Marine Ecosystems Midterm 1

Oceans earliest navigators

• Aristotle

• Leif Eriksson

• Benjamin Franklin

• James Cook

• Charles Darwin III

• Edward Forbes

Ship expeditions

• challenger expedition

• HMS challenger expedition

• D/V glomar challenger

• D/V joides resolution

• D/V Chikyu

HMS challenger expedition findings

• discovered:

  • mid atlantic ridge

  • undersea mountains

  • life on the ocean floor

  • salinity

  • temperature variations

  • seawater chemistry

  • measurement of ocean currents

D/V Glomar expedition findings

• discovered:

  • continental drift

  • seafloor spreading

  • age of ocean seafloor

Benjamin Franklin

• navigates the North Atlantic

• maritime observations

• description of gulf stream

James Cook

• first to use a chronometer

Charles Darwin III

• proposed theory of evolution

• mapped reefs and coastlines

• published theory on coral atolls formation

Edwards Forbes

• trawled the seafloor

• was a malacologist

• found animal density decreased with depth as well as diversity

Water high heat capacity

(0.9) absorbs a lot of heat before the temperature rises. water has one of the highest heat capacities of any naturally occurring substance.

water high heat of evaporation

(590 cal/g) helps to moderate temperatures of ecosystems

water high latent heat of melting

higher than any other commonly occurring substance. ice melts at relatively higher temperatures.

elements in sea water

• chlorine

• sodium

• magnesium

• sulfur

• calcium

• potassium

• bromine

• carbon

seawater density

influenced by salt, no maximum density at 4 degrees celsius

• increases with salinity

• increases with decreasing temperature

Coriolis effect

movement of fluids in relation to earth beneath results in deflections

oceanic circulation

Driven by two components

1. wind driven circulation

2. density driven

wind driven surface circulation

driven by heating or air near the equator which rises moves to higher latitude falls creating circulation cells that are affected by earths rotation

• prevailing westerlies

• trade winds

• combination of wind systems and shapes of ocean basins create gyres

• wind plus Coriolis effect tends to concentrate boundary currents on west sides of ocean

density driven thermohaline circulation

• water in ocean divided into water masses identified by distinct temp salinity and other chemical characteristics

• thermohaline circulation is movement of ocean water controlled mainly by density characteristics

global ocean conveyor belt

• high latitude surface waves - high salinity low temp —> high density

• waters sink move at depth toward lower latitude

• water masses each hace a characteristic depth bc of their density which is largely a function of their high latitude surface origin

tides

• drive water circulation - rhythmic rising and falling of sea surface levels

• moons gravitational pull causes this

• waters on the side closers to the moon cause high tide

• higher at night lower during daytime

• height difference called the tidal range

• tidal range higher when sun and moon are in line

diurnal tide cycle

one high tide and one low tide every lunar day

semidiurnal tide cycles

two high tides and two low tides each lunar day approximately equal in size every lunar day

mixed tide cycles

mixed semidiurnal tide cycle are has two high tides and two low tides of different sizes every lunar day

spring tides

occur when the sun earth and moon line up sun and moons gravitational forces combine to form a large tidal bulge

neap tides

sun moon and earth are positioned at 90 degree angle the gravitational bulges of the moon and sun overlap which causes the suns gravitational pull to go against that of the moon causes lower than average tidal height

building blocks of life

1. carbohydrates

2. proteins

3. lipids

4. nucleic acids

carbohydrates

• made of carbon, hydrogen, and oxygen

• used for energy

• some used to store energy

• some used as structural molecules

proteins

• composed of smaller units known as amino acids

• enzymes are specialized proteins carry out all chemical reactions in organisms

• some are hormones that act as chemical messengers within an organism

• others used as structural molecules

lipids

• do not mix with water

• marine organisms use coating of lipids as insulating layer

• provide buoyancy

• used to store energy within an organism

nucleic acids

• DNA and RNA are nucleic acids

• comprises arrangements of four smaller units called nucleotides

• genes are made up of sequences of DNA

• DNA is molecule of heredity RNA helps

autotrophs

makes its own carbohydrates

heterotrophs

gets carbohydrates by eating other organisms

prokaryotic cells

• lack nucleus

• absence of most organelles in cells

• cells contain a circular ring of DNA

• cell wall normally present

• unicellular

eukaryotic cells

• cells with DNA enclosed inside a nucleus

• cells posses many specialized organelles (nucleus, mitochondira, golgi complex, endoplasmic reticulum, ribosomes, chloroplasts, vacuoles)

