Gray whale (Eschrichtius robustus) post-mortem findings from December 2018 through 2021 during the Unusual Mortality Event in the Eastern North Pacific.

Beginning in December 2018, increased numbers of gray whale (Eschrichtius robustus) strandings were reported along the west coast of Mexico, the United States, and Canada, prompting declaration of a gray whale Unusual Mortality Event (UME) by the United States National Marine Fisheries Service. Although strandings declined in 2020 and 2021 from a peak in 2019, the UME is still ongoing as of fall 2023. Between 17 December 2018 and 31 December 2021, 503 animals stranded along the west coast of North America, with 226 strandings in Mexico, 71 in California, 12 in Oregon, 56 in Washington, 21 in British Columbia, and 117 in Alaska.

Neisseria montereyensis sp. nov., Isolated from Oropharynx of California Sea Lion (Zalophus californianus): Genomic, Phylogenetic, and Phenotypic Study.

A novel Neisseria strain, designated CSL10203-ORH2, was isolated from the oropharynx of a wild California sea lion (Zalophus californianus) that was admitted to The Marine Mammal Center in California, USA. The strain was originally cultured from an oropharyngeal swab on BD Phenylethyl Alcohol (PEA) agar with 5% sheep blood under aerobic conditions. Phylogenetic analyses based on 16S rRNA, rplF, and rpoB gene sequences and the core genome sequences indicated that the strain was most closely related to only N.

sp. nov. and sp. nov., isolated from northern elephant seals (), sp. nov., isolated from harbour porpoise (), and sp. nov., isolated from harbour porpoise and California sea lions ().

Seven novel independent strains of species were isolated from northern elephant seals (ES2806-NAS, ES2806-GEN, ES3157-GEN-MYC and ES3225-GEN-MYC), a harbour porpoise (C264-GEN and C264-NAS), and a California sea lion (CSL7498). These strains were phenotypically and genetically characterized and compared to the known species. Four strains (C264-GEN, C264-NAS, CSL7498 and ES2806-NAS) hydrolysed arginine but not urea and did not produce acid from carbohydrates.

sp. nov., isolated from oral cavity of northern elephant seal ().

Two independent strains of a species (ES3154-GLU and ES2714_GLU) were isolated from the oral cavity of northern elephant seals () that were admitted to The Marine Mammal Centre facilities in California, USA. The strains were isolated from oral swabs by cultivation in PPLO broth supplemented with serum, penicillin and colistin in anaerobic conditions. The strains were Gram-negative, pleomorphic, indole-, oxidase- and catalase-negative, non-spore-forming, non-motile rods/coccobacilli in short chains.

sp. nov. isolated from northern elephant seals () and sp. nov. isolated from California sea lions ().

Novel ureaplasma strains have been isolated from the genital tract of both sexes of northern elephant seals (; six strains) and California sea lions (; five strains) stranded along the Central California coast, USA. These strains were phenotypically and genetically characterized and compared to other seven known species. All novel ureaplasma strains hydrolysed urea, but did not metabolize arginine, and all were isolated and propagated using PPLO medium supplemented with urea under aerobic, microaerophilic, and anaerobic atmospheric conditions at +35-37 °C.

Proteomic Analysis of Urine from California Sea Lions ( Zalophus californianus): A Resource for Urinary Biomarker Discovery.

Urinary markers for the assessment of kidney diseases in wild animals are limited, in part, due to the lack of urinary proteome data, especially for marine mammals. One of the most prevalent kidney diseases in marine mammals is caused by Leptospira interrogans, which is the second most common etiology linked to stranding of California sea lions ( Zalophus californianus). Urine proteins from 11 sea lions with leptospirosis kidney disease and eight sea lions without leptospirosis or kidney disease were analyzed using shotgun proteomics.

Neisseria zalophi sp. nov., isolated from oral cavity of California sea lions (Zalophus californianus).

Three independent strains of Neisseria sp. were isolated from the oral cavity of California sea lions (Zalophus californianus) that were admitted to The Marine Mammal Center facilities in California, USA. The strains were isolated from oral swabs by cultivation on Trypticase Soy agar with 5% sheep blood under aerobic conditions.

Detecting signals of chronic shedding to explain pathogen persistence: Leptospira interrogans in California sea lions.

Identifying mechanisms driving pathogen persistence is a vital component of wildlife disease ecology and control. Asymptomatic, chronically infected individuals are an oft-cited potential reservoir of infection, but demonstrations of the importance of chronic shedding to pathogen persistence at the population-level remain scarce. Studying chronic shedding using commonly collected disease data is hampered by numerous challenges, including short-term surveillance that focuses on single epidemics and acutely ill individuals, the subtle dynamical influence of chronic shedding relative to more obvious epidemic drivers, and poor ability to differentiate between the effects of population prevalence of chronic shedding vs.

