Biofouling Flashcards Preview

NM969 - Renewable Marine Energy Systems > Biofouling > Flashcards

Flashcards in Biofouling Deck (14)
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1
Q

What are fouling and marine biofouling?

A
  • Fouling is the accumulation of microorganisms, plants and animals.
  • Marine Biofouling is the settlement and growth of organisms on submerged or semi-submerged surfaces.
2
Q

Give examples of hard-shelled animal fouling

A
  • Barnacles
  • Tube worms
  • Mussels
3
Q

Give examples of plant fouling

A
  • Microalgae (slime)

- Macroalgae (red, brown and green weeds)

4
Q

How does water temperature affect fouling?

A

Higher water temperature increases fouling

5
Q

Why is fouling important?

A
  • Increases roughness on surfaces
  • Increases fuel consumption/decreases efficiency
  • Increases weight
  • Damages electronic equipment in the sea (e.g. sonar domes)
  • Breaks paint on the surface and causes corrosion
6
Q

What are the ecological concerns of fouling?

A
  • Invasive species can be transported to other habitats due to fouling
  • Invasive species may be very dangerous in terms of ecological and economical aspects
  • They can cause the disappearance of the economically important species
  • They may harm biological diversity and/or transport and dissipate illnesses
7
Q

What are the environmental concerns of fouling?

A
  • Emission of NOX, SOX and Greenhouse Gases
  • Pressures to safeguard the marine environment from the harmful effects of chemical biocides, water quality and sediment contamination
  • Efforts to limit the spread of invasive non-indigenous species via ship fouling
8
Q

What are the economic concerns of fouling?

A
  • Global economy
  • Cost of fuel
  • Economic need to extend the interval between drydockings
  • Expensive maintenance and/or replacement of ships’ rudders
  • Cost of cleaning up the contamination and pollution caused by biocidal antifouling paint on ships’ hulls
9
Q

How does fouling affect the operation of the wave energy industry?

A
  • reduction in efficiency of energy extraction
  • decreased buoyancy of floating structures
  • inhibition of moving parts such as release mechanisms
  • blockage to water intakes
  • reduction in efficiency of heat exchangers
10
Q

How does fouling affect the longevity/structural design of equipment?

A
  • increased hydrodynamic loads and drag as a result of increased diameter/surface roughness, adding strain on structures
  • reduction of structural natural frequencies
  • increased structural weight
11
Q

How does fouling influence surface damage?

A
  • accelerated corrosion caused by microorganisms (e.g. sulphate reducing bacteria) that thrive in anaerobic microhabitats beneath biofouling
  • physical damage to coatings when biofouling is removed
12
Q

How does fouling affect the maintenance of equipment?

A
  • increased drag leads to higher fuel consumption and time loss when towing devices
  • prevention of access to key areas during maintenance or monitoring, potentially concealing cracks or corrosion on the surface of a structure
13
Q

How does fouling affect health and safety?

A
  • deterioration of maintenance access equipment (e.g. ladders) due to biofouling may make them too unsafe to use
14
Q

What are the two main categories of coatings used today to mitigate fouling?

A
  • Biocidal coatings (Controlled Depletion Polymer, Self-Polishing Copolymer and Hybrid SPC)
  • Non-biocidal coatings (Foul-Release/Non-Stick)