Aquatic Ecosystems Fundamental Division Freshwater Saltwater Aquatic Ecosystems also affected by Dissolved oxygen level, light penetration, pH, presence/absence of currents Three main ecological categories of organisms Plankton- free floating Phytoplankton – photosynthetic Zooplankton – animal-like Nekton - strong swimming Benthos - bottom dwelling

Freshwater Ecosystems Classified as: LOTIC = Flowing waters, includes rivers and streams LENTIC = “still water”, includes lakes and ponds, marshes and swamps (standing water) Fresh water ecosystems represent just 2% of earth’s surface Assist in recycling water back to the oceans and provide critical habitat

Larger streams and rivers Rivers and Streams Headwater streams Larger streams and rivers

Estuaries, deltas, coastal ocean Rivers and Streams Estuaries, deltas, coastal ocean Physical nature of aquatic ecosystems changes significantly

River continuum concept Water moves from headwaters to rivers to coastal ocean Change in physical features and food sources (abiotic differences) Results in change in biological features and ecosystem function In streams, organisms are adapted to fast flowing water (hooks, suctions, flattened bodies) In rivers, organisms are adaptated for swimming (streamlined)

Rivers & Streams Characteristics Headwaters: fast-flowing, many riffles, highly oxygenated, colder, bare rock substrate, low nutrient levels, rapids, waterfalls; typical fish include darters, trout, salmon Mouth: slower, warmer, more meanders, lower oxygen levels, higher nutrient levels, more sediments with clay, silt and sand substrates; typical fish include carp, catfish, etc.

Lakes and Ponds Body of freshwater that does not flow Three zones Littoral Limnetic Profundal Experience thermal stratification (depending on depth)

Lakes and Ponds Littoral Zone - shallow water area along the shore Limnetic Zone - open water beyond the littoral zone Profundal Zone - beneath the limnetic zone of deep lakes

Thermal Stratification Temperature changes sharply with depth Thermocline Temperature transition between warmer surface water and colder water at depth (difference in density) Only present in warm months

Fall Turnover

Wetlands: Marshes and Swamps Land with shallow, fresh water for at least part of the year Characteristic soil and vegetation includes clay & silt (poorly drained); and species adapted to being partly submerged in water

Marsh Characteristics: Marshes are periodically saturated, flooded, or ponded with water and characterized by herbaceous (non- woody) vegetation adapted to wet soil conditions. Marshes are further characterized as tidal marshes and non-tidal marshes.

Tidal Marsh Characteristics: Tidal (coastal) marshes occur along coastlines and are influenced by tides and often by freshwater from runoff, rivers, or ground water. Salt marshes are the most prevalent types of tidal marshes and are characterized by salt-tolerant plants such as smooth cordgrass, saltgrass, and glasswort. Salt marshes have one of the highest rates of primary productivity associated with wetland ecosystems because of the inflow of nutrients and organics from surface and/or tidal water

Salt Marsh Community

Marshes: Nontidal Marshes Nontidal (inland) marshes are dominated by herbaceous plants and frequently occur in poorly drained depressions, floodplains, and shallow water areas along the edges of lakes and rivers. Major regions of the United States that support inland marshes include the Great Lakes coastal marshes, the prairie pothole region, and the Florida Everglades.

Marshes: Nontidal Marshes Nontidal marshes are characterized by freshwater. They typically derive most of their water from surface waters, including floodwater and runoff, but do receive ground water inputs. Other examples of nontidal marshes: Wet meadows commonly occur in poorly drained areas such as shallow lake basins, low-lying depressions, and the land between shallow marshes and upland areas. Precipitation serves as their primary water supply, so they are often dry in the summer. ! Wet prairies are similar to wet meadows but remain saturated longer. Wet prairies may receive water from intermittent streams as well as ground water and precipitation. ! Prairie potholes develop when snowmelt and rain fill the pockmarks left on the landscape by glaciers. Ground water input is also important. ! Playas are small basins that collect rainfall and runoff from the surrounding land. These low- lying areas are found in the Southern High Plains of the United States. ! Vernal pools have either bedrock or a hard clay layer in the soil that helps keep water in the pool. They are covered by shallow water for variable periods from winter to spring, but may be completely dry for most of the summer and fall.

