Human Dependence on Ocean Systems Notes

Learning Target: Recognize human dependence on ocean systems and explain how human activities such as runoff, artificial reefs, or use of resources have modified these systems.

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Over 70% of our planet is water.

97% of the water on Earth is ocean water.

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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 frequently changing abiotic factors.

• Coral reefs and kelp forests are underwater coastal ecosystems that provide shelter and food for many species.

• 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.

• 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.

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How do humans use and depend on 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.

INSTRUCTIONS

• The following slides will discuss positive and negative human activities that have modified our ocean systems. You will need to use:– green to represent positive human activities– red to represent negative human activities.

These colors are already modeled for you in your notes. Anywhere you see these colors on the slide,

include that color in your notes for that slide.

Human Activities that MODIFY Ocean Systems:

Positive Activities (+)

• Creating artificial reefs• Laws restricting

overharvesting of fish• Renewable energy: Tidal

Power• Pollution clean up efforts

which slows global warming

• Proper disposal of chemicals

Negative Activities (-)• Overfishing/Overharvesting• Shipping accidents• Global warming• Pollution from urbanization:

– Algae Blooms caused by runoff (drainage of water FROM land TO water source) • Runoff from farms carries

fertilizer and pesticides • Runoff from cities carries oil

and gas from roads

• Introduction of Invasive Species

Each of these will be explained on the following slides.

Natural Coral Reefs• Natural underwater ocean structures made up of living

coral and their remains of limestone.– Provide humans with food, recreation (snorkeling), and

medicines.

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due to human activities caused by coastal

development. These include overfishing, ocean warming,

and pollution.

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Artificial Coral Reef (+)A man-made structure that is intended to mimic

a natural reef in order to reduce erosion and promote marine life through increasing

availability of habitats.

Natural Coral Reef

Artificial Coral Reef

https://www.youtube.com/watch?v=Q97IAUHICjo

Optional Video: Texas Clipper Artificial Reef

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Overfishing/Overharvesting (-)

• 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.

Shipping (-)

Shipping accidents:–Water and air pollution:• Oil spills• Dumping of waste water• Chemical accidents• Killing marine wildlife

Renewable Energy: Tidal Power (+)

• Energy from tides in the form of hydropower that converts the energy of tides into useful forms of power mainly for electricity.

Algae Bloom (-)• An excessive, accelerated growth of algae in

water that occurs as a result of polluted runoff water draining into the ocean.

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Factors Contributing to Algae Blooms• Excess nutrients from runoff (e.g.

phosphorus or nitrogen) from Agriculture and Urban sources.– Fertilizer and sewage

• Intense Sunlight and warmer temperatures

• Low-water levels or low-flow conditions

• Calm water (low-wind conditions)

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Ocean’s Impact on ClimateOcean currents transfer heat great distances around

the world that helps regulate Earth’s climate.

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Global Warming (-)

• Pollution increases CO2 in the atmosphere which traps in heat.

• Ocean water absorbs most of the heat from the sun causing ice caps to melt and ocean temperatures to increase.

The average increase in Earth’s global surface temperatures.

Invasive Species (-)

A species that is non-native (foreign) to the ecosystem and causes harm to the environment and/or human health.– Characteristics:• grows/reproduces and spreads rapidly• establishes over large areas, and persists• lack natural predators, competitors and diseases that

normally regulate/control their populations.

Zebra Mussels

• Native Origin: Eurasia: specifically Russia

• 1st observed in North America in 1988 in Lake St. Clair (between Michigan and Canada). Since then the zebra mussel has spread to various states located along the Mississippi Waterway, and has been recently reported in Texas, Utah, and California.

• You can't always see zebra mussels because their larvae are invisible to the naked eye. They can survive for days in water trapped in a boat

• Zebra mussels multiply rapidly over large areas, lack natural predators in Texas lakes and can cause tremendous environmental and economic damage.

• Zebra mussels can disrupt water supplies by colonizing inside pipelines and restricting the flow of water, damaging water intake structures that provide water to thousands of homes and businesses, making water more expensive.

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Assignment

In two paragraphs, explain how human activities have modified ocean systems.• Paragraph 1: negative human activities• Paragraph 2: positive human activities

Your paragraph must discuss EVERY activity that was included in these notes.