Chapter 7 Aquatic Ecosystems

What causes most coastal pollution in the United States?

Industrial waste and sewage

Most ocean pollution can be traced to activities on

Land

A river changes with the _____ and _____ through which it flows

Land and climate

What is a wetland?

A wetland is an area that is covered by water for at least part of the year

Because water ____ sunlight, photosynthesis is limited to the upper 100 meters of the ocean

Absorbed

Long, thin ___ islands typically run parallel to a shore

Barrier

Why are many of the worlds largest cities built on estuaries?

Because it's quick access it the ocean, for things like shipping and fishing or other recreational activities

Barnacles are a type of _____, or bottom-dwelling, organisms

Benthic

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

Both are dominated by marsh grasses

Coral polyps secrete skeletons of _______ that slowly accumulate and form coral reefs

Calcium carbonate

A(n) _____ lake has a large amount of plant growth due to nutrients

Eutrophic

Identify 3 freshwater ecosystems and 3 marine water ecosystems

Fresh-> lake, pond, river. Marine-> ocean, bay, estuary, salt marsh

In the__ zone, life is diverse and abundant

Littoral zone

Plankton form the____ or _____of the marine food web

Majority or the bases

Many rivers originate from ______ in mountains

Melting snow

In estuaries, fresh water and salt water mix, forming a _____ or _____ trap

Mineral or nutrient

Which of the following statements is not correct?

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

Where do more plants and animals live: on rocky shores or on sandy shores? Explain your answer

Rocky because plants can attach their roots to stuff and there will be more protection from the elements

Mosses use ___ to anchor themselves to rocks near churning river headwaters

Roots

Excessive nutrient growth in an aquatic ecosystem can be accelerated by

Runoff

The amount of dissolved salts in water is known as

Salinity

The majority of marine organisms are found in

Shallow, coastal waters

Downstream, a river often widens and flows more

Slowly

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

The amount of sunlight available, the temperature of water, the presence of nutrients, (all of the above)

An estuary functions as a mineral trap due to

The mixing action of river water and ocean water

An arctic ecosystem depends almost entirely on ______ for its available food

The ocean

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

What are two main types of freshwater wetlands

marshes and swamps

Fish are a type of _____, or free-swimming, organisms

Nekton

Three groups of aquatic organisms include plankton, ____, and benthos

Nekton

Marshes are dominated by ____ plants while swamps contain mainly _____ plants

Non-woody and woody

Which of the following is a threat to coral reefs

Oil spills, sewage, and pesticides (all of the above)

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

Most of the food in aquatic ecosystems is produced by

Phytoplankton

Two types of plankton are microscopic plants called ____ and microscopic animals called ____

Phytoplankton and zooplankton

Describe one threat to river ecosystems

Pollution, mining, logging, construction

Upstream, a river is usually cold and flows ____ through a shallow riverbed

Quickly

Why doesn't photosynthesis occur in deep ocean water

There is no sunlight

What beneficial role do decomposers play in an aquatic ecosystem

They break down dead organisms and add nutrients to the deep parts of waters

Corals live only in shallow, ____ water where there is enough light for photosynthesis

Warm

Which of the following is not a 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 (all of the above)

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

benthic

What adaptation prevents phytoplankton from sinking into deep waters?

flagella

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 (all of the above)

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