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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. NATURAL CAPITAL.
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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
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) Coastal habitats for humans Recreation Habitats and nursery areas Employment Oil and natural gas Genetic resources and biodiversity Minerals Scientific information Building materials Fig. 8-4, p. 165
Three Marine Life Zones • Coastal • Open ocean • Ocean bottom
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
NATURAL CAPITAL Freshwater Systems Ecological Services Economic Services Climate moderation Food Nutrient cycling Drinking water Waste treatment Irrigation water Flood control Hydroelectricity Groundwater recharge Transportation corridors Habitats for many species Genetic resources and biodiversity Recreation Employment Scientific information
Lake Age Over Time Oligotrophic Mesotrophic Eutrophic • Rate of aging varies based on basin characteristics: • Geology • Nutrient • Climate • Lake topography • Inflows and outflows
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
Human Impacts on Freshwaters • Regulation • Dams, channelization, levees • Water Abstraction • Irrigation • Diversion • Pollution • Organic • Nutrient loading • Metals and complex compounds