Aquatics Ecology meet 2012

Aquatic EcologyEpilimnion: Winds tend to keep the surface water mixed,

and this upper region of the lake is called the Epilimnion.

Thermocline: Below the mixing action of the wind and the penetration depth of the solar radiation, a strong temperature and accompanying density gradient develops; this region is called the thermocline.

Hypolimnion: The bottom region of the lake

Stratification: layers of water

Metalimnion: is the transition zone between the warm and cold water of the lake

Isothermal: if the water temperature of the lake is the same throughout

*From packetKnowing the vertical stratification in a lake provides a

better understanding of how lakes work in terms of chemistry, physics, and biology.

Dimictic: lakes that stratify twice a year; once in the winter and once in the summer

Monomictic:Lakes that stratify once a year

Amictic: Thermally stratified but doesn’t mix; ice cover protects lakes from mixing by the wind.

Polymictic: Frequently mix (Most shallow lakes frequently mix)

Meromictic: the top of the lake mixes, but it has a deep layer of nonmixing water

Wetlands

Wetlands Estuary: Where fresh and saltwater mix

Salt marshes are generally found along the edge along the ocean

Inland wetlands can usually be found along rivers and streams, in depressions surrounded by dry land, and along the edges of lakes and ponds.

Inland wetlands include: marches, wet meadows, shrub swamps or wooded swamps

Some wetlands are hard to identify, due to the fact that they are dry during part of the year, or it’s hard see the moisture from a distance

All wetlands share 3 common characteristics: 1) Hydrology: Wetlands are periodically flooded with water 2) Soil: They have unique hydric soils(saturated most of the year 3) Vegetation: Wetlands support hydrophytes (plant species

adapted to wet conditions

Wetlands In the past, wetlands were considered wastelands- the source of

mosquitoes, flies, diseases, and gross odors. As a result, more than ½ of America’s original wetlands were destroyed: drained for farmland, filled for residential and commercial use, and converted to landfills.

Through research, scientists know that wetlands are a valuable natural resource that provide many important benefits to people and wildlife; they improve water quality, reduce flood and storm damage, provide important habitat for fish/wildlife, and support recreational activities.

Wetlands are in most counties and climatic zone in the US

Wetlands are on every continent except Antarctica

Wetlands are among the most productive ecosystems in the world, comparable to rain forests and coral reefs

Physical and chemical features, such as climate, landscape shape, geology, and the movement and abundance of water, help to determine the plants and animals that can inhabit each wetland

Wetlands Detritus- dead plant leaves and stems broken down in the water

to form small particles of organic material

Wetlands play an integral role in the ecology of the watershed: the combination of shallow water, high levels of nutrients, and primary productivity, is ideal for the development of organisms at the base of the food web

Many species of birds and mammals rely on wetlands for food, water, and shelter, especially during migration and breeding

Wetlands store carbon in their plant communities and soil instead of releasing it to the atmosphere as carbon dioxide; thus, wetlands help moderate global climate conditions

Data from status and trends provide important long-term trend info about specific changes and places and the overall status of wetlands in the US

Water PollutionOver 2/3rds of earth’s surface is covered by water

With our growing population, we are putting more pressure on Earth’s water resources

Our oceans, rivers, and other inland waters are being squeezed by human activities- not so they take up less room, but so their quality is reduced.

Poorer water quality= Water pollution

Pollution is a human problem, because it’s a relatively recent development in history.

Water pollution is all about quantities

Water Pollution Surface waters- oceans, lakes and rivers

Groundwater- water stored underground in aquifers

Point source pollution- you know EXACTLY where the pollution came from

Non-point source pollution- pollution from many scattered sources

Transboundary pollution- pollution in one place has an effect hundred or thousands of miles away

Two ways of measuring water quality: Chemical indicators- if chemicals are too high Biological indicators- what fish live in the water

Atmospheric deposition- chemicals released into the air and then fall back to earth in rain/acid rain entering seas, rivers, and lakes, causing water pollution

Water Pollution What are the causes of water pollution?

Sewage Nutrients Waste water Chemical waste Radioactive waste Oil pollution Plastics Alien species- animals/plants from one region that have been introduced into an

ecosystem where they don’t belong. Thermal pollution- from factories/power plants cause problems by raising

temperature, it reduced amount of dissolved oxygen in the water Disruption of sediments(Fine-grained powders) that flow from rivers into the sea;

Dams can reduce the sediment flow, which reduces formation of beaches and increases coastal erosion, and reduces the flow of nutrients from rivers to seas

How can we stop water pollution? Education Laws Economics

Fish Anatomy Fish are cold-blooded, and have fins and a backbone.

The caudal fin (tail fin) is the main fin for moving forward

The dorsal(On top of fish) and anal(On bottom of fish) fins primarily help fish not to roll over onto their sides

The paired fins (Fins on the sides) help steer, stopping and hovering of the fish

Ctenoid scales- jagged edges

Cycloid scales- smooth, round edges

Ctenii- tiny, comb-like projections on the exposed edge of ctenoid scales

Operculum- gill cover

Piscivorous- eats mostly other fish

Fish Anatomy Lateral line- a sensory organ consisting of fluid filled sacs with hair-like

sensory apparatus that are open to the water through a series of pores

Lateral line primarily senses water currents and pressure, and movement in the water

The vent is the external opening to digestive urinary and reproductive tracts

Fish swim by contracting and relaxing a succession of muscle blocks, called myomeres, alternately on each side of the body

Otoliths- hard, calcium carbonate structures located directly behind the brain of bony fish

The age data gathered from otolith examinations allow scientists to model growth rates, max age, age at maturity, and trend of future generations

3 types of otoliths, all of which aid fish in balance and hearing Sagitta- larges of the 3 otoliths; involved in detection of sound and

process of hearing, or converting sound waves into electrical signals Asteriscus- involved in the detection of sound and the process of hearing Lapillus- Involved in the detection of gravitational force and sound

Aquatic Food Web Chlorophyll- green chemical in plants that capture energy from the

sun to make sugars

Photosynthesis- The process by which green plants and some other organisms use sunlight to synthesize sugars from carbon dioxide and water.

Respiration- opposite of photosynthesis

Trophic levels- food levels

Nutrient cycling- continuous cycle of nutrients through an ecosysem

Carbon cycle- movement of carbon through the ecosystems

Extirpated- be no longer (in an ecosystem)

Aquatic Food Web Biomagnification-Tendency of organisms to accumulate certain

chemicals to a concentration larger than that occurring in their inorganic, nonliving environment, such as soil or water, or in the case of animals, larger than in their food.

Ecotoxicology-The study of the effects of toxic chemicals on organisms and ecosystems. Ecotoxicology considers both direct effects of toxic substances and also the indirect effects caused, for example, by changes in habitat structure or the abundance of food.

Food-web accumulation-Tendency of certain chemicals to occur in their largest concentration in predators at the top of the ecological food web. As such, chemicals such as DDT, PCBs, and mercury in the aquatic environment have their largest concentrations in predators, in comparison with the non-living environment, or with plants and herbivores.

Hyperaccumulation-A syndrome in which a chemical is bioaccumulated to an extraordinary degree.