Oceanography Exam 3

Shore

zone between low tide and highest area on land affected by waves

Coast

extends inland as far as ocean related features are found

Coastline

boundary between shore and coast

Haloclines in coastal waters

can be well-defined and sometimes easily observed at surface or depth, Separates salinity horizontally and vertically

Coastal waters

• Relatively shallow waters overlying continental shelf

• Adjoin continents or islands

• Influenced by river runoff, wind, and tides

• Open ocean lies beyond

What impacts temperature in coastal waters?

• Winds

• Insolation

• Currents

Thermoclines

• a layer of rapidly changing temperature

• can be seen sometimes but always felt!

Estuaries

• Practically enclosed body of water in which freshwater runoff dilutes ocean water

• Highly productive marine ecosystems

Coastal plain/drowned river estuaries

Flooded w/ seawater

ex: Chesapeake Bay

Fjord estuaries

Former glaciated valley now flooded w/ seawater

ex: Alaska

Bar-built estuary

Lagoon separated from ocean by sandbar or barrier island

ex: Pamlico Sound

Tectonic estuary

Faulted or folded down dropped area now flooded w/ ocean

ex: San Francisco Bay

Salt Wedge Estuaries

• High volume river

• Surface fresh from head to mouth

• Salinity gradient at depth (horizontal and vertical)

• ex: Columbia River

Slightly Strained

• 2 level flow

• Upper layer less salty, lower layer more salty

• Estuarine circulation- mixing by wind and tides

• ex: Chesapeake Bay

Vertically mixed

• Shallow

• FW input low volume

• Net flow head to mouth

• Wind and tidal mixing

Highly strained (Fjord)

• Deep

• Surface salinity increases

• Bottom salinity uniform

• Relatively strong halocline

• Entrainment at interface

• ex: Delaware Bay, Pamlico Sound

Negative estuary

• Low to no river flow

• High evaporation

• Salinity in upper layer decreases towards mouth

• Salinity in lower layer increases toward head

• Vertical salinity profiles show gradual increase from the surface to the bottom

• ex: Laguna Madre

Daily patterns

• Dominated by tidal flushing

• Influenced by Coriollis Effect, North Hemisphere

• Flood currents flow on “right side” (east)

• Ebb currents on “left” (west)

• Isohalines slosh w/ tides

Seasonal patterns

• Dominated by spring fishnets or other fluctations in FW input

• Stratification and circulation patterns change w/ the seasons

• Can cause anoxia and fish kills

How do living organisms adapt to oscillations?

• Salinity

• Oxygen

• Temperature

• Suspended sediment

• Light

Wetlands

• Margins of estuaries and other coastal areas support wetlands

• Wetlands = ecosystems w/ water table close to surface

• Two most important types of coastal wetlands: Salt marshes (mid and high latitudes) and mangrove forests (low latitudes)

Salt Marsh

• Found from the Arctic to Southern Australia

• Salt marshes grow in muds and sands that are sheltered by barrier islands

• Tidal currents transport water, nutrients, plankton, and sediments in and out

Salt Marsh Zonation

Marsh divided into high and low marsh

• high is region above high tide

• low is flooded daily

• each has distinctive vegetation

Value of Marshes

• Important habitat

• Nurseries for more than ½ of commercially important fish in the SE US

• Help preserve water quality, filter pollutants

• Reduce erosion

• Prevent storm damage

• Aesthetics and recreation

Mangrove Forests/Mangal

community dominated by trees and shrubs that grow in salt water

Mangroves

• individual plants

• Leaves are tough and succulent

• Represent 8 families and 12 genera

• Support many fauna

Value of mangrove forests

• Fisheries

• Timber and plant products

• Coastal protection

• Tourism

Living things can…

• Capture, store, and transmit energy

• Reproduce

• Adapt to environment

• Change over time

Meaning of life

• Find food

• Avoid being eaten

• Reproduce

Who developed taxonomic classifcation?

