1. Unit 9 Lesson 4 Ecology of Marine Ecosystems Copyright © Houghton Mifflin Harcourt Publishing Company

2. Under the Sea Copyright © Houghton Mifflin Harcourt Publishing Company What are the major types of marine ecosystems? Coastal ocean ecosystems are found on or near coastlines, and they include sandy beaches, rocky shores, and coral reefs. Open ocean ecosystems are found far from coastlines and over very deep water. Deep ocean ecosystems are found in the deepest, darkest parts of the ocean. Unit 9 Lesson 4 Ecology of Marine Ecosystems

3. What abiotic factors affect marine ecosystems? Temperature, pressure, water depth, water flow rate, light levels, salt levels, and oxygen levels are all abiotic factors that affect marine ecosystems. These abiotic factors can interact in different ways in each marine ecosystem. Copyright © Houghton Mifflin Harcourt Publishing Company Unit 9 Lesson 4 Ecology of Marine Ecosystems

4. Where can marine ecosystems be found? Coastal ocean ecosystems, such as beaches, tidal pools, seagrass beds, coral reefs, and kelp forests are found along the edges of landmasses. Beaches, tidal pools, and seagrass beds are most affected by tides, so organisms there must be adapted to changing abiotic factors. Coral reefs and kelp forests are underwater coastal ecosystems that provide shelter and food for many species. Copyright © Houghton Mifflin Harcourt Publishing Company Unit 9 Lesson 4 Ecology of Marine Ecosystems

5. Where can marine ecosystems be found? Open ocean ecosystems are far from coastlines and can be divided into the sunlight zone, twilight zone, and midnight zone. Plankton live in the sunlight zone, and they are an important food source for many open-ocean animals. Some animals move between coastal and open ocean ecosystems. Copyright © Houghton Mifflin Harcourt Publishing Company Unit 9 Lesson 4 Ecology of Marine Ecosystems

6. Where can marine ecosystems be found? Deep ocean ecosystems are found in the deepest parts of the ocean and are often dark, cold, and under high pressure. No photosynthesis happens in these ecosystems because of the lack of light, so deep-ocean organisms have adaptations to get energy in other ways. Bacteria near hydrothermal vents use chemicals in the water to make food. Copyright © Houghton Mifflin Harcourt Publishing Company Unit 9 Lesson 4 Ecology of Marine Ecosystems

7. What are the feeding relationships in a marine ecosystem? Marine ecosystems are home to producers and consumers. Primary consumers get energy from producers. In a predator-prey relationship, secondary consumers eat primary consumers, and tertiary consumers eat secondary consumers. Marine organisms can also be hosts to parasites in a parasite-host relationship. Copyright © Houghton Mifflin Harcourt Publishing Company Unit 9 Lesson 4 Ecology of Marine Ecosystems Let’s Eat!

8. What are the feeding relationships in a marine ecosystem? How does energy move from one organism to another in a marine food web? Copyright © Houghton Mifflin Harcourt Publishing Company Unit 9 Lesson 4 Ecology of Marine Ecosystems

9. How do marine organisms compete with one another? Marine organisms of the same species may compete for food, space, and mates. Different species may also compete for space and food, or for space and sunlight if they are producers. Copyright © Houghton Mifflin Harcourt Publishing Company Unit 9 Lesson 4 Ecology of Marine Ecosystems

10. How do humans use oceans? Humans harvest billions of pounds of commercial fish from oceans every year. The oceans provide the raw materials for many products, such as fertilizers and food additives. Humans utilize the oceans for energy resources, including offshore wells for drilling oil. Oceans also provide many opportunities for recreation and transportation. Copyright © Houghton Mifflin Harcourt Publishing Company Unit 9 Lesson 4 Ecology of Marine Ecosystems In the Deep Blue Sea

11. How do human activities affect marine ecosystems? Human activities on land can produce runoff that affects marine organisms. Runoff from farms can carry pesticides and fertilizers. Runoff from cities can carry oil and gasoline that has spilled onto roads. Copyright © Houghton Mifflin Harcourt Publishing Company Unit 9 Lesson 4 Ecology of Marine Ecosystems

12. How do human activities affect marine ecosystems? Overharvesting happens when the rate of fishing is higher than the rate of reproduction in a population. As individuals are removed from a population faster than they can be replaced, the entire population may eventually disappear. Copyright © Houghton Mifflin Harcourt Publishing Company Unit 9 Lesson 4 Ecology of Marine Ecosystems

13. What are ways that humans can help conserve marine ecosystems? People can eat only fish that are not overharvested and properly dispose of chemicals. Governments can pass laws to reduce overharvesting and ocean pollution. Communities near oceans can build artificial reefs, which can have a positive effect by providing more habitat for coral reef species. Copyright © Houghton Mifflin Harcourt Publishing Company Unit 9 Lesson 4 Ecology of Marine Ecosystems