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Overview

Aquaculture, like any other industry, has its costs and benefits, as well as its proponents and opponents. Students will discuss some of the pros and cons related to aquaculture. As a class, the students will discuss the hypothetical case studies provided. In cooperative learning groups, students will engage in an aquaculture debate in the style of a town meeting.

Objectives

Students will:

  • Describe impediments to aquaculture development.
  • Describe the pros and cons of an aquaculture industry in their community.
  • Describe the position of several community groups regarding aquaculture development.

Grade Level

6 -12

Subjects

  • Science
  • Social studies
  • Environmental studies

Vocabulary

aquaculture, carnivorous, herbivorous, mangrove, sustainability

Time

2 class session

Materials

Copies of student handouts Two Florida Communities and Aquaculture Pros and Cons

National Science Standards

This activity supports the following National Academy of Sciences science education standards.

Grades 5-8:

  • Unifying Concepts and Processes - Systems, order and organization
  • Standard C: Life Science - Populations and ecosystems
  • Standard E: Science and Technology - Understandings about science and technology
  • Standard F: Science in Personal and Social Perspectives - Populations, resources, and environments
  • Standard F: Science in Personal and Social Perspectives - Risks and benefits
  • Standard F: Science in Personal and Social Perspectives - Science and technology in society

Grades 9-12:

  • Unifying Concepts and Processes - Systems, order and organization
  • Standard F: Science in Personal and Social Perspectives - Natural resources
  • Standard F: Science in Personal and Social Perspectives - Environmental quality
  • Standard F: Science in Personal and Social Perspectives - Science and technology in local, national, and global challenges

National Social Studies Standards

This activity supports the following National Council for the Social Studies standards.

Middle Grades:

  • Standard I: Culture - a, d
  • Standard III: People, Places, & Environments - k
  • Standard IV: Individual Development & Identity - h
  • Standard V: Individuals, Groups, & Institutions - g
  • Standard VII: Production, Distribution, & Consumption - f
  • Standard VIII: Science, Technology, & Society - b, d, e
  • Standard IX: Global Connections - d
  • Standard X: Civic Ideals & Practices - c, d, g

High School:

  • Standard I: Culture - a
  • Standard III: People, Places, & Environments - k
  • Standard IV: Individual Development & Identity - h
  • Standard VII: Production, Distribution, & Consumption - f
  • Standard VIII: Science, Technology, & Society - d, f
  • Standard IX: Global Connections - d
  • Standard X: Civic Ideals & Practices - c, d

Background

Aquaculture - the production of aquatic organisms for human use-is an increasingly important source of seafood. Many believe that it can help fill the gap between the growing demand for seafood and what can be caught in the wild. It can also provide jobs and rejuvenate the seafood processing industry in some places.

Aquaculture exists in almost every country in the world, but the US produces relatively little. Even though national policy is aimed at encouraging aquaculture initiatives, there are still many barriers to starting new aquaculture ventures including:

Economics
Starting a new aquaculture venture is expensive, it requires a large initial capital investment, and it may be quite some time before entrepreneurs begin to see a profit. Banks may be skeptical about loaning large sums of money to small aquaculture entrepreneurs. As a result, new aquaculture enterprises often favor large businesses over smaller, community operations.

Siting issues
Not every body of water can serve as a site for an aquaculture facility and many species are farmed inland in human-made ponds or raceways. Very specific requirements must be met. For example, to raise Pacific White shrimp, pond water must remain near 75-85 degrees for three to four months while the shrimp grow to full size. For salmon or other finfish grown in net-pens in the ocean, you must have very strong tides to disperse the wasted produced from the finfish or you risk polluting the surrounding waters. For oysters, mussels and other mollusks, you must have nutrient-rich water. Culturing mollusks and aquatic plants usually has minimal negative environmental consequences.

Aquaculture operations in the ocean and on the coast are always at the mercy of Mother Nature. Storms and other oceanographic and meteorological conditions can wreak havoc on one's fish, mollusk, or shrimp farm. A specific threat related to farmed bivalves is a tiny organism called fecal coliform bacteria which can enter the water via sewage, particularly during times of flooding. Because these bacteria can contaminate the bivalves and threaten the health of consumers, mollusks must be grown in clean waters. In spite of all these hazards, excellent environments for aquaculture operations across the U.S. do exist.

Environmental issues
Aquaculture production of some species and in some areas is being done in a way that minimizes environmental impact. Several conservation organizations such as Monterey Bay Aquarium, Environmental Defense, and Blue Ocean Institute publish seafood cards that rate farmed catfish and tilapia, for example, “green” (the best designation). But many people are concerned that some forms of aquaculture can create more problems than they alleviate. On fish farms, species such as shrimp and salmon are fed high-protein pellets which include high percentages of fishmeal and fish oil made from small wild fish such as anchovies. There is a range of scientific opinion about exact conversion ratios, but fisheries experts agree that raising carnivorous species currently consumes more fish than it produces, putting pressure on wild fish populations.

To make way for modern aquaculture operations, farm fields may be flooded for catfish ponds, shrimp farms may be adjacent to sensitive coastal forests, and waters in coastal areas may be fenced to raise “crops” of salmon, mollusks, and seaweed.

