3. Open Ocean Ecosystems

Lesson at a glance: Students will explore the interactions of species in an open ocean environment.

Goal: Students will be able to articulate and demonstrate adaptations that allow fish to survive in the open ocean environment and describe interactions between species.

Oregon Content Standards:

Science

4.2 Interaction and Change: Living and non-living things undergo changes that involve force and energy.

4.2L.1 Describe the interactions of organisms and the environment where they live.

Ocean Literacy: Essential Principals and Fundamental Concepts

1. The Earth has one big ocean with many features.

1.h. Although the ocean is large, it is finite and resources are limited.

5. The ocean supports a great diversity of life and ecosystems.

5.d. Ocean biology provides many unique examples of life cycles, adaptations and important relationships among organisms (symbiosis, predator-prey dynamics and energy transfer) that do not occur on land.

5.f. Ocean habitats are defined by environmental factors. Due to interactions of abiotic factors such as salinity, temperature, oxygen, pH, light nutrients, pressure, substrate and circulation, ocean life is not evenly distributed temporally or spatially, i.e. it is “patchy”. Some regions of the ocean support more diverse and abundant life than anywhere on Earth, while much of the ocean is considered a desert.

Materials:

  • Open space like schoolyard or gym

Estimated Time:

60 minutes total: Engage= 15; Explore= 30; Explain= 20

Activity:

Engage:

Show the students a short video clip on the Open Ocean from <youtube.com> The Living Planet video is great but long so it might be good to just show a clip that show some of the diversity of fish in the Open Ocean.

Introduce the term ecosystem and explain that an ecosystem is all of the living and non-living things in an environment and how the relationships between them. For example, a food chain is a way that animals interact in an ecosystem.

Explore:

Students are going to participate in a game to begin to understand the foundations of ecosystems. Review with students that all living things have needs. Ask the students what those needs are. Create a list on the board that includes food, water, shelter and air. Explain that this is true of marine ecosystems as well.

Explain that they are going to all become anchovies and play a game called “Oh, Anchovy!” While they are anchovies, they are going to be in pursuit of the things they need to survive; food for energy, shelter in the form of schooling, and water which they also receive oxygen from. Show them the gestures for each:

  • Food- hands over mouth
  • Water- using hand to make waves in front of them
  • Shelter- make a roof over their heads with their hands

Explain that they are going to graph how the population of anchovies and the number of resources changes over each “season.”

Play the game:

  1. Take the students to a large space and split them into two groups.
  2. Have each group stand in lines facing one another about 50 ft. from one another.
  3. Explain that one group are the resources (food, water, shelter) and the other group are the anchovies the first “season.” Plot on the bar graph how many anchovies and resources there are the first “season” on the graph.
  4. Explain that the groups are going to turn their backs to one another, choose what resource they are going to be or what resource they are going to get that “season” and make that gesture.
  5. When you say go, have the groups turn around and face each other while still making their gesture. The resources should stand still but the anchovies should run to the other side and grab one student that is the resource they are looking for. Anchovies that found the resource they were looking for survived and were able to reproduce, so the resource should follow them back to the anchovy side. Anchovies that were not able to get a resource did not survive and will be join the resource side for the next season.
  6. Repeat for about 10 seasons so that students can see the fluctuation in the population based on resource availability while continuing to graph.

Bring the students and the graph back to the classroom. Have students reflect on their experience as a class. Use prompting questions such as:

  • What three habitat requirements were in the activity?
  • How did the organisms act when their habitat requirements became limited?
  • Describe how populations of organisms change over time with respect to habitat availability?

Explain:

During class reflection on the activity, introduce vocabulary for the experience they are describing including:

Population: a group of animals of the same species in an environment

Competition: the contest to get the things one needs to survive

Consumers: organisms that obtain food by eating other organisms

Producers: the food at the bottom of the food chain, for anchovies this is phytoplankton

Have the students reflect on their experience in their science notebook using the new vocabulary.

Ask the students what the activity was missing compared to the real ecosystem of the open ocean? Predators and other consumers with similar needs. Ask the students how the activity would have been different if there had been these other factors? How do they think that would have affected the population of anchovies over the seasons? Explain that the interactions of species in ecosystems are very complicated.

Extension:

Explore the adaptations that allow animals to survive and compete for resources in an environment.

Have students complete another activity to further their understanding of fish adaptations, such as:

· Feeding Fishes

· Open Sea Swimmers

Evaluate:

Review students field notebooks, etc.