ballast water is highly important for the safe operation of practically any ship, there are some environmental concerns that you should be aware of. These concerns arise because of how the water is collected onto the ship and dispersed from it.

The Impacts of Ballast Water on the Environment

ocean water & fishes undersea

The main issue with ballast water when it concerns the environment is that the collection of the water into the ballast tanks stirs up sediments and microscopic organisms that are introduced directly into the ballast tank. Most of these organisms will survive in the voyage from the departure port to the destination port, after which they will be discharged into the water surrounding the destination port.

The main issue is that this water is taken from another location, which means that the microscopic organisms are placed into a source of water that they don’t originate from. The problems that this causes for the environment include:

  • The possibility that native species become extinct
  • Potential negative effects on public health
  • Negative effects for coastal industries that rely on water extraction
  • Negative effects for regional and local biodiversity

All of these issues have the potential to take place because of what happens when the organisms are introduced to new environments. If the water has the right conditions for the organisms to survive, it’s possible that they will be able to reproduce and become a dangerous invasive species. There are times when the organism will even become the dominant species in the area, which can cause native species to go extinct and create real problems with the region’s biodiversity.

Ballast Water & Biodiversity

face to face with a tinny white moray eel

Ballast water is particularly negative for biodiversity because of how much ballast water has been used over the past couple of decades. The traffic and trade volume has expanded greatly in that time, which is why the effects of ballast water have only recently begun to be understood. It’s also important to understand that the traffic and trade volume is expected to grow even more in the future, which means that the negative effects on biodiversity could become even more harmful. 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. However, they can turn into invasive species if it’s believed that the organisms will cause harm to the surrounding environment, human health, or the greater economy. The introduction of invasive species to different environments can pose problems to both freshwater and marine ecosystems.

Invasive Mollusks

As an example of how harmful invasive species can be, studies have shown that the introduction of invasive mollusks within the U.S. costs around $6 billion every year. 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.

Management of Ballast Water

international maritime organization logo

It’s important to manage the ballast water that your ship uses because it will allow you to protect the environment while also meeting any regulatory requirements in your region. Under the International Maritime Organization, every ship that moves through international waters is required to meet water treatment standards for ballast water. When you treat the water properly, invasive species and harmful organisms should be eliminated from the water, which should mean that bacteria and invasive plants don’t spread to other ecosystems.

While the U.S. isn’t officially a part of the IMO agreement mentioned previously, the Coast Guard has its own regulations that must be adhered to if you want to discharge the ballast water within American water. You will also be helping the environment and biodiversity significantly when you manage your ballast water. By not introducing invasive organisms and species to the water in areas where you discharge ballast water, native species will be able to survive, which also means that any issues with public health or the local economy should be effectively avoided.

Treatments of Ballast Water

SD7500CD Universal Differential pH Probe

Before you start treating your ballast water, you should first understand how to properly do so.

  1. The main method for treating ballast water is through UV disinfection, which uses ultraviolet light to kill most of the microbes and organisms that can be present in ballast water. You can even install one of these systems on your ship.
    • Your UV disinfection efforts can be monitored with the use of UV transmittance sensors, of which Sensorex has a couple that you can select from.
    • The online transmittance monitor and portable transmittance monitor can be used to identify the amount of organic content that’s currently in the water.
  2. You should also consider monitoring the pH levels of your ballast water. Understanding the pH level of your ballast water will help you determine what kinds of species, if any, can survive in the water.
    • There are many reliable pH sensors available at Sensorex, which include combination, differential, laboratory, and process sensors. If you require a heavy-duty sensor, consider the SD7500 probe. You could also consider the pH2000 if you want something simpler yet still highly effective.

If you don’t effectively maintain your ballast water, native species could be at risk of dying off while the great ecosystem could be negatively affected in a variety of ways.

Regulating Ballast Water for the Marine Environment

jellyfish in the ocean

Ballast water is used in order to bolster the maneuverability and stability of a ship. When a ship unloads its cargo, ballast water can be pumped into the ship to make sure that it remains stable and functions properly while it travels to its destination port. This water can be effectively managed by treating it with a process known as UV disinfection. To make sure that your treatment of the water is effective, you should monitor UV transmittance with a transmittance monitor. You could also monitor the pH levels to determine if organisms are able to survive in the water.

While ballast water is important for the proper operation of ships, this water adversely affects the surrounding marine environment and can introduce invasive species and organisms to water that alter the local ecosystem. A change in the ecosystem can cause native marine life to die while also creating problems with the economy of nearby coastal towns and cities. There’s even a chance that public health could be affected, which is why it’s essential that you try to maintain your use of ballast water whenever possible.

There are several Sensorex products that can help you manage your use of ballast water. In order to make sure that you use ballast water correctly without causing undue harm to the local environment, you may need to treat the water before discharging it. We offer a couple of highly effective UV transmittance monitors here at Sensorex that can help you identify if the pathogens and bacteria in the water has been destroyed. You could also obtain a pH monitor like the SD7000 to make sure that organisms are unable to survive in the ballast tank. When you’re looking to develop a water treatment plan for your ballast tank, these products can be helpful.

Contact Sensorex today to learn more about the water monitoring sensors and equipment that we provide or view our full product catalog.

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Posted by Sensorex on December 24, 2019

Sensorex is a global leader in the design and manufacture of quality sensors for water quality and process applications. The company offers more than 2000 sensor packages for pH, ORP, conductivity, dissolved oxygen, free chlorine, chlorine dioxide, UV transmittance and other specialty measurements, as well as a full line of sensor accessories and transmitters. Its expert technical support engineers solve analytical sensor challenges with custom designs and off the shelf products.

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