Pollution Flashcards
Human population growth and economic activity
Human pop has tripled since 1950 and 44% live within 150 km of ocean
econ activity has increased tenfold
Earth overshoot day
- need 1.7 earths
Ocean services
heat and carbon uptake provides: 50% of atm O2 rain 15% of food minerals and energy reusable energy cultural services like tourism
marine pollution
introduction by man, directly or indirectly, of substances or energy that results in deleterious effects
climate change
A change of climate that is attributed directly or indirectly to human activity,
altering the composition of the global atmosphere
physical resources
result from deposition, precipitation or accumulation of useful substances in the
ocean or seabed
→ Hydrocarbon deposits: petroleum, natural gas, methane hydrate
→ Mineral deposits: sand and gravel, magnesium and its compounds, manganese nodules, salt, etc
→ Freshwater
oil
a complex chemical soup of thousands of compounds, most of which are hydrocarbons
- petroleum products are are produced from processing crude oil
natural gas
naturally occurring hydrocarbon gas mixture consisting primarily of methane
oil and natural gas
occur in marine sediments 1/3 of reserves are at cont. margins
originate from sinking organic matter
dead orgs accumulate
temp and pressure transform them into hydrocarbons
3 million years to make a years worth of oil
salts
residue from evap of seawater
freshwater
important marine resource
extracted from seawater through desalination
biological resources
Living animals and plants collected for human use and animal feed
10 species make up ~95% of fish caught each year
Fishing employs more than 15 million people worldwide
65% of fish stocks are suffering from overfishing
bycatch
Animals unintentionally killed while collecting desirable organisms
→ 4 pounds of bycatch is discarded for every pound of shrimp caught in Gulf coast
maximum sustainable yield
The maximum amount of fish that can be caught without impairing future populations
whaling
8 of 11 whale species once hunted now commercially extinct
provide many resources
non-extractive resources
Uses of the ocean in place
e.g. transportation of people and commodities by sea, recreation, and waste disposal
Marine energy resources
From the extraction of energy directly from the heat or motion of ocean water
Wind power is the fastest growing energy source as an alternative to oil
- Extraction of wind power over or near the ocean is effective (steady and strong winds)
- At present rate of development, wind energy could provide ~12% of electricity demand by 2025
Waves, currents and tides can be used to produce electricity
- Successful tidal plants (see lecture on tides)
- Extraction of energy can be difficult though, infrastructure expensive
pollutant
A substance that causes damage by interfering directly or indirectly with an organism’s
biochemical processes
marine pollutant
Impact of a pollutant also depends on its persistence
Many pollutants are biodegradable (i.e. able to be broken down by natural processes into simpler
compounds)
Ocean’s great volume and relentless motion dissipate and distribute natural and synthetic substances - dumping ground
oil entering ocean
marine trans. of petrol, offshore drilling, nearshore , street runoff
runoff id main input of oil to ocean
refined more harmful than crude
oil spills
cleaning spills is also damaging
detergents are harmful to living things
toxic synthetic organic chemical
Some synthetic hydrocarbon compounds contain chlorine, bromine, or iodine
Used in pesticides, flame retardants, industrial solvents, and cleaning fluids
Enter the ocean through runoff and become incorporated into its organisms
heavy metals
Among the dangerous heavy metals being introduced into the ocean are mercury, lead, copper, and tin
Enter the ocean from mining operations, coal smoke, byproduct of industrial production
Even in small quantity, these metals can interfere with normal cell metabolism
bioaccumulation
Process by which certain marine organisms concentrate within their tissues many substances found in minute concentrations in seawater
biomagnification
Process by which when animals eat other animals, some of these substances move up food chains and become concentrated in the tissues of larger animals
plastic
majority of marine debris
entanglement and ingestion, adsorb toxic compounds, photo-degradation facilitates ingestion, microplastics
increased tenfold every 10 years in the 1970s and 1980s, then tenfold again in just 3 years in the 1990
Eastern Pacific Garbage Patch
- convergence of currents
in subtropical gyres
plastics far outnumber marine organisms
effects of pollution on estuaries
zones are densely populated and active and are also influenced by inland activities oil spills, sewage, viruses, pollutants urban dev high bio diversity severe impacts on plants and animals
introduced species
Foreign organisms introduced to a new environment through ships travelling across the ocean
- outcompete native species
- new marine diseases
coastal erosion
divert and dams rivers
build harbors
develop property
adverse effects to coastal erosion management
