Marine Biology Exam 2

Cal Poly Slo: MSCI 111

Environmental challenges for coral reefs, intertidal zones, estuaries, hydrothermal vents, and polar seas.

Coral reefs: High temperature and UV light

Intertidal Zones: Desiccation (removal of moisture) and temperature extremes

Estuary: High temperature, variable salinity, and low oxygen

Hydrothermal vent: High temperature and pressure

Polar seas: Freezing temperature

Phenotypic plasticity (acclimatization)

An individual organisms ability to produce different phenotypes when exposed to different environmental conditions. This is done to survive in the face of environmental challenge and stress.

Evolutionary Adaptation

A process were heritable (morph, phys, behav.) arise in population over generations due to natural selection

Examples of plasticity

Morphological: Barnacles that liven high wave action areas grow shorter, thicker cirri

Physiological: Squid can increase the amount of oxygen they can carry in their blood when exposed to hypoxia (low O2)

Behavioral: Many coral reef fish change their courtship/ aggression behaviors (and sex) based on social hierarchies

Examples of Evolutionary adaptation

Morphological: Diving mammals have flexible rib cages and fully collapsible lungs to deal with high pressure

Physiological: Antarctic icefish evolved to have high levels of anti-freeze compounds in their blood to prevent freezing

Behavioral: Intertidal organisms have evolved behavioral adaptations to avoid desiccation when out of water

Natural Selection

Process where organisms better adapted to their environment (or more likely to mate/reproduce) due to genetic variation

Fitness

how well an organism can survive and reproduce in its environment

Phenotype

An organism's physical appearance, or visible traits.

Genotype

genetic makeup of an organism

Phenotype and genotype relationship

Phenotypes and Genotypes affect and influence each other. Also, the genotype can be effected by the environment.

Four major sources of genetic variation

Genetic mutation, genetic recombination, gene flow, and genetic drift

asexual reproduction

A reproductive process that involves only one parent and produces offspring that are identical to the parent.

Forms of asexual reproduction

Binary fission: Organisms split into two different parts without sex taking place
Budding: New organism develops due to outgrowing which leads to separation
Fragmentation: Piece of the body of the parent breaks off and develops into an individual offspring
Rhizomes: Store food to produce energy for vegetative proposition

Sexual reproduction

A reproductive process that involves two parents that combine their genetic material to produce a new organism, which differs from both parents

Advantages/disadvantages of sexual and asexual reproduction

Asexual: Don't need a parter and doesn't use a lot of energy, but all the same genetics, which reduces overall fitness

Sexual: Genetic variation and improved fitness, but requires energy and you need a partner

Internal fertilization

Process in which eggs are fertilized inside the female's body

external fertilization

The process by which the female lays eggs and the male fertilizes them once they are outside of the female

Broadcast spawning

release millions of eggs and sperm into the water and hope they find each other, where fertilization occurs, parents have no interaction with offspring; EX: pelagic fish

Brooding

Eggs are fertilized in sperm within the body of the organism, and larvae are released into the water when more developed; EX

Oviparty

Female lays eggs that develop and hatch into young individuals, birds lay eggs and they hatch

viviparty

female gives birth to live young, shark

Pelagic

organisms that live in the water column away from the ocean bottom.

Plankton

microscopic marine organisms that cannot swim against the current

Nekton

All organisms that swim actively in open water, independent of currents

Benthic

bottom of an aquatic ecosystem; consists of sand and sediment and supports its own community of organisms

Infauna

animals that burrow in the substrate

Epifauna

Animals that live on the surface of the substrate

mobile

capable of moving on their own

Sessile

Describes an organism that remains attached to a surface for its entire life and does not move (OPPOSITE OF MOBILE)

autotrphs

Organisms that make their own food (primary producers and photosynthesize)

Heterotroph

organism that obtains energy from the foods it consumes, need food for energetic demands); also called a consumer (zooplankton, nekton)

primary producers

the first producers of energy-rich compounds that are later used by other organisms

