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PACIFIC SCIENCE, Vol. XVIII, October 1964 
fish have appeared only comparatively recently. 
The remaining six islands, Abaiang and Maiana, 
lagoon islands, Makin, Kuria, Tamana, and Aro- 
rae, reef islands, have no history of toxic fish. 
The toxic area on all these islands is in the 
same relative position on the atoll; that is, each 
toxic area is on the sheltered lee side, either in 
the northwest, west, or southwest. This finding 
does not agree with Brown ( 1945 ) , who reports 
that in the Bahamas the windward, exposed 
areas are more likely to be toxic than the lee- 
ward, sheltered ones. On a few islands part of 
the lagoon is toxic, but in no case is the toxicity 
confined to the lagoon; no non-navigable lagoon 
has any toxic reefs. Randall (1958) suggests 
that a body of water set off from the ocean by 
reefs may be more likely to contain toxic fish 
than more open water. In the Gilberts, although 
all the toxic reefs are in reasonably sheltered 
areas, there is a steady but not powerful ocean 
current, as well as currents caused by ebbing and 
flowing tides constantly washing over them. 
The islands of the Gilberts vary from wet 
toxic Butaritari (125 inches) and dry toxic Ni- 
kunau (44 inches), to wet nontoxic Makin 
(107 inches) to dry nontoxic Tamana (48 
inches ) . There is no island in the Gilberts with 
a fresh water stream, nor is the rainfall ever 
heavy enough to cause run-off. 
Wrecks are often cited as the location and 
cause of a toxic area (Randall, 1958). In the 
Gilberts, on no less than seven toxic reefs out of 
eleven, wrecks are given as the reason for the 
start of the toxicity. Of these seven wrecks only 
one may still be seen (on northern Abemama) ; 
the rest are merely remembered. Within the last 
thirty years there have been five authenticated 
wrecks, two at Ocean Island, two at Butaritari, 
and one at Nikunau, none of which appear to 
have had any effect on the areas concerned. The 
Nikunau reef was already toxic when the wreck 
occurred, but the toxicity was not increased. The 
two wrecks at Butaritari occurred within a 
couple of years of each other, during the Pacific 
war, but the toxicity was not reported from Bu- 
taritari until some years later. It should be noted 
that all the wrecks referred to are in or very near 
anchorages or passages to navigable lagoons. 
Again, heavy reef damage has been suggested 
as a possible factor in the chain of events lead- 
ing to toxicity (Randall, 1958). Yet damage to 
the Makin lee fringing reef ( by storm ) , to Bern 
lagoon reef (by blasting), and to Ocean Island 
reefs ( by continual blasting and workings ) pro- 
duced no change in toxicity. Of particular in- 
terest is Bern, where the fringing reef down- 
current from the blasted area was already toxic. 
However, on Tarawa there was a resurgence of 
the toxicity following the Battle of Tarawa with 
its reef damage, wrecks, and heavy casualties on 
the reefs, all of which must have produced at 
least a temporary change in the ecology of the 
reef areas around Betio. 
Vessels not only anchor in the usual cargo- 
working anchorages, as at Tarawa, Butaritari, 
Arunuka, Onotoa, and south Nonouti, where all 
these anchorages are in toxic areas, but, as may 
not be generally realized, vessels planning to 
enter a lagoon often must first anchor outside, 
in the entrance, or even in the passage itself, to 
await the optimum angle of the sun’s rays before 
navigating the unmarked channels through the 
reef patches. In these days of radar and depth 
indicators this approach is not so vital as it was 
a few years ago. It has been found that these 
anchorages at lagoon entrances and in reef pas- 
sages are frequently toxic, as at Tarawa, Abe- 
mama, Butaritari, and Tabiteuea. Nonouti is an 
island with a very difficult entrance into the 
lagoon, and many ships’ masters prefer to work 
the island from the southern anchorage (which 
is toxic), or to wait there before attempting to 
navigate the entrance which is to the north of 
Autaken reef. Nikunau and south Bern have 
rather poorer anchorages than the islands so far 
mentioned, but nevertheless vessels do anchor 
off these places to load cargo and, once again, 
these anchorages are toxic. 
Fanning Island, often quoted in papers on 
ciguatera (Randall, 1958; Banner et al., I960), 
is another example of an atoll where the an- 
chorage is toxic. In fact P. F. D. Palmer is quoted 
by Randall (1958) as saying that the areas 
where fish were toxic were only where the ships 
anchored. Randall continues to say that in the 
Line Islands where toxic fish appeared large 
ships had previously been anchored. The toxic 
area on Palmyra is also near the channel en- 
trance (Banner et al., I960). The toxic area on 
Christmas Island in 1953-54 was in and around 
the anchorage by the main lagoon entrance; 
since that time it has extended southward a con- 