• unicellular or multicellular

levels of organization in organisms

1. atom

2. molecule

3. cell

4. organelle

5. tissue

6. organ

7. organ system

8. complete organism

levels of organization

• population

• community

• ecosystem

diffusion

movement of solutes from areas where they are more concentrated to an area where they are less concentrated

osmosis

movement of water from an area where it is more concentrated to an area where it is less concentrated

osmoconformers

• their internal concentration caries as salinity changes

• don’t attempt to control solute/water balance

• can only tolerate narrow range of salinities

osmoregulators

• organisms that control their internal concentrations of solutes and water

• can be done in various ways secreting little urine or specialized glands to secrete salts

• can tolerate wider range of salinities

ectotherms

generate body heat metabolically but heat is rapidly lost so organisms cannot maintain a constant internal body temperature it matches that of the surrounding environment

endotherms

retain most metabolic heat and body temperature stays higher than that of the surrounding environment

poikilotherms

body temperature varies with the temperature of the surrounding environment

homeotherms

regulates body temperature so it doesn’t vary as much as the temperature of the surrounding environment

asexual reproduction

• doesn’t involve mating of two individuals

• offspring are reproduced by a single parent individual

• offspring genetically identical to the parent

  examples

  • fission: splitting of one organism

  • budding: organism develops buds that break off and become another

  • vegetative reproduction: a plant reproduces new individuals by send stem underground sideways

colonial reproduction

individuals are genetically identical if they are connected comprise a module each module may have arisen from a sexually formed zygote

sexual reproduction

• involves two individuals

• parents produce gametes that unite fertilization to produce new genetically unique offspring

types of sexuality

• gonochoristic - separate sexes

• hermaphroditism - individual can have male or female function simultaneous or sequential during sexual maturity

hermaphroditism

• simultaneous - organs to produce male and female gametes present simultaneously

• sequential

  • protandrous - first male then female

  • protogynous - first female then male

retroviruses

store genetic information in the form of nucleic acid known as RNA

lysogenic viruses

reproduce by inserting their DNA into the DNA of the host cell

bacteriophages

viruses that infect bacteria

lysis

bursting of cells infected with viruses spills contents and releases large amounts of organic matter that can be utilized by other organisms

archaea

• variety of metabolic types

• widely distributed at sea

• can tolerate wide ranges in temp salinity

marine bacteria

• variety of shapes

• cell wall structure is semi permeable

• normally microscopic

• wide variety of metabolic types

cyanobacteria

photosynthetic bacteria most important in marine ecosystem

stromatolites

massive calcareous mounds formed by cyanobacteria

Marine diatoms

• photosynthetic (chlorophyll A & C and carotenoids)

• shell of silica called frustule

• mostly solitary and unicellular

• store excess energy as oil that aids in buoyancy

How do diatoms reproduce?

• mainly cellular division

• cell secretes other half of frustule, diatoms gets smaller after each time they reproduce

Marine dinoflagellates

• mostly photosynthetic

• reinforced by plates of cellulose

• two flagella in grooves for motion

• some are bioluminescent

algal blooms

• diatoms and dinoflagellates going through periods of rapid growth known as blooms