Consumer

An organism that obtains energy by feeding on other organisms

Decomposer

Feed on remains of all aquatic organisms

Photosynthetic autotroph

an organism that uses carbon dioxide as a carbon source and light as an energy source to synthesize organic compounds

chemosynthetic autotrophs

make their own food using energy obtained by oxidizing inorganic substances

Prokaryote

A unicellular organism that lacks a nucleus and membrane bound organelles

Eukaryote

A cell that contains a nucleus and membrane bound organelles

Food webs are

interconnected food chains; very complex

First trophic level

primary producers (phytoplankton), microscopic organisms

Second trophic level

Primary consumers (zooplankton, herbivores)

third trophic level

Consumers (nektonic consumers, carnivores)

Energy flow between marine trophic levels

Autotrophs, herbivores, and carnivores all flowing to the bottom of the ocean

Only around 10% of chemical energy is passed onto next trophic level because

THE rest of the energy is lost as heat energy (through metabolic process)

Marine food webs

-phytoplankton much larger biomass than marine plants
- primary consumers \= herbivores

filter feeders

organism that takes in water to filter out the food and then releases the extra water; whales are an example of this, they do this because they're larger and can't move as fast to catch prey

Dominant marine microbes are found

In the domain bacteria and archaea under prokaryotes, and in the domain eukarya, Protista, and kingdom fungi under eukaryotes

Two major organismal groups that are considered algae

Phytoplankton and seaweed

heterotrophic bacteria

require organic carbon for food/growth

5 major groups of marine phytoplankton

cyanobacteria, diatoms, dinoflagellates, coccolithophores, silicoflagellates

Cyanobacteria

Bacteria that can carry out photosynthesis, among first photosynthetic organisms, thought to have important role in accumulating O2 in our atmosphere. cyanobacteria helps form fossil stromatolites

Diatoms

one of most abundant phytoplankton, unicellular, made up of a silica (SiO2) frustule with two closely fitting halves, can be centric (radial symmetry) or pennate (bilateral symmetry, capable of locomotion), colonial...PHOTOSYNTHETIC

diatomaceous ooze

glass frustules of dead diatoms sink to the sea floor, which is how this is formed, can be used commercially to remove unwanted material from drinking water

Dinoflagellates

very abundant and photosynthetic, have to flagella, one wrapped around a groove in middle of cell and one trailing free. have locomotion, many are bioluminescent and lead to glowing in the ocean, responsible for harmful algal blooms

Zooxanthellae (Dinoflagellates)

symbionts with coral, sea anemone, sponges, and giant squid

Coccolithophores

small, less abundant, unicellular, found as fossils in sediment

Silicoflagellates

small, less abundant, star-shaped internal skeleton made of silica

Harmful Algal Blooms (HABs)

sudden increase of nutrients in ocean leads to an explosive growth of a "harmful" species of phytoplankton

toxins produces can cause mass mortality of fish, marine mammals, and other marine invertebrates

Eutrophication

sudden increase in nutrients, caused by runoff (fertilizers) and upwelling

Saxitoxin

a neurotoxin produced by some dinoflagellates, can cause muscle paralysis of consumed in high concentration (paralytic shellfish poisoning)

domoic acid

causes gastrointestinal distress, dizziness and memory loss (amnesic shellfish poisoning)

HABS results in hypoxic and anoxic "dead zones" in waters because

organisms sink to the seafloor, are decomposed by bacteria, and most of the oxygen is used up in this process

Phytoplankton prevent sinking by

being small, having complex cell shape, lighter frustules, internal gas-filled vesicles

Why are phytoplankton so important?

1) produce 50-80% of oxygen on earth (much more then all land plants)
2) Represent the base f the food chain for virtually all marine ecosystems
3) Play a critical role in the storage of carbon in the deep-sealy way of the biological (or carbon) pump

biological pump

transport of organic carbon and nutrients from the surface ocean to the deep ocean which are then upwelled to the surface

carbon sequestration

gathering all carbon together at the bottom of the ocean

Climate change is due to the \______ and results in \________

1) rising atmospheric CO2
2) ocean warming and ocean acidification

Without phytoplankton, what would increase exponentially (2 things)

Atmospheric CO2 (climate change) and ocean acidification

How can we measure primary productivity in the ocean?

