Aquatic info Saltwater: AKA marine. 3.5% salt +35 ppm concentration. Brackish water is less salty than marine, but too salty to be freshwater. Places where fresh and salt water meet. Coastal estuaries, seas, few lakes Freshwater: less than 1% salt concentration. <35 ppm Rivers, lakes, ponds, streams. How have fish adapted to fresh and salt water? OSMOSIS REVIEW!!!!!

Aquatic Life - saltwater Plankton: drifting or weakly swimming life forms. Phytoplankton: plant plankton, floating…important? Zooplankton: animal plankton, weak swimming Ultraplankton: photosynthetic bacteria, microscopic.  May be responsible for 70% of primary productivity at ocean surface. Nekton: strong swimming consumers. Fish, turtles, whales Benthos/Benthic: bottom dwellers. Oysters, tube worms, lobsters, Crabs. Decomposers: mostly bacteria that break down dead organic matter.

Where do they fit?

Key Characteristics of Aquatic Ecosystems 1. Less pronounced and fixed boundaries than terrestrial ecosystems. 2. Longer, more complex food chains 3. Difficult to study and monitor because of size and they are hidden from view. 4. Life is found in distinct zones or layers – surface, middle, bottom

Limiting Factors for Life Under water Temperature – gets colder the deeper the water 2. Light – gets darker the deeper the water 3. Dissolved oxygen content 4. Dissolved nutrients such as C, P, and N 5. pH These are the basic measurements of water quality

Oxygen Oxygen a. Enters the system through atmosphere and photosynthesizing organisms b. Is depleted by respiration (fish gills) c. Can vary within an ecosystem due to temperature, number of producers, number of decomposers, and circulation of water

What about respiration rates of fish, DO and temp What about respiration rates of fish, DO and temp? Why do some fish seek cooler water?

What do you think happens to the diversity of critters with depth? DO in relation to depth What do you think happens to the diversity of critters with depth?

DO vs Depth of a lake

DO vs time of the year. Is this true for the whole earth?

Oxygen and Carbon Dioxide a. Enter through atmosphere and respiring organisms. b. Can be depleted by photosynthesizing organisms, organisms using carbonate ions to make shells skeletons, and through sedimentation (rock formation). c. Carbon sink

Where is the water and life at?

In the Zone! Its deep! •Euphotic zone: top layer that sunlight can penetrate.  Pollution, algae, etc, can reduce depth of this zone.  Photosynthesis usually confined to this layer. Higher D.O. levels. •Bathyal Zone: second layer down, “twilight” Typically between 200-1500m. Less animal life than euphotic zone. These animals come to the euphotic zone to feed •Abyssal zone: Extremely deep, below 1500m Few life forms; little D.O. Strange looking creatures!

Horizontal Zones Estuarine zone: places where freshwater meets sea water.  Salt concentrations will vary. Coastal Zones: teeming with life. Area above the continental shelf. Open sea: area beyond the reach of the continental shelf. Intertidal zones: area between high and low tides.

High tide Coastal Zone Open Sea Sun Low tide Sea level Photosynthesis Euphotic Zone Estuarine Zone Continental shelf Bathyal Zone Twilight Abyssal Zone Figure 6.5 Natural capital: major life zones in an ocean (not drawn to scale). Actual depths of zones may vary. Darkness

Found Nemo!! YUM!!!!

Nemo’s House Coral Reef: typically in warm, coastal marine regions.  Filled with life and biodiversity! More than Nemo lives here – 25% of all marine species, 66% of all marine fish species live here. Protect about 15% of coastline from erosion by slowing incoming waves In danger: we’ve lost 25% of coral reefs because of coastal development, pollution, overfishing, ocean warming

Coral Reef Can only form in warm, tropical, shallow oceans with stabile high salinity. Required temps: 18 – 30o C (64-86oF) Bleaching can occur at 31o C! Affected by: temperature increases, sedimentation, pollution, floods, storms, predatory fish. Good news: a growing number of coral reefs are now listed as preserves or protected. Artificial reefs…restoration

Coastal reefs

The Great Barrier Reef Aus.

Atoll reefs Found in the South Pacific Sea

Bleaching of coral

Nuke Testing on reefs!

Sunken ships Navy Scraps ships and sinks???

Used tires

Estuaries and Coastal Wetlands: They’re Productive! Estuaries include river mouths, inlets, bays, sounds, salt marshes in temperate zones and mangrove forests in tropical zones.

Mangrove Forests Are found along about 70% of gently sloping sandy and silty coastlines in tropical and subtropical regions.

Estuaries and Coastal Wetlands: Centers of Productivity Estuaries and coastal marshes provide ecological and economic services. Filter toxic pollutants, excess plant nutrients, sediments, and other pollutants. Reduce storm damage by absorbing waves and storing excess water produced by storms and tsunamis. Provide food, habitats and nursery sites for many aquatic species.

Rocky and Sandy Shores: Living with the Tides Organisms experiencing daily low and high tides have evolved a number of ways to survive under harsh and changing conditions. Gravitational pull by moon and sun causes tides. Intertidal Zone: area of shoreline between low and high tides.

Rocky and Sandy Shores: Living with the Tides Organisms in intertidal zone develop specialized niches to deal with daily changes in: Temperature Salinity Wave action

Barrier Islands Low, narrow, sandy islands that form offshore from a coastline. Primary and secondary dunes on gently sloping sandy barrier beaches protect land from erosion by the sea.

Primary Dune Secondary Dune Grasses or shrubs Bay or Lagoon Ocean Beach Trough Back Dune Intensive recreation, no building No direct passage or building Limited recreation and walkways No direct passage or building Most suitable for development Intensive recreation Grasses or shrubs Bay shore No filling Taller shrubs Taller shrubs and trees Figure 6.10 Natural capital: primary and secondary dunes on gently sloping sandy barrier beaches help protect land from erosion by the sea. The roots of grasses that colonize the dunes help hold the sand in place. Ideally, construction is allowed only behind the second strip of dunes, and walkways to the beach are built over the dunes to keep them intact. This helps preserve barrier beaches and protect buildings from damage by wind, high tides, beach erosion, and flooding from storm surges. Such protection is rare because the short-term economic value of oceanfront land is incorrectly considered much higher than its long-term ecological value. Rising sea levels from global warming may put many barrier beaches under water by the end of this century.

Productivity and Aquatic Ecosystems The more light and nutrients available in an ecosystem the more productive Shallow waters with lots of nutrient = high productivity.   Open ocean = low productivity What about deep ocean?