Nauticus - Port To Port: A Ship's Journey Curriculum

Curriculum Index

Curriculum Objectives

Curriculum Outline

Student Pages

Virginia SOLs

Lesson 1: Preparing For Your Journey

Lesson 2: Meet Your Ship

Lesson 3: Plotting The Course

Lesson 4: Adding It Up

Bibliography

LESSON 5: ENVIRONMENTAL IMPACT

Objectives
Materials
Background Information
Key Questions
Vocabulary
Procedure
Evaluation

Objectives

Students will access the Global Invasive Species database and collect data for invasive species for their ship's home port and port-o-call.
Students will write a short report on the role ships play in introducing invasive species into ports and what is being done to counteract this problem for their assigned ports.
Students will access the internet and write a short report on the environmental impact of ships on local waterways and estuaries.

Materials

Internet Access

Background Information

The taking on of ballast is an essential operation of ships. In order to maintain stability and make sure that the ship sits in the water correctly, all ships that are not carrying cargo must carry ballast. This is usually in the form of water.

Ships take on thousands of gallons of water for ballast, usually while docked in port. Living in the water, and in the sediment which is also carried into the ship, are millions of microorganisms.

When the ship crosses the ocean and reaches another port to take on cargo, ballast water is discharged. When the water is discharged, the microorganisms that survived the journey are discharged as well. If the conditions of this new environment are ideal for any particular organism, they will survive in the local waters and reproduce. This is when the foreign species becomes known as an invasive species. Invasive species compete with native flora and fauna for space, food, sunlight and can change the conditions of the environment.

An invasive species is:

non-native to the ecosystem being studied and
whose introduction causes or is prone to cause adverse economic conditions or can cause environmental damage, harm local flora and fauna or create a risk to human health.

Invasive species can include animals, plants, and microbes. Humans are the main introducers of invasive species.

There are many ways an invasive species can harm an ecological system. It is estimated that 80% of the world's endangered species could be further reduced due to predation and increased competition for food and space from invasive species. Purple loosestrife (Lythrum salicaria), a plant that chokes out native grasses and plants in wetland areas that provide nutrition for aquatic life, is endangering ducks and turtles that rely on native plants. Purple loosestrife was introduced to the US from Eurasia in the early 1800s in ballast water.

Impacts of invasive species fall into three categories:

Ecological: Native flora/fauna and ecological processes are disrupted.
Economical: Fisheries, industries that utilize the natural resources of the coasts, bays, watersheds, and oceans are disrupted by the impact of invasive species.
Human health: Toxic organisms, pathogens and diseases are introduced to the local ecological system via ballast water, which can cause death and/or illness in humans.

There are many examples of invasive species that are adversely impacting the three areas mentioned above. These include:

European Zebra Mussel (Dreissena polymorpha):
- Native to Eurasia
- Introduced to US through ballast water in 1988
- Currently invading the Great Lakes and Mississippi River
- Competes with native species and clogs pipes.
North Pacific Seastar (Asterias amurensis):
- Native to Japan, Korea, Russia, North China, and far North Pacific waters
- Larvae distributed through ballast water
- Invasive in Australia including Tasmania and Victoria
- Eats a wide range of prey, has potential for ecological and economic harm
Toxic dinoflagelattes (Alexandrium catenella) and (Gymnodinium catenatum):
- Found globally
- Spread via ballast water
- Cause of Red Tides
- Poisons oysters and scallops and other filter feeders
- Causes paralysis or death in humans who eat infected shellfish (Paralytic Shellfish Poisoning)

The shipping industry, national and international organizations, and environmental organizations are working together to combat this global threat.

In response, the International Maritime Organization (IMO) was created to developed guidelines for ballast water handling. The guidelines are:

Minimize introduction of organisms into a ship's ballast water.
Minimize build up of sediment in ballast tanks.
Problem solving techniques, such as dumping ballast water in open waters, before reaching port, to reduce the transfer of invasive species into a local ecological system.

Key Questions

What is an invasive species?
How are invasive species introduced into an ecosystem?
What are some concerns for the environment that ship traffic produces?

Vocabulary

Invasive Species - non-native to the ecosystem being studied and whose introduction causes or is prone to cause adverse economic conditions or can cause environmental damage, harm local flora and fauna or create a risk to human health.
Dredging - Dredging is an excavation activity usually carried out underwater in shallow seas, rivers or channels with the purpose of scraping sediments off the floor to increase the depth of water in a navigation channel used by shipping
Ballast Water - Water carried temporarily in an empty ship to provide stability.
Watershed - A region where rain water or melting snow drains into a river, lake, dam, estuary, wetland, sea or ocean. The drainage basin is made up streams or rivers that carry water and the land that water drains from.
Stormwater - Water that originates during precipitation events such as rain or the melting of snow. Stormwater that has not soaked into the ground is called stormwater runoff. This is what carries contaminants into the sewer system or nearby water sources.