Oceanography Prelim 2

_% of global photosynthesis takes place in the ocean

50

Plankton

small organisms that drift with the ocean currents

Types of phytoplankton

diatoms (require silica)

flagellates: motile so they avoid sinking in calm waters

Photosynthetic bacteria: can grow at very low nutrient concentrations

NPP

difference between amount of CO2 taken into cell by photosynthesis and the amount of CO2 exported from the cell  by respiration

Compensation light level

light intensity whereby CO2 gained by photosynthesis just compensates for CO2 lost by respiration (NPP = 0)

At high light levels, phytoplankton are

photoinhibited

Main source of iron to surface ocean

dust blowing off of continents

Shift from __ limitation to _ in North pacific Subtropical gyre

nitrogen; phsophate

Warm, nutrient poor water in subtropics is due to

surface convergence of the ekman layer

Subtropical gyre productivity is characterized by

low primary productivity per square meter and low seasonal variation

Tidal mixing

occurs in shallow continental shelf regions, seasonally steady, occurs as tide wave motion accelerates horizontally and is squeezed on the shallow shelf

Coastal upwelling from ekman transport features

seasonally variable, greatly enhances upward movement of deep water that is rich in nutrients

Critical depth

Depth at which mixing occurs where phytoplankton lose the same amount of carbon they gain in one day (mixing below this depth means loss>gain)

Spring phytoplankton bloom progression in westerly winds region

Winter: light limited, nutrient abundant

Spring: light abundant, nutrients abundant

Summer: light abundant, nutrient limited

Fall: light modest, nutrients modest

Oceanic NPP is _% of global NPP

46

_% of annual global ocean primary production is coastal

26

_ most often limits the growth of phytoplankton in the ocean, but and limit growth in certain important regions

nitrogen, iron, phosphate

hawaii is _ limited

phosphate

the southern ocean is _ limited

iron

Nekton

able to swim against ocean currents

Holoplankton

organisms that live their entire lives as plankton (copepods, some shrimp, arrow worms, some jellyfish)

Meroplankton

organisms that spend only part of their life as plankton (crabs, barnacles, oysters, fish larvae)

Exploitation efficiency

the efficiency w which a consumer population is able to find, capture, and ingest all of the potential prey present in their environment

Gross production efficiency

physiological/biochemical efficiency of converting ingested prey into consumer biomass

Trophic transfer efficiency

EE x GPE

Big phytoplankton means

short, efficient food chains

Bacteria make up more than _% of the living biomass in the ocean

50

Oligotrophic

naturally low plant nutrient concentrations (subtropical gyres)

Eutrophic

pelagic environment that has naturally high plant nutrient concentrations (coastal upwelling zones)

As a general rule, preferred prey size is _% of the consumer’s size

10

Study methods for plankton

transmission light microscopy and culture-plate colony counts

Epifluorescent microscopy

allows study of bacterial abundance and distinction between autotrophic and heterotrophic flagellate cells

Source of carbon and energy for heterotrophic bacterial growth

grow on DOM released from phytoplankton by natural leakage, cell senescence, or sloppy feeding by large zooplankton

The microbial loop

describes the role microbes play in the marine carbon cycle

Prochlorococcus

very abundant bacteria in the ocean, autotrophic with chlorophyll. Single handedly contributes more than 25% of ocean primary production, growth is expected to decline due to global warming

Heterotrophic bacteria are/are not highly abundant in all ocean environments

are

Most of living biomass in open-ocean is in the form of

bacteria

When phytoplankton are small…

grazers are small and fecal material is small, so it cannot easily sink and the carbon decomposes and is respired back to CO2 - inefficient biological pump

Vertical zonation

communities are divided into distinct bands [zones’ that are at characteristic heights in the intertidal

What sets the upper limit to species distributions in the intertidal?

Physical stresses such as desiccation, sunlight, temperature, and emersion

What sets the lower limit to species distributions in the intertidal?

Biological interactions such as competition for space and predation

Vibrio pectenicida

bacterial pathogen responsible for die-off of sunflower starfish

Corals receive -% of energy from zooxanthellae

60 - 90

Optimal temperature for corals

26-28

Restricted temperature range for corals

18-36 

Sunlight limits coral growth to a depth range extending from the ocean surface down to maximum of about _

25 m

_% of corals were exposed to bleaching

84

Pakicetus

hoofed mammal that is often classified as the earliest whale. lived about 53 mya, wolfish appearance.

How do we know pakicetus is an ancestor of whales?

ear region shape in skull

Modern whales

odonticeti and mysticeti

Baleen

used for gulp, skim (surface) feeding, and bottom plowing

First mysticeti appeared about _ mya due to..

35; a change in foodchain structure

Pacific humpback migration

summer feeding at high latitudes

winter calving at low latitudes

odontocetes

produce rapid bursts of clicks and whistles, used for echolocation and communication

Mysticetes

vocalizations primarily used in sexual selection, some echolocation (but only for depth/barriers, not prey)

Spectrograms

used to visualize vocalizations

Sources of anthropogenic sound in the ocean

naval operations

commercial shipping

oil exploration

half of orcas might be loss within to years due to

30 to 50; PCB accumulation

Treaty of Neah Bay

gave makah tribe right to hunt whales in exchange for land

International Convention for the Regulation of Whaling

agreement to set quota levels based on findings from scientific committtee

Latent heat of fusion

amount of heat to change from solid to liquidL

latent heat of vaporization

heat to convert 1 gram of water to water vapor

Specific heat capacity of water

amount of heat to raise 1 gram of water by one degree C

_% of excess heat energy accumulated in the earth system is taken up by the ocean

93

During condensation, latent heat is

released to the atmosphere

During evaporation, latent heat is

removed from the ocean

Hydrogen bonds below 100C

are strong enough to allow some individual water molecules to temporarily bind with others to form liquid water

Amount of salt in the ocean fluctuates T/F

F

input and export of salt in oceans through:

weathering

calcification and deposition into sediments

Conservative constituents

only varied by physical exchange processes at the surface (salinity, temperature, inert gas concentration)

non-conservative constituents

altered by chemical or biological processes that occur in the water column (biological uptake, phytoplankton nutrients)

Dissolved plant nutrients are low/high in surface waters because of…

low; uptake by phytoplankton

atlantic ocean is low in

phosphatepa

pacific ocean is high in

phosphate

old water is low/high in phosphate because…

high; it has had more time to accumulate biological matter (debris)

There has been a _% of oxygen in the ocean since the 60s

2

Global warming will increase/decrease the strength of the thermocline, lowering/raising oxygen content of the oxygen minimum zone

increase; lowering

Flux of CO2 across air-sea interface

deep ocean water rich in CO2 flixes CO2 out of ocean, overall there is a net flux of CO2 into oceanO

Ocean has uptaken _% of all CO2 emitted since industrialization

30

Ocean acidity has increased by _% since industrialization

26

Ability of ocean to uptake CO2 will increase/decrease due to…

decrease; increasing acidity and temperature

which region will acifify fastest?

polar regions and coastal upwelling regions

Pteropod

a type of zooplankton at the base of the marine food web that has a protective shell

Ocean acidity will increase by _% by the end of the century

170

Ocean acidification is irreversible on timescales of at least _ of years

tens of thousands