446 Aquatic Ecology Flashcards Preview

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Flashcards in 446 Aquatic Ecology Deck (279)
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61

anthropogenic P, N to aquatic systems lead to

eutrophication
algal blooms
fatal algal toxins
anoxia- loss of diversity/habitat
proliferation of waterborne pathogens
increased chlorination byproducts in drinking water

62

waterborne pathogens especially important in

tropical/subtropical regions, can be related to cholera

63

forms of land-use

agriculture
farming
waste disposal
fertilizer
harvesting
hydrology

64

effects of N,P loading are different

depending on structure of system
shallow vs. deep
large vs. small fish

65

population growth

increasing pop., more mouths to feed, more land-use required, world fertilizer growth, more N,P loading,

66

obtaining N, P for fertilizer

N atmospherically available, easier to obtain. P not atmospherically available, geological nutrient, limited

67

problem with speed of population growth

available, cultivatable agricultural land is NOT increasing, need GMOs to keep up with pop. increase

68

GMOs to keep up w/ pop. increase

rices that can grow through floods - multiple crops/year

69

problem with GMOs that allow us to increase agricultural yield

leaching soil nutrients, more and more fertilizer

70

population growth and water shortage

water hungry plants and animals (and nutrient loading)

71

examples of water hungry crops

70L/apple
3400L/kg rice
140L/cup of coffee
120L/glass of wine
15,500L/ kg of beef

72

changes in atmospheric NH4

30% increase in urea use as fertilizer (1960-1990)

73

observed relationship between N,P and Chl

positively correlated
nitrogen more tightly correlated

74

eutrophication defined as

excessive growth of algae, often associated with bluegreen and other harmful algal blooms

75

determines types of algal bloom

amount of nutrients, composition of nutrients (TN:TP)

76

N:P ratios for different runoff types

unfertilized field N:P 250
forests 75
rainfall 25
manure seepage 9
sewage 5

77

nutrient composition ratio

dependent on where nutrients come from
dictates algal bloom

78

bluegreen algae associated with what nutrient composition

low N:P ratio (towards the manure, sewage deposits)

79

differential response to increased [P] in N limited vs. P limited ecosystem

N limited systems does not respond as strongly to increased P

80

increasing phosphorus concentration =

increased dominance of cyanobacteria

81

other controls on levels and types of algal biomass blooms

seasonality of nutrient inputs (coastal and freshwater ecosystem)
physical properties of receiving system
structure of foodweb

82

N:P ratio as a control in number of red tides

as N:P decreases, #red tides increases, highest below 16
duration of blooms longer when N:P

83

redfield ratio

N:P
16:1

84

increasing nutrient, increasing algal biomass

responses are not proportional in all systems, dependent on structure of foodweb (small vs. large grazers) and physical structure of ecosystem

85

physical lake structure and response to changes in nutrients

deeper lakes can take more 'abuse' before showing response (less likely to become eutrophic)

86

algae harmful to animals, humans

cyanobacteria (bluegreen)
dinoflagellates
some diatoms

87

types of algal toxins

neurotoxins
hepatotoxins
lipo-polysaccharides

88

neurotoxins

alkaloids, b/g algae
cause neurodegenerative symptoms through disruption in communication between neutrons and muscles

89

neurotoxin examples

anatoxin-a, saxotoxin, neosaxotoxins, Nostoc, Anabaena, Oscillatoria, Aphanizomenon

90

hepatotoxins

peptides
affect liver, cause weakness, vomiting, diarrhea, respiratory blockages