
Invasive Species &
Marine Shipping
#invasivespecies #ballastwater #biofouling #clearfacts
Ships move species from port to port via two main routes:
Ballast Water
Ballast water is drawn from a vessel’s surrounding environment and stored in specialized tanks. Ballast is critical for maintaining weight and providing stability during the voyage and as a ship loads and unloads its cargo. Aquatic species can be swept up in ballast water when it is pumped into ballast tanks and released into a new environment when the vessel takes on cargo in a new port.
Propeller

Bilge Keel

Sea Chest

Bow Thrusters

Anchor

Biofouling
Live organisms ranging from algae and microbes to mussels and barnacles can attach to ships’ hulls in a process known as “hull fouling” or “biofouling”. Species attached to vessel hulls can be transported long distances where they can then dislodge and reproduce in a new environment. In addition to the flat surfaces of a vessel’s hull, there are several underwater niches on a ship where organisms can collect, including bow thrusters, rudders, propellers, intakes, and sea chests (protected cavities built into the hull of a vessel, covered with metal grates and exposed to a constant flow of seawater).
Many aquatic species have been introduced worldwide through the discharge of ballast water and through biofouling[13]. Both of these routes are important (and are not the only way invasive species can travel), but some species and regions seem to experience more invasions from one route than the other.

In New Zealand, biofouling was found to be responsible for about 70% of aquatic invasive species, compared to just 3% from ballast water.

In U.S. waters, hull biofouling accounted for about 35% of aquatic invasive species compared to 20% from ballast water.

Invasive Species in Canadian Waters
Learn more about how invasive species are impacting ecosystems and economies in Canadian waters through examples of invasives of concern in different regions.[19]
Initiatives Underway
There are a number of initiatives currently in place in Canada and internationally that are helping to reduce the risk of shipping as a pathway for invasive species.
- The Central Coast Indigenous Resource Alliance, which consists of four First Nations – Heiltsuk, Kitasoo/Xai’Xais, Nuxalk, and Wuikinuxv – is partnering with the Province of British Columbia to implement the Marine Plan Portal (MaPP) on the Central Coast of British Columbia through a coordinated response to three aquatic invasive species: European Green Crab, tunicates, and bryozoa.
- Ten people (Guardian Watchmen and other field staff) from the four Nations are monitoring these aquatic invaders and collecting baseline data on their presence, abundance, and damage to the ecosystem. The millennia-long connection of the four Nations to these ecosystems is integral to this work.
- In 2012, the Port of Prince Rupert entered a partnership with the Coast Mountain College Applied Coastal Ecology program and the Invasive Tunicate Network’s Plate Watch program to start one of the first aquatic invasive species monitoring programs on Canada’s Pacific coast.
- The program monitors for the presence of the European Green Crab, invasive tunicates and bryozoan species. Program participants collect and report findings to a coast-wide group of experts, contributing to an early detection system for invasive species. To date, no invasive species have been found in Prince Rupert harbour, although a few have been detected in the broader area of BC’s north coast.
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- Green Marine’s Environmental Certification Program includes performance indicators that encourage domestic and international ship owners adopt accepted best practices to prevent the introduction of invasive species, including keeping an annual ballast water inventory record and participating in research and development for new ballast water treatment systems.
- The indicators also recommend ship owners test or install ballast water treatment systems and implement anti-fouling measures.

- Initiated in 2017, this project brings together the Global Environment Facility, the United Nations Development Programme, the International Maritime Organization (IMO) and other partners including Transport Canada, to build capacity in developing countries to implement the IMO Biofouling Guidelines.
- Participating countries are working together to develop legal, policy and institutional reforms to address biofouling issues in their regions.
- New Zealand’s Ministry for Primary Industries introduced the world’s first national standard for biofouling rules for vessels arriving in the country’s territorial waters in May 2018.
- The Craft Risk Management Standard for Biofouling (CRMS) requires all vessels arriving in New Zealand to have a clean hull, and applies to any vessel that will anchor, berth or be brought ashore after a voyage originating outside of New Zealand’s territorial waters.

- New marine invasive species program updates came into effect as of January 1, 2022, to address ballast water and vessel reporting requirements in California’s waters.
- The State’s biofouling management plan and invasive species programs are considered to be more stringent than U.S. and International Maritime Organization regulations.[40]

