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Abstract: Domoic acid (DA) is a potent neurotoxin that has caused strandings and mortality of seabirds and marine mammals off the California coast. Pacific harbor seals (Phoca vitulina richardii) are an abundant, nearshore species in California; however, DA exposure and toxicosis have not been documented for harbor seals in this region. To investigate DA exposure in harbor seals, samples were collected from free-ranging and stranded seals off California to assess exposure, clinical signs of toxicosis, and brain lesions in harbor seals exposed to DA. Domoic acid was detected in 65% (17/26) of urine samples collected from apparently healthy free-ranging seals, with concentrations of 0.4–11.7ng/ml. Domoic acid also was detected in feces (2.4–2887ng/g), stomach contents (1.4ng/g; stranded only), milk (2.2ng/ml; stranded only), amniotic fluid (9.7ng/ml; free-ranging only), fetal meconium (14.6–39.8ng/g), and fetal urine (2.0–10.2ng/ml). Clinical signs indicative of DA toxicosis were observed in two live-stranded seals, and included disorientation, seizures, and uncoordinated movements. Histopathology revealed the presence of brain lesions consistent with DA toxicosis in two live-stranded seals, and one free-ranging seal that died during capture. Results indicated that harbor seals were exposed to DA, exhibited clinical signs and histological lesions associated with DA exposure, and that pups were exposed to DA in utero and during lactation via milk. Future investigation is required to determine the magnitude of impact that DA has on the health and mortality of harbor seals. [Copyright &y& Elsevier]

Abstract: The genome of a novel polyomavirus first identified in a proliferative tongue lesion of a California sea lion (Zalophus californianus) is reported. This is only the third described polyomavirus of laurasiatherian mammals, is the first of the three associated with a lesion, and is the first known polyomavirus of a host in the order Carnivora. Predicted large T, small t, VP1, VP2, and VP3 genes were identified based on homology to proteins of known polyomaviruses, and a putative agnoprotein was identified based upon its location in the genome. Phylogenetic analysis of the predicted late region proteins found that the laurasiatherian polyomaviruses, together with Squirrel monkey polyomavirus and Murine pneumotropic virus, form a monophyletic clade. Phylogenetic analysis of the early region was more ambiguous. The noncoding control region of California sea lion polyomavirus 1 is unusual in that only two apparent large T binding sites are present; this is less than any other known polyomavirus. The VP1 of this virus has an unusually long carboxy-terminal region. A quantitative polymerase chain reaction was developed and utilized on various samples from 79 additional animals from either managed or wild stranded California sea lion populations, and California sea lion polyomavirus 1 infection was found in 24% of stranded animals. Sequence of additional samples identified four sites of variation in the t antigens, three of which resulted in predicted coding changes. [Copyright &y& Elsevier]

Abstract: Between July 2005 and March 2009, 33 northern fur seals (Callorhinus ursinus) were collected after stranding along the central California coast between Sonoma and San Luis Obispo counties. Of these, 26 were collected live and could be observed for signs of neuroexcitotoxicity. Approximately half exhibited the classic clinical signs of domoic acid (DA) toxicosis including muscle twitches and ataxia, to seizures and coma, and had lesions in the central nervous system and heart. Several biological fluids were collected for DA analysis including aqueous humor, serum, stomach contents, feces, urine, abdominal fluid, amniotic fluid and milk. Four analytical methods were employed including receptor binding assay (RBA), enzyme-linked immunosorbent assay (ELISA), high performance liquid chromatography (HPLC-UV) and ultra performance liquid chromatography–tandem mass spectrometry (UPLC–MS/MS). The DA concentrations determined by each method were positively correlated. Domoic acid was detected in 83% of fecal samples collected from northern fur seals in the present study and in one animal was calculated to contain up to 18.6μg DA/g. Interestingly, DA was detected and confirmed in the aqueous humor of the only animal this sample-type was collected from, suggesting that this may prove to be a useful diagnostic body fluid for algal toxin detection in marine mammal mortality events. These data document for the first time that northern fur seals are impacted by DA-producing harmful algal blooms along the California coast. [Copyright &y& Elsevier]