THE BIOLOQY OF WOOD-BORINQ TEREDINID MOLLUSCS
47 7
suffocate and poison the shipworms within their burrows, though suggested repeatedly with interesting modifications (Hooper, 1909 ; Tatro
and Delius, 1910; Anon, 1912; Edwards, 1912; Hesse, 1914; Marshall,
1914) was subsequently found to have no appreciable effect on established borers in piles (McQuaid, 1924 ; Fries, 1925 ; Walker et al., 1926 ;
Mal’m, 1938).
Electrocution as a possible measure to destroy the shipworm, has
been tried by passing a current of high amperage and voltage with
special devices (Shuffleton, 1901 ; Prudden, 1907). Using appropriate
electrodes copper was deposited on the pile for added protection (Howe,
1908). The real effects of all these tests have not been reported. Contrary to the claim for electrocution, Nicholson (1920) got negative
results from Table Bay harbour, his wired pieces proved to be more
severely attacked than the control pieces! Of the various methods used
to protect timber against borer attack, chemical treatments appear to
be the most practicable and widely used. From ancient times wood
preservation has been practised using different empirical formulae with
varying degrees of success. The Egyptians with their expert knowledge
in the preservation of dead bodies also developed effective methods for
wood preservation. The submarine survey in the Mediterranean by the
French Navy brought to light hulls of ancient sailing ships which had
remained submerged for more than 20 centuries with timber still perfectly intact. Arabs and Indians also maintained large fleets of sailing
vessels both for colonization and commerce. Unfortunately we have no
records of the ways by which they preserved timber. The best preservative known is impregnation of timber with creosote (Teesdale and
Shackell, 1917 ; Hill, 1922 ; Atwood et al., 1924; Miller and Hill, 1927 ;
Ramage and Burd, 1927; Clapp, 1949, Becker and Schulze, 1950)
with suitable additives (Emery, 1935 ; Bryan, 1947 ; Mayfield, 1952 ;
Richards, 1953; MacLean, 1954). But even this leaches out in time
leaving the surface exposed to borer attack. This aspect of the problem
is the more acute in warm tropical waters.
Recent marine borer studies at the British Columbia Research
Council, Vancouver, Canada include among others monitoring studies
for marine borer attack (Walden, et al., 1967), sonic testing of marine
piling (Walden and Trussel, 1965) and development and possible
commercial application of underwater coatings for wood; marine borer
protection systems for commercial logs, dry-docks, marine installations
and evaluation of the resistance to continuous leaching of modified
creosotes, organo-lead compounds and formulations of zinc and chromium compounds. The rate of ingress of borer activity into harbours as
a result of the abatement of pollution is also under investigation.
47 7
suffocate and poison the shipworms within their burrows, though suggested repeatedly with interesting modifications (Hooper, 1909 ; Tatro
and Delius, 1910; Anon, 1912; Edwards, 1912; Hesse, 1914; Marshall,
1914) was subsequently found to have no appreciable effect on established borers in piles (McQuaid, 1924 ; Fries, 1925 ; Walker et al., 1926 ;
Mal’m, 1938).
Electrocution as a possible measure to destroy the shipworm, has
been tried by passing a current of high amperage and voltage with
special devices (Shuffleton, 1901 ; Prudden, 1907). Using appropriate
electrodes copper was deposited on the pile for added protection (Howe,
1908). The real effects of all these tests have not been reported. Contrary to the claim for electrocution, Nicholson (1920) got negative
results from Table Bay harbour, his wired pieces proved to be more
severely attacked than the control pieces! Of the various methods used
to protect timber against borer attack, chemical treatments appear to
be the most practicable and widely used. From ancient times wood
preservation has been practised using different empirical formulae with
varying degrees of success. The Egyptians with their expert knowledge
in the preservation of dead bodies also developed effective methods for
wood preservation. The submarine survey in the Mediterranean by the
French Navy brought to light hulls of ancient sailing ships which had
remained submerged for more than 20 centuries with timber still perfectly intact. Arabs and Indians also maintained large fleets of sailing
vessels both for colonization and commerce. Unfortunately we have no
records of the ways by which they preserved timber. The best preservative known is impregnation of timber with creosote (Teesdale and
Shackell, 1917 ; Hill, 1922 ; Atwood et al., 1924; Miller and Hill, 1927 ;
Ramage and Burd, 1927; Clapp, 1949, Becker and Schulze, 1950)
with suitable additives (Emery, 1935 ; Bryan, 1947 ; Mayfield, 1952 ;
Richards, 1953; MacLean, 1954). But even this leaches out in time
leaving the surface exposed to borer attack. This aspect of the problem
is the more acute in warm tropical waters.
Recent marine borer studies at the British Columbia Research
Council, Vancouver, Canada include among others monitoring studies
for marine borer attack (Walden, et al., 1967), sonic testing of marine
piling (Walden and Trussel, 1965) and development and possible
commercial application of underwater coatings for wood; marine borer
protection systems for commercial logs, dry-docks, marine installations
and evaluation of the resistance to continuous leaching of modified
creosotes, organo-lead compounds and formulations of zinc and chromium compounds. The rate of ingress of borer activity into harbours as
a result of the abatement of pollution is also under investigation.