(Shell)Fish out of water... Skills: calculating, reasoning, critical thinking, writing, participating

Transcription

1 (Shell)Fish out of water... Subject Areas: Science, Math Setting: Classroom or at upweller Duration: One class period Skills: calculating, reasoning, critical thinking, writing, participating Vocabulary: aquaculture, upweller, predation, shellfish, clam, quahog, oyster, silo, sluice, pump, tong, rake, dredge, treading, grower Correlation to Core Curriculum Standards: Science: 5.1 (A,B), 5.3 (A, C,D),5.4 (A), 5.10 (A,B); Math: 4.1(A,B), 4.4 (A), 4.5(A,C) Social Studies: 6.1 (A), 6.5(A,B), 6.6(E) Life skills: 9.2(A,C,E) Objectives: 1. Students can define aquaculture as farming seafood 2. Students can identify the parts of an upweller and how it works 3. Students begin to understand the economics of agriculture/aquaculture Materials: Upweller model, or upweller slide show, pen and paper or journal Background: Aquaculture is the process of raising seafood, like farming is raising crops. Aquaculture can happen in the water, or in tanks on land. As overfishing and pollution have contributed to the decline of natural stocks, aquaculture has become more important to help meet our demand for fresh seafood. This lesson will present the aquaculture 71

2 methods used by ReClam the Bay volunteers to raise clams and oysters for restoration in Barnegat Bay. Procedure: Describe to students common methods of harvesting shellfish from the wild. Tonging, raking, treading, and dredging are common methods of harvesting clams. Ask students to try to match the method names to the photos describing them. Both commercial and recreational clamming are very important to New Jersey. Ask students which methods seem better for recreational clamming versus commercial clamming. Which methods would bring in the biggest harvest? Tell them that New Jersey's commercial seafood harvest for 2005 was worth $159 million dollars, but it is estimated that for every dollar of landed value, seafood generates $6 additional dollars in our economy. Have students list where some of this money comes from (shellfish dealers, transportation, restaurants etc). Procedure: Activity - Short Term/Younger Grades Ask students what kinds of things would prevent someone from harvesting shellfish (bad weather, bed closures, equipment trouble, decline in stocks, etc). What would happen to the industry and the economy of New Jersey if we were no longer able to catch fish and shellfish in this way? Show students the graph of hard clam harvest (or oysters) over the past 50 years. What trend do they notice? What may cause this trend? If the demand for shellfish remains unchanged, how would this scarcity affect the availability and price of shellfish? We employ aquaculture to raise fish and shellfish on land to supplement wild stocks, as well as to produce more seafood in an economically viable manner. In the Barnegat Bay Shellfish Restoration Program, we use an upweller to raise clams and oysters. Show students the upweller diagrams, and describe all the parts. Have them guess what the benefits of using an upweller are. Procedure: Activity - In-Depth/Older Grades The way that ReClam the Bay raises shellfish is in a structure called an upweller. 72

3 Show students a diagram of an upweller and explain all the parts. Pass out the upweller quiz and have students label the parts and draw arrows to show the flow of water. Ask students what the benefit is of raising shellfish on land instead of in the water (controlled feeding, lack of predation, easier to keep an eye on). After the shellfish are larger, clams are planted on the bottom of the bay under predator screen, and oysters are put into Taylor floats. Ask students again why this is necessary? When the shellfish ReClam the Bay grows are large enough to fend for themselves, they will be placed in protected marine areas to help improve future populations. Extension: Taking it further Have students research the oyster industry of New Jersey in the 1920s-1950s. See if they can find out the value of that fishery, and what caused its decline. Have class or students individually visit an upweller site (see attached list) during one of the demonstration times over the summer. Alternately, use the instructions provided in this guide to construct a model upweller or mini Taylor Float as a class (See instructions). 73

4 Assessment: Harvest Matching exercise Upweller Anatomy Quiz Report on upweller visit Model upweller or Taylor Float Also see: Harvesting Relay, Shellgo from Beneath the Shell, NJDEP. Harvest Methods Matching Exercise Answers 1. Treading 2. Tonging 3. Raking 4. Dredging 74

5 Clam Harvest Graph Reported landings for hard clams in Ocean County 1,600,000 1,400,000 1,200,000 1,000,000 Pounds 800, , , , Chart by G. Calvo based on NMFS data N/A 2003 N/A

6 Harvest Methods Matching Exercise Fill in the name of the harvest method to match each picture below. Adapted from Beneath the Shell, NJDEP and Rice

7 Upweller Anatomy Adapted from ReClam the Bay 77

8 Upweller Anatomy Quiz Name the upweller parts by filling in the spaces. What are the advantages to growing shellfish in an upweller?

9 Upweller Anatomy Quiz Answers Name the upweller parts by filling in the spaces. From the top left, clockwise: Silo, Silo outfeed, sluice box, tank, tank infeed What are the advantages to growing shellfish in an upweller? 1. Protection from predators 2. Continual feeding. 3. Controlled environment/can get to them easily 79