Marine Biology MIDTERM 2 Questions

Pelagic vs. Benthic

-Pelagic zone: In the open ocean -Benthic zone: Near the sea bed

List the zones in the water column from surface to deepest (and say what their depths are):

1) Epipelagic Zone (to 200m) 2) Mesopelagic Zone (200-1000m) 3) Bathypelagic Zone (1000-4000m) 4) Abyssopelagic Zone (4000-6000) 5) Hadalpelagic Zone (6000+)

What are some things that result from daily, vertical migration? 3 Facts:

1) It enables animals to minimize the risk of predation during the day 2) Lower water temperatures at the deeper depths reduce an animal metabolic rate and its energy requirements 3) It enables animals to capitalize on the more abundant food resources of the photic zone

What is the Oxygen Minimum Zone (OMZ)? 3 Facts:

1) OMZ typically occurs at depths between 200 and 1,500 meters 2) In OMZ, dissolved oxygen is consumed by bacteria and animal 3) OMZ are the places in the world ocean where oxygen saturation in the water column is at its lowest

a pH of 7 is ______ than a pH of 8

10 times as acidic

The photic zone, or euphotic zone, is the uppermost layer of water that is exposed to intense sunlight. Generally, it extends form the water surface to about...

200m

Symbiosis

A close relationship between two species that benefits AT LEAST one of the species. (clown-fish and anemones)

Describe eutrophication

A phenomenon in which a body of water becomes rich in nutrients, most likely from fertilizer being washed into the water. This causes an algal bloom, which blocks out the sunlight that plants need for photosynthesis. This also results in more bacteria growth, that feed on the algal blooms. The bacteria take over and take up oxygen needed for fish and other organisms to survive, making the water anoxic. It's bad m'kay?

Commensalism

A relationship between two organisms in which one organism benefits and the other is unaffected (an organism feeding on food scraps left behind by another organism)

Parasitism

A relationship between two organisms of different species where one benefits and the other is harmed (ticks, parasitic fish lice)

Mutualism

A relationship between two species in which both species benefit (bird eats ticks which benefit cows)

Which of the following strategies are used by epipelagic organisms to stay within an optimal zone?

Accumulate oil in liver and muscles to reduce density

Autotroph vs Heterotroph

Autotrophs create their own energy through sunlight, Heterotrophs eat to obtain energy.

You are a voracious anglerfish living in the abyssopelagic zone, and you use a bioluminescent lure to attract prey within a range of your sharp teeth. What would be the most effective bioluminescent color?

BLUE

Which of the following animals has the most concentrated urine?

Bluefin Tuna

Describe the abyssal plains

Broad flat muddy areas on the deep sea floor that extend over hundreds of miles and are sparsely populated by animal communities. ***High Biodiversity but Low Biomass***

Fucoxanthin is a photosynthetic pigments found in...

Brown Algae

What causes ocean acidification?

CO2 diffusing from the atmosphere into the ocean

What reaction represents the reaction by which vent chemosynthetic bacteria "make their own food"?

CO2+ H2O + H2S + O2 ---> [CH2O] + H2SO4

What are the reactions that summarize the fate of CO2once it dissolved in seawater?

CO2+ H2O --><--- H2CO3H++ HCO3---><---H++ CO32-

What is an important supply of food to inhabitants of the deep-sea floor?

Chitinous exoskeletons shed by planktonic crustaceans

What photosynthetic pigment is found in all macroalgae?

Chlorophyll a

What is an essential structure associated with countercurrent flow within fish gills?

Close proximity of circulating blood to water flow

What regional factors can exacerbate acidification caused by global CO2 emissions?

Coastal Upwellings

Cold Seep Communities

Cold seeps are locations where hydrocarbon-rich fluid seeps up from below the sea floor, often as methane or hydrogen sulfide. Cold seeps have been found to support significant chemosynthetic communities.

Where are kelp forests are often found?

Cool, relatively shallow waters close to the shore

The way light hits organisms in the open ocean impacts how easily both predators and prey can see each other. Having darker dorsal pigmentation and lighter ventral pigmentation is called what?

Countershading

What are the different types of phytoplankton?

Cyanobacteria, Diaotms, Dinoflagalletes, Green Algae, and Coccolithophores

Fish species from which environment would you expect to have a higher developed lateral line?

Deep Ocean

Fish species from which of the following environment would you expect to have low amount of cone cells?

Deep Sea

Viscosity

Defined as a fluids resistance to flow. Low Viscosity is when a fluid flows easily, like water. High Viscosity is when a fluid flows difficulty, like honey.

Cavefish (i.e., fish adapted to live in caves) have evolved an integrated suite of behavioral, morphological, and physical adaptation to cope with environmental stresses. These include:

Degeneration of eyes, reduction in pigmentation, and enhancement of mechanosensory abilities

Meroplankton

Larval forms of benthic (ocean floor dwelling) and nektonic adults that are temporary members of the plankton community.

