Seagrass Habitats Flashcards
What are seagrass habitats?
Angiosperm - flowering plant
Colonial
Seasonal growth
Temperate and tropical
What is the global distribution of Seagrass?
Tropical and subtropical
Clear gradients in diversity
Largest beds in Florida
What are the requirements of seagrass?
Sunlight - clear shallow water
Nutrients but not too much
Soft substrate
How do seagrass reproduce?
Evolved from terrestrial ancestors
Reduced and simplified
Elongated pollen floats with tide and specialised to stick to o receptive stigma
Seeds can disperse over long distance (tropical)
What are seagrass meadows?
Continuous or patch formation
0-30m depth
< 15,000 shoots per m2
Global extent is the size of France
What is the importance of seagrass?
High local productivity Provision of O2 Trapping and cycling of nutrients Attachment sites Habitats
How does seagrass fit into the food web?
High biodiversity High secondary productivity Grow 2-5cm a day Few large animals graze directly Macroalgae provide large amounts of primary production.
How do seagrass act as a nursery?
Refuge for juvenile fish
Feeding resource
Hiding place
What are the threats to seagrass?
Vulnerable due to location
Anthropogenic and natural threats.
What are the anthropogenic threats?
Coastal development Water pollution Physical disturbance Trawling damage Non native species Climate change
What are some of the natural threats?
Wind driven waves Cyclones and floods Tsunamis Root damage Foraging animals Disease
