Biology of Marine Systems Exam 1

Pacific Ocean

largest and deepest ocean

-limits are Asia, Australia and the Americas

-Less influenced by terrestrial conditions

-Affected by plastic contamination

-lots of volcanic activity and island chains

Atlantic Ocean

saltiest ocean on average

-second largest ocean , between the Americas, Europe and Africa

-Drain most of the world's largest rivers

-Greatly influenced by terrestrial climates, river borne inputs of dissolved and particulate substances

Indian Ocean

warmest ocean on average

-Bounded by Asia, Africa and Australia

-Multiple local seas and gulfs with unique conditions

-Asia directly influences its temperature

Southern/Antarctic Ocean

Ocean that has a water border with other oceans

Subtropical/Antarctic convergence

water border where colder, saltier water from the poles mixes with warmer water

Antarctic Circumpolar Current

strong ocean current that keeps waters cold in the south pole and is hard for organisms to cross

Arctic Ocean

Smallest and shallowest ocean

-Lowest salinity due to heavy freshwater inflow

-surrounded by Eurasia and North America

-partly covered by sea ice throughout the year, more in winter months

Definition of a sea

A division of an ocean, delineated by landforms, currents, or specific latitude or longitude boundaries

Characteristics of a sea

-restricted connection to oceans

-usually shallow compared to oceans

-influenced greatly by conditions of surrounding land

The Sargasso sea has no...

terrestrial boundaries

-instead it is formed by 4 currents that make a gyre

continental shelf

a low-sloping platform, extends from the shoreline to roughly 10 km to over 300 km out to sea

continental slope

a steep incline of the ocean floor leading down from the edge of the continental shelf

-usually dissected by submarine canyons

abyssal plain

area around 4000m in depth and makes up 50% of Earth's surface

trenches

areas that occur just seaward of the base of the continental slope and may be more than 10,000m deep

Difference between island and ridge

Oceanic islands are just one of a handful of mounts that rise from the ocean bottom. Ridges are linear features

tectonic plates

massive slabs of rock that continents rest on

Lithosphere

created when molten rock rises from Earth's mantle, adding new seafloor

ridges

area where the seafloor is spreading, represented by underwater mountain ranges

subduction zone

areas at which the cold, dense crust sinks down into the mantle areas where plates collide

The oceanic crust is formed at...and destroyed at...

ridges, subduction zones

rate at which the seafloor is spreading

2 to 25 cm per year

Ring of Fire

activity between tectonic plates in the Pacific Ocean

Sea Water Properties

-asymmetric in charge

-universal solvent

-attraction to other molecules because of hydrogen bonds

-stores lots of heat

latitudinal gradient

temps are colder at the poles and warmer at the equator

Areas with largest seasonal changes

mid-latitudes

Thermocline

steep change in temperature gradient between the mixed upper layer and the cold deep water.

-influenced by seasons and upwellings

upwelling

process where deep waters reach the surface due to wind action, bringing cold water and nutrients from the bottom

-can disrupt thermocline

Solar heating, geothermal heating, internal friction and water vapor condensation are all...

heat additions

Thermal radiation of surface, convection of heat to atmosphere and evaporation are all...

heat losses

salinity

amount of salt in a body of water

-grams of dissolved inorganic salts per thousand grams of seawater (expressed as parts per thousand or ppt)

T/F Average salinity in the ocean is 35 ppt

True

Seas with high salinity (38-41 ppt)

Red Sea, Mediterranean

Seas with low salinity (10-20 ppt)

Baltic Sea, Black Sea

Chlorinity

concentration of chlorine in parts per thousand determined by titrating chloride ions

Conductivity

method to measure salinity since salts conduct electricity

Refractometer

optimal instrument that determines salinity based on light refraction through a seawater sample

-salinity increases with increased light refraction

Oligohaline

0.5-5 ppt

Mesohaline

5-18 ppt

Polyhaline

18-30 ppt

Euhaline

30-40 ppt

Hyperhaline

>40 ppt

wavelengths corresponding to what color are the first to be absorbed when entering the water column?

Red

Sunlight/Euphotic Zone

light barely penetrates beyond this zone (sea level-200m)

Twilight/Dysphotic Zone

sunlight decreases rapidly with depth. Photosynthesis isn't possible here (200-1000m)

Midnight/Aphotic Zone

Sunlight doesn't penetrate at all, area is bathed in darkness (below 1000m)

oxygen concentration is measured in

miligrams/Liter

Dissolved oxygen decreases with...