Dead fish, uneaten food, and excrement wash directly into waterways from many modern aquaculture operations. And the antibiotics, vaccines, and chemicals that many farmers use to fight disease get flushed away, too, with unknown effects on wild fish and their habitat. The U.S. Environmental Protection Agency recently established national standards to control the effluent from aquaculture operations.

Fish farms often raise fish that aren't native to the area. Farmed fish are usually stocked in cages when disease-free. They often catch diseases that are naturally occurring in the water and on wild fish, and then amplify the disease or parasite due to high stocking densities. Now the disease can become a much larger threat to wild fish that swim by the net-pens. When farmed fish escape, they can become established in the wild, and compete with or prey on native fish. Up to 50% of salmon caught in certain rivers in Norway are of farmed origin, and on average they estimate that 1/4 of all salmon in the wild are of farmed origin (not just escapees, but also offspring of escapees).

Opposition
Among the biggest barriers to starting new aquaculture ventures in the U.S. is a lack of appropriate areas for mariculture or culture of species along the coast combined with local public opposition. Although there are many people who support and encourage a growing aquaculture industry, there are others who oppose growth in this industry if it does not appear sustainable.

A long-term goal of the aquaculture industry and government proponents is to help offset the annual $8 billion seafood trade deficit (as of 2005). For example, the US is the largest importer of farmed shrimp, and currently, over 70% of the seafood that Americans consume is imported, and at least 40% of our seafood imports are aquaculture products. Success with aquaculture in the United States requires high rate and high yield production systems that are both environmentally and economically sustainable and yield a high quality product.


Before You Begin

  1. Make copies of the hypothetical case study, Two Florida Communities , handout for each student.
  2. If desired, make copies of the Aquaculture Pros and Cons handout for each student.

What To Do

Before the Activity

Prior to class, have the students read the Two Florida Communities handout.

The Activity

  • As a class or in cooperative learning groups, review the Two Florida Communities handout describing the hypothetical case study about Gull Island and Tern Island. Develop a possible pros and cons list for aquaculture or use the Aquaculture Pros and Cons handout provided.
  • Engage the class in a discussion about the case study. How and why did the two communities reach such different conclusions about the issue of shrimp farming?
  • Introduce the idea of a town meeting or debate in which various members of the community come together to reach a consensus on an issue or proposal which will affect their community. Explain that the class will conduct their own town meeting to decide whether to permit the establishment of an aquaculture venture in their own community.
  • Have the class set the parameters of the aquaculture site that is being proposed:
    • Will the company be culturing finfish, shellfish, or sea vegetables? Will it be a carnivorous or herbivorous species? What species?
    • Will the site be warmwater, coldwater or marine? A river, estuary, shorefront, land-based, or deepwater?
    • Is the area already used by others? By whom?
  • In the aquaculture debate, groups of students will role play a position on aquaculture and defend it in a town meeting. Select about six roles from this list, or create roles appropriate to your community: commercial fisherperson, tourist bureau representative, homeowner, vacationer, local/state politician, small-scale aquaculture entrepreneur (local), large-scale aquaculture entrepreneur (international), scientist, or conservation group representative.

    Before the debate, stress the professionalism and decorum which ought to take place in a town meeting. Establish a set of guidelines based on mutual respect so that the debate does not degenerate into a shouting match. You may need to stress that the point of a debate is to adopt the position of the group and defend that position. The position may or may not reflect the students' own opinions. Therefore, students ought not to feel personally attacked and have the advantage of learning how to argue positions other than their own. Students should gain an understanding of the complexity of community issues.

  • Break the class up into as many groups as there are roles. Assign (or let the groups choose) a different role for each cooperative learning group. You may want to provide a “blurb” describing each group's general position on aquaculture. However, be careful not to pigeonhole groups into black and white categories. There are advantages to letting the students struggle with defining the roles of these groups themselves, rather than providing them with a predetermined script. Encourage groups to approach this as a real-life scenario.

    Give students time (20-30 minutes) to prepare their case. They can use the Two Florida Communities handout and the Aquaculture Pros and Cons as reference materials to help build their arguments. Case statements can include stipulations such as: “I support aquaculture in the community if x, y, and z are included.”

  • Give each group three minutes to present their case. After all groups have spoken, any group may “counter” or challenge another group?s argument. Be sure to give the challenger a time limit (one or two minutes) and give the challenged group an opportunity to respond. Limit challenges and responses to one per group.
  • After the debate is over, individuals will be asked to vote on whether or not they want to start an aquaculture venture in their community and what, if any, stipulations they'd enforce. Write the final decision on the board or overhead and, as a group, list the reasons and/or stipulations for the decision.

Assessment

Ask students to write an essay describing their personal opinion regarding the class vote and explain their reasoning.


Extensions

  • Survey/Questionnaire: Ask students to create a survey/questionnaire to determine how members of the community would feel (or do feel) about having an aquaculture facility in their community. Have them survey family, friends, and members of the community and share their results with the class. Students may also choose to tape a personal interview with someone who has an interesting point of view.
  • Marine Issues: Divide students into groups and have each group monitor one local marine issue or controversy involving fisheries and/or aquaculture.

Credit

Adapted with permission from “To Culture or Not to Culture: The Controversy Continues” in the Maine Aquaculture Curriculum Guide by the Maine Aquaculture Innovation Center

Activity Handouts

All PDF files require Adobe Acrobat 5 or above. For additional classroom content, please visit PBS TeacherSource.