Seagrasses Flashcards
(21 cards)
Are seagrasses algae?
No, they are marine angiosperms (flowering plants)
What class do seagrasses belong to?
Monocotyledons
How do seagrasses reproduce vegetatively?
Through rhizomes (clonal, rhizomatous growth)
What kind of pollination do seagrasses use?
Hydrophilous pollination (pollen dispersed in water)
What adaptation helps seagrasses transport oxygen to roots?
Aerenchyma (large air channels in leaves)
Do seagrasses have stomata?
No, their leaves lack stomata
How many seagrass species exist globally?
Around 60 species
Where are seagrasses found?
From the Arctic to the Southern Ocean, in tropical and temperate regions
What sediment type do seagrasses require?
Oxic (oxygen-rich) mud or sand
What salinity range can seagrasses tolerate?
Optimal: 0–56 ppt; can tolerate up to 99 ppt
What environmental factor limits light availability in seagrass habitats?
Excess nutrients (can lead to algal overgrowth, reducing light)
Where are tropical seagrasses typically found?
Fringing reef flats, lagoons, coastal areas, deep water (>15 m)
Where are temperate seagrasses found?
Subtidal and intertidal zones
How do seagrasses help fight climate change?
By storing carbon (blue carbon ecosystems)
How do seagrasses improve water quality?
They trap and stabilize sediments
How do seagrasses protect coastlines?
By forming natural reefs that reduce wave energy
What organisms live in seagrass ecosystems?
Small invertebrates, fish, and rich infaunal communities
What herbivores feed directly on seagrass?
Manatees, dugongs, green turtles, and herbivorous fish
How do seagrass meadows support shorebirds?
As direct food sources and through supporting prey species
What percentage of seagrass meadows have been lost globally?
About 58%
Why are seagrasses susceptible to environmental changes?
Due to sensitivity to light, nutrients, temperature, and salinity
