Aquatic Biomes Flashcards
1
Q
Photic zone
A
Sufficient light for photosynthesis
2
Q
Aphotic Zone
A
Receieves little light
3
Q
Pelagic zone
A
Made up of the photic aphotic zones
4
Q
Abyssal zone
A
In the aphotic zone with a depth of 2000 to 6000m
5
Q
Benthic zone
A
Organic and inorganic sediment at the bottom of all aquatic zones
6
Q
Benthos
A
The communities of organisms in the benthic zone
7
Q
Detritus
A
Dead organic matter, falls from the productive surface water and is an important source of food
8
Q
Lakes
- Oligotrophic
- Eutrophic
- Littoral zone
- Limnetic zone
A
- Size varies from ponds to big lakes
- Seasonal thermoline in temperature; tropical lowland lakes have a year-round thermocline
- Oligotropic lakes are nutrient-poor and generally oxygen-rich
- Eutropic lakes are nutrient-rich and often depleted of oxygen if ice covered in winter. Have ore surface area relative to depth than oligotrophic lakes
- Littoral zone is shallow and well lit and rooted and floating aquatic plants live close to shore
- Limnetic zone is where the water is too deep and supports rooted aquatic plants
- Zooplankton are drifting heterotrophs that graze on the phytoplankton
- Invertebrates livin the benthic zone
- Fishes live in all zones with sufficient oxygen
- Human induced nutrient enrichment can lead to algal blooms, oxygen depletion and fish kills
9
Q
Wetlands
A
- Habitat that is inundated by water at least some of the time and that supports plants adapted to water-saturated soil
- Have high organic production and decomposition and have low dissolved oxygen
- Can develop in shallow basins, along flooded river banks, or on the coasts or large lakes and seas
- Among the most productive biomes on Earth
- Plants include lilies, cattails, seges, tamarack, black spruce
- Home to diverse invertebrates and birds, otters, frogs and alligators
- Humans have destroyed 90% of wetlands, wetlands purify water and reduce flooding
10
Q
Streams and Rivers
A
- Most prominent physical characteristic of streams and rivers is current. Headwaters are generally cold, clear, turbulent, swift and oxygen rich; they are often narrow and rocky
- Downstream waters form rivers and are generally warmer, turbid and more oxygenated; they are often wide, meandering and have silty bottoms. May contain phytoplankton or rooted aquatic plants
- Diversity of fishes and invertebrates inhabit unpolluted rivers and streams. Pollution degrades water quality and kill aquatic organisms
- Damming and flood control impair natural functioning of stream and river ecosystems
*
11
Q
Estuaries
A
- Transition area between river and sea
- Salinity varie with the rise and fall of the tides
- Nutrient rich and highly productive. includes tidal channels, islands, natural levees and mudflats
- Major producers are saltmarsh grasses and algae. an abundant supply of food sttracts marine invertebrates, fish, waterfowl and marine mammals
- Human consume oysters, crabs and fish
- Human interferene upstream has disrupted estuaries worldwide
12
Q
Intertidal Zones
A
- Periodically submerged and exposed by the tides
- Organisms are challenged by variations in temperature and salinity and by the mechanical forces of wave action
- High oxygen and nutrient levels
- Substrate varies from rocky (many animals have structural adaptation for attaching to the hard substrate) to sandy ( worms, clams, crustaceans bury themselves in sand)
- Other animals include sponges, sea anemones, echinoderms and small fish
- Oil pollution has disrupted many intertidal areas
13
Q
Oceanic Pelagic Zone
A
- Constantly mixed by wind-driven oceanic currents
- High oxygen levels
- Turnover in temperate oceans renews nutrients in the photic zones; year-round stratification in tropical oceans leads to lower nutrient concentrations
- This biome covers approximately 70% of Earth’s surface
- Phytoplankton and zooplankton are the dominant organisms in this biome; also found are free-swimming animals
- Zooplankton includes protists, worms, copepods, krill, jellies and invertebrate larvae
- Other animals include squids, fish, sea turtles marine mammals
- Overfishing has depleted fish stocks
- Humans have polluted oceans with dumping of waste
14
Q
Coral Reef
A
- Formed from the calcium carboate skeletons of corals
- Shallow reef-building corals lie in the photic zone in clear water about 20-30C; deep sea corals libe at 200-1500m
- Corals require high oxygen and a solid substrate for attachment
- Progresses from a fringing reef, barrier reef, then a coral atoll
- unicellular algae live within the tissues of the corals and form a mutualistic relationship that provides the corals with organic molecules
- Fish and invertebrate diversity is exceptionally high
- Global warming and pollution may be contributing to large-scale coral death
- Collecting of coral skeletons and overfishing have reduced populations of corals and reef fishes
15
Q
Marine Benthic Zone
A
- Consists of the seafloor below the surface waters of the coastal or neritic zone and the offshore pelagic zone
- Organisms in the very deep benthic zone are adapted to continuous cold and extreely high water pressure
- Subsstrate is mainly soft sediments; some areas are rocky
- Shallow areas contain seaweeds and filamentous algae
- Deep-sea hydrothermal vents of volcanic origin on mid-oceanic ridges are surrounded by unique chemoautotrophic prokaryotes, as well as echinoderms and arthropods
- Neritic benthic communities include invertebrates and fish
- Overfishing and dumping of waste have depleted fish populations
