newdefspart2 Flashcards
(40 cards)
why are marine aquatic systems important?
salwater ecosystems are irreplaceable reservoirs of biodiversity & provide major ecological & economic services
what is the view from a land dweller of aquatic wilderness
distorted/limited view –know more about surface moon than ocean
Natural Capital - ecological services marine ecosystems provide
bidiversity (species, genes), habitats/nursery, climate moderation, CO2 absorbtion (nutrient cycling), reduced storm impact (mangroves, barrier islands, coastal wetlands)
Natural capital - economic services marine ecosystems provide
Food, transportation, coastal habitat humans, pharmaceuticals, employment, recreation, natural resource–nonrenewable oil /gas.
what are the 3 major life zones
coastal zone, open sea, ocean bottom
coastal zone
warm, nutrient rich , shallow water extends high-tide mark on land to sloping shallow edge of continential shelf
continental shelf
submerged portion continent)
what % does the coastal zone make up
makes up 10% world’s ocean, but contains 90% marine species,
what does productivity depend upon
Productivity depends on a number of factors, including (1) the total amount of sunlight the biome receives, (3) rainfall during the growing season, (2) temperature, (3) variability in climate, (4) number of species living there (more species means more productivity 5) nutrient availability (nitrogen)
primary productivity
the amount of organic matter (or fixation of energy) produced from solar energy in a given area for a given period of time by autotrophs. 2) rate of generation of biomass in an ecosystem
estuaries and costal wetlands are highly ____
productive
estuaries
where rivers meet sea–partially enclosed bodies water where seawater mixes with freshwater as well as nutrients & pollutants from streams, rivers and run off land
coastal wetlands
land along a coastline-extending inland from an estuary that is covered with salt water all or part of the year: marshes (salt), bays, lagoons, tidal flats, mangrove swaps (compared to inland wetlands)
inland wetland
land away from the coast, (swamp, marsh, bog, that is covered all or part of time with freshwater.
marsh
an area of low-lying land that is flooded in wet seasons or at high tide, and typically remains waterlogged at all times.
tidal flats
Tidal flats are sand or mud areas found in many estuarine areas and typically lack recognizable plant life
why are coastal wetlands earths most productivie ecosystems?
high nutrient inputs from rivers and nearby land, rapid circulation of nutrients by tidal flows, ample sunlight penetrating shallow waters.
why are sea grass beds important part of marine biodiveristy
they are present in low marineand estuarine areas along most continental coastlines. Highly productivive help stablize shorelines and reduce wave impacts
why are coastal ecosystems so harsh
Life must adapt to 1. daily/seaonal changes in tidal&river flows, water temp, salinity, and runoff eroded soil sediment (other pollutants) from land. Some ecosystems hav elow plant diversity composed of few species that can withstand dail/seaonal variations.
mangroves where found how work
70% sandy sloping coastlines tropical & subtropical regions -esp Australia and SE Asia. They can grow in saltwater extensive root systems that often extend above water –where they obtain oxygen and support trees during periods changing water levels
what is value of coastal aquatic systems in terms of ecological and economic services
improve water quality: filter toxic pollutants, excess plant nutrients, sediments. Provide food, habitat, nursery sites for aquatic and terrestrial species. Reduce storm damage and coastal erosion (absorb waves and storing execess water produced by storms/tsunames). Timber + fuelwood. Loss leads-polluted drinking water from inland intrustion of saltware into aquifers that supply clean freshwater. lost 1/5 b/t 1980 & 2005
how are tides produced
gravitational pull moon & sun causes tides to rise & fall every 6 hrs most coastal areas
intertidal zone
are of shoreline b/t low & high tides
why is intertidal zone so harsh for organisms
must avoid swept away/crushed by waves, immersed during high tide, left high/dry low tides (and hotter). Changing salinity (heavy rains dilute saltware). To deal, they hold on, dig in, add protective shells.