Exam 1 (ex equations and tmr lecture)

Benthic

organisms associated with the seafloor

Pelagic

associated with the water column

Benthos compared to Plankton

• slower time scales

• composition and abundance reflects past and present, shells, scales, and roots can reflect history

• Benthos use more energy than they produce

Allochtonous

non-local production

Benthopelagic

organisms that move between the water column and sea floor

Pelago-benthic Coupling

connections between the pelagic and benthic realms

Relationship between Prokaryote Abundance and Depth

Both increases

Microorganisms

visable only through microscope

meiofauna

>20-30 um and < 0.5-1 mm in size

Macrofauna

retained on 0.5 of 1 mm sieve

Megafauna

visable with the naked eye and in photographs

Organism Biodiversity and Size are ______ Related

Inversley

Viruses

biological entities, sub-microscopic in size, that cannot live or reproduce outside a host cell, because they lack metabolic activity and biosynthetic functions

Viriosphere

totallity of environments in which viruses occur, spanning every envrionement on Earth

Capsid

the protein coat of viruses

Capsomeres

identical repeating units that comprise the capsid and surround the viral genome

Pericapsid

the exterior glycoprotein-lipid coating of viruses

lytic Viruses

viruses that infect a cell, replicate, and release once the infected cell dies

→ fast

Lysogenic Viruses

infect the cell and integrate their DNA into the host genome, replicating thier genome until some additional factor (high temp, UV, ext) induce the lytic cycle

→slower

Heterotrophs

obtain energy from other organisms

Bacterial OTU’s (Operational Taxoniomic Units)

Decreases with Depth

metabarcoding

considers a single gene marker for all organisms in a sample

Metagenomic Analysis

considers all the genes of all organisms

Mixotrophic

primary producers and consumers of organic matter, depending on conditions

epielon

cyanobacteria and eukaryotic algae on sediments

Episammon

attached to sediment

Endopelon

live within the sediment

Epilithon

live on hard substrates

Epiphython

live on other plants

Epizoon

live on animals

Gyres

large systems of ocean surface currents moving in a circular fashion driven by wind movements and caused by the Coriolis effect

Relationship between distance from land and nutrients

Closer to land equates to more abundant nutrients, while being farther away from land results in less nutrients

Landmuir Circulation

occurs when wind blows steadily across relatively calm seas. Vortices revolve around vertical axes that leads to upwelling. This concentrates phytoplankton for enhanced feeding and regeneration of nutrients

Shelf Bank Fronts

occurs along edges of continental shelves or other banks, caused by sudden shallowing of water and change in current speed. This turbulence causes nutrients to rise to surface

River-Plume Fronts

rivers carry high nutrients (natural fertilizers + sewage), so there is increased productivity near mouth of river

Wind Driven Ocean Circulation

causes large divergent frontal zones along edges of continents

ENSO / El Nino Southern Oscillation

cyclical alternation of south central Pacific Ocean extreme weather → downwelling where normally upwelling would occur

Deep Scattering Layer (DSL) / Reflective Deep Layer

depth layer of the ocean with high zooplankton concentrations sufficient enough to scatter sound waves

Diel Migration

synchronised movement of organisms up and down in the water column over a daily cycle

diurnal

related to daytime movement

nocturnal

related to nighttime movement

Dipause

“programmed” biological development disrupted by the genome that suspends the life cycle of an organism, typically in advance of unfavorable environmental conditions

Main hypotheses to explain vertical migration

• reduced energy expenditure

• predator avoidance

• increased gene exchange among populations

Velocity of taxon

V = K x L²

• k = constant for taxa, L = lenght

Turnover time

the time required by an organism to duplicate itself

Succession

a series of progressive changes in the composition of an ecological community over time

Succession is more common at _____ seas

colder

Primary Production Rates in Open Water Communities

low primary production

Dominate Species in Open Water Communities

• dominated by micro-phytoplankton

• zooplankton are dominated by tintinnids, herabvore copepods, and other carnivorous species

