Deep sea moorings fishbite handbook
Citable URI
https://hdl.handle.net/1912/1850DOI
10.1575/1912/1850Keyword
Deep-sea mooringsAbstract
The purpose of this handbook is to bring awareness and a degree of
expertise to the very real problem of fish attacks on mooring lines and
cables deployed in the open seas.
Over the years the authors have carefully examined a large sample of
damaged, sometimes entirely severed ropes retrieved from the sea.
Often direct evidence and/or biological observations showed that the
ropes were the victims of fish attacks. In many cases however the cause of
rope failure remained difficult to ascertain. Techniques and rationales
therefore had to be devised to elucidate the more thorny cases.
Understanding a problem, the saying goes, is half of the solution. The
other half, as far as this handbook is concerned, is of course to make known
the ways which, at the moment, could help prevent fishbite attacks or at
least abate its effects.
Thus the handbook will follow a natural progression. A short
introduction retraces the early suspicions which soon translated into
confirmed fish attacks. The next two chapters cover the recognition and the
extent of the fishbite problem in great depth.
Chapter 2 presents in meticulous details the techniques which can be
used to determine how a rope was damaged while in service, either by
fishbite or any other plausible cause. The analysis of a data base which
spans over twenty years and encompasses close to a thousand moorings is
presented in Chapter 3: Dimensions of the fishbite problem. This chapter
provides valuable information for use in estimating fishbite hazard.
Who are the culprits and why they do it is reviewed in Chapter 4:
Biting organisms and predisposing factors. This chapter identifies the
marine organisms which have significant biting capabilities and outlines
some of the environmental factors and processes which incite and result in
fishbite damage.
The last chapter: Prevention and control of fishbite damage, reviews
the preventive methods used to reduce the incidence or the severity of fish
attacks and the curative methods - including up to date techniques for
jacketing metallic and non-metallic ropes and cables - which hopefully will
protect mooring lines from the mechanical damage inflicted by fish teeth.