Aquatic Ecology- week 2

aquatic ecology

study of relationships in all aquatic environments (freshwater & marine)

what is life not possible without?

water. all living organisms contain large proportion of water.

specific heat capacity of H2O

very high (H2O temp change very little w/input of water). hence H2O forms valuable buffer against changing environmental temp, both H2O within organisms and for aquatic environments

freshwater environment

cover 0.78% of earth's surface. generate 3% net primary production (NPP) and contain 41% world's known fish

Net Primary Productivity (NPP)

The energy captured by producers in an ecosystem minus the energy producers respire

how much earth's surface is covered in freshwater?

0.78%

how much NPP does freshwater generate?

3%

what percentage of world's know fish species is found in freshwater?

41%

transitional environment

have mix of fresh & saltwater

marine

have high salt content. cover 70% earth's surface. account for 97% of earth's H2O supply

what percentage of the earth is covered by marine environment?

70%

what percentage of the earth's water supply comes from the marine environment?

97%

light (sun) freshwater

abiotic factor of freshwater. start of life in all ecosystems. several can affect intensity & length of time ecosystem is exposed to sun

aspect, freshwater

abiotic factor of freshwater. angle @ which light strikes surface of H2O. during day, more light can be absorbed into H2O due to directness of light

season, freshwater

abiotic factor of freshwater. varying seasonal conditions affect which organisms suited to them. affect tides, amount of sunlight, & temp.

location, freshwater

abiotic factor of freshwater. extreme latitudes have 6 mths sun

altitude, freshwater

abiotic factor of freshwater. every 1000 meter above sea level (asl) avg temp drops by 1 degree Celsius. also affects how much oxygen absorbed in H2O

oxygen, freshwater

abiotic factor of freshwater. major factor affecting aquatic communities

salinity, marine

abiotic factor of marine. total salt dissolved in seawater. salinity tolerance is an important limiting factor.

temperature, marine

abiotic factor of marine. species distribution affected by temp. also signals breeding/migration

density, marine

abiotic factor of marine. seawater gets denser as it gets saltier, colder, or both

hydrostatic pressure, marine

abiotic factor of marine. pressure caused by height of H2O

diffusion, marine

abiotic factor of marine. molecules tend move from high to low concentration. also mechanism by which H2O molecules pass through cell membranes (osmosis)

osmosis

Diffusion of water through a selectively permeable membrane

ocean circulation, marine

currents move & mix ocean waters & transport heat, nutrients, pollutants, and organisms

tide, marine

abiotic factor of marine. movement of H2O due to gravitational pulls if sun and moon. also to the rotations of the earth, sun, and moon

autotrophs (plants and bacteria)

convert solar energy via by photosynthesis. make own food.

cyanobacteria

Bacteria that can carry out photosynthesis

primary consumers

feed on plants. example= zooplankton

secondary consumers

feed on primary consumers. example= krill & fish larvae

tertiary consumers

feed secondary. example= fish & sharks

decomposers

attain energy by breaking down dead organic material (detritus). reactions releases elements & compound required by plants

detritus

Dead organic matter

organic matter

play part altering an ecosystem. drawn into ecosystem by various sources (absorption by plants; decomposition)

lenctic

freshwater ecosystem. slow moving water. pools, ponds, & lakes

lotic

freshwater ecosystem. faster moving water. streams and rivers

wetlands

freshwater ecosystem. areas static water where ground water saturated for @ least part of time

how many recognized transitional ecosystems are there?

5

salt marshes

transitional ecosystem. zone between land & open saltwater/brackish water that's regularly flooded by tides.

mudflats

transitional ecosystem. coastal wetlands found in intertidal areas where sediments been deposited by tides or rivers

swamps

transitional ecosystem. forested wetland may have fresh H2O, brackish H2O, or seawater

brackish water

mixture of fresh and salt water

mangroves

transitional ecosystem. salt tolerant trees or forests that grow in coastal saline or brackish H2O

estuaries

transitional ecosystem. partially enclosed coastal body of brackish H2O. rivers/streams flow into it & have free connection to open sea

how many types of marine ecosystems?

2

near shore

marine ecosystem. lagoons. intertidal zones. neritic zones. coral reefs. seagrass meadows

neritic zones

regions that extend past the intertidal zone until you reach the edge of the continental shelf

off shore

marine ecosystem. surface ocean. pelagic zone. hydrothermal vents & cold seeps. deep sea & sea floor.

aquatic zones

life is influenced by temperature. access to sunlight for photosynthesis. dissolved oxygen content. availability of nutrients

how many freshwater zones are there?

4 main

littoral

freshwater zone. topmost zone that borders shore of lake or pond.

limnetic

freshwater zone. near surface open H2O surrounded by littoral zone

profundal

freshwater zone. deep water part of lake/pond

benthic

freshwater zone. bottom sediment layer. lake or pond floor. shallow ponds & lakes tend not have benthic zone

how many marine zones are there?

4

intertidal

marine zone. ocean meets land. sometimes submerged and other exposed as waves & tides come in and out

pelagic

marine zone. offshore water. surface and open ocean

abyssal

marine zone. deep, deep ocean. dark, cold, high pressure, and oxygen deficient water