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

CO2 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

RecreationHabitats 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 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

Economic Services

Climate moderation Food

Nutrient cycling Drinking water

Waste treatmentIrrigation water

Flood control

HydroelectricityGroundwater 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