Chapter 14, Question 2

What is compensation depth? What happens to phytoplankton below that depth? To zooplankton?

At a certain depth, the production of carbohydrates and oxygen by photosynthesis through a day’s time will exactly equal the consumption of carbohydrates and oxygen by respiration. This break-even depth is called the compensation depth. Changes with sun angle, turbidity, surface turbulence and other factors

phytoplankton: The deeper a phytoplankton's position is, the less light it receieves. Eventually, if it stays below the compensation depth for more than a few days, it will consume its carbohydrate reserves and die.

Zooplankton:

Because they are not autotrophic (they don’t make food by photosynthesis or chemosynthesis), zooplankton have no compensation depth.

Chapter 14, Question 4

Where in the ocean is plankton productivity the greatest? Why?

the distribution of plankton corresponds to the distribution of nutrients. Because of coastal upwelling and land runoff, nutrient levels ae highest near the continents. Plankton are most abundant there, and poductivity is highest.

The tropical oceans away from land (where there is very low amounts of nutrients) are oceanic deserts, devoid of visible plankton.

you need a host, and so you are fairly reliant upon the availability of host organisms. The reason for their success is probably due to the fact that being a parasite allows you to hijack certain elements of the host's internal mechanisms, and use up various products without doing the hard work to convert them in the first place. This allows parasites to be relatively simple and not expend lots of energy on things like metabolism.

another benefit is that once you've found your host, your pretty much set; no further energy expenditure necessary till your host dies or you are forcefully ejected. Also, the insides of other animals is a very good place to raise little parasites; plentiful warmth and food!

Chapter 16, Question 2

What is a limiting factor? give a few examples.

A limiting factor is a physical or biological environmental factor whose absence or presence in an inappropriate amount limits the normal actions of an organism.

Chapter 16, Question 5

What problems confront the inhabitants of the intertidal zone? How do you explain the richness of the intertidal zone in spite of these rigors?

The problems confronting the intertidal zone include the fact that the tide rises and falls, alternately drenching and drying out the animals and plants. Additionaly, the powerful force of crashing waves (wave shock) tears at the structures and underpinnings of the residents. Temperature can change rapidly as cold water hits warm shells, or as the sun shines directly on newly exposed organisms. In high latitudes, ice grinds against the seashoreline; in the tropics intense sunlight bakes the rocks. Predators and grazers from the ocean visit the area at high tide, and those from land have access at low tide. too much fresh water can osmotically shock the occupants during storms. Annual movement of sediment onshore and offshore can cover and uncover habitats.

Despite these rigors, the richness of the intertidal zone is the fact that there is a large quantity of food available. The junction between land and ocean is a natural sink for living and once-living material. Minerals dissolved in water running off the land serve as nutrients for the inhabitants of the intertal zone as well as for plankton in the area. The crashing surf and strong tidal currents keep nutrients stirred and ensure a high concentration of dissolved gases to support a rich population of autotrophs. many of the larval forms of adult organisms of the intertidal community depond as plankton as their primary food source. Another reason for the success of organisms is the large number of habitats and nichs to be occupied. These spaces provide hiding places, quiet places to rest, attachement sites, jumping-off spots, cracks from which to peer to obtain a surprise meal, footing from which to lanch a sneak attack, secluded mating nooks, or darkness to shield a retreat.

Chapter 17, Question 4

What are the signs of overfishing? How does the fishing industry often respond to these signs? What is the usual result? What is bycatch?

The signs of overfishing include the dissapearance of worldwide stocks of many different types of fish (including tuna, cod and other large ocean fishes). Fleets are obtaining fewer tons per unit of effort and are ranging farther afield in their urgent search for food. And the near catastophic collapse of more fisheries.

The fishing industry responds to these signs by focusing on quick financial returns, even if it means depleting a stock and disrupting the equilibrium of a fragile eco-system. The industry tends to increase the number of boats and develops more efficient techniques for capturing the remaining animals. Sometimes the government will set limits and step in.

