Oceanography Exam 2 Module 4
hydrothermal vents
"Dark Biosphere" - Hydrothermalvent biocommunities - Organisms previously unknown to science - Unusually large for depth in ocean o Blacksmokers: underwater chimney vents emit sulfides
What % of global PP do they account for?
0.7% at the low end to 8.1%
How do we define life?
1 - Made up of cells Cells are the basic unit of life. Living things are composed of cells. 2- Cellular Organization Living things are able to organize simple things into complex things. Humans can organize cells that are alike into tissues and organs. 3 - The Chemicals of Life Living cells are composed of similar chemicals, water, carbohydrates, proteins, lipids, and nucleic acids. 4 - Energy Use Living things use energy to repair and function -- your brain cells are using energy right now. 5 - Response to Surroundings Living things react to changes in environment. Populations evolve over time. You respond to your surroundings when you are startled by a car horn. 6 - Growth and Development Living things grow from the energy found in organic molecules and develop, becoming more complex over time. 7 - Reproduction Living things duplicate their genetic code and produce offspring.
How much (what %) gets transported to deep ocean? What % is lost to the sediments?
1%, 99%
What % of oceanic PP do they account for?
99%
kelp beds
A brown alga o One of the fastest growing plants on earth o Found in kelp forests of western North America o Source of alginate *Thrive in areas of intense upwelling
How is biology organized? What are the 3 domains of life? How do they differ? How are they similar?
Bacteria, Eukaryia, Archaea
What is chlorophyll? How do oceanographers use it to understand phytoplankton distribution globally?... via satellites?
Chlorophyll-pigments capture sunlight for photosynthesis -satellites take readings of chlorophyll -shows location of phytoplankton
Water Bears!!
Common name: Water Bear o Live in-between sand grains on the beach o Tough as nails, can survive boiling water, extreme freezing, vacuum, high pressure, desiccation... cockroaches have nothing on them o Ubiquitous, meaning they can be found anywhere- has been speculated that they can travel through space (Panspermia)
What"is"'coral"bleaching'?..."explain."
Coral"bleaching" o Corals will expel their zooxanthellae into the surrounding water o Loss of photosynthesis source
What"are"corals?"Why"are"they"unique?"Why"do"coral reefs"represent"a"paradox" in"ocean"primary"productivity?"
Corals are Cnidarians, related to sea anemones and jellyfish o Most coral species are very small- sized animals in crowded communities o Coral polyps actually construct the reef by secreting crystalline CaCO3 o Receive food and nutrition from symbiotic algae, and by capturing and eating plankton
intertial zone probs
Desiccation (drying out) Strong wave action Predators Mating Rapid change in temperature, salinity, pH, oxygen Lack of space
Contrast"photosynthesis"and"chemosynthesis,"how"do" they"differ,"how"are"they" similar? Where does each occur?"
E from chemicals- chem (deep ocean) E from light - photo (closer to surface)
How has life been impacted by past cataclysmic events on Earth?
Evolution/adaptation
Threats"to"coral"reefs?..."what"are"the"causes"and"how" are"these"harmful"to"corals?"
High surface water temperatures Elevated UV levels Decrease in sunlight-blocking atmospheric particles Pollution Salinity changes Disease
How is it distributed on Earth? Where is it high? Where is it low? Why?
Highest: Euphotic zone - light enables productivity Lowest: deeper, more central areas of the oceans
Biological Pump: What is it and why is it important
It is the part of the oceanic carbon cycle responsible for the cycling of organic matter formed by phytoplankton during photosynthesis (soft-tissue pump), as well as the cycling of calcium carbonate (CaCO3) formed by certain plankton and mollusks as a protective coating (carbonate pump).
What"type"of"benthic"habitats"are"there?"How"is"most"benthic"biomass" distributed"globally?"
