Lecture 5

hardtofindcurtainUrban and Civil

Nov 16, 2013 (3 years and 6 months ago)

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Aquatic Biodiversity


Ocean 91%

of all water


Polar ice caps and glaciers 2.3%


Lakes, streams, and rivers 2.8%


Rest

largely groundwater


Aquatic Biota


Plankton


live in
water column


Nekton


active
swimmers in water
column


Benthos


live on or in
bottom sediments

Fig. 8
-
4, p. 165

Marine Ecosystems

Economic
Services

Climate moderation

Food

CO
2

absorption

Animal and pet feed

Nutrient cycling

Pharmaceuticals

Harbors and
transportation routes

Waste treatment

Reduced storm impact
(mangroves, barrier
islands, coastal
wetlands)

Coastal habitats for
humans

Recreation

Habitats and nursery
areas

Employment

Genetic resources
and biodiversity

Oil and natural gas

Minerals

Scientific information

Building materials

Ecological
Services

NATURAL
CAPITAL

Three Marine Life Zones


Coastal


Open ocean


Ocean bottom

Differences in diversity
and life histories

Coastal Zone


Book = “harsh”


Spatial and temporal
variation in abiotic
conditions


High diversity (10% of
ocean area, 90% of marine
species)


Among most productive
environments


Most commercial fisheries
(60% human pop along
coast and estuaries)


Why diverse?


Estuaries


Critical Habitats


Junction of river and
ocean (can be
expanded to other
aquatic environments)


Nutrient and sediment
inputs


highly
productive


Important nursery
and productive
hotspot

Estuaries


Threatened Habitats


Loss sediment inputs


Nutrient loading


Channelization


River regulation


Development


Also, Chesapeake Bay
(p. 172
-
173)

Mississippi River
d
eltaic fan

Threats not limited to coastal zone


Many continental shelf
fisheries replaced with
deepwater

fisheries
(600


1800 m)


Example


orange
roughy


Slow growing


Slow population
growth (delay to
reproductive maturity

Fig 8
-
12

NATURAL CAPITAL

Freshwater Systems

Ecological
Services

Economic
Services

Climate moderation

Food

Nutrient cycling

Drinking water

Waste treatment

Irrigation water

Flood control

Hydroelectricity

Groundwater
recharge

Habitats for many
species

Transportation
corridors

Genetic resources and
biodiversity

Recreation

Scientific information

Employment

Lake Biodiversity

Lake Age Over Time

Oligotrophic

Mesotrophic

Eutrophic

Rate of aging varies based on basin characteristics:


Geology


Nutrient


Climate


Lake topography


Inflows and outflows

Steams and Rivers

This is a general pattern, but is an oversimplification
of the dynamics of streams and rivers (river networks)

It is not where you are
on a longitudinal
gradient (e.g., river
continuum concept)


Hydrological and
geomorphological
character of the area of
interest determines:



Nutrient and sediment
storage and transport


Ecological structure
and function

Thorp et al. (2008). Riverine Ecosystem Synthesis

Not all Rivers Find Their Way to the Ocean

Human Impacts on Freshwaters


Regulation


Dams, channelization, levees


Water Abstraction


Irrigation


Diversion


Pollution


Organic


Nutrient loading


Metals and complex compounds