Lecture 1 & 2 - Introduction to Marine Ecosystems

Question 1

Explain the earth with regards to oceanic life at 3.9 BBP

Answer 1

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

Question 2

What life formed 3.9 BBP

Answer 2

The harsh environment saw the development of Cynobacteria

Question 3

What occurred at 2.5 BBP

Answer 3

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

Question 4

Define Endosymbiosis

Answer 4

This is when one cell “engulfs” another cell, the engulfed cell forms a “factory” this is to say it becomes specialized such a chloroplast.

Question 5

What occurred at 0.57 BBP (give an example too)

Answer 5

The first organisms with primitive skeletons such as Anomalocaris - first predators

Question 6

What is the Burgess Shales in Canada

Answer 6

These are fossil records of the earliest form of multicellular organisms at around 530 MBP, these organisms had calcium carbonate of calcium phosphate exoskeletons

Question 7

What is the origins of life?

Answer 7

RNA, self replicating chains of chemical compounds such as amino acids and proteins from geothermal energy in hot rocks and hydrothermal energy

Question 8

What proved the formation of self replicating compounds was possible?

Answer 8

L. Miller and C. Urey in 1953, with there simple experiment they showed they managed to create self replicating chemical compounds

Question 9

What is the Endosymbiot thoery

Answer 9

This is the theory that bacteria and cyanobacteria (prokaryotes) where englufed (through endosymbosis) and formed the first mitochondria and cholorplasts

Question 10

Explain the structure and importance of a Stromatolites

Answer 10

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

Question 11

How old are the oldest stromatolites

Answer 11

3.7 MBP

Question 12

List the seven fundemental properties of water which are key to life in the oceans

Answer 12

High specific heat capacity 
Surface tension
Salinity
Oxygen content
Carbon Dioxide
Density 
Light

Question 13

Explain the high specific heat capacity of water

Answer 13

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

Question 14

Explain surface tension of water

Answer 14

This is key for organisms but also key on a cellular level for cellular processes

Question 15

Explain the O2 content of the water

Answer 15

This is pretty low, 50x less than air which make conditions ideal for photosynthesis

Question 16

Explain the CO2 content of water

Answer 16

This is where 98% of the worlds CO2 is stored which means its just fantastic news for photosynthesis!

Question 17

Density in water

Answer 17

Can range from 1 to 1.02 g/cm which provides support for organism (which is why whales can explode on land hah)

Question 18

Explain light

Answer 18

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)

Question 19

Explain the depth zones of the Ocean (4) on average

Answer 19

0-200 Euphotic Zone
200 - 1000 Aphotic Zone
ALL IN THE 0-1000 palegic zone
1000-4000 Bathyplagic

Question 20

Explain salinity in the water

Answer 20

varies from 0 to 35, sometimes over, creates niche

Question 21

What are the zones of the ocean floor from top to bottom (5)

Answer 21

Benthic zone (extreme enviroment)
Bathyal Zone
Abyssal Zone
Hadal Zone
Trench (extreme enviroment)

Question 22

Define pelagic

Answer 22

Open ocean water coloum

Question 23

Define benthic

Answer 23

Associated with bottom substrate, i.e. sea floor

Question 24

Define Protozoa

Answer 24

Single celled animals

Question 25

Define Metazoa

Answer 25

Multi celled organism

Question 26

What are the 5 functional groups of the Pelagic zone

Answer 26

``` Viruses Bacteria Phyotoplankton zooplankton Nekton ```

Question 27

Tell me about Viruses in the Pelagic zone!

Answer 27

0.02 to 0.2µm, regulate through depth

Question 28

Tell me about Bacteria in Pelagic zone :)

Answer 28

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

Question 29

What can Pytoplankton and zooplankton not do that nekton can

Answer 29

Swim against the current! the just go with the flow

Question 30

Little information on Phytoplankton and the four types!

Answer 30

These are primary producers that cannot swim against the current and come in four types: Cyanobacteria Diatoms Dinoflagellates Other - coccolithophorids, prymnesiopythes

Question 31

Get some info out on Cyanobacteria

Answer 31

``` These contain a range of pigments which are productive at different wave lengths which are Chlorophyll a Phycobilins B-carotene xanthophylls ```

Question 32

Tell me about Diatoms

Answer 32

``` 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 ```

Question 33

Information on Dinoflagellates

Answer 33

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)

Question 34

The other types of phyotoplankton, give a bit of info

Answer 34

Coccolithophorids - unicellular nano plankton, calcareous plates and may have 2 flagella Prymnesiophytes - unicellular or colonial, 1 flagella

Question 35

What are the 5 types of zooplankton!

Answer 35

``` Protoza Cnidarians Ctenophore Mollusca Arthropoda ``` (eat other zooplankton and phyotoplankton

Question 36

What are the five types of protoza (zooplankton) and some characteristics

Answer 36

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

Question 37

Information on Cnidarians (zooplankton)

Answer 37

Medusaea, tentacles with nematocysts (stinging cell) these are jelly fish! colonial cells with some specialised. also included are corals (not pelagic zone, benthic )

Question 38

information on Ctenophorea

Answer 38

Similar to cindarians but have no nematocysts

Question 39

Information on Mollusca

Answer 39

These have shells - gastropoda, snails! and come in two forms heteropods and pteropods

Question 40

Information on Arthropoda

Answer 40

These are like krill shrimp and have many different forms (but dont think we are gonna need to know for the exam)

Question 41

What are nekton and the four types!

Answer 41

``` 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 ```

Question 42

What are the two ways in which a food web can be controlled!

Answer 42

Bottom up control OR Tropic cascade But in the marine environment it can very often be a mix of the two

Question 43

What is bottom up control?

Answer 43

Resource dependant growth, in marine systems this is normally using the availability of the limiting nutrient, in most cases nitrogen.

Question 44

What is Trophic cascade

Answer 44

This is top down control from grazing and predation

Question 45

What is the Monod Equation

Answer 45

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

Question 46

Draw a classic food web involving the microbial food web

Answer 46

``` Cant do it on here but should include (classic) Piscivores Planktivors Zooplankton Phyotoplankton AND as well should include (microbial): Bacteria DOM Nutrients ```

Question 47

Explain coastal upwelling and give an example

Answer 47

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

Question 48

The Benthic Zone! tell me about it

Answer 48

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