L10-Macroalgae(kelp) Flashcards
What are the key features of kelp forests?
- Phylogenetically diverse
- Structurally complex
- Highly productive, rapid growth
What are kelps
large Brown algae,
Where are kelp forests found?
- well developed at 40-60º latitude*
- shallow open coastal waters
- cold (< 20°C) nutrient-rich waters
- 15-40 m depth
What are kelp forests constrained by?
• light at high latitudes
• nutrients, warm water and competition with
other macroalgae at low latitudes
What are the Morphological groups of kelp?
Canopy kelp
Stipitate kelp
Prostrate kelp
how does kelp affect water movement?
calms the water
What lives under kelp canopy?
red algae(low light adapted)
What are the animals associated within holdfast?
polychaetes, amphipods,decapods, gastropods, ophiuroids (brittle stars)
How do kelp forests effect larvae?
kelp forests serve as a gauntlet that larvae must pass through due to the high number of plankton feeding fish that live in them.
How does kelp recruitment?
- often seasonal,
- dispersal and settlement of spores
- growth and maturation of gametophytes,
- fertilisation and growth of zygotes
What is the dispersal range of kelp?
very short often only 3m
How productive is kelp?
extremely productive only beaten out by rainforests?
What is kelps growth rate
50cm/day(max growth rates)
Why are kelps successful?
• Efficient transport
• rapid growth
• absorption and use of N & P from deeper water
(richer)
How long does kelp live?
maximum of 10 years
How much of kelp enters the food web as detritus?
approx 90%
Why can urchins be such a problem?
humans eat predators
even if kelp dies urchin persists up to 5 years
What are major predators of kelp?
sea otters
cod
Why might kelp replanting efforts fail?
urchins still around hibernating
still no predators
replanting just feeds the urchins
What is a possible solution to urchins?
urchin fishing
but hibernating urchins are useless to fisheries
