There are few problems that has
faced more false alarms than the pressing search for final solution to the
problem of ship fouling. It has been pressing
since the Bronze Age and I am sure a magnificent prize was offered then.
This time it sounds as if we may
have a practical solution able to last between dry docking trips. That is great news and will be welcome to
seamen everywhere.
Perhaps even the oldest problems
can get solved. Perhaps it is time to
tackle the n body problem.
Bacterial byproduct keeps barnacles from clinging to ships' hulls
By Ben
Coxworth
19:13 October 5, 2011
The hull of a boat that was painted with a coating containing
macrocyclic lactones, with the exception of the stripe down the middle
While the sight of barnacles on ships' hulls may seem like a very
normal part of the maritime environment, the fact is that the presence of such
organisms makes a vessel much less streamlined. The harder it is for a ship to
slice through the water, the harder its engines have to work and the more fuel
it uses. Although there are some anti-fouling coatings that can be applied to
hulls, these are often toxic, and can leach into the surrounding water and harm
marine organisms. Some recent efforts at eco-friendly solutions have included
using fungus and seed-inspired coatings, but scientists at Sweden 's University of Gothenburg
are now reporting success with the use of molecules created by a certain type
of bacteria.
The molecules are known as macrocyclic lactones, and barnacles don't
like them. In field tests, trace amounts of the lactones were added to a
regular anti-fouling coating, which was then applied to a boat's hull - a
binding agent kept the molecules from dispersing into the water. Although the
barnacle larvae then colonized the hull as per usual, when they matured into
adults and tried to establish a more secure hold, they lost their footing and
were swept away.
Apparently, a marine species of brown algae uses the molecules in the
same way, to keep barnacles from accumulating on its leaves.
The University of Gothenburg researchers believe that such
coatings could completely replace more toxic copper-based coatings, and that
one application should be able to repel barnacles for several seasons.
Scientists at the same institution have also been looking into using medetomidine, a veterinary medicine, for keeping larval
barnacles from settling on hulls in the first place.
A paper on the macrocyclic lactone research was recently published in
the journal Biofouling.
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