Lecture 31- Inland Aquatic Systems

Question 1

What are the types of inland water bodies?

Answer 1

• lentic or lotic
• permanents or temporary
• coastal, mountain or inland
• natural or man made

Question 2

How many algae are found in freshwater?

Answer 2

• 13 divisions
• some are micro and some macroscopic
• some live both in marine and freshwater
• there are 400 genera and 3000 species of freshwater algae in Australia

Question 3

What are the most common macroscopic freshwater algae?

Answer 3

-most common macroscopic forms are filamentous greens

Question 4

Is the Australian freshwater flora very endemic?

Answer 4

-“The tentative conclusions . . . are that the freshwater algal flora of Australia contains a considerable number of endemic species and genera, many of great novelty . . . some
of phylogentic significance”

Question 5

What are the most common algae in freshwater?

Answer 5

• chlorophyta: majority freshwater
• single cells, filaments, colonies
• several macroscopic marine species
• includes stonewarts

Question 6

What are the most abundant microscopic forms in both marine and freshwater?

Answer 6

• dinoflagellates and diatoms

- important primary producers

Question 7

What are the blue-greens algae like and what do they include?

Answer 7

-cyanobacteria= small, some of the earliest organisms to photosynthesize on Earth
-prokaryotic
photosynthetic
-can tolerate environmental extremes
-many fix nitrogen= this is important for us

Question 8

What are the higher plants that you could find in freshwater habitats?

Answer 8

• monocots or dicots
• both in tropical and temperate water
• can draw nutrients from both sediments and water as they have proper root systems
• they can be floating, submerged or emerged
• attached or not
• feathery or leafy

Question 9

What is an example of flowering plants that live in freshwater?

Answer 9

.duckweeds

-stemless, very small leaves, small trailing roots

Question 10

What is a ferns example living in freshwater?

Answer 10

• symbiotic with cyanobacteria
• blue green algae associated with trailing roots
• the azolla provide habitat and shelter
• the cyanobacteria provide nutrients

Question 11

What are some seagrasses living in freshwater?

Answer 11

• paddleweed, genus also marine
• -Zanichellia palustrus: not a seagrass per se but it is threatened in NSW, it has become threatened but no management in place

Question 12

What are some useful aquatic plants?

Answer 12

• Musk grasses/ Stonewarts
• they are algae but look like higher plants
• can purify water
• early colonizers in water and clean it up, the stonewarts have mucus around the body of the plant and this absorbs nutrients and minerals from the water: purifies water
• help stabilize the sediments when they settle

Question 13

What are some pest species in freshwater?

Answer 13

• noxious weeds
• salvinia molesta= it shades other plants and results in lack of oxygen and fish can die
• water hyacinth= eichornia crassipes= tolerates wide range temp, salinity and pH
• also import from S. America, grows densely, similar effects to the salvinia

Question 14

What is the Didymo? (rock snot)

Answer 14

• micrscopic algae referred to as rock snot
• occur in freshwater
• transferred by waders most often

Question 15

What are the microalgal blooms?

Answer 15

• blue greens, dinoflagellates and diatoms can all bloom
• pose risk to stock and humans
• release toxins that can be harmful
• block waterways

Question 16

What are the threats to aquatic plants?

Answer 16

• habitat loss
• salinity changes: reduction in abundance, decline in species richness, change in community structure
• also harvesting by collectors: e.g. waterlily