Chapter 7 E.S.

What causes most coastal pollution in the United States?

Industrial waste and sewage

Plankton form the (Base Pinnacle) of the marine food web. _

Base

Barnacles are a type of(nekton benthos), or bottom-dwelling, organisms. _

Benthos

Which of the following is not characteristic of salt marshes and mangrove swamps?

Both are dominated by marsh grasses

Which of the following statements is not correct?

Rivers generally move faster, and their oxygen levels decrease, as they near the ocean.

Excessive nutrient growth in an aquatic ecosystem can be accelerated by (runoff industrial pollutants). _

Runoff

Downstream, a river often widens and flows more (slowly swiftly). _

Slowly

Upstream, a river is usually cold and flows (slowly swiftly) through a shallow riverbed. _

Swiftly

Coral reefs are intricately shaped rocklike structures that are formed as a result of

The secretion of calcium carbonate by tiny marine animals.

The arrangement of organisms in the open ocean is determined by the

amount of nutrients and sunlight that are available

Estuaries

are ecosystems where both fresh water and salt water are present

In the _____ zone, life is diverse and abundant.

littoral

What are the two main types of freshwater wetlands?

marshes and swamps

The majority of marine organisms are found in

shallow coastal waters

The types of organisms found in a pond or lake depend on

the amount of sunlight available, the temperature of the water, the presence of nutrients

Fish are a type of (nekton benthos), or free-swimming, organisms. _

Nekton

Which of the following is a threat to coral reefs?

Oil spills, sewage, and pesticides.

What mainly distinguishes nekton from benthos?

One swims freely and the other often lives attached to a hard surface.

The least productive marine ecosystem is the (open ocean coastal water) . _

Open ocean

Why doesn't photosynthesis occur in deep ocean water?

There is no sunlight

Corals live only in shallow, (warm cool) water where there is enough light for photosynthesis. _

Warm

Which of the following is not characteristic of wetlands?

Wetlands are limited to inland freshwater environments.

As they flow down a mountain to flatter ground, rivers generally become

Wider, warmer, and slower

In the _____ zone, the water is cool and dark.

benthic

Swamps are commonly found on

flat, poorly drained land

Which of the following is not an environmental function of wetlands?

increasing runoff

Most pollutants that enter estuaries break down over time, yet they are still considered a problem because

it is the volume of the pollutants, more than the time factor, that harms estuaries

Two threats to ocean ecosystems are

nutrient runoff and industrial waste discharges, overfishing and entanglement of marine mammals in trawl nets, sewage and algal blooms

Which organism produces most of the food in an aquatic ecosystem?

phytoplankton

Estuaries are very productive ecosystems because they receive fresh nutrients from

rivers and oceans

Which ecosystem has the highest level of salinity?

salt marsh