ESCI 130 - Human Impacts

Marine Pollution

Any harmful substance or energy put into the oceans by humans

Pollution

The presence of a substance where it should not be or at concentrations above background

Contamination

Contamination that results in adverse biological effects to resident communities.

Assimilative Capacity

The maximum amount of input of fresh water, dissolved substances, and organic matter without harming the oceans.

Main Types of Marine Pollution

Petroleum, Sewage sludge, DDT and PCBs, Mercury, Non-point-source pollution & Trash, Biological 'pollution'

Petroleum Pollution

Oil spills often from transport accidents, extraction, or loading/unloading accidents.

Exxon Valdez Oil Spill

On March 29, 1989, almost 44 million liters (11.6 million gallons) of oil spilled into Prince William Sound, AK.

Deepwater Horizon

The world's largest accidental ocean oil spill, which spilled more than 780 million liters (206 million gallons) from April 20 to July 15, 2010.

Toxic Compounds in Petroleum

Petroleum contains various hydrocarbons and toxic compounds that can sicken humans, animals, and plants in small doses.

Long-term Impacts of Petroleum Pollution

Can change gene expression, cause developmental abnormalities, and decrease embryo survival.

Environmental Bioassay

A widely used technique for determining how particular pollutants affect marine organisms.

Drawbacks of Environmental Bioassay

Does not predict long-term effects of pollution, does not account for pollutants combining with other substances, and is time-consuming and organism-specific.

Oil Spill Cleanup Methods

Workers using high-pressure, hot-water washing to clean an oiled shoreline.

Surface Oil Decline

The amount of surface oil visible at NOAA's study sites in Prince William Sound followed a decline in the years after the Exxon Valdez spill (1989 to 1997).

Oil Spill Consequences

Many animals, including birds and otters, were killed outright, and long-term consequences remain unknown.

Hydrocarbons

Compounds made of hydrogen and carbon found in petroleum.

Biodegradability of Petroleum

Petroleum is organic and can be biodegraded.

Oil Spill Dates

Deepwater Horizon spill date was from April 20 to July 15, 2010, with the well officially sealed on September 19, 2010.

Petroleum Pollution Sources

Includes oil spills from transport accidents, extraction, and loading/unloading accidents.

Biological Pollution

Refers to the introduction of invasive species or pathogens into marine environments.

Mercury Pollution

A type of marine pollution that poses risks to marine life and human health.

BP Oil Spill

An environmental disaster that killed 11 people and devastated the coast.

Oil Pollution Act of 1990

Legislation that barred single-hulled tankers from U.S. ports and restricted their operation near France and Spain.

Bioremediation

A cleanup method that uses microorganisms to break down pollutants.

Sewage Sludge

A semisolid byproduct of sewage treatment containing human waste and various chemicals.

Clean Water Act, 1972

Legislation that prohibited the dumping of sewage sludge in the ocean after 1981.

New York's Sewage Sludge Disposal at Sea

A project that initially used shallow-water sites for sludge disposal, later moving to deeper-water sites.

Boston Harbor Sewage Project

A court-ordered cleanup project for Boston Harbor that involved treating sewage and releasing it into deep water.

DDT

A pesticide that caused a decline in bird populations and was banned in the U.S. in 1972.

PCBs

Industrial chemicals that are toxic, have a long life in seawater, and accumulate in fatty tissues.

Thin eggshells

A consequence of DDT exposure leading to reduced bird populations.

Long Island osprey

A bird species affected by DDT, leading to population decline.

California brown pelican

A bird species that experienced population decline due to DDT.

Accumulation in food chain

The process by which toxic substances like DDT and PCBs build up in organisms at different trophic levels.

DO NOT EAT Fish

White Croaker, Barracuda, Black Croaker, Barred Sand Bass, and Topsmelt due to contamination from DDT, PCB, and mercury.

Adverse effects on fish

Negative impacts on fish populations due to sewage sludge disposal.

