Ciguatera in the Gilbert Islands — COOPER 
siderable distance (Helfrich, unpublished data). 
It is of interest that, with the exception of 
Abaiang, islands which are free of toxicity have 
the worst anchorages and are islands where ves- 
sels must often drift while working cargo (for 
instance Makin, Kuria, Tamana, and Arorae ) . 
Marakei, another island with a very poor an- 
chorage, is toxic, but it has been suggested that 
the cause of toxicity was an L.S.T. which was 
able to "land” on the reef. Abaiang, an island 
with excellent anchorages for small ships inside 
the lagoon, is near enough to Tarawa for ves- 
sels to time their arrival so that they may enter 
the lagoon at daylight without anchoring in the 
entrance. Larger vessels, infrequent at Abaiang, 
must drift off the island. Maiana, another non- 
toxic island very close to Tarawa, has a very 
shallow lagoon, navigable only by the smaller 
colony vessels (length about 50 ft) at high 
spring tides. All cargo and copra is worked on 
Maiana by these vessels or by larger vessels on 
the drift. 
Washington Island, in the Line Islands, so 
often cited as one which is inexplicably free of 
toxic fish (Randall, 1958; Banner et al., I960; 
Bouder et al., 1962), under normal conditions 
has no anchorage. Continual, heavy surf beats 
all around the atoll Cargo, copra, and passengers 
must be moved in surf boats, while the vessel 
being loaded drifts some way off the island. 
From evidence in the Gilbert and Ellice Is- 
lands Colony, it would appear that shipping may 
in some way be associated with the spread of 
toxicity. Allen (1953) discusses the large part 
played by ships in the world-wide distribution 
of a variety of marine invertebrates. He sug- 
gests that, as well as invertebrates, certain algae, 
in particular Enteromorpha intestinalis ( Linne ) 
and Ulva lactuca ( Linne ) , may owe their almost 
universal distribution to ships. There is a mini- 
mum number of new organisms, he says, that 
must be introduced to start a new population, 
and concludes that in Australia harbors are the 
logical place for this to happen. In the Gilbert 
Islands there are no harbors, but merely an- 
chorages; and it may be noted that all the most 
frequently used anchorages (lying outside la- 
goons) in the Gilbert Islands are toxic. Perhaps 
this means that there is a particular organism 
found in and around these anchorages which is 
not found elsewhere in the Gilbert Islands. If 
433 
wrecks are indeed "the cause” of toxicity, per- 
haps the wrecked vessels were carrying this 
organism, which then spread along the reef. 
OTHER TYPES OF POISONING 
Sharks’ Liver Poisoning 
The liver from large sharks is thought to be 
potentially poisonous throughout the Gilberts, 
whether the shark is caught in a lagoon or in 
the ocean. The Gilbertese have a great liking for 
shark flesh, considering it more digestible than 
the flesh of other fish. In particular they like the 
liver; sometimes this is made into a kind of 
sausage, using the shark intestines as the casing. 
Not all large sharks have toxic livers; certain 
species are more likely to be toxic than others. 
According to the Gilbertese the most dangerous 
species are the tiger shark, Galeocerdo cuvier i 
( Lesueur ) , and the "white tipped lagoon shark” 
(possibly Triaendon ohesus [Ruppell]), but 
they say that any exceptionally large shark may 
have a toxic liver. 
The different assistant medical officers con- 
sulted say that there appears to be no difference 
in the symptoms caused by sharks’ liver poison- 
ing and those caused by toxic teleost fishes; their 
list of symptoms for sharks’ liver poisoning is 
the same as that described under ciguatera poi- 
soning. However, the poisoning caused by toxic 
sharks’ liver is extremely rapid and severe; the 
victims often become comatose after suffering 
from severe vomiting, stomach cramps, and 
diarrhea. There are no Gilbertese remedies for 
sharks’ liver poisoning other than those given 
for ciguatera. 
It has been considered that sharks’ liver poi- 
soning may be due to an excess of Vitamin A 
(Lonis, 1950). However, in 1949 samples of 
sharks’ livers from the Gilberts were analyzed 
for Vitamin A content with a view to starting 
an industry. The report stated that there was in- 
sufficient Vitamin A to make commercial ex- 
traction worthwhile. The Vitamin A content of 
livers from several species of sharks from various 
areas in the tropical Pacific was also investigated 
by the U. S. Fish and Wildlife Service in 1949; 
none were found to contain enough to be used 
as a commercial source ( unpublished report ) . 
The traditions associated with sharks’ liver 
poisoning vary slightly from island to island, but 
