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
