OCNG Exam 3

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Life

An entity that has organization, metabolism, growth, response to stimuli, and reproduction.

Linnaean Classification System

A hierarchical system for classifying organisms (Domain, Kingdom, Phylum, Class, Order, Family, Genus, Species).

Three Domains of Life

Bacteria, Archaea, and Eukarya.

Plankton

Organisms that drift with currents and cannot swim against them.

Nekton

Actively swimming organisms that can move independently of currents.

Benthos

Organisms that live on or in the seafloor.

Water Column

The vertical portion of the ocean from surface to bottom.

Benthic Environment

The seafloor and organisms living there.

Marine Biodiversity

The variety of life in the ocean; generally higher than on land due to stability and volume.

Surface Area to Volume Ratio (SA:V)

Amount of surface area relative to volume; higher SA:V allows faster exchange.

Buoyancy

Ability to float or remain suspended in water.

Osmoregulation

Regulation of salt and water balance.

Marine Adaptations

Traits such as gills, streamlining, buoyancy control, and salt regulation.

Epipelagic Zone

Sunlit surface waters where photosynthesis occurs.

Mesopelagic Zone

Twilight zone with limited light and no photosynthesis.

Bathypelagic Zone

Deep, dark ocean with cold temperatures and high pressure.

Abyssopelagic Zone

Extremely deep ocean waters above the seafloor.

Primary Productivity

Rate at which energy is converted into organic matter.

Gross Primary Productivity (GPP)

Total energy produced by photosynthesis.

Net Primary Productivity (NPP)

Energy remaining after respiration.

Photosynthesis

Process using light, CO₂, and water to make sugars and oxygen.

Factors Affecting Photosynthesis

Light, nutrients, temperature, and CO₂.

Phytoplankton

Microscopic photosynthetic organisms forming the base of food webs.

Diatoms

Silica-shelled phytoplankton.

Dinoflagellates

Flagellated phytoplankton; some cause harmful algal blooms.

Coccolithophores

Phytoplankton with calcium carbonate plates.

Cyanobacteria

Photosynthetic bacteria important to nutrient cycles.

Biological Pump

Transfer of carbon from surface to deep ocean via sinking organic matter.

Trophic Level

Feeding position in a food chain or web.

Food Chain

Linear transfer of energy.

Food Web

Network of interconnected food chains.

Overfishing

Harvesting fish faster than populations replenish.

Maximum Sustainable Yield

Largest catch without population collapse.

Neutral Buoyancy

Remaining suspended without sinking or floating.

Swim Bladder

Gas-filled organ for buoyancy control.

Oil Storage

Lipids used to increase buoyancy.

Reduced Skeletal Density

Lighter bones aiding buoyancy.

Zooplankton

Drifting animal plankton feeding on phytoplankton.

Copepods

Abundant crustacean zooplankton.

Krill

Shrimp-like zooplankton important to polar food webs.

Fish Fins

Structures for propulsion, steering, and stability.

Caudal Fin

Tail fin used for propulsion.

Deep-Sea Fish Adaptations

Large mouths, bioluminescence, slow metabolism.

Bioluminescence

Light produced by living organisms.

Schooling

Group behavior reducing predation and improving feeding.

Lateral Line System

Sensory system detecting water movement.

Marine Mammals

Mammals adapted to marine life.

Cetaceans

Whales, dolphins, and porpoises.

Pinnipeds

Seals, sea lions, and walruses.

Sirenians

Manatees and dugongs.

Blubber

Fat layer for insulation and energy storage.

Countercurrent Heat Exchange

Heat conservation in extremities.

Baleen Whales (Mysticeti)

Filter-feeding whales with baleen plates.

Toothed Whales (Odontoceti)

Predatory whales with teeth.

Baleen

Keratin plates used for filter feeding.

Rorquals

Baleen whales using lunge feeding.

Right Whales

Slow-moving baleen whales that skim feed.

Coral Reef

Diverse ecosystem built by coral skeletons.

Zooxanthellae

Symbiotic photosynthetic algae in corals.

Symbiosis

Close relationship between species.

Mutualism

Symbiosis where both benefit.

Crustose Coralline Algae

Calcifying algae that cement reefs.

Coral Bleaching

Loss of zooxanthellae due to stress.

Ocean Acidification

Lower ocean pH from increased CO₂.

Nutrient Limitation

Corals thrive in low-nutrient waters.

Eutrophication

Excess nutrients causing algal blooms.

Hydrothermal Vents

Seafloor openings emitting heated, mineral-rich water.

Chemosynthesis

Energy production using chemical reactions.

Sulfur-Oxidizing Bacteria

Vent microbes using hydrogen sulfide.

Riftia Tube Worms

East Pacific hydrothermal vent species.

Giant Clams

West Pacific vent-associated species.

Vent Mussels

Atlantic vent species.

Feedback Loop

Process that amplifies or reduces change.

Positive Feedback

Enhances an initial change.

Negative Feedback

Reduces an initial change.

Ice Cores

Trapped air bubbles recording past climate.

Sediment Cores

Layered sediments revealing past climate.

Tree Rings

Growth patterns showing past climate.

Corals (Climate Proxy)

Growth bands recording ocean conditions.

Fossils

Remains showing past ecosystems.

Isotopes

Ratios indicating temperature and ice volume.

Solar Variability

Changes in solar output.

Volcanic Activity

Cooling from aerosols.

Milankovitch Cycles

Orbital variations affecting climate.

Plate Tectonics

Movement altering ocean circulation.

IPCC

International group summarizing climate science.

Greenhouse Effect

Heat trapped by atmospheric gases.

Greenhouse Gases

CO₂, CH₄, N₂O, water vapor.

Keeling Curve

Record showing rising atmospheric CO₂.

PETM

Rapid warming event ~56 million years ago.

Climate Projections (2100)

Warming, sea level rise, acidification.

Sea Level Rise

Increase from ice melt and thermal expansion.

Oil Spill

Release of petroleum into marine environments.

Exxon Valdez Spill

Led to improved oil spill regulations.

Deepwater Horizon Spill

Massive blowout from offshore drilling.

Oil Spill Cleanup

Booms, skimmers, dispersants, bioremediation.

Hypoxia

Low oxygen conditions.

Dead Zone

Area unable to support most life due to low oxygen.

Bioaccumulation

Toxin buildup in organisms over time.

Biomagnification

Toxin increase up the food chain.