Watersheds: Human Impact & Conservation

Watersheds

• A watershed is an area where all water drains into a common body of water like a river, lake, or ocean.

Human Impacts on Watersheds

• Pollution from factories, farms, and urban areas harms wildlife and makes water unsafe.
• Deforestation reduces rainwater absorption, increasing runoff, erosion, and habitat loss.
• Urbanization prevents water absorption due to concrete surfaces, which can lead to flooding and pollution.
• Agriculture introduces pesticides and fertilizers into water bodies, causing pollution.
• Planting trees, cleaning waterways, and using sustainable farming practices improve watershed health.

Importance of Watersheds

• Watersheds provide drinking water, support wildlife, control flooding, and allow recreational activities.

How to Help Watersheds

• Reduce pollution by not littering.
• Plant trees.
• Conserve water.
• Educate others on watershed protection.

Oceans

• Oceans cover about 71% of the Earth's surface.
• They provide oxygen, food, climate regulation, and habitat for marine life.

Human Impacts on Oceans

• Pollution includes plastic waste, oil spills, chemical runoff, and sewage.
• Pollution harms marine life, damages ecosystems, and makes water unsafe.
• Overfishing depletes fish populations, disrupts food chains, and threatens species with extinction.
• Climate change warms ocean temperatures, causes coral bleaching, and increases sea levels.
• Habitat destruction caused by coastal development, dredging, and bottom trawling damages coral reefs and mangroves.
• Invasive species outcompete and harm local marine life, disrupting ecosystems.

Why Oceans Are Important

• Oceans support biodiversity, regulate the climate, and provide food, medicine, and recreation resources.

Trophic Levels

• Trophic levels represent the position of organisms in a food chain or web based on what they eat.

Main Trophic Levels

• Producers (1st Trophic Level): Plants and algae make their own food through photosynthesis and form the foundation of the food chain.
• Primary Consumers (2nd Trophic Level): Herbivores like rabbits and deer eat producers for energy.
• Secondary Consumers (3rd Trophic Level): Carnivores and omnivores like snakes and mice eat primary consumers.
• Tertiary Consumers (4th Trophic Level): Top predators like hawks and sharks eat secondary consumers and have few predators.
• Decomposers: Fungi and bacteria break down dead organisms, returning nutrients to the soil and supporting producers.

Energy Flow

• Energy decreases as you move up trophic levels; only about 10% of energy is passed from one level to the next.

Body Systems Overview

• The human body comprises multiple systems working together to maintain health and functionality.
• Each system has a specific role involving organs performing particular functions.

Major Body Systems

• Skeletal System: Provides structure and support, protects organs, and allows movement, includes 206 bones, cartilage, and joints.
• Muscular System: Allows body movement and maintains posture, includes skeletal (voluntary), smooth (involuntary), and cardiac muscles.
• Circulatory System: Transports blood, nutrients, oxygen, carbon dioxide, and hormones, includes the heart, blood vessels, and blood.
• Respiratory System: Responsible for gas exchange, bringing in oxygen and expelling carbon dioxide, includes the nose, mouth, trachea, lungs, and diaphragm.
• Digestive System: Breaks down food into absorbable nutrients, includes the mouth, esophagus, stomach, small and large intestines, liver, pancreas, and gallbladder.
• Nervous System: Controls body functions and responses by transmitting signals, includes the brain, spinal cord, and nerves.
• Endocrine System: Regulates body functions through hormones, includes glands like the pituitary, thyroid, and adrenal glands.
• Immune System: Protects the body against infections and diseases, includes white blood cells, lymph nodes, and the spleen.
• Integumentary System: Protects the body, regulates temperature, and provides sensory information, includes skin, hair, and nails.
• Reproductive System: Responsible for producing offspring, containing different parts for males and females.

Key Concepts to Remember

• Interconnectedness: All body systems work together; for example, the respiratory and circulatory systems deliver oxygen to cells.
• Homeostasis: The body’s ability to maintain stable internal conditions (like temperature and pH) despite external changes.