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.

浮游植物物种短小Karenia brevis及其相关的神经毒素，brevetoxin（PbTx）所产生的有害藻华遍布整个墨西哥湾，并且对同时出现的宽吻海豚（Tursiops truncatus）（一种重要的海洋前哨物种）造成破坏性影响。但是，大多数已记录的影响来自墨西哥东部海湾地区，严重缺乏得克萨斯州沿海水域宽吻海豚中PbTx暴露程度和频率的信息。这项研究记录了2007年至2017年间德克萨斯州宽吻海豚体内的PbTx暴露及其与同时发生的短毛K.布鲁姆花的关联。在60％（n = 112）的动物。肝组织样品的检出率最高（62％），其次是粪便（41.4％）和胃内容物（30.4％）。在尿液或肠组织中未检测到PbTx。粪便中检出的PbTx浓度范围（1.2–216，平均38.4 ng / g），胃内容物（3.3–1016，平均158 ng / g）和肝脏（0.6–52.4，平均8.5 ng / g）的浓度范围是有序的幅度小于报告的相同样本类型的佛罗里达海豚的值。在绽放后4周内检测到PbTx呈阳性的海豚比例（“绽放”组； 75％）显着高于绽放结束后5-8周内恢复的海豚（“绽放后”组） ； 36％； p = 0.004）。没有观察到开花关联的PbTx阳性动物的比例（“基线”组；60％）也显着高于布卢姆后组（p = 0.012）。在Bloom和Baseline组之间未检测到PbTx阳性动物比例的显着差异（p = 0.242）。3个暴露组的任何成对组合之间均未观察到肝PbTx浓度的显着差异（p = 0.261）。总体而言，这些发现表明，这些人群中许多人持续暴露于PbTx，尽管这种暴露对健康的影响尚不清楚。