Carolous Linneaus - 1758

Taxonomy

systematic classification of organisms, by physical characteristics and genetics

Plankton

organisms that float instead of swim

Nekton

organisms that actively swim

Benthic

habitat the bottom of the ocean

Pelagic

habitat in the water column

Neritic

habitat in shallow areas <200 m

Oceanic

habitat in deeper areas >200 m

Number of marine species

• Land species - 86%

• Ocean has relatively uniform conditions

• Less adaptation required, less speciation

• Marine species overwhelmingly benthic (98%)

• Temperature and marine environment more stable than land

Maintaining position in a fluid environment

• Need to be where food and mates are

• Photosynthetic organisms need light at surface

• Organisms that actively swim need to conserve energy

• Most adaptations relate to viscosity - warm water, lower viscosity, cold water higher viscosity. Higher salinity high viscosity, lower salinity lower viscosity

Viscoscity

resistance to flow

Buoyancy best high SA:V

• Small size

• Appendages

SA:V impacts

• gas exchange

• nutrient uptake

• excretion of waste

Buoyancy

• Resistance to sinking

• Appendages - fewer in cold, more in warmer

• Smaller size

• Oil in some, esp. micro-organisms

• Gas chambers, bladders, pneumatocysts

• Resistnace to sinking: copepods

• Oithona sentigera, gaussia princeps

Viscosity and swimmers

• Viscosity of water can hinder swimmers

• Water must be displaced in front

• As water moves back into place behind, creates turbulence

• Streamlining reduces drag

Streamlining

• Shape w/ least resistance to fluid flow

• Flattened body

• Tapered back-end

Why do warm muscles result in faster swimming?

Counter-current circulation transfers heat in rete mirable

Ocean temperature

• Narrow range, small variations

• Deep ocean is nearly isothermal, large range in coastal areas

• Ocean temps. more stable than land (higher heat capacity of water, solar radiation does not penetrate to deep ocean layers, warming reduced by evaporation, mixing)

Stenothermal

• Organisms withstand small variation in temp

• Most in open ocean at depth

• Some in tropics or polar regions

Eurythermal

• Most large swimming organisms

• Many in coastal waters

• Organisms withstand large variations in temperature

Cold vs Warm Water Species

• These are generalizations, not rules

• Plankton

• Tropical organisms grow faster, live shorter, reproduce more

• More species in warmer seawater

Salinity vs Osmoregulation

• Osmoregulators regulate the concentration of salts in cells or bodies

• Concentration of salt in seawater higher than in cells

• Diffusion goes from areas of high concentration to low

• Salts cannot easily diffuse across cell membrane, but water can

• Most organisms in sea continually lose water

• Must either prevent loss or replace it

• ex: Teleost fish

Salinity and plants

• Leaves are tough and succulent

• May concentrate salt in leaves and drop

• Some use salt glands to excrete salt

• Some exclude salt at the roots (reverse osmosis)

Dissolved gases

• Animals extract dissolved O2 from seawater thru specialized organs- branchlae, gills, integuncht, respiratory trees

• Exchange O2 and CO2 directly w/ seawater

• Branchiae/gill structure structure and location varies among animals

• Low marine oxygen levels can kill

Fish gills

Study notebook drawing

Broadcast spawning

Form of reproduction where eggs and sperm are released into seawater

Brooding

form of reproduction where eggs/young protected

Avoiding predation techniques

• Countershading

• Transparency

• Disruptive coloration

• Camouflage

Behavioral Adaptation

• Mutualism

• Commensalism

• Schooling

• Parasitism

Match the organism to the adaptation it belongs to.

Octopus	Answer 1 Question 1Choose...Swim BladderCamouflageStreamline Body ShapeBuoyancyTransparency
Jellies	Answer 2 Question 1Choose...Swim BladderCamouflageStreamline Body ShapeBuoyancyTransparency
Fish	Answer 3 Question 1Choose...Swim BladderCamouflageStreamline Body ShapeBuoyancyTransparency
Flounder	Answer 4 Question 1Choose...Swim BladderCamouflageStreamline Body ShapeBuoyancyTransparency
Dolphins	Answer 5 Question 1Choose...Swim BladderCamouflageStreamline Body ShapeBuoyancyTransparency
Phytoplankton	Answer 6 Question 1Choose...Swim BladderCamouflageStreamline Body ShapeBuoyancyTransparency

Which of the following is the most specific way to group organisms according to the current taxonomic classification system?

Species

Why do most fish and marine mammals have the same torpedo-like streamlined shape?

The streamlined shape minimizes energy expended to move through the water.

Which classification scheme is correct taxonomy classification from general to specific (Not all categories are considered)?

Kingdom, phylum, class, order, family, genus, species

Biological oceanographers discuss biomass frequently. Just what is biomass?

The mass of living organisms

Satellites monitor the color of the oceans and this information can be used to estimate the amount of primary production occurring.  How does this work?

