Human Impact on the Oceans. Human population growth. The Bountiful Ocean. If a human falls on the ocean, will anywhale hear it?

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1 Human Impact on the Oceans If a human falls on the ocean, will anywhale hear it? or To err is human. Period. Too many people on the bus from the airport Too many holes in the crust of the earth The planet groans Every time it registers another birth Paul Simon, Born at the Right Time Human population growth The Bountiful Ocean billion people on Earth billion (123 years later) billion (33 years) billion (14 years) The Plague Today billion (13 years) billion (12 years) world population doubled between 1960 & 1999! Resources from the sea Food Transportation Recreation Dumping ground Hydrocarbons (gas, oil) Hydroelectric (waves, tidal) Salt Medicine Study of Earth Evolution of life climate Food (fish, shellfish, seaweed) Sand & gravel, shell &coral sand for construction Salts and several elements are commercially extracted (Magnesium, Bromine, Iodine) Hydrocarbons (oil, natural gas) Mineral sands containing metals Phosphorite for fertilizers Manganese nodules on the seafloor, metal-rich deposits at hydrothermal vents Hydroelectric power from tidal energy Shipping (90% of world trade!) Recreation!! 1

2 Law of the Sea - Who owns the Oceans? Dutch statesmen declared ocean is free to all nations national domain = as far as you could shoot a cannon ball from shore ~3 miles st United Nations Convention on Law of the Sea (UNCLOS) established rights over adjacent continental shelves nd UNCLOS conference produced no international agreements rd UNCLOS conference eventually led to April 1982 New Law of the Sea Ruling 1982 Law of the Sea 1. coastal nations jurisductions 12 mile territorial sea 200 mile Exclusive Economic Zone (EEZ) 2. ship passage rights Free passage in open seas Free passage through straits in territorial waters 3. deep ocean mineral resources United Nations Enterprise Co. must be involved. Human issues facing the marine environment 1. pollution 2. dredging 3. environmental degradation of coastal waters 4. overfishing 5. global warming Pollution the introduction by humans, directly or indirectly, of substances or energy into the environment resulting in deleterious effects on living organisms and ecosystems on human health on marine activities (incl. recreation and fishing) some of what is considered to be pollution may be occurring naturally concentrated in three zones of the water column on the sea floor (flocculation, settling) in the pycnocline (neutral buoyancy) in mm surface layer (dissolved chemicals, tiny particles) eventually broken down by various oceanographic and biological processes 2

3 Oil / Petroleum only ~3% of the oil in the sea comes from major oil tanker accidents river runoff of untreated wastes = 31% normal tanker operations = 22% refineries = 13% oil is toxic at all levels of the food chain several methods employed to clean a spill: floating booms easily breached chemical dispersants often more toxic than oil burning the oil at the surface ineffective skimming most effective method bioremediation new idea The Fate of an Oil Slick Municipal and industrial effluent each year humans produce over 20 billion tons of wastes much is disposed of in the ocean most comes from farmland, cities and industrial areas enters the sea by rivers tends to be concentrated in harbors, bays and estuaries bodies of water have a natural capacity to clean themselves, but this can be exceeded pollution in the sea can be greatly diluted by waves, tides, and currents Am Effluent Plume Biological effects of pollution bioaccumulation organisms retain and concentrate toxic material within their bodies biomagnification toxic material increases in concentration at each trophic level of the food chain results from bioaccumulation at each trophic level 3

4 Ocean dredging / dumping Dredging accounts for 80 to 90% of the material dumped at sea each year. If the dredged material is clean, dumped slowly enough, and is the same material as the original substrate, it presents no long-term problem. Contaminated dredge spoils represent initial and long-term pollution. Solid wastes dumped into the sea tend to spread out across the ocean bottom and along existing pycnoclines. Degradation of coastal waters and loss of habitat Causes: Pollution (toxic chemicals, heavy metals, pesticides, sewage) poisoning of fish and shellfish by biomagnification Agricultural runoff (fertilizers) and nutrification algal blooms including red tides, oxygen depletion, massive fish kills Sediment runoff due to clear-cutting chokes the life out of coastal areas Over-development of the coast wetlands filled-in or modified Hypoxia as a result of dumping sewage and other chemical waste Decompostion uses up all the oxygen in the water column Hypoxia = low levels of Oxygen Anoxia = no Oxygen at all. Our impact at the coast >50% of total world population lives within 100 km (62 mi) of the coast nearly 20% of world population lives in coastal cities (includes 9 of the 10 largest cities) coastal population growth is the fastest <1% of the planet s marine environment has been designated as protected (compared to >6% of the land) 10% of the coral reefs have been dredged beyond recovery coral bleaching loss of zooxanthellae due to warming waters over the past 50 years, water use world-wide has increased four-fold We do have choices; knowledge & awareness will help us make the best choices 4

5 Our impact at the coasts Unchecked development and greater demand for fresh water put coastal communities at risk in the face of rising sea level: shrinking area necessary for ground water recharge threat of salt water intrusion greater risk to life and property due to storm surge United Nations study 1989 Group of Experts on the Scientific Aspects of Marine Pollutants (GESAMP) sanctioned by the United Nations current state of the marine environment: Most of the water of the open ocean is clean, except for heavily traveled shipping lanes. Coastal waters and shelf waters are contaminated to varying degrees everywhere and the amount of contamination depends upon population density, degree of urbanization, agricultural practices and shipping activity. Coastal habitats (beaches, wetlands, bays, estuaries, coreal reefs, mangrove forests) are being severely affected and destroyed at an increasing rate. Major pollutants in the ocean (oil, plastics, sewage, heavy metals, radioactive wastes, nutrient loading, synthetic organics) should be the immediate concern, but the longterm presence of minor pollutants is uncertain. Too little is being done to reduce human activity on land that impacts the ocean. What can be done? R 3 Reduce! Reuse! Recycle! Treat wastes that cannot be R 3 d. Use pesticides and fertilizers responsibly, ensure that they don t enter the marine environment. Use sea disposal only for those materials compatible with the marine environment. Use locations for sea disposal of wastes that will not interfere with other uses of the sea. Use waste-disposal practices at sea that minimize impacts at point of disposal. Monitor the health of the oceans on a continuing, world-wide basis. Manage the sea s resources to prevent depletion on a world-side basis. Iver W. Duedall, Florida Inst. of Tech. 5

6 What will your impact be? 6