Marine Bio Exam 1

Benthos

organisms that live attached to or near the ocean floor

Epifaunal

live on the seabed surface, like crab walking

Infaunal

organisms that live under the sediment

Semi-infaunal

living partially below the sediment but protruding above it

boring

bore into the sides of something

Plankton

Live in water and cannot swim fast enough to beat the currents

Nekton

All organisms that swim actively in open water, independent of currents

Neuston

Planktonic organisms living where the water touches the atmosphere

Pleuston

Organisms that live right at the sea surface, with part of the body projecting into the air.

Neritic

coastal zone, comes before the shelf slope break

Pelagic

Oceanic, seperated into mesopelagic and bathypelagic

Mesopelagic

known as the twilight zone, faint light, deeper

Bathypelagic

known as midnight or dark zone, no sunlight, deepest

Percent of Earth occupied by water

71%

Ths percent of biosphere where life exist is in the ocean

99.9%

Southern hemisphere is this percent ocean

80%

Northern Hemisphere is this percent ocean

61%

This percent of the ocean is deeper than 2000m

84%

Average depth of the ocean

3682 m

This percent of Earth's surface is the abyssal plain

50%

Deepest known point of the ocean at about 11000 m

Mariana Trench

This percent of the ocean has been mapped

10%

Smallest ocean and shallowest, completely surrounded by land

Arctic

Second smallest Ocean

Southern Ocean

Third smallest ocean

Indian Ocean

Second biggest ocean

Atlantic Ocean

Biggest ocean and least affected by terrestrial climate

Pacific

Marginal seas

Limited exchange with open ocean, strongly affected by regional climate, precipitation-evaporation balance, river input of fresh water and dissolved solids. Ex: Gulf of Mexico and Mediterranean Sea

Four general properties of water

High heat capacity, High heat of evaporation, high dissolving power, high transparency (absorbs infrared and Uv light)

Salinity formula

g of dissolved salts per 1000g of seawater; units are ‰ or ppt or psu (practical salinity unit)

Positive control for salinity

Evaporation (sea ice formation)

Negative control for salinity

Precipitation (river runoff)

Salinity percent of open ocean

32-38%

Major elements of seawater PPM

Greater than 100ppm

Minor elements of seawater PPM

1-100ppm

Trace elements of seawater

1ppm

Principle of constant element ratios

Ratios between many major elements are constant all over the ocean, even though salinity varies. Why? Because residence time of elements with constant ratios is much greater than time to mix them evenly throughout ocean by water currents (\~1000 y)

Seawater density (mass/volume) increase with ... salinity

increasing salinity

Seawater density (mass/volume) increase with ... temperature

decreasing temperature

How oxygen is added to seawater

mixing with atmosphere and photosynthesis

Oxygen is lost in seawater by

respiration and chemical oxidation of various compounds

oxygen increase as you go ... in the ocean

deeper

base of marine food web

Photosynthetic organisms

Light absorbed very quickly in ocean

red

Adaptations to survive near surface of ocean

Photoprotective pigments

Countershading

protective coloration of some animals in which top is dark and bottoms is bright to blend in with sun lit surface waters

Bioluminescence

the production of light by living organisms

benefits of bioluminescence

Searching for food, attracting prey, defending territory, communicating, escaping/avoiding predators, camouflage

Coriolis Force

The apparent force, resulting from the rotation of the Earth, that deflects air or water movement.

uneven heating of earth's surface

causes pressure gradients with a relative high pressure at poles and low at the equator

Net movement of water in northern hemisphere

90 degrees to the right

Net movement of water in the southern hemisphere

90 degrees to the left

western boundary currents

Warm waters from equatorial regions, Western edge of ocean basins.

el nino/la nina

represent the varying warming and cooling trends in the ocean surface temperature on the equatorial area of the pacific ocean

In order for water to sink in the ocean it must be both very...

cold and salty

Waves feel bottom when

depth is 1/2 L

Amplitude (height) \=

H

Period \=

T

Velocity \=

V \= L/T

When H/L exceeds 1/7

The wave support its own weight, and topples over

Tides are caused by

differences in the gravitational force of the moon at different points on Earth.

spring tide

when the sun and moon are lined up the tides produced reinforce each other and so are greater than normal

neap tide

Whe the moon is in the first/last quarter, the tides produced by the sun partially cancel the high tides of the moon, making them lower than usual

semi-diurnal tide

Having two high tides and two low tides each day.

diurnal tide

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

mixed semidiurnal tide

a tidal pattern with two successive high tides and two low tides of different heights each day

esturaies

areas where freshwater rivers merge with the ocean

salt wedge estuary

An estuary in which rapid river flow and weak tidal/wind mixing

Moderately stratified estuary

An estuary in which seaward flow of surface low-salinity water and moderate vertical mixing result in a modest vertical salinity gradient.

vertically homogeneous estuary

An estuary in which, at any given location, wind or tidal mixing homogenizes salinity throughout the water column

Terriotoriality

the defense of a bounded physical space against encroachment by other individuals. Feeding/breeding/nesting site

Predation

Includes stationary and mobile predators. Locate prey, entrap/kill, and ingest

Optimal Predator Models

Diet breadth - rule: food scarce, increase breadth. Time spent in a patch - rule: greater the distance between patches, spend more time in a given patch. Size selection - maximize energy intake, usually leads to selection for intermediate size

optimal prey size

Maximize energy intake by choosing intermediate sized

Crypsis

camouflage

escape response

Time: active at night to avoid detection. Detection and movement away

Batesian mimicry

A type of mimicry in which a harmless species looks like a species that is poisonous or otherwise harmful to predators.

Mechanical/chemical defenses

thick shells, spines, poisons

Commensalism

A relationship between two organisms in which one organism benefits and the other is unaffected

Mutualism

A relationship between two species in which both species benefit

Parasitism

A relationship between two organisms of different species where one benefits and the other is harmed

Ectoparasites

Parasites that feed on external surface of host.

endoparasite

parasite living on the inside of its host

population density

Number of individuals per unit area (individuals/m^2)

metapopulation

a group of spatially distinct populations that are connected by occasional movements of individuals between them

source population

supplies new individuals to different populations

sink population

A population that relies on immigration

foundation species

Determine structure (provide habitat)

interference competition

one species overgrows another, agnostics interaction

exploitation competition

organisms compete indirectly through the consumption of a limited resource. One species utilizes a resource more efficiently

consequence of competition

either extinction or coexistence

disturbance

physical change in the environment that causes mortality or affects reproduction

Types of spatial scale of disturbance

habitat wide and localized in patches

Why disturbance effects are similar to predation

Suppresses effects of competition

Effect of predation on competiton

Suppresses competitive success of superior species over inferior species

intermediate disturbance hypothesis

the hypothesis that ecosystems experiencing intermediate levels of disturbance are more diverse than those with high or low disturbance levels

Low levels of disturbance or predation

competitive dominant species takes over

high levels of disturbance or predation

most individuals removed, reduces total number of species

response to environmental change

response requires a sense of change and translate into adaptive response

sense

receptors