Ch 13 – 4 Life in the Oceans A. Types of Ocean Life Many different kinds of organisms live in the ocean. Where the organism lives and how it moves classifies it as plankton, nekton, or a bottom dweller. Plankton are tiny marine organisms that drift in the surface waters of every ocean.

A. Types of Ocean Life 3. Most plankton are one-celled, microscopic organisms. Eggs of ocean animals, very young fish and larval jellyfish are plankton. 4. Nekton are marine animals that actively swim in ocean water. 5. Fish, whale, shrimp, turtles, and squid are examples of nekton. They are found in all temperatures and depths of the ocean.

A. Types of Ocean Life 6. Bottom dwellers are animals that live on the ocean floor. 7. Bottom dwellers are include crabs, snails, and sea urchins. They can swim or move along the floor searching for food.

A. Types of Ocean Life 8. Some bottom dwellers, such as sponges and anemones, are permanently attached to the ocean floor. They must obtain food by filtering out particles from the seawater.

B. Ocean Ecosystems An ecosystem is a community of organisms, which includes producers, consumers, and decomposers, that interact with each other and their surroundings.

C. Producers 1. A producer is an organism that can make its own food. They are a food source for other organisms. 2. Producers near the surface of the water contain chlorophyll and perform photosynthesis. 3. These producers use sunlight and carbon dioxide to make food and oxygen.

C. Producers 4. Since sunlight cannot penetrate deep water, producers that live in deep water perform chemosynthesis. 5. Chemosynthesis is a process in which bacteria make food from dissolved sulfur compounds. 6. Chemosynthesis occurs most often along mid-ocean ridges.

C. Producers 7. Along mid-ocean ridges, water is heated from gases, like sulfur, escaping through Earth’s crust. Bacteria use the dissolved sulfur to produce food.

D. Consumers and decomposers A consumer is an organim that gets its energy from eating other organisms. Consumers can use the energy stored in the cells of producers and other consumers. When producers and consumers die, decomposers digest them.

D. Consumers and decomposers 4. Decomposers break down tissue and release nutrients and carbon dioxide back into the ecosystem. Bacteria are common decomposers.

E. Food chains Throughout the ocean, energy is transferred from producers to consumers and decomposers through food chains. 2. Most food chains are complicated. Usually a species depends on more than on organism for food.

E. Food chains 3. Food chains that are complicated and interconnected are called food webs.

F. Ocean Nutrients Nearly everything in an ecosystem is recycled. 2. When organisms respire, or breathe, carbon dioxide is released back into the ecosystem. When organisms get rid of wastes, or die and decompose, nutrients are recycled.

G. Nutrients recycled in coral reefs Coral reefs are ecosystems that need clear, warm, sunlit water. Each coral animal builds a hard capsule around its body using calcium it removes form seawater. Each capsule then cememts to another, and a large colony called a reef is formed. Bottom dwellers and nekton move to the reef.

G. Nutrients recycled in coral reefs 3. Nearly 25 percent of all marine species and 20 percent of all fish live on coral reefs. 4. A healthy reef is a delicate balance.

G. Nutrients recycled in coral reefs 5. Producers, consumers, and decomposers all share a reef. They form a complex food web. Energy, nutrients, and gases are cycled among them all.

Section Check Question 1 What is a decomposer?

Section Check 4 Question 2 What would happen to this food web if pollutants entered the water and killed the algae?

Question 3 Which of these is NOT a consumer? A. bees B. elephants Section Check Question 3 Which of these is NOT a consumer? A. bees B. elephants C. humans D. phytoplankton