Marine Bio Chapter 10

Abiotic factors

Non-living physical factors: salinity, substrate, temperature, light

Community

A kelp forest plus all the organisms living in it

Exponential growth

Slowed by reduced light and nutrients, or more predators

Competition

Interaction where one organism uses a scarce resource at another's expense

Competitive exclusion

When one species overcompetes and eliminates another

Ecological niche

A species' role in the community plus all biotic and abiotic factors

Predation

An animal eating any other organism

Coevolution

A limpet evolving behavior to escape a sea star predator

Mutualism

Zooxanthellae living in coral tissues, both organisms benefiting

Cleaning symbiosis

Symbiosis because the partners have coevolved into a close association

Autotrophs

Synonym for primary producers

Food webs

More complex than food chains; show interconnected feeding relationships

Trophic level above primary producers

Primary consumers

Tertiary consumer

A carnivore

Energy transfer between trophic levels

About 10% passes to the next level

Pyramid of biomass

Shows the weight of organisms in each trophic level

Detritus

Dead organic matter in the water

Decomposers

Release nutrients to be used by autotrophs

Net primary productivity

Biomass created by producers after energy lost to metabolism

Dark bottle experiment

The dark bottle measures respiration

Chlorophyll in water

A direct estimate of the standing stock of phytoplankton

Carbon cycle role of seaweeds and plants

Decrease dissolved carbon dioxide via photosynthesis

Nitrogen fixation at sea

Performed by cyanobacteria

Sessile organisms

Part of the benthos

Subtidal zone

Between the intertidal zone and the edge of the continental shelf

Competitive exclusion factors

Affected by resource abundance, habitat disturbance, temperature changes

Self-regulation

Acts only when the population is large

Intraspecific competition

Two clownfish in a population using the same anemone

Carrying capacity

The number of individuals a habitat can support with available resources

Competitive exclusion outcome

One species is a better competitor for resources

Disadvantage of resource partitioning

Size of competing populations may decrease

Coexistence in a salt marsh

Fish and snail share the same habitat but different niches

Trophic

Refers to feeding

Trophic cascade

A chiton boosts coralline algae by eating its competitor

Inducible defense

Algae producing chemical defenses after being grazed

Benthic organisms

Most likely found in the neritic zone

CO2 deposition in oceans

Large amounts stored chemically as calcium carbonate

Loss of marine habitats

Increases vulnerability because these habitats store carbon and provide breeding and nursery areas

Ocean acidification

Rising atmospheric CO2 dissolves into the ocean, making water more acidic

Reactive nitrogen

About 70% in the environment comes from human activities

Ozone

Harmful in the stratosphere; a natural layer in the lower atmosphere protects us from UV radiation

Pollock overfishing cascade

Killer whales switched from seals/sea lions to sea otters, reducing sea urchins and kelp forests

Climate change action

The only way to avoid the worst impacts is to take strong action now

Weather

Short-term conditions over days, months, or maybe a year or two

Climate

Long-term average conditions over decades or longer