• result of high nutrients in the water

pfiesteria

dinoflagellate that produces very serious toxins that cause massive fish kills, harm shellfish, and impair the nervous system

red tides

toxic dinoflagellates that reproduce in larger numbers toxic to marine ecosystems and humans

foraminiferans

• exclusively marine

• non photosynthetic

• pseudopods - extend through pores in the shell where they are used to capture minute foot particles such as phytoplankton

radiolarians

• planktonic mostly microscopic

• shell of silica

• pseudopods

silicoflagellates

• star shaped skeleton of silica

• two flagella of varying lengths

coccolithophorids

• exclusively marine

• photosynthetic

• two flagella for motion

• annual blooming events

ciliates

• hair-like cilia for locomotion

• live as solitary cells

• some build shells of organic debris

marine fungi

• eukaryotic

• heterotrophic

taxonomy levels of classification

• domain

• kingdoms

• phylum

• class

• order

• family

• genus

• species

three domains:

• archaea (prokaryote) - single celled

• bacteria (prokaryote) - lacks a nucleus

• eukarya (eukaryote) - nucleus is present

invertebrate characteristics

• eukaryotic, multicellular

• at least tissue level organization (most have organ and system level)

• heterotropic

• require oxygen

cell layers in invertebrates

two layers in Cnidaria but most have three layers

1. ectoderm

2. mesoderm

3. endoderm

invertebrate phlya

have structures of several cell layers that perform functions

coelom

cavity that develops in embryo within mesoderm found in several phyla

radial symmetry

involved similar form with respect to a center point in all directions

bilateral symmetry

involves plane of symmetry with similar form on either side of the plane

protostomes

• cleavage: asymmetric, spiral

• ventral nerve cord sold structure

deuterostomes

• cleavage: symmetrical, radial and indeterminate

• dorsal nerve cord, hollow structure

invagination

a sheet of cells that bends/folds

sponges

• asymmetrical body plan with no tissues organs

• tiny pores (ostia) allow water to pass through body for filter feeding

• spongin - support protein

• spicules - support structures made of silica or calcium carbonate

• reproduction: asexual budding, sexual

• hermaphrodites

cnidarians

• radial symmetry

• body forms: medusa and polyp

• two tissue layers: epidermis and gastrodermis

• reproduction: sexual or asexual

types of cnidarians

• hydrozoans

• scyphozoans

• cubomedusae

• anthozoans

arthropods

• jointed legs and appendages

• chitin exoskeleton (molting to grow)

• often divided into head, thorax, and abdomen

crustaceans

• dominant marine arthropods

• two pairs antennae

• head and thorax fused as cephalothorax

• open circulatory system ( no veins , blood moves through holes in heart)

• reproduction: internal fertilization

symbiosis

living together

• members of different species living in close association

• smaller partner called symbiont and larger one is the host

mutualism

both species benefit from relationship

commensalism

one species obtains shelter or some benefit without impacting other species

parasitism

the symbiont benefits at the hosts expense

competition

neither species benefits both are competing for same resources

predation

one species benefits while the other one dies

neutralism

the species do interact with each other but don’t affect each other

lophophorates

• three groups of invertebrates characterized by feeding structure known as lophophore

  • bryozoans

  • phoronids

  • lamp shells

• set of ciliated tentacles

• suspension feeders

• bilateral symmetry

bryozoans

• called moss animals

• form colonies

• interconnected individuals called zooids

phoronids

• worm like

• living in tubes of sand grains

lamp shells

• two shells enclosing body

• coiled lophophore

echinoderms

• 5 time radial symmetry in adults

• water vascular system with tube feet for locomotion and feeding

• skin gills for respiration

• decentralized nervous system

• no brain

• regenerate body parts

types of echinoderms

• sea stars

• brittle stars

• sea urchins

• sea cucumbers

• crinoids

sea stars

• move with tube feet

• eyes on each arm

• madreporite - perforated plate that allows entry of seawater

• internal organ extend through entire body

• mostly carnivores

brittle stars

• central disc surrounded by then flexible arms

• internal organs restricted to central disc

• tube feet without suckers

• no anus

• no eyes but can still see

sea urchins/sand dollars

• conspicuous moveable spins

• rigid plates fused into solid test

• move with tube feet

• mouth on bottom anus on top of body