Final Flashcards
Nutrient cycle is thought to be limited in marine ecosystems compared to terrestrial ecosystems?
Nitrogen-nutrient
Nutrient cycle is the basis for most of the biomass in all ecosystems?
Carbon-nutrient
How does the flow of energy through the food web affect an ecosystem ?
Determining how much energy is available for organisms at higher tropic levels
Niche
Organism’s role in its habitat
Microhabitat
Exists on a very small scale
Habitat
The area and conditions in which you find an organism
Population
Group of the same species living and interacting in a community
Community
Collection of different organisms living and interacting in an ecosystem
Ecosystem
Physical boundaries, energy source, and a community of interacting organisms through which energy is transferred
Ecology
Science that studies how organisms relate to each other and their environment
Compensation depth
Depth at which the oxygen produced by autotrophs = the oxygen they need for respiration
How does light availability affect primary productivity?
Light diminishes with depth, so depth also affects photosynthesis and primary productivity
Limiting factor
Physiological or biological necessities that affect survival
Silicoflagellate
Silica internal supporting structure
Coccilithophore
Calcium carbonate shell
Most primary production in the sea is from
Phytoplankton
What is plankton?
Wide variety of organisms that share habitat and lifestyle
Difference between zooplankton and phytoplankton
Phytoplankton -plants
Zooplankton- animals
Biomass
Mass of living tissue
Standing crop
Mass of living tissue at a given time in an ecosystem
Main “product” of primary production and how is it measured ?
Carbohydrates; grams of carbon per square meter of surface area per year
What two deep-sea ecosystems have primary productivity associated with chemicals emerging from the earth?
Hydrothermal vents
Cold seeps
Stages whale-fall ecosystems go through
1st: scavengers arrive and consume wales soft tissue in a few months
2nd: last about a year eat remaining soft tissue and detritus
3rd: lasts several years or decades and it’s the decay of the whale skeleton
Whale fall
Please where a dead whale comes to rest on the deep ocean floor
What types of organisms are found most commonly in the abyssal zone?
Echinoderms
Meiofauna
What provides nutrients for most of the deep ocean?
Marine snow
Constant fall of sediment, dead organisms, fecal pellets, and other nutrients from the productive shallow water above
Why is there no primary productivity and most of the deep ocean?
No sunlight
What is the northern limit of the Antarctic’s productive seas?
Antarctic Convergence
50-60 degrees south latitude
What makes the Antarctic seas some of the most productive marine ecosystems?
Rich, deep water surfaces to create the largest nutrient-rich area on earth
Where and when do you find the most productivity in the Arctic?
Extremely high productivity occurs along an arc in the North Pacific and across the north Atlantic from April to August
What conditions challenge marine ecosystems in the arctic?
Reduced sunlight under the ice and water that’s barely above freezing
Threats coral ecosystems face
Sedimentation
Coral diseases
Thermal stress (global warming)
Why do coral ecosystems require water that is in moderate motion and free of nutrients?
Prevents sentiments from accumulating on polyps
Can’t photosynthesize
Motion
What marine ecosystem is thought by most scientists to be the most taxonomically diverse?
Coral reefs (diverse but fragile)
How has human hunting of sea otters disrupted the ecological balance of kelp forest ecosystems?
Killing sea otters=more sea urchins=more kelp eaten
How do beaches affect other marine ecosystems?
Works as a giant filter
Caused by coastal erosion
Conditions that challenge organisms in littoral ecosystems
Drying out
Thermal stress
Water motion
Competition
(Between high and low tide)
Greatest challenges to life in supralittoral ecosystems
Drying out
Thermal stress
Water motion
(Only submerged during highest tide)
How do seagrass ecosystems differ from other halophyte based ecosystems?
Don’t have freshwater source
Can exist in deep water
Edible food to inhabitants
How do seagrasses differ from other halophytes?
Reproduce by releasing pollen
Live entirely underwater
No means of extracting fresh from seawater
No freshwater source (internal salinity)
Adaptations that allow halophytes to survive in salt water
Lower:
Salt glands
Pores in the leaves
Upper: sacrificial leaves
How do Upper and lower marsh conditions differ?
Upper: rarely flooded by tides
Lower: flooded by salt water and a regular part of the tidal cycle
Estuaries contribute to the productivity of surrounding marine ecosystems by
Juveniles
Shelter
Nutrients while trapping sediment
What factors limit the productivity of estuary ecosystems?
Wide salinity ranges
Osmotic stress
Variations in salinity tend to reduce species
Eutrophication
Overabundance of nutrients that causes an ecological imbalance
Why do you human activities have wide ranging potential effects on coastal ecosystems?
Living near water
Activities that aren’t obvious (fertilizer/pollutants)
Why are coastal ecosystems generally highly productive?
Benefit from nutrient-rich run off from land
Shelter (diverse and rich)