_______ are _________. They hatch at sea and then they migrate into lakes and streams, where they grow to maturity.

Eels; catadromous

Each type of sensory information is detected by a specialized receptor cell. How do the sensory stimuli make it to the brain from the sensory receptor?

Electrical Signals

Which area of the ocean has the highest rate of oxygen consumption?

Epipelagic

Describe vertical migration of zooplankton

Every day, zooplankton make their way to deep water in the morning and rise as the sun sets. The reason for this has long been attributed to the trade-off between obtaining tasty morsels in the surface ocean and avoiding becoming a tasty morsel for predators while they're there. Zooplankton eat phytoplankton.

What is marine snow?

Falling particles and aggregates of the remains of once-living plankton organisms; named so because of their appearance when illuminated in spotlights on submersibles. In the deep ocean, marine snow is a continuous shower of mostly organic detritus falling from the upper layers of the water column.

True or False: In the deep-sea, given the relatively high biodiversity in the deep sea, finding a mate is generally not a limitation

False

True or false: OMZ are generally located in the photic zone

False

True or false: Sheephead fish are found in a mangrove

False

True or false: Whereas kelp forests constitute one of the most productive marine ecosystems in the world in terms of CO2 consumption/O2 production, they are often characterized by low diversity of epibenthic organisms.

False

True or false: Active fish have low gill surface area to volume ratio as compared to sedentary fishes:

Falses

Most of deep-water scavenger organisms are:

Food Generalists

It is suggested that many large clam species that live in hydrothermal vents obtain their food

From symbiotic bacteria living in their gills

Food Generalists vs. Specialists?

Generalists are able to survive a wide variety of conditions and changes in the environment: food, climate, predators, etc. Specialists thrive when conditions are just right. They fulfill a niche and are very effective at competing with other organisms.

Oysters growing in water with relatively high concentration of CO2:

Grow slower and are deformed

Blue whales are the largest animal in the world and require a lot of energy to survive. Think about how animals spend energy. Which life process might be compromised when food is limiting?

Growth and Reproduction

When CO2 enters seawater, it combines with water for form _________ but quickly _________ into HCO3- and _________, which ________ seawater pH

H2CO3; dissociates; H+; reduces

Plankton is a general term that refers to organisms that ________

Have limited power of locomotion and generally drift with the current (i.e. cannot swim against the current)

Recent studies indicate that abyssal plains have ______ biodiversity but relatively ______biomass. _______, hydrothermal vents have ________ biodiversity, and _______biomass.

High; low; contrarily; low; high

Which of the following is not a limiting factor for organisms in deep sea waters?

Low Oxygen

It has been demonstrated that ovarian growth is one of most energetically demanding processes in the life of Pacific salmon. During this period, which other processes may be affected?

Maintenance and body growth

Which of the two ecosystems may live in close association with coral reefs?

Mangrove Forests

A countercurrent flow system between a substance A and B:

Maximizes the exchange by having A and B flow in opposite directions

You are an elite marine biologist that is part of the 2015 Team Zissou Research expedition. You have been sleeping in your bunk but you arise to find a fish that has been caught and brought onto the main deck. It is small (<10 cm), weak and flabby, has large eyes, and has photophores on the bottom of its body. From which zone of the ocean was this fish probably caught?

Mesopelagic

Mangals are primarily found in:

Muddy shores in warm climates

It has been demonstrated that metabolic rates decline strongly with depth in visual pelagic taxa, but not in non-visual pelagic or benthic taxa. Can you connect these differences in metabolism to NATURAL SELECTION?

OVERALL, visual pelagic animals have HIGH metabolism A high metabolic rate helps an organism both avoid visually hunting predators and perform well as a visual predator itself OVERALL, non-visual pelagic or benthic animals have LOW metabolism Below the euphotic zone, the efficiency of visual predation is substantially reduced, and thus high metabolic rates are no longer needed

Where are hydrothermal vents primarily located?

On the axes of oceanic ridge or rise systems

What is the difference between osmoregulators and osmoconformers?

Osmoregulators maintain a more or less stable internal osmolarity by physiological means regardless of their external enviornment. Osmoconformers' internal osmolarity changes depending on the external enviornment.

Which of the following structures can be used to determine fish age?

Otoliths

Vision is dependent upon the presence of _____

Photoreceptors

The amount of dissolved oxygen in the water can be lowest at depths of approximately 500 to 1,500 meters. Why would this zone have such low oxygen levels?

Photosynthesis does not occur and respiration rates are higher than in the deep sea

Cyanobacteria

Photosynthetic, oxygen-producing bacteria that can carry out photosynthesis (formerly known as blue-green algae).

As opposed to terrestrial systems, filter feeding is possible in marine systems because:

Potential food particles can remain suspended due to water's greater density and viscosity

Although there is ________ in the deep ocean, the main source of nutrients comes from ______________.

