Chapter 16: The Oceans
I.
Collapse of the Cod Fisheries:
II. The Oceans
1. Oceans influence;
A. Oceans cover most of Earth’s surface. The oceans cover ___________% of world.
B. The oceans contain more than water: fig. 16.3
1. Ocean water is salty because:
2. The salinity of ocean water generally ranges from _______________ parts per thousand (ppt),
varying from place to place because of differences in:
3. Seawater also contains nutrients such as ___________________ and ___________________
that play essential roles in nutrient cycling.
4. Another aspect of ocean chemistry is dissolved gas content, particularly the dissolved oxygen
upon which:
C. Ocean water is vertically structured.
1. Water density increases as ____________ rises and as _________________ falls, giving
rise to different layers of water.
2. The waters of the surface zone are heated by sunlight each day and are stirred by
_____________
3. The pycnocline is:
4. The _____________ of the ocean lies beneath the pycnocline and is not affected by
_________and ________________.
D. Ocean water flows horizontally in currents.
1. The ocean surface is composed of currents:
2. Currents transport:
E. Vertical movement of water affects marine ecosystems.
1. Upwelling is:
2. Downwelling transports:
F. Seafloor topography can be rugged and complex.
1. Parts of the ocean floor are just as complex as the terrestrial portion of the
_____________________
2. In the bathymetric profile, gently sloping continental shelves:
3. Most of the seafloor is flat, but there are:
4. Oceanic zones differ greatly, and some support more life than others.
a. The well-lit top 10 meters, called the photic zone, contains:
b. Between the ocean’s surface and the floor are the _____________habitats.
c. benthic area:
III. Marine and Coastal Ecosystems
A. Open-ocean ecosystems vary in their biological diversity.
1. Much of the ocean’s life is concentrated:
2. In the deep ocean:
3. hydrothermal vents:
B. Kelp forests harbor many organisms in temperate waters.
1. Kelp is:
C. Coral reefs are treasure troves of biodiversity.
1. A coral reef is:
2. Corals are tiny invertebrate animals related to:
3. zooxanthellae:
4. Coral reefs host an incredible diversity of life, and they protect:
5. Coral reefs are experiencing worldwide declines, probably due to:
D. Intertidal zones undergo constant change.
1. The intertidal or littoral zone lies:
2. Tides are the periodic _________ and ___________of the ocean’s height at a given
location, caused by the ______________ pull of the _________ and ___________.
3. The intertidal zone is a tough place to make a living, but is home to:
4. The rocky intertidal zone is so diverse because:
E. Salt marshes:
F. Mangrove forests line coastlines throughout the ___________________.
1. Mangroves are trees with unique:
2. In south Florida and elsewhere, mangrove forests have been removed as:
G. Freshwater meets salt water in estuaries.
1. Estuaries are:
2. Estuaries provide critical_________________ for many organisms.
3. Estuaries around the world have been affected by:
IV. Human Use and Impact
A.
The oceans provide ____________________________ routes.
B.
We extract energy and minerals.
1.
By the 1980s, about ________________% of our production of crude oil and natural gas
came from exploitation of ocean deposits.
2.
Methane hydrate is:
3.
a.
The U.S. Geological Survey estimates that:
b.
Destabilizing a methane hydrate deposit could lead to:
We extract minerals from _________________________.
C.
Marine pollution threatens resources.
D.
Nets and plastic debris endanger marine life.
1. Because most plastic is not ______________________, it can drift for decades before
washing up on beaches, and may be mistaken for_________________ by marine mammals,
seabirds, fish, and sea turtles, which may ____________ as a result of ingesting it.
2. Lost or discarded fishing nets frequently continue:
E. Oil pollution comes not only from massive spills.
1. The majority of oil pollution comes not from large spills, but:
2. Minimizing the amount of oil we release is important because petroleum pollution is:
3. Over the past three decades, the amount of oil spilled in U.S. waters and worldwide has
________________ in part because of an increased emphasis on spill prevention and response.
F. Excess nutrients can cause algal blooms.
1. The release of excess nutrients into surface waters can spur unusually high growth rates
of algae, called ___________________________. Some algal species produce reddish pigments,
and blooms of these species are nicknamed ______________________
2. Harmful algal blooms can cause:
V. Emptying the Oceans
A. Overfishing is nothing new.
1. Humans have been harvesting sea life for ______________________
2. A recent synthesis of historical evidence revealed that ancient overfishing likely affected:
3. Florida Bay is suffering today from:
B. Modern fishing fleets deplete marine life rapidly. Explain:
C. Three commercial methods for fishing include:
1.
2.
3.
D. Fishery declines are masked by several factors.
1. Despite the fact that fish stocks have been depleted in region after region as industrialized
fishing has intensified, the amount of overall global fish production has remained:
2. Fishing fleets travel ___________ distances, fish in ________________waters, spend
more ____________ fishing, and set out more______________ and lines.
3. Improved technology, including:
E. We are “fishing down the food chain.”
1. Fisheries data reveal that as fishing increases, the _____________and __________________
of fish caught decline.
2. We are also shifting from:
F. Some fishing practices kill nontarget animals and damage ecosystems.
1. By-Catch:
a. Boats that drag ___________________ through the water capture substantial
numbers of large __________________ species. This method has been banned or
restricted by many nations.
b. Longline fishing involves:
c. ___________________ involves dragging weighted nets over the floor of the
continental shelf to catch_______________ organisms, resulting in damage to entire
benthic ecosystems. Trawling crushes many organisms and leaves long swaths of
______________ sea bottoms.
G. Consumer choice can influence fishing practices.
1. Purchasing ________________ seafood products exercises consumer choice, and thus
influences the fishing industry.
2. Several nonprofit organizations have devised ________________ to help consumers
make ecologically sound choices.
VI. Marine Conservation Biology
A. Fisheries management has been based on maximum ______________ yield.
1. The goal of this strategy is to:
2. Despite such efforts, many fish stocks have ____________________.
3. A suggested key change is to shift the:
B.
We can protect areas in the ocean.
1. Marine protected areas (MPAs):
2. Marine reserves:
C.
Marine reserves have met forceful opposition.
1. Nearly every marine reserve proposed has met _________________ from people and
businesses that use the area for fishing or recreation.
2. In the Florida Keys, _____________________ advocates who had opposed the sanctuary
protested the 1998 establishment of reserve zones.
3. Within 3 years of the establishment of the no-take zones in the Florida Keys there were:
D.
Reserves can work for both fish and fishers.
1. Data in 2001 indicate:
E.
How should reserves be designed?
1. How large do reserves need to be, how many should there be, and where should they be
placed?
2. Involving fishers directly in the planning process is crucial. Why?
3. Studies have estimated that from ______% to __________% of the ocean should be
protected in no-take reserves. Most estimates range between 20% and 50%.
4. Other studies are modeling how to:
VII. Conclusion
A. What is the main thing we are doing to protect ocean fisheries?