green antifouling alternatives
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BIOFOULING : THE SEARCH FOR
GREEN ANTIFOULING ALTERNATIVES
Elisheba Muturi December 1’06
Biofouling defined
Biological fouling (Biofouling) is the undesirable attachment of microorganisms, plants and animals to artificial surfaces submerged under water
Microfoulers: tiny organisms such as bacteria Macrofoulers: barnacles, zebra mussels
Biofouling effects
Affects shipping, offshore, oil and gas, water treatment, fishing industries
Ship hulls: reduce efficiency, corrode, cause drag (50% of marine transport costs)
Ship heating and cooling systems Fishing equipment, mesh cages (80% of pearl
industry costs)
Zebra mussels infestations in pipes
Antifouling technologies
Antifouling technologies refer to the means of combating biofouling:
Hull cleaning with harsh chemicals Mechanical removal Application of anti-fouling coatings to
submerged surfaces
Environmental impact The most effective anti-fouling coatings are
organotins: contain tin eg. tributyltin (TBT). TBT is very effective but toxic to non-target
organisms: imposex in whelks Compounds persist and could enter the food
chain Mechanical removal results in transfer of
invasive species
In November 1999, IMO adopted … International Convention on the Control of Harmful Anti-fouling Systems on Ships
… a global prohibition on the application of organotin compounds which act as biocides in anti-fouling systems on ships by 1 January 2003, and a complete prohibition by 1 January 2008
.
The search for green alternatives
Research into natural products antifoulants and non-toxic alternatives: Foul release coatings; non-stick surfaces Biological control methods
predation Marine bioactive compounds from sponges etc.
Mechanical or electrochemical deterrents: pulse power devices, cathodic, vibration
Cross-disciplinary
Marine and fresh water biology Oceanography Toxicology Water pollution Environmental Engineering Environmental chemistry Shipping Aquaculture
Key databases Environmental Sciences
Environmental Sciences & Pollution Management ASFA Oceanic Abstracts EnviroNetBase E-book collection
Biology Biosis Previews Zoological Record
Databases…
Chemical Chemical Abstracts SciFinder Scholar
General Web of Science GrayLit
Lay sources
Clare, Anthony Natural ways to barnish barnacles, New Scientist , 1995
Stanczak, Marianne Biofouling: It's Not Just Barnacles Anymore (CSA Discovery Guide)
Scientific journals
CSA controlled vocabulary
CSA controlled vocabulary
CSA Search strategy
((natural or non?toxic or "non toxic" or alternative? or biocide?free or "biocide free" or ((Tributyltin or TBT) NEAR alternative*) or (environment* (sound or friend* or benign)) or DE= ((biological control) or (pollution prevention) or (water pollution prevention) or (water pollution control)))) and ((DE= ((antifouling substances) or (fouling control) or (antifoulants))))
Web of Science articles
Web of Science subject areas
Key authors
Key researchers
• Research Groups affiliated to Academic Institutions – Biofouling Research Group, Russian
• Individual researchers
– Canada Centre for Marine Biofouling and Bio-Innovation, U of Calgary
– University of New South Wales Centre for Marine Biofouling and Bio-Innovation
Impact of alternatives Positive
Research into more efficient antifoulants for industry
Reduced transfer of alien species Much better for the environment
Negative Non-stick surfaces not effective in slow vessels:
increase in fouling Uneven regulation may lead to black market
Barriers to alternatives
No alternative with global approval; no commercial applications available
Long-term toxicity of alternatives unknown Higher costs of foul-release coatings Poor disposal of toxic coatings
Stakeholders
Government agencies at national and international level
Transportation authorities: International Maritime Organization
Environmental agencies such as World Wide fund, UNEP
Shipping companies, aquaculture industry Paint manufacturers
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