-increasing temp

-increased organic matter

-low circulation/mixing

Hypoxia

low concentration of oxygen (< 2 mg/L)

Anoxia

lowest concentration of oxygen ( < 0.5 mg/L)

Normoxia

normal levels of oxygen (up to 8 mg/L but open ocean is around 5 mg/L

Process for formation of GOM dead zone

1. High nutrient input

2. Plankton "Blooms"

3. Once they die, they get decomposed by bacteria

4. Microbial activity increases, depleting oxygen

5. Organisms flee or die

Pressure is measure in...

Bars, and is almost the same as one atmosphere

T/F Pressure increases by 1 bar per 10 m

True

Boyle's Law

as pressure increases, volume decreases

-The absolute pressure exerted by a given mass of gas is inversely proportional to the volume it occupies

Adaptations to elevated pressure

-absence of air filled sacs in deep-sea organisms

-collapsible ribs and lungs in mammals

-cell membrane with more unsaturated fatty acids

-Piezolytes protect large molecules (gives seafood its smell)

-changes in protein structure to avoid bending

Density

Mass per unit volume (g/ml)

-directly affected by salinity and temperature

T/F High salinity=high density

true

T/F Low temp=high density

true

Average density of saltwater

1.025 g/ml

Pycnocline

section of the water column where density changes quickly with depth

Plume

section of freshwater that sits on top of ocean

Wedge

section of sea water that sits underneath freshwater

Viscosity

a measurement of a liquid's resistance to flow (stickiness between layers of a fluid)

T/F: The viscosity of a liquid "increases" with increasing temperature

false

-harder to move in cold water

Reynolds number (Re)

measure of relative importance of viscous and inertial forces in fluid

-increases with increase of velocity or size

Re formula

(velocitysizedensity)/viscosity

T/F The movement of an organism with low Reynold's number (Re<1) is mostly dominated by viscosity

true

Which force dominates when Re is <1.0?

viscosity

Which force dominates when Re is >1000

inertia

laminar flow

The movement of water particles in straight-line paths that are parallel to the channel. The water particles move downstream without mixing. Re is low

turbulent flow

an irregular, mixing flow pattern. Re is high

Water that is very close to an organism will create a _ where velocity of the water is zero or close to zero

boundary layer

Principle of continuity

A1V1=A2V2

-permits organisms to regulate water velocity

Drag

force that opposes the movement of an organism moving in water

T/F Drag increases with laminar flow

false

T/F Marine organisms have a teardrop (fusiform) shape because this will increase drag and turbulent flow, which is beneficial for swimming

false

Most waves are produced by... and represent motion of energy not water

wind

What happens when a wave breaks?

they move water into the shore

Tsunami

A water wave caused by an earthquake/volcanic eruption

Wavelength

distance between crests

wave height (amplitude)

the vertical distance from the crest of a wave to the trough

Period

time of passage of successive crests

Velocity

length divided by period

The orbital motion of water particles in a wave is propagated to a depth of approximately:

1/2 wavelength

longshore current

a water current that travels near and parallel to the shoreline

-responsible for erosion on the shore

rip current

currents that carry large volumes of water from the shore to the sea, formed by irregularities that cause regular currents to run offshore

Which factors influence tides?

gravitational effects of sun and moon, earth's rotation, basin shape

T/F The moon has more influence of tides because it's closer

true

T/F Spring tides, those with maximum tidal range, are generated when the sun and the moon are in line with each other:

true

Spring tide (syzygy)

tides with maximum tidal range, are generated when the sun and the moon are in line with each other

neap tide

tides with minimum amplitude, are generated when sun, earth and moon form a right angle "canceling" gravitational effects

A tidal day is how long?

24 hours and 50 minutes

How many low and high tides are there per day (typically)?

two of each

diurnal tide

A tidal cycle of one high tide and one low tide per day.

-happens in GOM during equinox

semidiurnal tide

A tidal cycle of two high tides and two low tides each lunar day, with the high tides of nearly equal height.

mixed tides

two high tides and two low tides each day, but the amount of water at each time is different - Pacific Coast of the US

Estuary

costal body of water that has connection to the open sea

highly stratified estuary

layers are separate due to density, little mixing

Moderately stratified estuary

lines of equal density run in diagonal towards the sea

-Ex: Hudson River

vertically stratified estuary

vigorous mixing, strong tidal control so quick changes in salinity

-mostly in shallow estuaries