Live on or in the ocean bottom o Habitat may be: • Shallow or deep • Warm or cold • Full of food and life or virtually sterile o Diverse associations with the ocean bottom
What are the main macro- and micro-nutrients needed for life in the ocean?
Macronutrients: Nitrogen in form of nitrate (NO3-) Phosphorus in form of phosphate (PO43-) Silicon in form of silicate (H4SiO4) - but only for diatoms Carbon Dioxide (CO2) - but always in large supply Micronutrients: precious/trace metals (iron)
Why are marine microbes (viruses, Bacteria, Archaea, phytoplankton) so important to life in the oceans?
Marine microbes play many important roles in the Earth system: they influence our climate, are the major primary producers in the ocean, dictate much of the flow of marine energy and nutrients, and provide us with a source of medicines and natural products.
Know"the"general"classes"and"adaptations/characteristics"of"marine"mammals." How"have"they"adapted"to"live"in"the"oceans"having"derived"from"land" mammals?"
Most advanced vertebrate group o >4000 species o 3 extant groups (each arose independently) • Cetacea (porpoises, dolphins, whales) • Carnivora (seals, sea lions, walruses, sea otters) • Sirenia (manatees, dugongs) o Marine mammals possess the classic mammalian traits and share common features • Streamlined body shape • Generate internal body heat • Modified respiratory system • Osmotic adaptation to seawater
When did life originate? What form did it take?
Oldest microbial fossils of cyanobacteria appear in the fossil record at 3.5 Ga 'inventors of oxygenic photosynthesis'
phytoplankton: cyanobacteria
Oldest microbial fossils of cyanobacteria appear in the fossil record at 3.5 Ga 'inventors of oxygenic photosynthesis'
abyss
Only 1-3% of euphotic food present, no primary productivity. • Very stable temperature and salinity. • Special adaptations to find food. holothuran, Tripod fish, Apsuedes: a blind crustacean
What controls the spatial distribution of macro-nutrients (P and N) in the ocean?
Photosynthesis, respiration, currents
Know"what"happens"when"phytoplankton"'bloom'...what"is"required?"Where" does"it"occur?"What"happens"after"the"bloom"'crashes'?
Primary productivity increases; macro elements are needed; Euphotic zone
Cobble/Sand beaches
Probably the most hostile, rigorous and dangerous environments for small living things on earth! o Very few species have adapted to wave-swept sandy beaches o Fast-burrowing clams and sand crabs, polychaetes and other small worms
Boney"fishes"are"extremely"diverse"and"have"evolved"specific"strategies"for"living" in"the"oceans—such"as"propulsion,"buoyancy"control,"breathing,"and"defense" (know"some"specifics)."
Red fish, lion fish
What"controls"the"distribution"of"coral"reefs"globally?"Light?"Temperature?" Turbidity?"Nutrients?"Circulation?"
Reef development is generally more abundant in areas that are subject to strong wave action. Waves carry food, nutrients, and oxygen to the reef; distribute coral larvae; and prevent sediment from settling on the coral reef.
Why does net PP show a maximum value at some depth in the euphotic zone and not at the surface? (this relates to your in-class exercise).
Since the photic zone is where almost all of the photosynthesis occurs, the depth of the photic zone is generally proportional to the level of primary production that occurs in that area of the ocean. About 90% of all marine life lives in the photic zone
What do all phytoplankton need?
Sunlight to perform photosynthesis
Where in the water column do photosynthesis and respiration occur?
The Euphotic zone
What is the Euphotic Zone? How does it differ in open oceans & by the coast?
The Euphotic zone is where 90% of marine life lives. It is where most PP takes place. It is more productive by the coasts because the light reaches it more, and there are more nutrients being produced.
What is needed to stimulate primary productivity?
Water, CO2, light, nutrients (macro and micro-precious metals i.e. iron).
Trophic food webs...how do they work? What % of material is transferred between each trophic level.
