What is a virus? Outline the diversity, abundance and ecological significance of marine viruses

Question 1

What is a virus?

Answer 1

• What is a virus- genetic material surrounded by a protein coat
• Quintessential parasite- they require a host to provide nutrition and reproduce

Question 2

Outline the diversity and abundance of marine parasites:

Answer 2

Virus diversity and abundance:
• Would have to be one of the most diverse groups: one for each other organism, essentially a parallel universe
• Very abundant: 106-1012 L-1 (27-270 Mt C)
• Important at species and ecosystem level

Question 3

Outline the ecological significance of of bacteria in the marine environment:

Answer 3

Ecological significance of bacteria in the marine environment:
• Important agent of mortality (cause diseases in organisms ranging from bacteria to whales
• Major players in biogeochemical cycles
Species level:
o Cause disease in marine organisms
 Australian pilchards introduced virus: spread 5000km at 30 km day
 North Sea seals distemper virus
Ecosystem Level:
o Important effects on plankton communities
o Plankton productivity limited by nutrients or organic carbon
o Viruses cause cell lysis, releasing nutrients:
Up to 1 mg L-1 DOC per bacterial generation