Oceanography - Exam 3

Covering: Marine Life, Plankton, Nutrients Cycles and Blooms, Fishes, Marine/Aquatic Mammals, Fisheries, and Deep Ocean Communities

Biology

Study of life; involves complexity at multiple levels

Ecology

Study of life beyond individual organisms - includes populations, communities, and ecosystems

All Organisms:

Process energy and materials, matintain internal conditions, respond to stimuli, reproduce and evolve

Phylogenetic tree

Shows evolutionary relationships from LUCA (Last Universal Common Ancestor)

Taxonomic Hierarcy

Domain > Kingdom > Phylum > Class > Order > Family > Genus > Species

Domains:

Archaea, Bacteria, Eukarya

Prokaryotes

Arachnae & Bacteria; simple cells, fast reproduction, extreme environments

Eukarya

Complex cells with nucleus and organelles

Eukarya includes:

Protista, chromista, fungi, animalia

Protista

Single-celled eukaryotes

Chromista

photosynthetic eukaryotes

Fungi

Multicellular decomposers and parasites

animalia (metazoa)

invertebrates and vertebrates

Population ecology

study of one species’ distribution, abundance, and reproduction

community ecology

interactions among multiple species

ecosystem ecology

interactions between organisms and their environment (energy, nutrients, gases)

Pelagic zone

open water

benthic zone

seafloor

Photic (epipelagic) zone

<100-200m, photosynthesis possible

Dysphotic (mesopelagic) zone

<1000m, low light

Aphotic

no light

Plankton travel by:

drifting

HOLOplankton

Entire life as a plankton

MEROplankton

Part of life as a plankton

Nekton travel by:

swimming

Demersal fish live:

near the bottom

Benthos

Creatures living in benthic zone

Epibenthos live:

On the bottom

Epiflora

plants on the bottom

epifauna

animals on bottom

infauna

live in sediment

vertical zonation

species vary by depth; intertidal zones

In intertidal zones, organisms must:

tolerate drying, temp. changes, and salinity shifts

Sandy/Muddy bottoms:

fewer visible organisms, rich in infauna

Abiotic factors

Temp, Salinity, Light, Nutrients, Substrate, Dissolved gases, Currents, Waves

Temperature effects:

metabolism, chemical reactions and biological activity

Diffusion

Movement of molecules from high to low concentration until evenly distributed

Diffusion is important at:

small scales

Osmosis

Special type of diffusion through a partially permeable membrane

Average ocean salinity:

~35 ppt

Saltwater fish

Lose water to environment

Freshwater fish

gain water from environment

Marine plant adaptations:

no roots, may stay near surface for light, adapted to float/grow in shallow water

Smaller organisms have _____ SA/V ratios

higher

High SA/V improves:

nutrient and gas diffusion, buoyancy

Structures like frills, hairs, and spines increase ______

SA/V

Nekton maximize _____ and minimize _____

thrust, drag

surface drag is reduced by:

smooth surfaces

form drag is reduced by:

streamlined shapes

turbulent drag is reduced by:

tapered bodies

Caudal fin shape affects:

swimming

Low aspect ratio (caudal fin)

quick bursts, less efficient cruising

high aspect ratio (caudal fin)

efficient long-distance swimming

Plankton

microscopic drifters in water

Seston

All suspended particles (including plankton)

Femtoplankton

viruses, smallest

Picoplankton

bacteria, cyanobacteria

Nanoplankton

small phytoplankton

Microplankton

diatoms, dinoflagellates

Macroplankton

jellyfish, fish larvae

Megaplankton

large jellyfish, tunicates

Plankton are classified by:

life cycle and location

Neritic plankton live:

over continental shelf

oceanic plankton live:

beyond continental shelf

epiplankton live:

0-50m down

subplankton live:

50-200m down

infraplankton live:

200-500m down

bathiplankton live:

>500m down

zooplankton

animals

phytoplankton

plants

phytoplankton produce ____% of Earth’s oxygen

~50%

Phytoplankton are the _______ of the marine food chain

base

bacterioplankton

bacteria in aquatic environments

bacterioplankton are mostly:

saprophytic, some autotrophic

bacterioplankton are important in:

biogeochemical cycles

organic matter

contains carbon

inorganic matter

non-living substances

photosynthesis converts ______ to ______

inorganic, organic

respiration (from animals) converts ______ matter to _______ matter

organic, inorganic

autotrophs

make their own food

heterotrophs

consume other organisms for nutrition

primary production

organic matter from inorganic sources

secondary production

organic matter from consuming other organisms

primary producers:

diatoms, coccolithophores, dinoflagellates, cyanobacteria

diatoms

silica shells

coccolithophores

calcium carbonate shells

dinoflagellates

cause red tides and bioluminescence

cyanobacteria

blue-green algae, photosynthetic prokaryotes

Harmful algae blooms (HABs) are caused by::

dinoflagellates and other algae

HABs produce:

toxins harmful to marine life and humans

In primary production, water and CO₂ are:

not limiting

In primary production, nutrients (N, P, Si) are:

often limiting

In primary production, sunlight is:

limiting

compensation depth

depth where photosynthesis = respiration

turbidity

reduces light penetration, affecting productivity

Macronutrients

Nitrogen (N), Phosphorus (P), Silicon (Si)

Micronutrients

Iron (Fe), Manganese (Mn), Copper (Cu)

Nutrients cycle through ______ and ______

decomposition and upwelling

Upwelling and mixing:

bring nutrients to surface waters

Coastal upwelling zones are _____ productive

highly