Lecture 1 & 2 - Introduction to Marine Ecosystems Flashcards
Explain the earth with regards to oceanic life at 3.9 BBP
Violent unstable earth covered almost entirely by water, high level of UV light. Atmosphere consisted of reducing gases such as Carbon Monoxide, Ammonia but no Oxygen
What life formed 3.9 BBP
The harsh environment saw the development of Cynobacteria
What occurred at 2.5 BBP
Continents formed, oxygen levels increased due to high activity of first primary producers and endosymbosis formed the first eukaryotes –> multi-cellular organisms started to form
Define Endosymbiosis
This is when one cell “engulfs” another cell, the engulfed cell forms a “factory” this is to say it becomes specialized such a chloroplast.
What occurred at 0.57 BBP (give an example too)
The first organisms with primitive skeletons such as Anomalocaris - first predators
What is the Burgess Shales in Canada
These are fossil records of the earliest form of multicellular organisms at around 530 MBP, these organisms had calcium carbonate of calcium phosphate exoskeletons
What is the origins of life?
RNA, self replicating chains of chemical compounds such as amino acids and proteins from geothermal energy in hot rocks and hydrothermal energy
What proved the formation of self replicating compounds was possible?
L. Miller and C. Urey in 1953, with there simple experiment they showed they managed to create self replicating chemical compounds
What is the Endosymbiot thoery
This is the theory that bacteria and cyanobacteria (prokaryotes) where englufed (through endosymbosis) and formed the first mitochondria and cholorplasts
Explain the structure and importance of a Stromatolites
These are still found in the world today of the coast of AUS, they consist of cyanobacteria, heterotophic bacteria, small sized sediment particles, calcuim carbonate and calcium phosphate precipitated from the sea water by bacteria
How old are the oldest stromatolites
3.7 MBP
List the seven fundemental properties of water which are key to life in the oceans
High specific heat capacity Surface tension Salinity Oxygen content Carbon Dioxide Density Light
Explain the high specific heat capacity of water
This is real high! almost 25x more than air, which means it takes more heat to get a change of just 1 degree C, making a stable environment
Explain surface tension of water
This is key for organisms but also key on a cellular level for cellular processes
Explain the O2 content of the water
This is pretty low, 50x less than air which make conditions ideal for photosynthesis
Explain the CO2 content of water
This is where 98% of the worlds CO2 is stored which means its just fantastic news for photosynthesis!
Density in water
Can range from 1 to 1.02 g/cm which provides support for organism (which is why whales can explode on land hah)
Explain light
It varies with depth! the eupotic zone ends where only 1% of penetrated light remains, also though red light is absorbed preferentially due to high penetration (what makes seaweeds brown / red)
Explain the depth zones of the Ocean (4) on average
0-200 Euphotic Zone
200 - 1000 Aphotic Zone
ALL IN THE 0-1000 palegic zone
1000-4000 Bathyplagic
Explain salinity in the water
varies from 0 to 35, sometimes over, creates niche
What are the zones of the ocean floor from top to bottom (5)
Benthic zone (extreme enviroment) Bathyal Zone Abyssal Zone Hadal Zone Trench (extreme enviroment)
Define pelagic
Open ocean water coloum
Define benthic
Associated with bottom substrate, i.e. sea floor
Define Protozoa
Single celled animals
Define Metazoa
Multi celled organism
What are the 5 functional groups of the Pelagic zone
Viruses Bacteria Phyotoplankton zooplankton Nekton
Tell me about Viruses in the Pelagic zone!
0.02 to 0.2µm, regulate through depth
Tell me about Bacteria in Pelagic zone :)
10^3 to 10^5 cells per ml. These comes in two forms Rods or Cocci, are are POM (particle) and DOM (disolved matter) recyclers, grazed upon by nanoplankton. Anoxic Processes
What can Pytoplankton and zooplankton not do that nekton can
Swim against the current! the just go with the flow
Little information on Phytoplankton and the four types!
These are primary producers that cannot swim against the current and come in four types:
Cyanobacteria
Diatoms
Dinoflagellates
Other - coccolithophorids, prymnesiopythes
Get some info out on Cyanobacteria
These contain a range of pigments which are productive at different wave lengths which are Chlorophyll a Phycobilins B-carotene xanthophylls
Tell me about Diatoms
These have pigments: chlorophyll a Chlorophyll c (unique to diatoms) B-carotene xanthophylls They are unicelluar but may form chains and reproduce through binary fission and sexual reproduction at critical size and stress levels, species spore and reproduce during adverse conditions
Information on Dinoflagellates
Have a flagella! (tiny tail used to sorta guide movement) may have thick cellulose plates can be Auto, hetro and mixotrophic and associated with red tides (blooms)
The other types of phyotoplankton, give a bit of info
Coccolithophorids - unicellular nano plankton, calcareous plates and may have 2 flagella
Prymnesiophytes - unicellular or colonial, 1 flagella
What are the 5 types of zooplankton!
Protoza Cnidarians Ctenophore Mollusca Arthropoda
(eat other zooplankton and phyotoplankton
What are the five types of protoza (zooplankton) and some characteristics
Protoza are all single-celled
Heterotrophic Dinoflagellates - form coastal swams
Zooflagellates - these account for 80% of nanoplankton
Foraminifera - have a calcerous shell with rhizopodia to trap bacteria and algea
Radiolaria - have a silcate capsule feed on bacteria and algea
Tintinnids - ciliate protozoa, appearance of a bowl vase or tube
Information on Cnidarians (zooplankton)
Medusaea, tentacles with nematocysts (stinging cell) these are jelly fish! colonial cells with some specialised. also included are corals (not pelagic zone, benthic )
information on Ctenophorea
Similar to cindarians but have no nematocysts
Information on Mollusca
These have shells - gastropoda, snails! and come in two forms heteropods and pteropods
Information on Arthropoda
These are like krill shrimp and have many different forms (but dont think we are gonna need to know for the exam)
What are nekton and the four types!
These are pelagic spp. capable of swimming against the current there are four types Palagic Fishys (key for industry) Cephalopods (squid) Marine Reptiles (turtles) Marine Mammals (whales) Pelagic sea birds
What are the two ways in which a food web can be controlled!
Bottom up control OR Tropic cascade
But in the marine environment it can very often be a mix of the two
What is bottom up control?
Resource dependant growth, in marine systems this is normally using the availability of the limiting nutrient, in most cases nitrogen.
What is Trophic cascade
This is top down control from grazing and predation
What is the Monod Equation
Dont need to know the excat maths, but is essentially as the amount of limiting nutrient increases as does the growth throughout tropic levels, but growth rates will become “saturated” meaning it levels off. Not really too smart
Draw a classic food web involving the microbial food web
Cant do it on here but should include (classic) Piscivores Planktivors Zooplankton Phyotoplankton AND as well should include (microbial): Bacteria DOM Nutrients
Explain coastal upwelling and give an example
Upwelling water rich in nutrients comes to surface where light levels are high giving a huge level of primary productivity such as Benguela upwelling, Namibia
The Benthic Zone! tell me about it
These are a wide range of habitats which may be coastal or deep sea most of which have their own lectures or the key ones do anyways
