Marine Pollution

DDT and PCBs

pesticide and industrial chemicals now found throughout the marine environment

mercury

a silvery metal with the rare property of being liquid at normal room temperature

Pollution

"any harmful substance"

Why does the World Health Organization's definition of pollution have to be so specific?

"any harmful substance" is quite broad...the WHO's definition of pollution is specific so scientists can determine which substances are "harmful"

sewage sludge

one of the main types of marine chemical pollution

What are some techniques to clean up oil spills?

-it can be collected with specially designed skimmers or absorbent materials -naturally biodegraded by microorganisms (release bacteria directly into affected marine environment, or provide conditions that stimulate the growth of naturally occurring oil-degrading bacteria)

What are some drawbacks to using an environmental bioassay to determine whether or not a substance should be classified as a pollutant?

-it does not predict the long-term effect of pollution on marine organisms -it does not take into account how pollutants may combine with other substances to create new types of pollutants -time consuming, laborious, and organism-specific

Which animal populations suffered most from the effects of DDT?

-serious decline in the brown pelican population of Anacapa Island off Southern California -decline of osprey population (in both cases, eggs had excessively thin shells)

What properties of plastics make them damaging to the marine environment?

-they are lightweight, so they float and concentrate at the surface -they are strong, so they entangle marine organisms -they are durable, so they don't biodegrade easily -they are inexpensive, so they are mass-produced

What were the worlds largest accidental and intentionally released oil spills?

-world's largest occurred because of intentional dumping by the Iraqi army during their invasion of Kuwait during the 1991 Persian Gulf War (20 times the amount spilled by Exxon Valdez) -world's largest accidental spill occurred in 2010 when the Deepwater Horizon oil-drilling platform in the Gulf of Mexico exploded, causing the deep well it was drilling to flow unabated for about 3 months before it was brought under control (well released the equivalent of an Exxon Valdez-sized spill about every four days)

4 major components of the Law of the Sea treaty

1- coastal nations jurisdiction- 19 km territorial sea and a 370 km EEZ from all land within a nation 2-ship passage- right of free passage for all vessels 3-Deep-ocean mineral resources- private exploitation of sea floor resources may proceed under the regulation of the ISA 4-arbitration of disputes- UN Law of the Sea will settle any disputes

variables considered in establishing safe mercury levels in fish:

1- rate at which each group of people consumed fish 2- methylmercury concentration in the fish consumed by that population 3- minimum ingestion rate of methylmercury that induces disease symptoms

What major country has not yet adopted the Law of the Sea treaty?

US

environmental bioassay

a carefully controlled experiment that assesses how a particular pollutant impacts marine organisms

Petroleum (oil)

a naturally occurring liquid composed of hydrocarbons and other organic compounds

zebra mussel

a non-native aquatic species which was first discovered in the Great Lakes region in 1988.

non-point source pollution

any type of pollution entering the ocean from multiple sources rather than from a single discrete source, point, or location

Why can non-native species be so damaging to ecosystems?

because they inhabit new areas where they may lack predators or other natural controls

bioaccumulation

certain marine organisms concentrate within their tissues many substances found in minute concentrations in seawater

hydrocarbons

composed of the elements hydrogen and carbon

plastics

constitute the vast majority of marine debris.

How would dumping sewage in deeper water off the East Coast help reduce negative impacts on the ocean floor?

deep water sites usually have a well-developed density gradient separating surface water from deep water, and internal waves transport particles horizontally faster than they can sink

How did Caulerpa taxifolia and zebra mussels get released into new environments?

dumping of household saltwater aquariums; ballast water of a freighter from Europe

secondary treatment

exposed to bacteria-killing chlorine

Why is oil considered among the least damaging pollutants in the ocean?

hydrocarbons are largely biodegradable

How does non-point source pollution get to the ocean? How else does trash get into the ocean?

in most cases, runoff from storm drains; ocean dumping

United Nations Conference on the Law of the Sea

in response to new technology that facilitated mining the ocean floor, established that prospecting and mining of minerals on the continental shelf was under the control of the country that owned the nearest land

Why is it important to clean up oil immediately?

it forms a viscous substance that aggregates into tar balls and eventually sinks

Minamata disease

mercury poisoning caused by an acetaldehyde plant

What causes Minamata disease? What are the symptoms of the disease in humans?

mercury poisoning; sensory disturbances, brain damage, birth defects, paralysis, and even death

Eastern Pacific Garbage Patch

reportedly twice the size of Texas and contains an estimated 91,000 metric tons of debris

microplastics (microbeads)

small plastic particles generally between 1 and 5 millimeters in diameter

nurdles

small pre-production plastic pellets that range in size from a BB to a pea, nearly all plastic products are produced from these

primary treatment

solids are allowed to settle and separate from the liquid

non-native species (exotic, alien, or invasive species)

species that originate in a particular area but are introduced into new environments either by the deliberate or accidental actions of humans and so are classified as biological pollutants

MARPOL

the International Convention for the Prevention of Pollution from Ships,in 1988 proposed a treaty banning the disposal of all plastics and regulating the dumping of most other garbage at sea

territorial sea

the sea out to the distance that could be protected by cannons from the shore

bioremediation

using microorganisms such as bacteria and fungi to naturally biodegrade oil

toxic compounds

vary in crude oil, but the most worrisome are polycyclic aromatic hydrocarbons (PAHs) such as napthalenes, benzene, toluene, and xylenes

biomagnification

when animals eat other animals, some of these substances move up food chains and become concentrated in the tissues of larger animals