Aquatic Ecology

Saltwater (Marine) Ecosystems Ocean: estuaries & coastal wetlands barrier islands coral reefs mangroves Freshwater Ecosystems lakes rivers & streams wetlands

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

Factors Affecting Aquatic Ecosystems Light (solar radiation) decreases with depth because of absorption by water, suspended materials, & phytoplankton; essential for photosynthesis Turbidity (cloudiness) effects light Temperature decreases with depth because of decreasing energy input from sun; affects dissolved gases, rates of chemical reactions, & where organisms can live;

Dissolved oxygen- factors that affect DO Temperature – less dissolved gasses at warmer temperatures. Rate of production through photosynthesis Rate of consumption through cellular respiration Pressure Nutrient availability most limiting macronutrients are phosphorus (P) & nitrogen (N); limiting micronutrients include iron (Fe); essential for growth of phytoplankton. Factors Affecting Aquatic Ecosystems Cont.

Low tide Coastal Zone Open Sea Depth in meters High tide Sun Sea level 50 Estuarine Zone Euphotic Zone 100 Photosynthesis Continental shelf 200 Bathyal Zone 500 1,000 Twilight 1,500 Water temperature drops rapidly between the euphotic zone and the abyssal zone in an area called the thermocline. Abyssal Zone 2,000 3,000 4,000 Darkness 5,000 10, Water temperature (°C)

Changes in Temp., O, & N with Depth in Ocean

Nitrate Concentrations High concentrations of nitrates found in areas of: low productivity (in areas of high productivity- nutrients are quickly utilized by living things) High upwellings- upwellings bring cold, nutrient rich H 2 O How do areas of high nitrates along coast of South America relate to weather unit?

Surface Ocean Topography Created by prevailing wind directions and ocean temperature

Life zones of the Ocean Vertical Zones: Euphotic Zone: m Greatest amount of light. (Eu = good, photo = light) Bathyl Zone: m Abyssal Zone: ,000 “marine snow” – dead organisms from above (Abyss= the deep) Hadal Zone: > 6000m

Benthic Zone = Region along bottom of sea Benthos = bottom dwelling sea creature. Pelagic Zone = open sea Region that is not near the shore or close to the bottom.

extends from high–tide mark to edge of continental shelf entirely within the euphotic zone & includes estuaries, wetlands, mangroves, barrier islands, & coral reefs nutrient–rich & the site of most commercial fisheries high primary productivity: sunlight + nutrients from land & ocean currents Coastal Zone of the Ocean

Importance nutrient rich and high primary productivity nurseries for fish & other aquatic animals waterfowl & shorebird breeding areas filter water pollutants Estuaries & Coastal Wetlands Estuary: where seawater mixes with freshwater from land, generally at the mouth of a river Coastal wetland: areas of coastal land covered all or part of the year with salt water Brackish= mix of salt water and fresh

Human Impacts Estuaries & Coastal Wetlands world has lost over half of its estuaries & coastal wetlands percentage lost in the U.S. even higher. Most lost to coastal development causes of degradation: urban runoff, sewage treatment plant effluent, sediment & chemical runoff from agricultural lands

Barrier Islands: long, thin, low offshore islands of sand that run parallel to the shore. They do not remain stationary over time. Importance protect mainland from offshore storms shelter inland bays, estuaries, & wetlands Barrier Islands

Human Impacts Development on barrier islands –destroys dunes & dune vegetation –causes beach erosion (through trying to keep islands in place) –destroys or disturbs wildlife habitat (e.g., some endangered birds nest on barrier islands) Protecting barrier islands –jetties & seawalls –beach replenishment –replanting dune vegetation, controlling development Barrier Islands Ocean City, MD

reefs formed by mutualism between polyps & algae reefs built as colonies of polyps secrete limestone; hard deposits remain when the polyps die reefs located in coastal zones of tropical oceans Coral Reefs

Importance high biodiversity: “tropical rain forests of the ocean” protect coastlines from storms & high waves nurseries for many fish species disappearing Coral Reefs Vulnerability slow growing easily disturbed thrive only in clear water Human Impacts sediment runoff & effluent increased UV radiation (ozone depletion) fishing with cyanide & dynamite

Mangrove Swamps Salt-tolerant trees & shrubs Warm tropical coastal areas Too silty for coral reefs Protect coastlines from erosion, especially during typhoons & floods Trap nutrient-rich sediments Provide habitat for fish, birds, invertebrates, and plants

NATURAL CAPITAL Freshwater Systems Ecological Services Economic Services Climate moderationFood 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

Lakes Littoral zone: shallow area near the shore, to the depth at which rooted plants stop growing. Limnetic zone: open, sunlit, surface layer away from the shore. Depth is the limit of light penetration. Profundal zone: deep, open water where there is no light penetration. Benthic zone: the bottom of a lake; inhabited by insect larvae, decomposers, & clams. Freshwater Ecosystems

Sunlight Painted turtle Blue-winged teal Green frog Muskrat Pond snail Littoral zone Plankton Limnetic zone Profundal zone Diving beetle Benthic zone Northern pike Yellow perch Bloodworms

Thermal stratification: during summer (temperate lakes) epilimnion: warm, upper layer of water thermocline: zone of lake where temperature changes rapidly with depth hypolimnion: colder, denser lower layer of water can be depleted of oxygen in eutrophic lakes LAKES

Overturn: spring & fall (temperate zone lakes) upper layer of water cools and sinks, winds mix layers redistributes oxygen & temperature evenly redistributes nutrients from the lower layers LAKES

Watershed: the land area that delivers water, sediment, & dissolved substances to a water body. Zones source zone: cold, clear, fast–running streams in upper watershed (headwaters) transition zone: middle part of watershed, where streams widens & join, flow slows, water temperature increases flood plain zone: many streams join to form a broad, slow–moving, meandering river in lower watershed Streams & Rivers

Waterfall Lake Glacier Rain and snow Rapids Source Zone Transition Zone Tributary Flood plain Oxbow lake Salt marsh Delta Deposited sediment Ocean Water Sediment Floodplain Zone

Riparian Zone is the zone along a stream or river.

Wetlands Lands covered with fresh water all or part of the time (excluding lakes). Wetland functions wildlife habitat, especially for waterfowl & amphibians filter sediments & pollutants from runoff, “nature’s kidneys” flood attenuation Human impacts: some states have lost over 90% of their wetlands by filling or draining.