11.1 What is pollution?

the ocean serves as the dumping ground for many of society’s wastes. as the use of the ocean by humans has increased, marine pollution has increased as well

Marine Pollution: A Definition

Pollution: broadly defined as any harmful substance - how do scientists determine which substances are harmful?

• certain types of pollution cannot be easily detected by humans, but can do harm to the environment

• a substance may not immediately be harmful but may cause harm, years, decades, centuries later

• to who is this harm done? - some species thrive when exposed to a particular compound that’s toxic to others

• amount of a pollutant is important; if a substance that causes pollution is present in extremely tiny amounts, is it still a pollutant?

WHO defines pollution of marine environment as follows:

“The introduction by man, directly or indirectly, of substances or energy into the marine environment, including estuaries, which results or is likely to result in such deleterious effects as harm to living resources and marine life, hazards to human health, hindrance to marine activities, including fishing and other legitimate uses of the sea, impairment of quality for use of sea water, and reduction of amenities.”

Environmental Bioassay

environmental bioassay = widely used technique for determining concentration of pollutants that negatively affect the living resources of the ocean - conduct a carefully controlled experiment to assess how a particular pollutant impacts marine organisms.

• drawbacks:

  • doesn’t predict long-term effect of pollution on marine organisms

  • doesn’t take into account how pollutants may combine with other substances to create new types of pollutants

  • time-consuming, laborious, organism-specific —> results in data not applicable to other species

The Issue of Waste Disposal in the Ocean

waste disposal facilities on land have limited capacities that re being exceeded in some cases - should additional waste be discarded in opean ocean?

• unlike coastal areas, open ocean has mixing mechanisms (waves, tides, currents) that distribute pollutants over a wide area - entire ocean basin

• diluting pollutants often renders them less harmful - on the other hand, do we really want to distribute a pollutant across an entire ocean without knowing what its long-term effects might be?

some ppl say don’t dump anything in ocean, others think it can be a repository as long as proper monitoring is conducted.

CONCEPT CHECK 11.1

(1) Examine WHO’s definition of pollution. why does it need to be so specific?

(2) what is an environmental bioassay? what are some drawbacks to using an environmental bioassay to determine whether or not a substance should be classified as a pollutant

• environ bioassay = conduct controlled experiment to see how and if pollutants affect marine organisms

• drawbacks:

  • expensive, time-consuming - may only tell us things about specific organisms, and not others

  • doesn’t predict long term effects of pollution

  • doesn’t account for the fact that the pollutant might mix w/ another pollutant and create something dangerous

(3) from memory, define pollution. then consider these items and determine whether each one is a pollutant based on your definition.

Definition: the presence of a substance in the environment that, bc of its chemical comp or quantity, prevents naturally occurring processes and produces undesirable enviro or health effects.

a. dead seaweed on a beach

a. natural oil seeps

c. a small amount of sewage

d. warm water from a power plant dumped into the ocean

e. sound from boats in the ocean