When something is eaten, 10% of its energy is transferred to the other organism
What"is"symbiosis?"Why"is"it"a"key"component"to"life"in"the"oceans?"What"are" some"examples"that"we've"discussed"in"class?
Zooxanthellae, tiny symbiotic dinoflagellates o Coral's success in nutrient poor water depends on this relationship o Zooxanthellae perform photosynthesis, absorb waste products, grow and divide in coral cells---> provide O2, carbohydrates, proper pH o Coral provide a safe/stable environment and provide nutrients o Short, direct, very efficient cycling within the coral
What"are"zooxanthellae?
Zooxanthellae, tiny symbiotic dinoflagellates; Zooxanthellae perform photosynthesis, absorb waste products, grow and divide in coral cells---> provide O2, carbohydrates, proper pH
corals
among the most diverse and producDve communiDes on Earth Conditions for Coral Reef Development o Warm seawater, but not too warm o Sunlight (for zooxanthellae - symbiotic photosynthetic microscopic algae in coral tissues) o Strong waves or currents o Clear seawater, low nutrients o Normal salinity o Hard substrate
Be able to draw water column depth profiles of: temperature, salinity, density, nutrients, gases (O2 & CO2).
depth on the y axis and the other (temperature, salinity, density, nutrients, gases (O2 & CO2)) on the x-axis and plot the points -- like the exercise!!
phytoplankton: 4 kinds
diatoms, coccolithophores, dinoflagellates, cyanobacteria
The"pelagic"realm"is"comprised"of"a"wide"diversity"of"marine"organisms,"which" inhabit"ocean"waters"from"the"surface"to"the"abyss."Know"some"examples"of" different"types."
dolphins, squid, diatoms, brittle star larva
Plankton___with the currents whereas nekton ___
drift; swim
What are the 3 ecosystem pathways in the ocean?
grazing food chain, vertical sinking flux ('biological pump') microbial loop
Most"plankton"are"'holoplankton'"and"live"their"entire"lives"in"the"plankton." Others"are"'meroplankton'—(larvae"of"crabs,"fish,"sea" urchins,"worms)."
holo- radiolarians mero- sea urchins
Where is most of the genetic diversity in the oceans?... microbial! How do the Global"Ocean"Survey"and"TARA"Oceans"missions"relate"to"the"Challenger" Expedition"and"the"voyage"of"the"HMS"Beagle?"
microbial, molecular twist on past expeditions
Copepods"represent"the"most"abundance"zooplankton"(accounting"for"~70%)."
on front
Krill"(euphausids)"are"also"abundant"zooplankton."They"dominate"Antarctic" foodwebs"and"are"the"primary"food"source"for"baleen"whales."
on front
Marine"microbes"(bacteria"and"viruses)"are"the"most"abundant"entities"in"the" oceans."If"you"combine"phytoplankton,"bacteria"and viruses,"they"account"for" >90%"of"the"biomass"in"the"oceans!"The"small"stuff"is important!"Marine"bacteria" are"the"primary"nutrient"recyclers"in"the"oceans.
on front
Nekton"are"very"diverse,"encompassing"invertebrates"(squids,"octopus,"nautilus)," fish,"mammals,"and"reptiles."
on front
Pelagic"organisms"are"comprised"of"different"functional"categories:"plankton"and" nekton"
on front
Plankton"composition"has"traditionally"been"collected"and"studied"using" plankton"nets."Different"pore"sizes"(i.e.,"holes)"can"be"manufactured"for"plankton" nets"and"this"will"influence"the"size"organisms"that"will"be"caught"in"the"net."
on front
The"structure"of"the"coral"animal:"polyp,"symbionts,"calcium"carbonate"structure." The"roles"of"feeding"and"photosynthesis"in"corals."
on front
CCD (Cal. Carbonate)
ooze accumulates above the line & dissolves below the line
What types of primary productivity are there?
photosynthesis & respiration
What group of marine organisms dominates oceanic productivity?
phytoplankton!
