Presentation on theme: "Aquatic Ecology: Biodiversity in Aquatic Systems."— Presentation transcript:
Aquatic Ecology: Biodiversity in Aquatic Systems
Two Types of Aquatic Zones Marine (saltwater) Freshwater Estuaries Coastlines Coral reefs Coastal marshes Mangrove swamps Oceans Lakes and ponds Streams and rivers
Main types of organisms in aquatic life zones: Phytoplankton– plant plankton—microscopic photosynthesis organisms. Zooplankton—animal plankton– nonphotosynthetic primary and secondary consumers range from single- celled to large invertebrates. Nekton—strong swimming consumers such as fish, turtle, and whales. Benthos—bottom dwellers Decomposers—mostly bacteria
Characteristics of Aquatic Life Zones Less pronounced and fixed physical boundaries than terrestrial ecosystems. More complex and longer food chains and food webs More difficult to monitor due to their size and because they are largely hidden from view.
In addition to salinity levels, the most important abiotic factors in aquatic life zone are: 1. Sunlight for photosynthesis. Photosynthesis is confined mostly to the upper laver, or euphotic zone.
2. Temperature 3. Dissolved oxygen (DO)—most fist die when the dissolved oxygen levels fall below 5 ppm. Factors influencing DO levels include: Temperature Number of producers (add oxygen) Number of consumers and aerobic decomposers (remove O 2 ) 4. Availability of nutrients
Special Aquatic Life Zones: Estuaries—An ecotone between the marine environment and the land where large volumes of fresh water from land and salty ocean water mix. Intertidal Zone—the area between high tide and low tide; changing moisture and salinity levels, numerous ecological niches.
Special Aquatic Life Zones: Coral reefs—form in clear, warm coastal waters of the tropics and subtropics. Among the world’s oldest, most diverse, and productive ecosystems. Home for about one-fourth of all marine species. Often called the (Rainforest of the Sea) Vulnerable to damage because they: Grow slowly Are disrupted easily Corals can live only in water temps. of 18-30 deg. C. (64-86 F)
Standing water—lakes and ponds Flowing water—streams and rivers
Freshwater Lakes Classified according their nutrient levels. Oligotrophic—young, deep lake with low nutrient levels and limited food. Eutrophic—old, more shallow lake with high nutrient levels and complex feeding relationships. Mesotrophic –fall between the two extremes.
Cultural eutrophication—occurs when human activities speed the eutrophication processes. Nutrients in runoff are carried into a lake causing a rapid increase in algae growth that then die and decay. Aerobic bacteria causing the decay of the plants, remove large amounts of oxygen causing the death of many other species.