After 48 h the effects of increased lubricant on adult
branchlets of A. formosa were clearly visible, beginning
with the lightening of coral tips and corallites followed
by severe bleaching of the consentium (coral branch)
and mortality at the highest exposures (Fig. 1C, D). The
visible symptoms were more pronounced for branchlets
exposed to VDL-1A and VDL-1B (same formulation)
and this was reflected in greater mortality levels at 48 h.
The lowest concentration of WAF that resulted in
excessive bleaching, necrosis and mortality after 48 h
was 149 mg l1 and 140 mg l1 for VDL-1A and VDL-1B
respectively. The MDL only caused mortality at the
highest concentration tested of 190 mg l1 and the
modified VDL-2 exposure resulted in only one death at
140 mg l1 but no mortalities at twice this concentration.
These results showthat there was little difference in
toxicity between the lubricants, however, the
coumarin-free VDL was the least toxic of all lubricants
tested.