Marine Ecosystems and Chemical Processes Overview

Net Primary Production

Difference between CO2 gained and lost in photosynthesis.

Phytoplankton Nutrients

Nitrogen, phosphorus, silica, and iron limit growth.

Iron Input Source

Dust blown off continents enriches surface ocean.

Iron Limited Regions

Southern ocean, subpolar North Pacific, eastern equatorial Pacific.

Nutrient Control in Surface Ocean

Light is plentiful; nutrients are often limiting.

Nutrient Control in Deep Ocean

Nutrients are plentiful; light is often limiting.

Thermocline

Layer separating surface and deep ocean waters.

Subtropical Gyres

Low primary production due to warm water lens.

Equatorial Upwelling

Brings nutrient-rich cold water to surface.

Tidal Mixing

Mixes water column, enriching surface with nutrients.

Critical Depth Theory

Cells below critical depth lose carbon, negative NPP.

Seasonal Bloom Forcing

Winter mixing brings nutrients; spring stratification enhances NPP.

Global Ocean NPP

Accounts for 46% of global net primary production.

Pelagic Environment

Water column habitat, includes plankton and nekton.

Benthic Environment

Seafloor habitat, includes coral reefs and intertidal zones.

Holoplankton

Organisms living entire life in fluid suspension.

Meroplankton

Organisms only partially living in fluid suspension.

Prey Size Rule

Optimal prey size is 1/10 of consumer size.

Exploitation Efficiency

Consumer's ability to find and capture prey.

Gross Production Efficiency

Efficiency of converting ingested prey into biomass.

Diel Vertical Migration

Zooplankton migrate to surface at night.

Bioluminescence

Short-term light emission to deter predators.

Oligotrophic

Low nutrient concentration in pelagic environments.

Eutrophic

High nutrient concentration in coastal upwelling zones.

Prochlorococcus

Main primary producer in oligotrophic oceans.

Carbon Cycling Pump

Process of carbon transport via biological activity.

Rocky Intertidal Zones

Habitats characterized by tidal fluctuations.

Zonation

Distinct bands of species in intertidal zones.

Vertical Zonation

Species arranged by height in intertidal zones.

Physical Stresses

Environmental factors limiting species distribution.

Desiccation

Drying out due to exposure to air.

Ambush Strategy

Predators wait for prey to approach.

Cruising Strategy

Active pursuit of prey by predators.

Escape Response

Behavioral reaction to avoid predation.

Schooling

Group behavior for protection against predators.

Trophic Cascade Effects

Changes in ecosystem structure due to predator removal.

Anthropogenic Sound

Human-made noise affecting marine life.

Odontocetes

Toothed whales using echolocation for navigation.

Mysticetes

Baleen whales producing long, low-frequency sounds.

Nutrient Cycling

Movement of nutrients through ecosystems.

Standing Stock

Amount of biomass available at a given time.

Primary Production

Rate of organic matter produced by photosynthesis.

Upper limit physical stress

Maximum environmental stress affecting species survival.

Lower limit biological factors

Minimum biological influences restricting species presence.

Species Diversity Control

Regulation of species variety in rocky intertidal communities.

Physical Disturbance

Environmental changes that affect species distribution.

Intermediate Disturbance Hypothesis

Periodic disturbances enhance species diversity.

Keystone Species

Species with significant community impact relative to abundance.

Pisaster Starfish

Regulates mussel populations in rocky intertidal zones.

Trophic Cascade

Ecological phenomenon where predator removal affects community structure.

Sea Otter-Kelp Example

Otters control urchin populations, preserving kelp forests.

Sunflower Starfish

Predator of sea urchins, influences kelp forest health.

Coral Anatomy

Calcium carbonate structure supporting coral growth.

Zooxanthellae

Symbiotic algae providing energy to corals via photosynthesis.

Coral Nutrition

60-90% nutrition from photosynthetic products.

Coral Growth Temperature

Optimal growth between 26-28°C; restricted 18-36°C.

Coral Light Requirements

Growth limited to 25 meters depth for photosynthesis.

Sweeper Tentacles

Coral structures used to compete for space.

Crown of Thorns Starfish

Predator causing significant coral mortality.

Coral Reef Formation

Process of reef development around sinking islands.

Fringing Reef

Reef developing in shallow waters near new islands.

Barrier Reef

Formed as islands sink and coral grows upward.

Coral Atoll

Submerged island remnants surrounded by coral reefs.

Drowned Coral Reefs

Corals stop growing if submerged too deeply.

Compensation Light Level

Light intensity where NPP equals zero.

Compensation Depth

Depth where ambient light equals compensation light intensity.

Coastal Upwelling

Wind-driven movement of nutrient-rich deep water.

Autotrophs

Organisms using non-organic sources for growth.

Heterotrophs

Organisms consuming previously formed carbon material.

Trophic Level

Nutritional feeding levels in food webs.

Trophic Transfer Efficiency

Efficiency of energy transfer between trophic levels.

Predation

Biological interaction affecting species distribution.

Competition

Struggle for limited resources among species.

Hibernation

State of inactivity during unfavorable conditions.

Trophic Levels

Hierarchical levels in a food chain.

2015-2016 Starfish Die-Off

Disease reduced starfish, increasing sea urchin populations.

Kelp Forest Loss

95% loss in Northern California due to urchin overpopulation.

Human Impacts

Nutrient runoff favors macroalgae over coral.

Eutrophic Conditions

High nutrients increase phytoplankton and starfish larvae.

Overfishing

Removes fish that control macroalgae growth.

Coral Bleaching

Corals expel zooxanthellae due to stress.

Coral Recovery

Possible if stress levels are low.

Temperature Sensitivity

Corals bleach above 1°C increase for weeks.

Mass Bleaching Events

Corals bleach with 1°C rise above acclimated levels.

Global Temperature Rise

Currently 1.1°C above pre-industrial levels.

Great Barrier Reef

Half bleached in 2015; Acropora vulnerable.

Crown-of-Thorns Starfish

Predator of coral, thrives with nutrient runoff.

IPBES 2019 Report

50% coral cover decline in 150 years.

Ocean Acidification

Increased CO2 leads to higher ocean acidity.

Calcium Carbonate Precipitation

Slowed by increased ocean acidity.

Atmospheric CO2 Levels

Current level at 419 ppm, projected 480 ppm.

Coral Survival Scenarios

70-90% decline at 1.5°C warming.

Properties of Water

Hydrogen and oxygen form polar water molecules.

Hydrogen Bond

Attraction between polar molecules' charges.

Solvation Effects

Interactions between water and dissolved substances.

States of Water

Solid, liquid, gas determined by temperature.

Latent Heat of Fusion

80 calories to convert ice to water.

Latent Heat of Vaporization

540 calories to convert water to vapor.

Specific Heat Capacity

Heat to raise 1g water by 1°C.

Heat Capacity Consequence

Oceans absorb 93% of excess heat.