Satellite imaging of chlorophyll A pigment (green)

TWO most important resources that marine phytoplankton must have continuous access to

Sunlight and nutrients

3 limiting factors that produce primary productivity

Grazing (predation), light availability, and nutrient availability

Phytoplankton prey population density and predatory grazer population density

see graph

Light intensity and photosynthesis rate

Remember light limitation, photo-saturation, and photo-inhibition

Photosynthesis equation

6CO2 + 6H2O --\> light energy --\> C6H12O6 + 6O2

Phytoplankton resources needed

C, H, O, sunlight, nutrients, all needed for productivity and photosynthesis

Phytoplankton get their resources FROM

terrestrial runoff, and rely on upwelling to move nutrients from deep, cold nutrient-rich waters to the photic zone

Limiting nutrients for phytoplankton

nitrogen (nitrate), phosphorus (phosphate), iron, and/or silica

Upwelling

Occurs when wind-drive currents (of warm surface water) are displaced by the Coriolis effect. Cool, deep nutrient-rich waters move upwards to replace it. Areas of upwelling tend to have primary productivity.

(Coastal and wind-driven upwelling)

Dominant upwelling on our globe

Iron fertilization

Scientists have been experimenting with dumping iron out at sea to induce phytoplankton blooms and facilitate carbon sequestration. This would serve to mitigate climate change.

Primary productivity varies with latitude and time of the year due to

Available light and the amount of nutrients provided by water mixing above the thermocline

(be able to graph this)

Phylum Chlorophyta (color, productive type, found where, cell strucuture)

green algae, dominant, photosynthetic, chlorophyll pigment, mostly found in FW environments, both uni and multi cellular species

Phylum Rhodophyta (color, productive type, found where, cell strucuture)

red algae, dominant, photosynthetic pigment is red accessory phylocobin, more species then red and brown, almost all marine

Phylum Ochrophyta (color, productive type, found where, cell strucuture)

brown algae, dominant photosynthetic pigment is yellow-brown accessory pigment fucoxanthin, almost all marine species, include largest and most complex seaweeds, and often dominant primary producers in temperate and polar rocky shores

Seaweeds (productivity type, cell structure, where are they found)

multicellular photosynthetic organisms that don't produce flowers or seeds, found attached to hard surfaces in intertidal zone, different photosynthetic pigments give them each their characteristic color

What organism contributes to a greater % of primary productivity?

Phytoplankton

General structures of seaweed

Thallus (body), stipe, blade, holdfast, haptera

example of green seaweed

sea lettuce

example of red seaweed

encrusting coralline algae

example of brown seaweed

kelp

Land plants are thought to have originated from what type of algae?

Green algae

Encrusting coralline algae

mostly red algae, and are calcareous, characterized by extensive deposits of calcium carbonate in cell walls, they play an important role in reef-building

Sargasso Sea

An area in the middle of the Atlantic Ocean in which green seaweed grows thick. Sargassum is unique because it is pelagic (originating in open sea!)

Types of kelp

Feather boa kelp, bull kelp, stiff-stiped kelp, giant kelp

Kelp forests

incredibly biodiverse, productive, marine ecosystems. high densities flare brown algae.

where do kelp forests occur

cold, nutrient-rich water of shallow open
coastal waters, typically in the temperate regions

Why do kelp forests grow in narrow bands offshore?

Wave action and depth

Kelp zones

Canopy, style, and holdfast zones

Kelp growth rates

kelp is one of the fastest growing "plants" in the ocean or on land, it can grow up to 2 ft per day and up to 100 feet tall

Economic use of kelp seaweed

Can be used as fertilizer, pet/agriculture food, and used a natural cervical dilator for female birth