The usual result of the fishing industry's reaction is that the govnermnet will eventuall step in and there will be a large impact on the balance of marine communities. 

Bycatch is a term used to describe animals unintentionally killed while collecting desirable organisms.

Chapter 18, Question 1

Why is refined oil more hazardous to the marine environment than crude oil? Which is spilled more often? What happens to oil after it enters the marine environment?

It is much more tocis than crude oil becuase it has developed carcinogenic and metallic components from the heat and pressure within internal combustion engines.

Spills of crude oil are generally larger in volume and more frequent than spills of refined oil.

Aftter it enters in the marine environment, it is very hard to tell what will happen. That is because it depends on its location and proximity to shore, the quantity and composition of the oil, the seaon of the hyear, currents, and weather conditions.

Crude oil does not dissolveeasily in water, but those that do can harm the delicate juvenile forms of marine organisms. The remaining oil that does not dissolve form sticky layers on the surface that prevent free diffusion of gases, clog adult organisms' feeding structures, kill larvae and decrease the sunlight available for photosynthesis.

Chapter 18, Question 2

What heavy metals are most toxic? How do these substances enter the ocean? How do they move from the ocean to marine organisms and people?

The most dangerous heavy metals being introduced into the ocean are mercury, lead, copper, and tin.

 Heavy metals enter the ocean by natural leaching from the seabed, by deposition from the atmosphere, and by runoff from land.  Ingestion of bioavailable forms can result in damage to the nervous system, especially if the organism is exposed early in life.

They move from the ocean to marine organisms and people through the progression of the food chain. Smaller marine animals (bacteria) digest the toxins and then the toxins move up the food chain as the smaller animals get eaten by larger ones. Eventually humans eat the fish that contain the toxins.

Chapter 18, Question 3

Few synthetic organic chemicals are dangerous in the very low concentrations in which they enter the ocean. How are these concentrations increased? What can be the outcome when these substances are ingested by organisms in a marine food chain?

These concentrations increase through biological amplification (small bacterial digest the chemicals with very low concentrations of the chemical then a larger animal eats more of the infected bacteria thus increasing the concentration of the chemicla.

The outcome of the ingestion of these substances can include the disformation of pelican eggs (as seen in the 1960s) and a deadly viral epidemic among dolphins and other negative effects.

Chapter 18, Question 5

What is the greenhouse effect? is it always detrimental? What gases contribute to the greenhouse effect? Why do most scientists believe that the Earth's average surface temperature will increase over the next few decades? What may result?

Glass in a greenhouse is transparent to light but not to heat. The light is absorbed by objects inside the greenhouse, and its energy is converted into heat. The temperature inside a greenhouse rises because the heat is unable to escape. The greenhouse effect is necessary for life.  Without it, Earth’s average atmospheric temperature would be about -18°C (0°F).Earth’s recent rapid surface warming is probably the result of an enhanced greenhouse effect caused by greenhouse cases such as carbon dioxide and methane.

The gases that contribute to the greenhouse effect are Carbon dioxide, water vapor, methane, and chlorinated fluorocarbons

they believe that the average surface temperature will increase ove the next few decades because they believe that more carbon dioxide will continue to be introduced into the atmosphere. they believe this because the human growth rate is continuing to grow by about 2% each year and we are producing carbon dioxide at a greater rather than can be absorbed by the ocean, and at a greater rate than ever before.

some results of this include potential changes in global winds and rainfall, a rise in ocean temperature, a decrease in dissolved gases, declining productivity, more rapid spread of disease, distruption of ecosystems and terrestrial crop production, and damage to coastal structure.

Chapter 18, Question 6

How might global warming directly affect the ocean?

Global warming might directly affect the ocean as if it continues at the current rate, melting arctice ice would open the northwest passae in summer by 2020, which would cut 5,000 nautical miles from shipping route between europe and Asia.

It could also add water to the ocean as it would accelerate the melting of the land-based greenland and Antarctic ice caps

it would also increase the temperature of the ocean