Seagrass Systems Flashcards
What are Angiosperms
True flowering higher plants but not grasses
What is SAV
Submerged aquatic vegetation
Why are seagrasses important
Important associated fisheries, important ecosystem for several endangered species and important for sediment stabilisation
Name the 6 marine families of seagrasses
Zosteraceae; Posidoniaceae; Cymodoceaceae; Hydrocharitaceae; Ruppiaceae; Zannichelliaceae
Give examples of seagrass species
Zostera spp. eg Z.marina; Halodue beaudettei (shoal grass); Halophila decipiens (paddle grass); Syringodium filiforme (Manatee grass); Ruppis maritima (Wigeon grass); Posidonia oceanica; Thalassia testudinium (Turtle grass)
Where would you generally find seagrasses
They favor soft sediments in shallow coastal water
What is a lacunar gas transport system
These are continuous channels for gas transport to roots. O2 transported to rhizomes during periods of light when photosynthesis releases O2 into aerenchyma. Forms an oxidised zone around roots with radial O2 loss into surrounding anoxic sediments.
How do seagrasses reproduce
Sexually though classic plant pollination; Asexually (vegetative through fragments of drifting rhizome).
What does Dioecious mean
Having separate male and female plants - majority of seagrasses.
What are epiphytes
Organisms growing on the surface of plants but not deriving nutrition from them such as sessile bryozoans.
What is the main problem of epiphytic growth on seagrasses
Reduces light availablity to seagresses
What species can cope with 90% epiphyte coverage
Posidonia oceanica
Roughly how many fish and invertebrates in a single acre of seagrass bed
4000 fish and 50million invertibrates
What kinds of macrofauna are common to seagrass systems, (answer 6 kinds)
Sea turtles, parrotfish, surgeonfish, sea urchins, queen conch, manatees and dugongs
Why is Queen conch important to seagrasses
They graze on epiphytes