Primary productivity; the epipelagic zone

What are cyanobacteria?

Prokaryotes

What is the most diverse group of macroalgae?

Rhodophyta

Which of the following organisms can potentially benefit from ocean acidification?

Seagrasses (Why tho...)

chitinous exoskeleton

Skeleton made of tough, semi transparent substance that makes a protective shell

Abyssal plains consist primarily of:

Soft Mud Sentiments

photic zone

Surface layer of the ocean that receives sunlight.

What does provide the basis of life in vent communities?

The altered chemistry of the water

oxygen minimum zone (OMZ)

The layer of the water column below the photic zone where dissolved oxygen concentration is lowest and occurs in the Mesopelagic Zone. (200-1500m)

Describe the process of osmoregulation in FRESH WATER:

The salt concentration is HIGH in the fish and LOW in the fresh water. So, water moves into the fish, and salt moves out of the fish. The fish takes in water through the gills. To prevent excess loss of salt, the fish releases Hypotonic Urine which is less concentrated/has more water, and also uses its scales to prevent excess salt loss.

Describe the process of osmoregulation in SEA WATER:

The salt concentration is HIGH in the sea water and LOW in the fish. So, salt moves into this fish, and water moves out of the fish. To prevent excess loss of water, the fish drinks water, and releases Hypertonic Urine which is more concentrated/has less water, and also removes excess salt through the gills membrane.

Define biomass

The total mass of organisms in a given area or volume.

euphotic zone

The uppermost 80 m (260 feet) or more of the ocean, which is sufficiently illuminated to permit photosynthesis by phytoplankton and plants, is called the euphotic zone. (Upper layer of a body of water through which sunlight can penetrate and support photosynthesis.)

Why do coral reefs have more species and more diverse fish communities than most other environments?

There are many different habitats and niches within coral reefs and there is an abundance of light, which allows zooxanthellae to be very productive

What is FALSE about daily, vertical migration?

They are always triggered by changes in light intensity - under constant light, animals stop migrating

Which of the following is not an attribute of mangrove forests?

They influence the health of rivers and freshwater lakes

True or False: Whereas marine flowering plants, like seagrasses, are vascular plants and have roots, stems and leaves, seaweeds are multi-cellular algae and have little or no vascular tissues.

True

True or false: External auditory canal in dolphins is about six times less sensitive to sound than the lower jaw

True

True or false: Hydrothermal vent and cold seep communities have similar sets of dominant species: tube worms, clams, mussels and arthropods, although they range taxonomically.

True

How do hydrothermal vent bacteria obtain energy?

Use oxygen to oxidize hydrogen sulfide, which is converted to sulfate ion

Fill in the blanks with the best option below: I am a _______. I spend only part of my life freely in the water column and am referred to as a_______.

Zooplankton, Meroplankton

Kelp forests

areas in cold waters where the ocean has a rocky floor allowing large algae stalks to grow quickly

What is FALSE about the marine snow? a. On the way down, sinking particles or organic material are repeatedly consumed and defecated by pelagic scavengers b. The time lag between the initial production of organic material in the photic zone and its arrival on the deep-sea floor may be a few days or as much as several weeks c. As consequence of the continue accumulation of organic material, the nutritive value of the marine snow increases as it travels down the water column, which allows to fuel most life in abyssal plains d. The amount of photic zone productivity that reaches the sea bottom is typically only a few percent

c. As consequence of the continue accumulation of organic material, the nutritive value of the marine snow increases as it travels down the water column, which allows to fuel most life in abyssal plains

What is FALSE? a. Typically, cones serve as high intensity and color reception, whereas rods serve as low-intensity receptors b. For all fishes with one type on cone, vision is limited to detecting variations in light intensity -they cannot see varying colors c. The relative proportion of cone vs. rod cells increase when moving from the epipelagic to the mesopelagic zone d. It is relatively common to find reef fish with three different types of cones, whereas this is not true in deep-sea fishes

c. The relative proportion of cone vs. rod cells increase when moving from the epipelagic to the mesopelagic zone

cone cells....

detect color

Define filter feeding

feeding by filtering out plankton or nutrients suspended in the water

ogliotrophic enviornments are....

nutrient poor

Phototrophs

obtain energy from light

Photic zone vs. Aphotic zone vs. Benthos

photic zone - the sunlit region near the surface in which photosynthesis can occur apohtic zone - below the photic zone; dark, so photosynthesis cannot occur here benthic zone - aquatic organisms that live on or in rocks and sediments on the bottoms of lakes, streams, and oceans

Holoplankton

species of zooplankton that remain in a planktonic stage throughout their lives. Jellyfish are holoplankton

mangrove forests

woody, specialized types of trees of the tropics that can live on the edge, where rainforests meet oceans

Describe hydrothermal vents

•Small and localized rocky habitats •Axes of ridges •Highly populated by animal communities ***Low Biodiversity but High Biomass***