Ch. 15: Environmental Issues

_________ is a type of ocean pollution that is frequently caused by nutrient runoff from agriculture and from disposal of livestock and human waste, leading to the artificial enrichment of waters with a previous low nutrient level.

Eutrophication

Marine ______ is "the introduction by man, directly or indirectly, of substances or energy into the marine environment which results in deleterious effects" (World Health Organization).

pollution

Plastic bottles, plastic bags, and cans are types of ______ waste that pollute beaches and coastal areas.

solid

For many years, Boston Harbor received sewage effluent in a variety of stages and became seriously polluted. The 1972 Clean Water Act mandated a(n) ______.

upgrade of sewage treatment to the secondary treatment level

Reason: Secondary treatment requires substantial degradation of the biological content of the waste.

A ______ is a substance such as heavy metals, chemical compounds, and excessive concentrations of nutrients that degrades the environment and is harmful to organisms.

toxicant

______ is most likely the first type of major human impact on the oceans.

Overfishing

Marine pollution includes ______. (Mark all that apply.)

heavy metals

noise

excess nutrients

What is the most common type of waste found on beaches worldwide?

Cigarette butts

Choose all the toxicants that are capable of degrading water quality.

Hydrocarbons

Heavy metals

Pesticides

Bacteria

Which of the following two toxicants have been banned because of their negative impact on the environment?

DDT and PCBs

1. Bioaccumulate:

2. Biomagnify:

1. When levels of toxicants, such as methyl mercury, build up in an organism's body

2. When concentrations of a toxic substance increase as one organism consumes another (as it moves up the food chain)

Most of the plastic trash coming from the commercial fishing industry is ______

fishing gear

The most common type of pollutant on U.S. beaches is ______.

plastics

Which of the following are impacts of plastics on marine animals?

Animals may become entangled in plastics.

Animals may ingest plastics, mistaking them for prey.

The three leading sources of plastic trash in the oceans are ______.

naval, merchant, and fishing vessels

As plastic debris in the ocean breaks down into smaller pieces over time, it ______.

may release toxic chemicals

may concentrate toxic chemicals at higher levels than in the surrounding water

A(n) _______ area in the ocean has low oxygen levels; it has also been called a dead zone because the area can no longer support most marine life.

hypoxic

When marine mammals become entangled in plastic fishing nets, it is frequently fatal because ______.

marine mammals must come to the surface for air

Hypoxic waters can ______ slow-moving, bottom-dwelling organisms such as crabs, snails, clams, and worms.

suffocate

The Eastern Pacific garbage patch concentrates floating bits of plastic and other debris because ______.

ocean gyres, or circulating currents, tend to trap it in floating patches

The dead zone in the Gulf of Mexico is caused by ______.

nitrogen-based fertilizers

animal manure

sewage

When increased levels of organic matter enter the ocean, there is a(n) ______ in marine algae. Then, when the algae die and are consumed by bacteria, the oxygen levels ______.

increase; drop

True or false: The Gulf of Mexico contains the only dead zone that we know of at this time.

False

Which of the following are sources of oil spills in the ocean?

Oil tanker accidents

Offshore oil well drilling

The ______ spill was the largest oil spill in U.S. history.

Deepwater Horizon

The dead zone in the Gulf of Mexico is primarily caused by too much ______.

nitrogen

What were the sources of the oil spills that occurred as a result of the Gulf War?

Bombing of some sites led to oil being released.

Some oil was deliberately released.

Some oil spilled from a refinery that was damaged in the battle.

A short-term effect of an oil spill includes wildlife mortality, whereas a long-term impact includes ______.

damage that results from the cleanup efforts, including people and equipment that alter the environment while they attempt to clean the site

______ are the single greatest source of oil in the marine environment.

Natural seeps

Which of the following are true regarding marine wetlands?

Marine wetlands are important for the life cycle of many commercially valuable species such as crabs, shrimp, and oysters.

Marine wetlands are important spawning areas for marine fish.

Which of the following are examples of ways humans have played a role in introducing species to new geographic areas in time spans that far exceed a natural rate of species expansion

The steel hulls of today's modern ships fill and discharge ballast water before and after transoceanic crossings.

European sailors coming to settle the North American continent had barnacles and snails attached to their boats.

A ship's ballast water (water that is pumped in and released in order to preserve the ship's stability as it unloads and loads cargo) is problematic for the marine ecosystem because it ______.

contains populations of small floating organisms that can be rapidly transported to nonnative regions

If a fisherman is attempting to catch tuna but accidentally catches dolphins in the net, the dolphins are considered ______.

incidental bycatch

______ is the removal of fish from a population faster than the population can reproduce.

Overfishing

In regard to the Atlantic cod fishery, the two major factors that led to its collapse were ______.

increasing fishing technology and increases in the size of the fishing fleets

The population of ______ dropped 80% between 1970 and 1993. Being the world's most valuable fish, there is incentive to stop the collapse of this fishery.

bluefin tuna

"Fishing down the food web" describes the fishing practice of ______.

taking the largest fish first, and when those are gone, then the next largest, and so on

What are indirect consequences of overfishing?

Removing the major predator to another organism

Removing the major food source of another animal

The capture of bycatch

With the world's demand for seafood on the rise but declines in harvests of wild fish stocks occurring, the _______ market has become the fastest-growing area of global food production.

aquaculture/mariculture

The ______ fishery management approach views the entire ecosystem as relevant to managing a fishery and allows for the diverse societal uses of fish stocks, including fishing, recreation, tourism, and overall ecosystem health.

ecosystem-based

Indirect impacts of fishing include all of the following except ______.

fishery collapse from overharvesting

Marine protected areas ______, and marine reserves ______.

include a wide range of legal restrictions on human activity; are focused on prohibiting fishing and other consumptive activities

The ecosystem-based fishery management approach differs from the maximum sustainable yield approach because it ______.

acknowledges diverse societal uses of fish stocks, including fishing, recreation, and tourism

acknowledges uncertainties in the system