Zooplankton,"what"are"they?"What"are"the"major"groups?"What"strategies"do" zooplankton"use"to"stay"buoyant"and"not"sink"into"the"deep"ocean?"
primary consumers; heterotrophs) - animal members of plankton community - most abundant primary consumers in ocean - largely graze on phytoplankton - amazing variety (microscopic to several meters ) Holoplankton vs. Meroplankton
Net PP?
rate at which all the plants in an ecosystem produce net useful chemical energy; it is equal to the difference between the rate at which the plants in an ecosystem produce useful chemical energy (GPP) and the rate at which they use some of that energy during respiration.
What is the Redfield Ratio?
ratio of the main gasses we need C:N:P 106:16:1 <-- recipe for plankton
We specifically talked about Phosphorus....what are the major sources into the euphotic zone?
river run off
What is biogeochemistry?
scientific discipline that involves the study of the chemical, physical, geological, and biological processes and reactions that govern the composition of the natural environment (including the biosphere, the cryosphere, the hydrosphere, the pedosphere, the atmosphere, and the lithosphere).
How does oceanic productivity compare to terrestrial productivity?
terrestrial is a little higher due to the plants on land
What is gross PP?
the amount of chemical energy as biomass that primary producers create in a given length of time. (GPP is sometimes confused with Gross Primary productivity, which is the rate at which photosynthesis or chemosynthesis occurs.)
Many"zooplankton"migrate"vertically"in"the"water"column..."why?"
the migrate to the rhythm of the sun
Primary Productivity - what is it? Why is it important? What types are there?
the rate at which energy is converted by photosynthetic and chemosynthetic autotrophs to organic substances.
What is 'Microbial Oceanography'?
the scientific discipline concerned with the biology and ecology of microorganisms that inhabit the sea -Fundamentally new context for ecology, evolution and biogeochemistry • Microstructure of microbial communities in the sea • Microscale mechanisms to predict ecosystem response to stress • Unexplored scale; develop the science of microscale ecology
How"are"coral"reef"geologic"history"and"tectonic"processes"tied"to"the"type"of" coral"reef"you"have?"
they form at divergent boundaries; the slow movement of the Earth's crust over millions of years has gradually created the biodiversity pattern we see across the Oceans today.
Be familiar with how a variety of physical/chemical factors affecting life in the oceans and some biological strategies that organisms use to deal with these... DNA diversity & evolution, temperature, nutrients, light, salinity, gases.
• 6 elements that limit life in the ocean o Nutrients o Light o Temperature o Gases o Salt o Pressure
Autotrophs vs. heterotrophs / (Photosynthesis vs. Respiration) -- what is the difference?
• Autotroph-make their own food (E)-Primary producers o Photoautotroph- photosynthesis (plants-food from light E) • Light E → Chemical E o Chemoautotroph- use chemicals to make food for itself • Heterotroph-Can't make our own food (E) o I.e. Humans • Primary consumers=vegetarians • Secondary, tertiary=MEAT
intertidal zone
• High Tide zone: relatively dry • Middle tide zone: covered by all high tides/exposed by all low tides • Low tide zone: usually wet
Know the major aspects of how evolution works... a logical framework to explain how organisms change with time and how they have adapted to every possible niche in the oceans...mutation and natural selection.
• Mutations (randomness)-Making mistakes while replicating DNA-accumulation of random mutations • Natural selection- environment selecting is very critical • Deep time- enough time to allow these mutations to happen and the environment to select o Climate change- will organisms adapt? But what if the temperature increases too quickly for organisms to adapt
Be able to explain generally how nutrient cycles work in the oceans.
• Nutricline-change in nutrients w/ depth. • Why are nutrients lower in the surface/ in the deep? o Nutrients are being used by phytoplankton (on the surface) • NO4 & SI(OH)4- same prevalence in the ocean - phytoplankton use them up in the same rate • Phytoplankton require less PO4 than the other 2
