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
NATURAL
CAPITAL
Marine Ecosystems
Ecological
Services
Economic
Services
Climate moderation
Food
CO2 absorption
Animal and pet feed
Nutrient cycling
Pharmaceuticals
Waste treatment
Harbors and
transportation routes
Reduced storm impact
(mangroves, barrier
islands, coastal
wetlands)
Habitats and nursery
areas
Genetic resources
and biodiversity
Scientific information
Coastal habitats for
humans
Recreation
Employment
Oil and natural gas
Minerals
Building materials
Fig. 8-4, p. 165
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 deltaic 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
Climate moderation
Nutrient cycling
Economic
Services
Food
Drinking water
Waste treatment
Irrigation water
Flood control
Groundwater
recharge
Hydroelectricity
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