Deck 20: Oceans in Jeopardy

Question 1

What effect does an oil spill have on the ecology of a rocky shore?

Answer 1

Oil spills have an effect on all the organisms that inhabit the rocky shore environment. Oil prevents bird from flying, and from repelling water and insulating them from water and cold. Oil prevents mammals from swimming and insulating their bodies from the cold. When the animals try to clean the oil from their bodies, they can ingest lethal amounts or ingest enough to be carcinogenic. Oil clogs their orifices (eyes, ears, nose) and as a result for most birds, does not allow them to process the excess salt from their body. Some of the rocky shore inhabitants (mollusks, barnacles, limpets, and snails) can survive the smothering oil, however their bodies become infused with the toxic substance that is persistent up the food chain. Some animals will be poisoned and lose their grip, being washed to sea. Eventually, the vacant spaces will fill with resistant species and algae, simplifying the food chain and diversity of the rocky shore environment.

Question 2

An industrial waste is being dumped into the ocean off the coast of California, and you are asked to determine if it is accumulating in the aquatic food chains. How might you determine this?

Answer 2

To determine if a particular waste was infiltrating an aquatic food chain, a scientific sampling of the ecological species of the location would be appropriate. First, one would need to know the component molecules and their solubility. Then, samples of relevant size would be taken from as many trophic levels of the food chain as is possible. Looking at the results from the highest trophic levels toward the lowest trophic levels would be telling if, and how deep in the food web, the infiltrant is effective. If sampling were done laterally, it would be revealing of how wide spread the effects of the pollution reached. Because we know that 10% of energy is passed upward at each trophic level, we can make assumptions even for levels that are not sampled. These results can also be applied to what we know about weather patterns and water circulation in the areas to project the distance of the effects of the pollutant.

Question 3

Nonnative species may outcompete the native species causing their populations to decline or even driving them to extinction. Since many introduced species are free of natural predators, their populations grow rapidly putting more pressure on the native populations and causing changes in ecosystem structures.

Answer 3

Every organism attempts to survive in its environment, and either adapts or dies when the environment changes. Whether introduced intentionally (aquaculture or pet fish that are no longer wanted) or incidentally (aquarium accidents or on the hull, or in the ballast of a boat), alien species will attempt to survive in the new environment. In an effort to do so, the nonnative species will take up space habited by inferior species. Because the invaders have no natural predators, this can result in displacing and destroying native species and upsetting the ecological balance of resources.

Question 4

Damage to _______has the greatest impact on many commercial species of fish and shellfish.
a. sand beaches
b. rocky beaches
c. wetlands
d. the benthos
e. the open sea

Question 5

What activities are most damaging to wetlands?

Question 6

You find that a snail from the Philippines has been accidentally introduced in the Bahamas and has spread to the reefs associated with most of the islands. What might be done to control the spread of the nonnative snail and eradicate it?

Question 7

Many pollutants, both organic and inorganic, can enter food chains and sometimes accumulate in higher trophic levels, a process known as biomagnification.

Question 8

There are many ways that concerned individuals can help preserve the marine environment even if they do not live close to the coast. Using cloth bags instead of plastic, making good food choices when it comes to selecting seafood, and making informed choices when voting are just some of the ways you can get involved.

Question 9

An example of a persistent toxin would be
a. fertilizer
b. human waste
c. DDT
d. red-tide toxin
e. lead

Question 10

Describe how toxins and other pollutants can enter ocean food chains.

Question 11

What environmental problems are associated with plastic trash?

Question 12

List some of the major problems that are associated with the agricultural runoff that enters the ocean.

Question 13

Seashell collectors are frequently blamed for decreases in local mollusc populations in Florida and other areas of the world. The collectors state that development and pollution are more to blame than overcollecting. Do you think that the collectors' argument is valid? Explain.

Question 14

Describe how an oil spill causes injury to birds and mammals.

Question 15

Plastic is a serious hazard to marine organisms because it persists in the environment for long periods of time. Marine vertebrates can become tangled in plastic debris and lose limbs, strangle, or drown. Some marine animals mistake the plastic for food and are killed when their digestive tracts become obstructed. Microparticles of plastic can be consumed by invertebrates, killing them or their predators.

Question 16

How do changes in wind patterns caused by climate change affect marine organisms?

Question 17

Biological magnification refers to
a. the increase in size of organisms as trophic levels increase
b. the increase in populations of algae in response to nutrients
c. the change in population size from generation to generation
d. the accumulation of toxins in the flesh of animals at higher trophic levels
e. the accumulation of pollutants in the marine environment

Question 18

Why does the introduction of a nonnative species frequently result in a decrease in the number of native organisms?

Question 19

What are the major sources of oil pollution?

Question 20

What are some ways in which nonnative species are introduced into new environments?

Question 21

What portion of the East Coast of the United States do you think would be more likely to experience algal blooms resulting from agricultural runoff?

Question 22

Describe how recreational and commercial use of beaches affects beach ecology.

Question 23

Climate change is causing some marine animals to expand their ranges, while for others their ranges are shrinking. As animals expand from their usual range, they start to compete with the indigenous organisms and sometimes outcompete them. Climate change also allows disease organisms to spread over a wider range. Climate change is responsible for some coral diseases. The decreased oxygen in warmer water stresses many organisms. The melting of polar ice adds freshwater to the sea and raises sea level while having a negative effect on Arctic ecosystems. Changes in wind patterns cause changes in ocean currents and the distribution of planktonic food.

Question 24

What are some causes and consequences of eutrophication?

Question 25

Sewage from beachfront cottages usually enters
a. sewer system
b. septic tanks
c. the sea directly
d. drainage ditches
e. compost heaps