L3 - Marine Ecology Flashcards
What is ecology?
The branch of biology that studies the relationships between living organisms and their environments.
What factors influence organisms?
Growth, abundance, distribution, fecundity.
The factors affecting the organism are either?
Biotic or Abiotic
What does Biotic mean? Example?
How organisms affect each other. Predation, facilitation, mutualism, competition
What does Abiotic mean? Example?
Physical and chemical factors. Temperature, salinity, waves, water pressure
What are the interactions between abiotic and biotics factors?
They are complex and involve the organism and its habitat. Effects are often context-specific
Define community?
All populations of organisms living in a defined area
Define habitat?
The physical place where an organism lives
Define niche?
The resources that an organism uses to grow, survive and reproduce and the role it plays in its environment.
Define ecosystem?
A biological community of interacting organisms and their physical environment
How do populations grow?
In practice, all populations are limited by the availability of at least one resource. When the resources limit the size of a population in a given area, we call this the carrying capacity (often called k)
In what ways does growth in populations differ?
Different strategies for reproduction : R versus K selected species
What are characteristics of r-selected species?
Large no. of offspring, little or no parental care, low juvenile survivorship, early sexual maturity, short life expectancy, small, often unstable environments
What are characteristics of k-selected species?
Small number of offspring, high parental investement, high juvenile survivorship, later maturity, longer-lived, large, often stable environments
What are most marine lifestyles?
Pelagic & Benthic
What are some pelagic organisms?
Neuston, Nekton, Plankton
What are some benthic organisms?
Benthos
Where do Benthos marine organisms live?
Live on, or buried in, the seafloor, might be sessile or mobile.
Where do Neuston, Plankton, Nekton marine organisms live?
Live in the water column
Where do Plankton marine organisms live?
Drift at the mercy of currents, e.g. phytoplankton, zooplankton
Where do Nekton marine organisms live?
Can swim against the current (but can be benthic)
Where do Neuston marine organisms live?
Live on, at or near the surface, sometimes under their own movement, sometimes at the mercy of e.g. winds
What are major subdivisions of the marine environment based on?
Distance to land, water depth, whether organisms are benthic or pelagic
What are continental margins of ocean basins?
The boundaries between continental and oceanic crust
Pelagic - what is the neritic zone?
Above the continental shelf
Pelagic - what is the oceanic zone?
Above the deep sea ; beyond the shelf break. Further divided by how much light can reach a certain depth
Pelagic - what are the three subdivisions of the oceanic zone?
Epipelagic, Mesopelagic, Bathypelagic and below
Pelagic - oceanic zone, what is the subdivision epipelagic?
Photic zone
Pelagic - oceanic zone, what is the subdivision mesopelagic?
Light, but not enough to support photosynthesis
Pelagic - oceanic zone, what is the subdivision bathypelagic?
Constant darkness
Benthic - what is the intertidal zone?
Also called the littoral zone, exposed to air in when the tides go out
Benthic - what is the subtidal zone?
The continental shelf below the intertidal (always submerged). Sometimes referred to as the sublittoral zone
What is another Benthic environment?
Deep-sea floor - Bathyal, Abyssal, Hadal. Abyssal
Food webs are ….?
Very complex
What are energy flows?
The transfer of energy and matter (e.g. nutrients) gives rise to trophic structure (food webs/chains/pyramids).
What are the two broad categories of organisms?
Autotrophs and Heterotrophs
What are autotrophs?
Primary producers (they make the food). Usually use photosynthesis (e.g. algae and plants), but some use chemosynthesis (e.g. bacteria at hydrothermal vents)
What are heterotrophs?
Heterotrophs are consumers, not all heterotrophs consume autotrophs
What is the transfer of energy called?
Trophic transfer
How much energy/biomass is passed onto the next trophic level?
10%