Stability in Open Water Communities

high stability

Diversity in Open Water Communities

high diversity

Control in Open Water Communities

features top down control

Primary Production in Intermediate Communities

moderate primary production rates and biomass

Control in Intermediate Communities

bottom-up control of primary production

Diversity in Coastal Communities

low diversity

Primary Production in Coastal Communities

high primary production and biomass

• top-down grazing cannot control phytoplankton dynamics

principal of competitive exclusion

two species cannot occupy the same niche

Biodiversity Drivers

geological age, habitat heterogeneity, climatic factors, productivity, competition, predation, intermediate disturbance, history

Rapport’s Rule

latitudinal ranges of species are generally smaller at lower than at higher latitudes

Relationship between macrofaunal biodiversity and depth

decreasing abundance with depth after peak rises mid-slope

endemic species

unique to a particular location

bipolar species

present at both poles but absent inbetween

Circumboreal Species

span the cold-temperate oceans and seas of the northern hemisphere

Panoceanic Species

occur in all oceans

Paleoendemic Species

formerly widespread species now restricted

as much as __% of marine biology is unknown

91%

Lessepsian Migration

the entry of alien species from the Red Sea through the Suez Canal

Negative Water Balance

evaporation losses exceed riverine and rainfall inputs

Neoendemic Species

new, relativley localized species that evolved relativley recently

_____ brings tropical species

North Atlantic Oscillation (NAO)

Stability-Time Hypothesis

a theory of biodiversity wherein; physical environmental stability allows species to adapt and specialize

Habitat Heterogeneity Hypothesis

a theory of biodiversity wherein; more habitats equals more diversity

Predator Cropping / Biological-disorder hypothesis

a theory of biodiversity wherein; predators reduce competition which promotes diversification

Intermediate Disturbance Hypothesis

a theory of biodiversity wherein; episodic natural phenomena lower diversity and high stability promotes competition and lowers diversity

Patch Mosaic Theory

a theory of biodiversity wherein; mosaic of stages of heterogeneity and disturbance creates microenvironments

Epineuston

above the sea surface

Neuston

in contact with sea surface

Planetary Frontal Systems

formed by convergence or divergence of two current systems

Eppiplankton

live in the upper 200m

Mesoplankton

live in the mesopelagic (200-1000m)

Bathylplankton

live at 1000 - 3000/4000 m

Abyssoplankton

live at 4000 - 6000 m

Hadoplankton

live in ocean trenches at 6000 - 11000 m

Haloplankton life cycle

live their entire lives in suspension in water column

Meroplankton / Temporary Plankton

spend part of their life cycles in the plankton

Larval Metamorphosis

transformation from a larval stage to an adult form

Larval Settlement

process where free-swimming planktonic larva metamorphoses and settles to the bottom to begin its adult life → irreversable

Factors Influencing Mortalit of a meroplankton larva

light, depth, salinity, pressure, adult presence, suitability of substrate, currents, chemical stimuli, food, predator abundance, mirobial biofilm on substrate (provides settlement cue)

Planktonic Size Classes

Viruses may comprise % of the plankton and represent the most abundant biological entities in the ocean, but only __% of total biomass

94%,5%

Hypervolume

multidimensional space of a population that determines population survival, where each dimension represents an environmental factor

Fundamental Niche

entire set of conditions actually used by given organisms, accounting for other interactions such as predation and competition

Killing the Winner

a model that postulates that viral infection controls microbial community diversity whereas non-specific grazing controls microbial abundance

Examples of Cyannobacteria

• Synechococcus spp. →unknown until 1970’s

• Prochloroccus spp. → unknown until 1980’s

Archaea

initially considered typical of high salinity, high temperature, and anaerobic environments represent a significant fraction of picoplankton in most marine environments

marine snow

the rain of organic material that falls from shallow water into the deep ocean

Nitrogen Fixation

conversion of N2, which most organisms cannot use, into ammonia, which many organisms can, via specialized bacteria

Nitrification

microbial process that sequentially oxidizes reduced nitrogen compounds (mostly ammonia) to nitrate and nitrite