About Clear Seas
Clear Seas is a Canadian not-for-profit organization that provides independent fact-based information to enable governments, industry, and the public to make informed decisions on marine shipping issues. We work to build awareness and trust so that all people can feel a part of the marine sector. Our vision is a sustainable marine shipping sector that is safe, vibrant, and inclusive, both now and for future generations.
As an independent research centre, Clear Seas operates at arm’s length from our funders. Our research agenda is defined internally in response to current issues, reviewed by our research advisory committee, and approved by our board of directors.
Our board of directors is composed of mariners, scientists, community leaders, engineers and industry executives with decades of experience investigating human, environmental and economic issues related to our oceans, coastlines and waterways.
Our reports and findings are available to the public at clearseas.org
Sources & Citations
- Council of Canadian Academies. (2017). The Value of Commercial Marine Shipping to Canada.
- Hildebrand, J. A. (2005). Impacts of anthropogenic sound. In J. E. Reynolds III, (Ed.), Marine Mammal Research: Conservation Beyond Crisis (pp.101-124). Baltimore: The John Hopkins University Press.
- Hildebrand, J. A. (2009). Anthropogenic and natural sources of ambient noise in the ocean. Marine Ecology Progress Series, 395, 5-20.
- Sound recordings courtesy of: Rain – Sonatech, Inc.; Earthquakes – Ocean Networks Canada; Hydrothermal Vents – Tim Crone; Storms – Henry Bass, Roy Arnold and Anthony Atchley; Cracking Ice – Ocean Networks Canada; Marine Life – Sheila Patek; Surface Waves – Earth Vibes; Ship Passing Pod of Orcas – OrcaLab; Commercial Vessels – OrcaLab; Recreational Vessels – Ocean Networks Canada; Snowmobile on Ice – Ocean Networks Canada; Pile Driving – Orca Sound; Sonar – Ocean Networks Canada; Seismic Experiments – J & A Enterprises, Inc.
- Transport Canada. (2017). Understanding Anthropogenic Underwater Noise.
- Ross, D. (1976). Mechanics of underwater noise. Pasadena: Pergamon Press.
- The International Maritime Organization. (2013). Noise from commercial shipping and its adverse impacts on marine life.
- Veirs, S., Veirs, V., and Wood, J. D. (2016). Ship noise extends to frequencies used for echolocation by endangered killer whales. PeerJ. doi: 10.7717/peerj.1657
- Lesage, V., Barrette, C., Kingsley, M. C. S., and Sjare, B. (1999). The effect of vessel noise on the vocal behavior of belugas in the St. Lawrence river estuary, Canada. Marine Mammal Science, 15(1), 65-84.
- Discovery of Sound in the Sea. (2017). Beluga whale, white whale.
- Discovery of Sound in the Sea. (2017). North Atlantic Right Whale.
- Orca Network (2017). Southern Resident Orca Community Demographics, Composition of Pods, Births and Deaths since 1998.
- Port of Vancouver. (2017). ECHO Program.
- Fisheries and Oceans Canada. (2017). Evaluation of the Scientific Evidence to Inform the Probability of Effectiveness of Mitigation Measures in Reducing Shipping-Related Noise Levels Received by Southern Resident Killer Whales.
- Fisheries and Oceans Canada. (2017). North Atlantic Right Whale.
- Canadian Whale Institute. (2017). Changing Marine Policy to Protect Right Whales.
- Fisheries and Oceans Canada. (2017). Beluga Whale (St. Lawrence Estuary population).
- Species at Risk Public Registry. (2017). Species Profile.
ballast water
Most ships are equipped with a range of ballast capabilities and capacities. The typical amount of water carried is approximately 25 – 30% of the ship’s deadweight tonnage (DWT).[10][11]
For example, a Seawaymax bulk carrier of 28,500 DWT (able to pass through the locks of the St. Lawrence Seaway) can hold up to 24 million litres of water in its ballast tanks – the amount of water needed to fill nearly 10 Olympic swimming pools.
It is difficult to predict which organisms will survive a journey inside a ballast tank. Larger ones may survive by eating smaller ones; smaller ones may survive hostile conditions by adopting a dormant form and become active once conditions improve.
Biofouling
Once a surface, such as a ship’s hull, enters the water, it is rapidly colonized by a range of species. In addition to transporting invasive species, biofouling lowers fuel efficiency by increasing a ship’s resistance to the water. When ships burn more fuel, they also increase greenhouse gas emissions and reduce air quality. A ship with a heavy coating of slime can require up to 38% more energy to maintain speed than a vessel with a clean hull.
Canadian Ballast Water Regulation
The Great Lakes are a shared water body and resource, jointly managed by Canada and the United States. Differences in regulation pose a challenge to this joint management as the United States is not a signatory to the international Convention and instead maintains its own regulations to manage ballast water. Canadian and U.S. officials conduct joint inspections of ships’ ballast water to verify that vessels entering the Great Lakes-St. Lawrence Seaway from overseas comply with both nations’ ballast water regulations, working together in an effort to uphold the Great Lakes Water Quality Agreement.
The IMO biofouling guidelines
The IMO Biofouling Guidelines were adopted in 2011 following three years of consultation with IMO member states and are in the process of being reviewed and updated.[39] The guidelines recommend the following practices:
- Biofouling management plan
- Biofouling record book
- Anti-fouling system installation and maintenance
- In-water inspection, cleaning and maintenance
- Ship design and construction
- Dissemination of information
- Training and education
- Other measures










