© 2016 Cengage Learning. All Rights Reserved. 18 Oceanography, An Invitation to Marine Science | 9e Tom Garrison The Ocean and the Environment

© 2016 Cengage Learning. All Rights Reserved. Since 1961, human demand on Earth’s organisms and raw materials has more than doubled and now exceeds Earth’s natural replacement capacity by at least 20% A pollutant causes damage by interfering directly or indirectly with the biochemical processes of an organism. About three- quarters of the pollution in the ocean comes from human activities on land Key Concepts

© 2016 Cengage Learning. All Rights Reserved. The ocean’s increasing acidity is a serious threat to calcium deposition organisms. Coral reefs are especially endangered by acidification The global temperature trend has been generally upward in the 18,000 years since the last ice age, but the rate of increase has recently accelerated Rates of consumption and environmental degradation are unsustainable Key Concepts (cont’d.)

© 2016 Cengage Learning. All Rights Reserved. Human demand exceeds Earth’s ability to generate resources –Since the 1980s –Currently demand exceeds replacement capacity by at least 20% 18.1 An Introduction to Marine Environmental Issues

© 2016 Cengage Learning. All Rights Reserved. Marine pollution – affects the physical, chemical, or biological environment Natural pollutants –Volcanic eruptions Pollutants interfere with mechanical or biological processes in an organism –Quantity –Toxicity –Persistence 18.2 Marine Pollutants May Be Natural or Human-Generated

© 2016 Cengage Learning. All Rights Reserved. Natural oil seeps Human-caused oil in the ocean –Crude oil –Refined oil Oil In the Ocean

© 2016 Cengage Learning. All Rights Reserved. Methods for cleaning sometimes cause more damage –Detergents Deepwater Horizon spill –About 206 million gallons released 16% captured by direct recovery 8% recovered by skimming and burning Remaining released into the environment Cleaning Oil Spills

© 2016 Cengage Learning. All Rights Reserved. Oil Spills

© 2016 Cengage Learning. All Rights Reserved. Halogenated hydrocarbons –Chlorine, bromine, iodine Biomagnification –Organisms high in the food chain concentrate hazardous chemicals Toxic Synthetic Chemicals

© 2016 Cengage Learning. All Rights Reserved. The Concentration of the Pesticide DDT

© 2016 Cengage Learning. All Rights Reserved. DDT in water ppm DDT in fish-eating birds (pelicans) 25 ppm Concentration has increased 10 million times DDT in small fish (minnows) 0.5 ppm DDT in small zooplankton 0.04 ppm DDT in large fish (needlefish) 2 ppm Stepped Art

© 2016 Cengage Learning. All Rights Reserved. Heavy metals –Mercury, lead Eutrophication –Some organic substances act as nutrients and speed growth of some organisms –Detriment to other organisms –Hypoxia – depletion of free oxygen in surface water Other Types of Marine Pollution

© 2016 Cengage Learning. All Rights Reserved. Eutrophication

© 2016 Cengage Learning. All Rights Reserved. Plastics and Solid Waste

© 2016 Cengage Learning. All Rights Reserved. Bays and estuaries – particularly hard hit Introduced species –Exotic species can harm ecosystems 18.3 Organisms Cannot Prosper if Their Habitats Are Disturbed

© 2016 Cengage Learning. All Rights Reserved. Coral bleaching –Corals expelling their symbiotic dinoflagellates –Not well understood Rising ocean acidity Coral Reefs

© 2016 Cengage Learning. All Rights Reserved. Sound As Pollution

© 2016 Cengage Learning. All Rights Reserved. Human activity is restricted U.S. government established 1600 MPAs –Covers 36% of U.S. marine waters Other countries as well 18.4 Marine Protected Areas Are Refuges

© 2016 Cengage Learning. All Rights Reserved. Surface temperature is rising –Greenhouse effect –Greenhouse gases 18.5 Earth’s Climate Is Changing

© 2016 Cengage Learning. All Rights Reserved. Atmospheric Carbon Dioxide Through Time

© 2016 Cengage Learning. All Rights Reserved. Mean Global Temperatures

© 2016 Cengage Learning. All Rights Reserved. Mathematical models –Help predict climate change Can global warming be curtailed? Future Predictions

© 2016 Cengage Learning. All Rights Reserved. “Tragedy of the Commons” Solution lies in education and action 18.6 What Can Be Done?

© 2016 Cengage Learning. All Rights Reserved. Our species has always consumed and polluted Now we are affecting Earth on a planetary scale We now rush into the unknown Chapter in Perspective

© 2016 Cengage Learning. All Rights Reserved. What can an individual do to minimize his or her impact on the ocean and atmosphere? What are the most dangerous threats to the environment, overall? Some Questions from Students