THE PROBLEM O F OIL POLLUTIOS OF THE SEA
276
Environment Research Council, 1969). An analysis of this sort was
made before deciding how to deal with a small spill of bunker oil near
Plymouth (Holme and Spooner, 1968) which polluted a popular
swimming beach, rocks which are visited by fair numbers of people and
an extensive reef which is little used and supports a rich fauna and flora.
It was decided to leave the latter area untreated, although there is
still much controversy about the fate of such pollution. Those in charge
of clearance operations are understandably concerned about the possibility of untreated oil floating off to re-pollute amenity beaches (see,
e.g., Dudley, 1969). Observations on areas polluted but left untreated
are not very informative; the deposits of oil removed by grazing
molluscs in Milford Haven (George, 1961) and at Marazion, Cornwall
(Smith, 1968), were fairly light. At Eleuthera in the Bahamas (Spooner
and Spooner, 1968) it had soaked into the porous coral rock, while in
Lower California (North et al., 1964) the polluted cove is so isolated
that the ultimate fate of the oil went unreported. " Torrey Canyon ')
pollution was heavy enough to cause raasonable apprehension about
re-pollution. On some untreated beaches in Brittany, oil deposits were
still visible a year or more later (Zuckerman, 1968) and much of the
oil from others was later carried to beaches previously cleaned. However, according to some French authorities, " mousse "-type emulsions
float off a polluted beach more readily than crude oil which has not been
emulsified.
Where removal of the oil is necessary, a working guide has been
provided by the Ministry of Technology (Wardley Smith, 1968a).
Additional comments on the methods available have been made by
Beynon (1968) and Mayo (1968). Wherever good access permits,
mechanical collection is the method of first choice, using bulldozers,
scrapers, powered or manual shovels and rakes for solidified material.
Liquid oil in large quantities can be collected into pits or troughs and
carted by gully-emptiers or sewage tankers. There are often backshore
regions where trenches can be dug to receive this material, but the
possibility of contaminating water supplies should always be borne in
mind. Much of it could be burned in incinerators supplied with a
compressed-air draught. Many of the absorbents used at sea can also
be spread on a polluted beach, gathering the oily straw and other fibrous
materials for burning but leaving deposits dusted with stearated rockdust or siliconized ash to erode naturally or hosing them into the sea.
Thick deposits of fresh oil can be burned in situ, using flamethrowers or igniting either with " oxygen tiles ') or magnesium flares,
but it is a slow process and may require the addition of extra fuel or
oxidizing agents. Water-in-oil emulsions or oil floating on rock pools
276
Environment Research Council, 1969). An analysis of this sort was
made before deciding how to deal with a small spill of bunker oil near
Plymouth (Holme and Spooner, 1968) which polluted a popular
swimming beach, rocks which are visited by fair numbers of people and
an extensive reef which is little used and supports a rich fauna and flora.
It was decided to leave the latter area untreated, although there is
still much controversy about the fate of such pollution. Those in charge
of clearance operations are understandably concerned about the possibility of untreated oil floating off to re-pollute amenity beaches (see,
e.g., Dudley, 1969). Observations on areas polluted but left untreated
are not very informative; the deposits of oil removed by grazing
molluscs in Milford Haven (George, 1961) and at Marazion, Cornwall
(Smith, 1968), were fairly light. At Eleuthera in the Bahamas (Spooner
and Spooner, 1968) it had soaked into the porous coral rock, while in
Lower California (North et al., 1964) the polluted cove is so isolated
that the ultimate fate of the oil went unreported. " Torrey Canyon ')
pollution was heavy enough to cause raasonable apprehension about
re-pollution. On some untreated beaches in Brittany, oil deposits were
still visible a year or more later (Zuckerman, 1968) and much of the
oil from others was later carried to beaches previously cleaned. However, according to some French authorities, " mousse "-type emulsions
float off a polluted beach more readily than crude oil which has not been
emulsified.
Where removal of the oil is necessary, a working guide has been
provided by the Ministry of Technology (Wardley Smith, 1968a).
Additional comments on the methods available have been made by
Beynon (1968) and Mayo (1968). Wherever good access permits,
mechanical collection is the method of first choice, using bulldozers,
scrapers, powered or manual shovels and rakes for solidified material.
Liquid oil in large quantities can be collected into pits or troughs and
carted by gully-emptiers or sewage tankers. There are often backshore
regions where trenches can be dug to receive this material, but the
possibility of contaminating water supplies should always be borne in
mind. Much of it could be burned in incinerators supplied with a
compressed-air draught. Many of the absorbents used at sea can also
be spread on a polluted beach, gathering the oily straw and other fibrous
materials for burning but leaving deposits dusted with stearated rockdust or siliconized ash to erode naturally or hosing them into the sea.
Thick deposits of fresh oil can be burned in situ, using flamethrowers or igniting either with " oxygen tiles ') or magnesium flares,
but it is a slow process and may require the addition of extra fuel or
oxidizing agents. Water-in-oil emulsions or oil floating on rock pools