Bacteria counts during wet weather

A measure indicating the level of bacteria in water, with lower counts being preferable.

Oil initially floats

The physical property of oil that allows it to remain on the surface of water.

Oil and water mix to form mousse

A phenomenon where oil combines with water to create a thick, foamy substance.

Redesigning ships

An approach to improve tanker safety and reduce oil spills.

Single-hulled tankers

Vessels that are barred from U.S. ports due to safety concerns.

Double-hulled tankers

Safer vessels designed to prevent oil spills.

Methyl mercury

Toxic to most living organisms; released by a chemical plant in Minamata Bay, Japan, in 1938; first reported ecological changes in 1950.

Minamata Disease

Neurological disorder caused by mercury poisoning.

Safe levels of mercury

Determined by the rate of fish consumption by people, mercury concentration in fish consumed, and minimum ingestion rate of mercury to cause damages.

Non-point-source pollution

Pollution that enters the ocean from multiple sources, making it difficult to pinpoint origin.

Marine debris

Vast majority of marine debris is plastics; 80% of marine debris from land sources.

Plastics

Entangle fish, marine mammals, and birds; plastic bags choke turtles mistaking them for jellyfish.

Nurdles

Small pre-production plastic pellets found in the ocean and all beaches due to spillage.

Microbeads

Plastics between 1 and 5 millimeters (0.04 and 0.2 inches) that transport pollutants and are eaten by fish.

Laws Regarding Ocean Dumping

In 1988, the International Convention for the Prevention of Pollution from Ships (MARPOL) proposed a treaty banning disposal of plastics and regulating other trash dumping at sea.

Non-Native Species

Originate elsewhere, introduced by humans intentionally or accidentally; outcompete and dominate native populations.

Invasive species

Cause extensive damage annually; have invaded the Great Lakes of North America and altered the ecology of freshwater lakes and streams.

Mare Liberum

Free sea; assumed fish supply to be inexhaustible.

Territorial sea

De Dominio Maris - 1702; every country has ownership over a 3-mile territorial limit from shore.

United Nations Conference on the Law of the Sea

First Meeting: 1958, Geneva, Switzerland; controls prospecting and mineral mining on the continental shelf under the control of the country owning nearest land.

Marine plastic particles

Increasing significantly; regions of floating trash are evident.

Ecological changes

First reported in 1950 due to mercury pollution.

Trash

Includes pesticides and fertilizers, road oil; washed down storm drains to ocean.

Floating plastics

Break into smaller pieces, contributing to marine debris.

Chemical plant in Minamata Bay

Released mercury in 1938, leading to significant ecological and health impacts.

Plastic pollution

Includes various forms of plastic waste, which are harmful to marine life.

Convention on the Territorial Sea and Contiguous Zone

(1964)

Convention on the Continental Shelf

entry into force (1964)

Convention on the High Seas

(1962)

Convention on Fishing and Conservation of Living Resources of the High Seas

(1966)

Baseline

is drawn between the outermost points of the outermost islands

Maritime Zones

from mean low tide line inland

Extension of land

out to the edge of the continental shelf or 200 km, whichever is greater

1994 Agreement

Eliminate production controls on sea floor mining

Overfishing

harvesting too much marine life at a rate that is greater than the reproductive rate

Causes of Overfishing

Efforts in the mid 1900s to increase the availability and affordability of protein-rich foods caused an increase in fishing hauls

Change in fishing methods

favor large catches with increased bycatch

Open access fisheries

a cause of overfishing

Poor fisheries management

a cause of overfishing

Illegal fishing

a cause of overfishing

Subsidies

a cause of overfishing

2006 study in Science

predicted that all of the world's fisheries would collapse by 2048 if no changes occurred

UN Food and Agriculture Organization Study (2006)

showed various states of fishery depletion

Overfishing of top predators

disrupts the marine ecosystem

System collapse

overfishing + pollution + climate change + habitat destruction + ocean acidification

Sustainable fisheries

what can be done to address overfishing