Publication Date:
2022-05-25
Description:
Author Posting. © The Author(s), 2014. This is the author's version of the work. It is posted here by permission of Elsevier for personal use, not for redistribution. The definitive version was published in Harmful Algae 34 (2014): 56–68, doi:10.1016/j.hal.2014.02.007.
Description:
Ciguatera is a serious seafood poisoning syndrome caused by the consumption of
ciguatoxin-contaminated finfish from tropical and subtropical regions. This study
examined the community structure of ciguatera-associated dinoflagellates and the
distribution pattern, taxonomy and toxicity of Gambierdiscus spp. from a high-risk area
of Marakei, Republic of Kiribati. The genera Gambierdiscus, Prorocentrum, Ostreopsis,
Amphidinium and Coolia were present, and generally the former three dominated the
dinoflagellate assemblage. Among these three, Gambierdiscus was the most abundant
dinoflagellate genus observed at three of the four sites sampled, two of which (Sites 1 and
2) were on the northern half of the island and two (Sites 3 and 4) on the southern half.
The following patterns of abundance were observed among sites: (1) Average
Gambierdiscus spp. abundance at the northern sites exceeded the southern sites by a
factor of 19-54; and (2) Gambierdiscus spp. abundance at shallow sites (2-3 m) exceeded
deeper sites (10-15 m). The distribution of Gambierdiscus spp. at Marakei corresponded
with previously observed patterns of fish toxicity, with fish from southern locations being
much less toxic than fish sampled north of the central channel. DNA sequencing
identified three Gambierdiscus species (G. carpenteri, G. belizeanus, G. pacificus) and
three previously unreported ribotypes (Gambierdiscus sp. type 4, Gambierdiscus sp. type
5, Gambierdiscus sp. type 6) in the samples; Gambierdiscus sp. type 4 may represent a
Pacific clade of Gambierdiscus sp. ribotype 1. Toxicity analyses determined that
Gambierdiscus sp. type 4 isolates were more toxic than the Gambierdiscus sp. type 5 and
G. pacificus isolates, with toxin contents of 2.6-6.0 (mean: 4.3± 1.4), 0.010 and 0.011 fg
P-CTX-1 eq cell-1, respectively. Despite low densities of
Gambierdiscus spp. observed at
Marakei relative to other studies in other parts of the world, the presence of low and
moderately toxic populations may be sufficient to render the western coast of Marakei a
high-risk area for ciguatera. The long history of toxicity along the western side of
Marakei suggests that large-scale oceanographic forcings that regulate the distribution of
Gambierdiscus spp. along the western side of Marakei may have remained relatively
stable over that time. Chronic as well as acute exposure to ciguatoxins may therefore
pose an important human health impact to the residents of Marakei.
Description:
Funding for this work was provided by the
Centers for Disease Control and Prevention (U01 EH000421), USFDA
(F223201000060C), NOAA NOS (Cooperative Agreement NA11NOS4780060,
NA11NOS4780028), National Program on Key Basic Research Project of China (973
Program, 2013CB956503), the Nonprofit Research Project for the State Oceanic
Administration (China, 201005006-01), and the National Natural Science Foundation of
China (41276110).
Keywords:
Ciguatera fish poisoning
;
Ciguatoxins
;
Gambierdiscus
;
Ostreopsis
;
HABs
;
Kiribati
Repository Name:
Woods Hole Open Access Server
Type:
Preprint
Format:
application/pdf
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