Primary producers use a green pigment for photosynthesis, so the amount of this pigment can be plugged into an algorithm that approximates productivity.

Living organisms rely on the organic matter formed during primary production for energy (food).  Which type of primary production does 99.9% of the ocean's biomass rely on?

Photosynthesis

Primary productivity

the rate of primary production

Photosynthetic productivity in the ocean is limited by the amount of sunlight and the supply of nutrients.

True

All ecosystems must have a flow of energy to thrive. What are the three basic categories of these organisms?

Producers, consumers, decomposers

Which statement is accurate?

Food chains are simple, direct and linear, while food webs are complex, containing many interconnected food chains.

Where would you expect the highest density of zooplankton?

In the coastal surface ocean where primary production is high

____________ is any class of organisms that occupy the same position in a food chain, such as primary consumers or secondary consumers.

Trophic level

What is the average efficiency of transfer for energy passing from one trophic level to the next?

10%

Temperate ocean productivity is limited by…

Seasonal differences in light and nutrients

Polar ocean productivity is limited by…

Light

Tropical ocean productivity is limited by…

Nutrients

In which of these localized areas would you expect the highest productivity?

Upwelling center

Which region of the world ocean has the highest overall productivity (annual amount)?

Temperate regions (mid-latitudes)

Organisms that live in soft sediments (burrow)

Infauna

Organisms that live in soft sediments (burrow)

Epifauna

Primary producers in hydrothermal vent communities are:

sulfur-oxidizing archaea

Which intertidal zone is uncovered only during spring tides?

Low tide

True or false: 99.9% of the ocean’s biomass relies directly or indirectly on photosynthesis for food

True!

Photosynthesis

Light energy input - turns warer and carbon dioxide into sugar and oxygen

Respiration

Heat energy released - sugar and oxygen create water and carbon dioxide

True or false: Most primary producers in the ocean use photosynthesis to store energy in carbon bonds, but they do not use those carbon rich molecules for energy themselves.

False!

Gross primary production (GPP)

The amount of photosynthetically fixed carbon - Usually 50 GT C y-1 in the ocean

Net primary production (NPP)

amount of photosynthetically fixed carbon avaliable to the first heterotrophic level ( NPP = GPP - respiration of the autotrophs)

Global primary production rate in central gyres

Low

Global primary production rate in equatorial and coastal regions

High

Global primary production rate in polar regions

Moderate/high

Measurement of primary production

• Collect water

• Incubate

• Measure O2

• or… Add radioactive carbon tracer

Satelitte methods of measuring primary production

• Monitor ocean color w/ satellites

• SeaWiFS (Sea viewing Wide Field of View Sensor) satellite sensor collected ocean color data 1997-2010

• MODIS (Moderate Resolution Imaging Spectroradiometer) - current (measures 36 spectral frequencies)

Anthophyta

• Type of photosynethic marine organism - seed bearing plants

• Restricted to shallow coastal waters

• Only seagrasses grow fully submerged in seawater

• Marsh grasses and mangroves tolerate salty roots but flower in air

Macroscopic (large) algae

• Brown (phaeophyta)

• Red (Rhodophyta)

• Green (chlorophyta)

Microscopic Algae

Chyrsophyta (diatoms, coccolithophores)

Pyrrophyta (dinoflagellates)

Photosynthetic Bacteria

May be responsible for half of total photosynthetic biomass in oceans!

Factors Affecting Primary Productivity

• Solar radiation (uppermost surface seawater and shallow seafloor, compensation depth (net photosynthesis becomes zero. Euphotic zone - from surface to about 100 meters (330 ft))

• Nutrient avaliability (nitrate, phosphorous, iorn silicia, river runoff, upwelling, recycling)

Upwelling and Nutrient Supply

• Flow of deep water to surface

• Cooler, deeper seawater is nutrient-rich

• Areas of coastal upwelling are sites of high productivity (western continental margins)

Polar Ocean Productivity

• Winter darkness

• Summer sunlight

• Phytoplankton (diatoms) bloom seasonally

• Zooplankton (krill) productivity follows

• Ex: Arctic Ocean’s Barents Sea

• Isothermal waters

• Stratifcation from ice

• Plankton remain at surface

• Animals migrate to feed on zooplankton

Productivity in Tropical Oceans

• Permanent thermocline is barrier to vertical mixing

• Low rate of primary productivity - lack of nutrients

• High rate of primary productivity in areas of equatorial upwelling, coastal upwelling, and coral reefs