Chapter 11: Marine Pollution

pollution

pollution

any harmful substance or energy put into the oceans by humans

United Nations Convention

defines pollution of marine environment:

introduction by man of substances or energy into marine environment which results in harm to living resources and marine life, hazards to human health, a hindrance to marine activities, fishing, other legitimate uses of the sea, impairment of quality for use of sea water and reduction of amenities.

what is considered harmful?

standard lab bioassay: [ ] of pollutant that causes 50% mortality among test organisms

environmental bioassay

widely used technique for determining how pollutants affects marine organisms.

pollutant [ ] limits established

drawbacks of environmental bioassay

doesn’t predict long term pollution

doesn’t affect for pollutants combining with other substances

time consuming and organism specific

why is studying pollution difficult?

lack of sufficient studies of polluted areas.

marine environment is affected by decate to century long cycles, so hard to determine whether a change is due to natural biological cycle or any number of introduced pollutants

waste disposal in oceans

diluting pollutants with huge volume of ocean water

long term effects not known: debate about dumping wastes in ocean, some say none at all, some say okay as long as monitored

main types of marine pollution

petroleum, sewage sludge, DDT and PCB’s, mercury, non point source pollution and trash

petroleum

commonly called oil, naturally occurring liquid made of hydrocarbons

oil spills: often from transport accidents

some from extraction: 2010 GoM Deepwater Horizon

Exxon Valdez Oil Spill

March 29, 1989

44 mill liters of oil spilled into Prince William Sound, AK

spilled by supertankers, animals killed (birds, otters)

long term consequences unknown, beaches left alone were cleaned more quickly and completely than cleaned beaches

petroleum makeup

made of hydrocarbons

toxic compounds in petroleum: polycyclic aromatic hydrocarbons

can sicken humans, animals, plants in small doses

have long term impacts on organisms: change gene expression, developmental abnormalities, decreased embryo survival

cleaning oil spills

initially floats, can disperse, can be skimmed. Oil and water mix to form mousse

bioremediation: use of bacteria and fungi help clean oil spills. Release bacteria into marine environment. create conditions to stimulate growth of naturally occurring oil degrading bacteria

primary source of oil in oceans

oil spills not primary source, 47% comes from oil seeps.

most petroleum in oceans from human activities. small but frequent widespread oil releases

ecosystem response from oil spill

marine organisms fur or feathers lose insulation properties when covered in oil

high fatality rates

oil biodegradable, ecosystem rebounds to higher levels

bioremediation

use of bacteria and fungi to help clean oil spills

preventing oil spills

Oil Pollution Act 1990

single hulled tankers barred from US ports, not allowed within 320 km of France and Spain

Double hulled tankers designed and better for prevention

redesigned ships

sewage sludge

semisolid material after treatment: human waste, oil, zinc, copper, lead, etc

primary treatment: solids settle and dewater

secondary treatment: sludge exposed to bacteria killing chlorine

clean water act of 1972

no dumping of sludge in ocean after 1981.

DDT and PCB’s

DDT: dichloro diphenyl trichloroethane

PCB: polychlorinated biphenyls

widespread in oceans

persistent organic pollutants: result of human activities, toxic causing cancer, birth defects, other harms, long life, dissolved in seawater.

side effects of DDT

decline in bird populations, thin eggshells, used in 1950’s, banned in 1972.

rebound some marine bird populations

effects of PCB’s

once widely used liquid coolant and insulation in power transformers

also in wiring, paints, caulking, hydraulic oils

cause harmful genetic mutations and reproductive issues

DDT and PCB’s banned by countries, sink to sea floor bottom, pervasive in marine environment, found in antarctic

positives of DDT

Great insect toxicity

Rapid onset of toxic action \n Little or no mammalian or plant toxicity. \n No irritant effect and no or only a faint \n odour (in any case not an unpleasant one) \n The range of action should be as wide as \n possible, and cover as many Arthropoda \n as possible \n Long, persistent action, i.e. good \n chemical stability \n Low price (= economic application)

mercury and minamata disease

methyl mercury toxic to most living organisms.

chemical plant in Minamata Bay Japan released mercury in 1938

first reported ecological changes in 1950

by 1953 humans poisoned, neurological disorder

bioaccumulation

organisms concentrate pollutant from seawater

biomagnification

organisms gain more pollutant by eating other contaminated organisms

mercury accumulations

safe levels of mercury determined by

1. rate of fish consumption by people

2. mercury [ ] in fish consumed

   1. minimum ingestion rate of mercury to cause damages

non point source pollution and trash

poison runoff

pollution enters ocean from multiple sources rather than a single discrete source, point or location.

trash

pesticides, fertilizers

road oil

non point source pollution and trash

difficult to pinpoint origin

trash washed down storm drains to ocean

road oil, pesticides, fertilizers washed into drains

plastic pollution

80% of marine debris from land sources

not biodegradable

entangle fish, marine mammals and birds

plastic bags choke turtles, mistake for jellyfish

some attract poisons, DDT, PCB’s

plastic origin

debut in 1862 at Great International Exhibition of London

commercial development during WWII. disposal strains environment

properties: lightweight-float

strong-entangle

durable- dont

nurdles

small pre production of plastic pellets

found in ocean and all beaches due to spillage

orange county CA - 98% of beach debris are nurdles

microbeads

btwn. 1 and 5 mm

in cleaners and scrubbers, hand cleaners, exfoliating facial scrubs, toothpaste.

transport pollutants, eaten by fish, 46 million pounds in Pacific Ocean

plastic in ocean

floating plastic photodegrades

breaks into smaller pieces

marine plastic particles increase significantly

regions of floating trash, E. Pacific garbage patch.

twice size of texas

laws regarding ocean dumping

in 1988 International Convention for Prevention of Pollution from Ships (MARPOL)

proposed treaty banning disposal of plastics

regulating other trash dumping at sea

122 nations ratified by 2005

facilities not available for garbage disposal

biological pollution: non native species

originate elsewhere, introduced by humans intentionally or accidentally

outcompete and dominate native populations

invasive species cause extensive damage annually, lack predators

Caulerpa taxifolia: tropical sea weed, cold tolerant clone, introduced to mediterranean, overwhelmed ecosystems, also in S. California, Australia

zebra mussel

invaded great lakes of N. America

drove out local mussels

altered ecology of freshwater lakes, streams

blocked water pipes of industrial facilities

territorial sea

providing for national domain over distance from shore that could be protected by cannons. every country has ownership over 3 nautical mile limit from shore.

law of the sea

united nations conference in 1958, Geneva Switzerland

1994 law provisions

1. Eliminate production controls on sea floor mining \n 2. Reduced structure of seabed floor mining organization \n 3. U.S. has permanent political say on deep sea mining provision changes \n 4. Objectionable technology transfer provisions eliminated \n 5. Assured access for future qualified miners \n The United States has not yet adopted the treaty,

law of sea 4 main components

1. coastal nations jurisdiction

2. ship passage: right of free passage of all vessels

3. deep ocean mineral resources: controlled by UN

4. arbitration of disputes: UN laws of sea tribunal will arbitrate any disputes