Aquatic life Unit 1, Topic 2

1 Aquatic habitats Vary in characteristics Streams Rivers Ponds Lakes Vernal pools

2 Aquatic flora Ecological requirements Types: Sunlight, carbon dioxide, oxygen, nutrients, space Microscopic photosynthetic protists Macroscopic photosynthetic protists Plants

3 Aquatic fauna Ecological requirements Types: –Microfauna (microscopic plankton) –Macrofauna (invertebrates and vertebrates) Oxygen, space, plants, habitat, tolerance limits

4 Microfauna

5 Macroinvertebrates Worms Insects Molluscs

6 Vertebrates Amphibians Reptiles Fish Birds Mammals

7 Indicator Species: Biological Smoke Alarms Species that serve as early warnings of damage to a community or an ecosystem. –eg: Presence or absence of trout species in freshwater bodies because they are sensitive to temperature and oxygen levels.

8 Indicator species: Amphibians Frogs serve as indicator species because different parts of their life cycles can be easily disturbed. Figure 7-3

9 Why are Amphibians Vanishing? Habitat loss and fragmentation. Prolonged drought. Pollution. Increases in ultraviolet radiation. Parasites. Viral and Fungal diseases. Overhunting. Natural immigration or deliberate introduction of nonnative predators and competitors.

10 Invertebrate indicators Macroinvertebrates are good measures of longterm water quality Broadly classify as “sensitive”, “somewhat tolerant”, and “pollution tolerant” Scenarios: –We only find organisms that are “tolerant”. What can we definitively say about the longterm water quality? –We find numerous individuals of a species that is “sensitive” to pollution and many individuals of various species that are “tolerant”. What can we definitively say about the longterm water quality?