 Chapter 7  Freshwater  life zones  Marine  Life zones  Chapter 24  Importance of Aquatic Biodiversity  Human impacts  Laws of Protection  Sustainability

 Freshwater -defined as having a low salt concentration— usually less than 1%  Lakes  Ponds  Rivers  Streams  wetlands  Saltwater or Marine  Estuaries  coastlines,  Coral refs  Marshes  mangrove swamps  oceans

 Phytoplankton –free floating cyanobacteria  Zooplankton – primary consumers eat phytoplankton, secondary consumers eat other zooplankton  Nekton – strong swimmers  Benthos – bottom dwellers  Decomposers - bacteria

 Temperature  Access to sunlight  Highest in the upper layer (euphotic zone)  Dissolved oxygen  Produced by photosynthesis  Atmospheric interaction (waves)  Nutrient availability

range in size from just a few square meters to thousands of square kilometers ponds may be seasonal, lasting just a couple of months (such as sessile pools) lakes may exist for hundreds of years or more may have limited species diversity since they are often isolated from one another and from other water sources like rivers and oceans

divided into three different “zones” determined by depth and distance from the shoreline littoral zone limnetic zone profundal zone

warmest since it is shallow and can absorb more of the Sun’s heat sustains a fairly diverse community, which can include several species of algae (like diatoms), rooted and floating aquatic plants, grazing snails, clams, insects, crustaceans, fishes, and amphibians the egg and larvae stages of some insects are found in this zone vegetation and animals living in the littoral zone are food for other creatures such as turtles, snakes, and ducks

near-surface open water surrounded by the littoral zone well-lighted (like the littoral zone) and is dominated by plankton, both phytoplankton and zooplankton plankton are small organisms that play a crucial role in the food chain – most life would not be possible without them variety of freshwater fish also occupy this zone

Plankton have short life spans—when they die, they fall into the deep-water part of the lake/pond much colder and denser than the other two little light penetrates all the way through the limnetic zone into the profundal zone animals are decomposers

Temperature varies seasonally. Summer from 4° C near the bottom to 22° C at the top Winter from 4° C while the top is 0° C (ice) between the two layers is a narrow zone called the thermocline where the temperature of the water changes rapidly with depth

during the spring and fall seasons is a mixing of the top and bottom layers resulting in a uniform water temperature of around 4° C mixing also circulates oxygen throughout the lake many lakes and ponds do not freeze during the winter resulting in the top layer being a little warmer

ice can develop on the top of lakes during winter blocks out sunlight and can prevent photosynthesis oxygen levels drop and some plants and animals may die called "winterkill."

 bodies of flowing water moving in one direction  found everywhere—they get their start at headwaters, which may be springs, snowmelt or even lakes  travel all the way to their mouths, usually another water channel or the ocean

 describes an area of land that contains a common set of streams and rivers  drains into a single larger body of water, such as a larger river, a lake or an ocean

 characteristics change during the journey from the source to the mouth  Source  temperature is cooler at the than it is at the mouth  water is also clearer, has higher oxygen levels, and freshwater fish such as trout and heterotrophs can be found there

 Transition Zone  the middle part of the stream/river  the width/depth increases  Temperature increases  species diversity increases — numerous aquatic green plants and algae can be found

 Mouth  Wider/deeper/slower  water becomes murky from all the sediments that it has picked up upstream  decreasing the amount of light that can penetrate through the water  less light  less diversity of flora  lower oxygen levels  fish that require less oxygen, such as catfish and carp, can be found

 A wetland is any area that is inundated (flooded) or saturated for a certain number of days in a row that add up to 7.5% of the growing season in an area.  Contains:  Water  Hydrophyllic (water loving) plants  Hydric (saturated) soils with low oxygen content

 Wildlife Habitat  Flood control  Sediment filters and erosion control  Water quality  Water supply  Recreation

 Bogs  Pocosin  Fen  Swamps  Forested  Marshes  Tidal  Salt Water Marsh  Non-tidal  Vernal Pools  Fresh Water Marsh

 Extremely flat with poor natural drainage  Thick layers of peat – decomposed organic material  Shrub vegetation is common, pond pines, loblolly and longleaf pines are also present.  Fire adapted

 Fed primarily by rainwater  Acidic  Vegetation varies from mosses and grasses to trees depending on elevation

 Fed by surface and/or groundwater  Water is alkaline (basic)  Usually inhabited by mosses and grasses  Can be a stage in succession from lake to woodland

 seasonal (yearly) marshes that occur in depressions of land  covered with ice and water from winter to spring  dry during the summer and fall. all.  bottom of the pools are made of bedrock or hard clay which keeps the water from leaking out.  Creatures may include the spring peeper, eastern spotted newt, green frog, spotted salamanders

 A shallow wetland with few trees and standing water for most of the year  Not Tidal  Flocks of wading birds, fish, exotic plants, alligators, and numerous invertabrates

 Dominated by trees with few shrubs  water inflow through streams, rivers, and run- off.  Trees have shallow root systems to gain exposure to oxygen.  Common trees include red maple, bald cypress, sweet gum and American elm.  Wood ducks, gray treefrog, wood frogs, barred owls and pileated woodpeckers live in the forested swamp