The Everglades Original extent Today, after extensive construction and draining of wetlands Original extent

Swamps: SWAMPS are fed primarily by surface water inputs and are dominated by trees and shrubs. Swamps occur in either freshwater or saltwater floodplains. They are characterized by very wet soils during the growing season and standing water during certain times of the year. Well-known swamps include Georgia’s Okefenokee Swamp and Virginia’s Great Dismal Swamp. Swamps are classified as forested, shrub, or mangrove.

Mangrove Community

Mangrove Forest Locations…

Mangrove forests Tropical equivalent of salt marshes Should cover >70% of coastlines Services Buffers storm energy (saves lives) Nurseries for fish and organisms

Mud Flat Community

Estuaries Where freshwater and saltwater mix Highly variable environment Temperature, salinity, depth of light penetration Highly productive Nutrient transported from land Tidal action circulates water High level of light penetrates shallow water Plants provide photosynthetic carpet Provide abundant habitats and biodiversity

Ecosystem Services of Marshes Swamps, & Estuaries Flood protection Water filtering Groundwater recharging Nutrient sinks, etc. Buffer land from storm energy (Superstorm Sandy) Large cycling of organic matter for coast Habitat (particularly birds) Nurseries for Fish Provide drought relief

Human Impact on Marshes Swamps, & Estuaries Often thought of as useless Drained and developed by humans, often times paved over Fragmented and channelized for shipping lanes (coastal wetlands) Excessive sedimentation due to nearby erosion Excessive nutrient loading due to nearby farming or sewage inputs Pollution (garbage dumped into wetlands, oil spills, etc.)

Protection of ecosystem (organism) services

Marine Ecosystems Subdivided into life zones Intertidal zone Benthic zone Pelagic environment Neritic Province Oceanic Province

Marine Ecosystems

Marine Ecosystems

Intertidal Zone Area of shoreline between low and high tide Biologically productive habitat Stressful habitat Splash zone Wave action Flooding Drying out

Intertidal Zone Area of shoreline between low and high tides Habitat Sandy or rocky Mussels Crabs Algae Oysters Barnacles Animals must adapt to changing conditions

Benthic Zone Ocean floor, extending from tidal zone to deep sea trenches Sediment is mostly mud Burrowing worms and clams Three zone Bathyal: 200m – 4000m deep Abyssal: 4000m – 6000m deep Hadal: 6000m – bottom of deep sea trenches

Productive Benthic Communities Seagrass Beds Present to depth of 10 m Provide food and habitat to ecosystem Kelp Forest 60-m long brown algae found off rocky shores Large Biodiversity Coral Reefs (essential fish habitat in ocean) Built from accumulated layers of CaCO3 Colonies of millions of tiny coral animals Similar to upside down jelly fish Found in shallow warm water Most diverse of all marine environments

Productive Benthic Communities Left: Seagrass Bed Right: Kelp Forest

Coral Reef Environments Three types of coral reefs Fringing reef - directly attach to continent- no lagoon Atoll - circular reef in a lagoon Barrier reef - separates lagoon from ocean

Distribution of Coral Reefs

Human Impact on Coral Reefs Sedimentation From clear-cutting, coastal construction Overfishing, destructive fishing Coral bleaching (stress condition) Mining of corals as building materials Runoff and sewage pollution Ocean acidification and rising sea temperatures

Pelagic Environment All the open ocean water Main divisions based on depth and light penetration Euphotic zone Surface to 150m Sufficient light for photosynthesis Organisms are all floaters or swimmers

Pelagic Environment Neritic Province Organisms are floaters or swimmers (zooplankton, whales) Water that overlies the continental shelf (to depth of 200m)

Pelagic Environment Oceanic Province Water that overlies depths greater than 200 m Organisms are filter feeders, scavengers and predators No light for photosynthesis, organisms adapted for darkness Marine snow (food particles falling from euphotic zone) support some life Hydrothermal vent communities in deep ocean support life too

National Marine Sanctuaries Protected areas in worlds oceans NOAA administers in U.S. “no take” and other restrictions for use

Human Impacts on the Ocean