Dearest MARMAM-ers,
My collaborators and I are pleased to announce the publication of our recent
article, "Association between red tide exposure and detection of corresponding
neurotoxins in bottlenose dolphins from Texas waters during 2007-2017", in
Marine Environmental Research.
Abstract:
Harmful algal blooms produced by the phytoplankton species Karenia brevis and
its associated neurotoxin, brevetoxin (PbTx), occur throughout the Gulf of
Mexico and have had devastating impacts on co-occurring populations of
bottlenose dolphins (Tursiops truncatus), an important marine sentinel species.
The majority of documented impacts, however, are from the eastern Gulf of
Mexico, with a critical lack of information on the degree and frequency of PbTx
exposure in bottlenose dolphins from Texas coastal waters. This study documents
PbTx exposure in Texas bottlenose dolphins between 2007 and 2017 and their
association with co-occurring K. brevis blooms. PbTx was detected in 60% (n =
112) of the animals tested. Liver tissue samples had the highest frequency of
detection (62%), followed by feces (41.4%) and gastric contents (30.4%). PbTx
was not detected in urine or intestinal tissue. The concentration ranges of
PbTx detected in feces (1.2-216, mean 38.4 ng/g), gastric contents (3.3-1016,
mean 158 ng/g) and liver (0.6-52.4, mean 8.5 ng/g) samples were an order of
magnitude less than values reported for Florida dolphins for the same sample
types. The proportion of dolphins recovered within 4 weeks of a bloom that
tested positive for PbTx ('Bloom' group; 75%) was significantly higher compared
to those that were recovered 5-8 weeks after termination of a bloom
('Post-Bloom' group; 36%; p = 0.004). The proportion of PbTx-positive animals
with no observed bloom association ('Baseline' group; 60%) was also
significantly greater than the Post-Bloom group (p = 0.012). No significant
difference in proportion of PbTx-positive animals was detected between Bloom
and Baseline groups (p = 0.242). No significant differences in liver PbTx
concentrations were observed between any pairwise combinations of the 3
exposure groups (p = 0.261). Overall, these findings suggest persistent PbTx
exposure for many individuals in these populations, although the health impacts
of such exposure are not known.
Fire SE, Leighfield TA, Miller GA, Piwetz S, Sabater E, Whitehead H (2020).
Association between red tide exposure and detection of corresponding
neurotoxins in bottlenose dolphins from Texas waters during 2007-2017. Marine
Environmental Research 162:105191.
https://doi.org/10.1016/j.marenvres.2020.105191
Feel free to contact me directly for any comments or questions.
Best regards,
SF
---------------
Spencer Fire, Ph.D.
Asst. Professor of Biological Sciences
Florida Institute of Technology
150 W. University Blvd.
Melbourne, FL 32901
321.674.7138
[email protected]<mailto:[email protected]>
The Fire Lab website<https://firelabfit.weebly.com/>
The Fire Lab on Instagram<https://www.instagram.com/thefirelab/>
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