Deck 20: Oceans in Jeopardy

Question 1

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

Answer 1

Because the introduction of non-native species can alter large parts (if not entirely) of the ecosystem, it is difficult to control the harmful and spreading effects. Additionally, efforts to control or eradicate a foreign species are limited by what is known of the species and then only in its natural environment, and any attempt will result in loss of or stress to the native ecology. It is important to know what the natural history, tolerance, and genetics are of an introduced species; this takes time and research. One method to mitigate invasive species is the physical removal from the environment; in order to be effective, removal would need to occur at a rate that is faster than that of reproduction Physical removal is more often than not, an inefficient approach to the problem. Biological controls might be more efficient, however, introduction of one alien to control or remove another alien is risky. In all cases of mitigation, the more that is known about a species and those of the native environment, the lower the risk of methodology.

Question 2

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

Answer 2

Pollution in the ocean effects all organisms in many ways. Human and industrial wastes dumped into the ocean can injure and/or kill, interfere or enhance (in a negative way) reproduction, and interfere with the productivity of organisms that eventually interfere with the health of other ocean, and human, organisms. Pollutants enter the food chain via human, industrial, commercial, and military dumping directly into the water, as well as runoff from the land and precipitation from the air. Though plastics are not biodegradable, they breakdown over long exposure to sun and heat, releasing chemicals that end up in the marine food chain. Another way pollutants enter the food chain is through "biological magnification", the process by which pollutants are carried up the food chain through the trophic levels.

Question 3

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.

Answer 3

The most important, and first step, to conservation and preservation of oceanic systems is awareness of connection of every other activity with the marine environment. One needs to actively and conscientiously participate in preservation of marine environments through education and action regarding waste disposal, commercial and industrial activities in and near the ocean, and land use and development. It is important to find a balance between the needs of humans and those of marine ecosystems when making decisions regarding pollution, waste disposal, oil mining and transportation, farming, and building residential and commercial developments. The key to these balances is knowledge of the environments and ecologies we are trying to conserve.

Question 4

An example of a persistent toxin would be

A) fertilizer
B) human waste
C) DDT
D) red-tide toxin
E) lead

Question 5

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 6

What environmental problems are associated with plastic trash

Question 7

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

Question 8

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 9

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

Question 10

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 11

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

Question 12

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 13

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

Question 14

What are the major sources of oil pollution

Question 15

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

Question 16

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 17

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

Question 18

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 19

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

Question 20

Birds that are tolerant of humans and thrive on human garbage are

A) pelicans
B) lesser terns
C) piper plovers
D) gulls
E) sandpipers

Question 21

What are some causes and consequences of eutrophication

Question 22

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

Question 23

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

Question 24

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.

Question 25

Sewage from beachfront cottages usually enters

A) sewer system
B) septic tanks
C) the sea directly
D) drainage ditches
E) compost heaps

Question 26

What activities are most damaging to wetlands