Development and validation of a quantitative PCR for rapid and specific detection of California sea lion adenovirus 1 and prevalence in wild and managed populations.

California sea lion adenovirus 1 (CSLAdV-1) has been associated with hepatitis and enteritis in several wild and captive populations of diverse pinniped species. Currently available tests have been limited to pan-adenoviral polymerase chain reaction (PCR) followed by sequencing. We present the development of a quantitative probe-hybridization PCR (qPCR) assay for rapid, sensitive, and specific detection of this virus in California sea lions ( Zalophus californianus) and other pinnipeds.

ISOLATION AND CHARACTERIZATION OF A NOVEL MARINE BRUCELLA FROM A SOUTHERN SEA OTTER (ENHYDRA LUTRIS NEREIS), CALIFORNIA, USA.

We characterize Brucella infection in a wild southern sea otter ( Enhydra lutris nereis) with osteolytic lesions similar to those reported in other marine mammals and humans. This otter stranded twice along the central California coast, US over a 1-yr period and was handled extensively at two wildlife rehabilitation facilities, undergoing multiple surgeries and months of postsurgical care. Ultimately the otter was euthanized due to severe, progressive neurologic disease.

Cetacean Morbillivirus in Odontocetes Stranded along the Central California Coast, USA, 2000-15.

Effects of cetacean morbillivirus (CeMV) on dolphins vary from causing epidemics to subclinical infections. The former have been documented in the North Atlantic Ocean and Mediterranean Sea but not in the North Pacific Ocean, and the reasons for this are unknown. To explore the distribution of this virus in areas that have not experienced epidemics, we reviewed evidence for morbilliviral infection in odontocetes stranded along the California coast, US from 2000-15.

An unprecedented coastwide toxic algal bloom linked to anomalous ocean conditions.

A coastwide bloom of the toxigenic diatom in spring 2015 resulted in the largest recorded outbreak of the neurotoxin, domoic acid, along the North American west coast. Elevated toxins were measured in numerous stranded marine mammals and resulted in geographically extensive and prolonged closures of razor clam, rock crab, and Dungeness crab fisheries. We demonstrate that this outbreak was initiated by anomalously warm ocean conditions.

Detection and characterization of diverse coccidian protozoa shed by California sea lions.

Tissue-cyst forming coccidia in the family Sarcocystidae are etiologic agents of protozoal encephalitis in marine mammals including the federally listed Southern sea otter (Enhydra lutris). California sea lions (Zalophus californianus), whose coastal habitat overlaps with sea otters, are definitive hosts for coccidian protozoa provisionally named Coccidia A, B and C. While Coccidia A and B have unknown clinical effects on aquatic wildlife hosts, Coccidia C is associated with severe protozoal disease in harbor seals (Phoca vitulina).

Managing marine disease emergencies in an era of rapid change.

Infectious marine diseases can decimate populations and are increasing among some taxa due to global change and our increasing reliance on marine environments. Marine diseases become emergencies when significant ecological, economic or social impacts occur. We can prepare for and manage these emergencies through improved surveillance, and the development and iterative refinement of approaches to mitigate disease and its impacts.

Algal toxin impairs sea lion memory and hippocampal connectivity, with implications for strandings.

Domoic acid (DA) is a naturally occurring neurotoxin known to harm marine animals. DA-producing algal blooms are increasing in size and frequency. Although chronic exposure is known to produce brain lesions, the influence of DA toxicosis on behavior in wild animals is unknown.

A Systematic Review of Changes in Marine Mammal Health in North America, 1972-2012: The Need for a Novel Integrated Approach.

Marine mammals are often cited as "sentinels of ocean health" yet accessible, synthesized data on their health changes that could effectively warn of ocean health changes are rare. The objectives of this study were to 1) perform a systematic review of published cases of marine mammal disease to determine spatial and temporal trends in disease from 1972-2012, including changes in regions and taxa affected and specific causes; and 2) compare numbers of published cases of neoplasia with known, hospital-based neoplasia records to explore the causes of discrepancy between numbers of published cases and true disease trends. Peer-reviewed literature was compiled, and data were collected from The Marine Mammal Center database in Sausalito, California for comparison of numbers of neoplasia cases.

A NOVEL GAMMAHERPESVIRUS IN NORTHERN FUR SEALS (CALLORHINUS URSINUS) IS CLOSELY RELATED TO THE CALIFORNIA SEA LION (ZALOPHUS CALIFORNIANUS) CARCINOMA-ASSOCIATED OTARINE HERPESVIRUS-1.

Otarine herpesvirus 1 (OtHV1) is strongly associated with California sea lion (CSL, Zalophus californianus) urogenital carcinoma, the most common cancer documented in marine mammals. In addition to CSL, OtHV1 has also been found in association with carcinoma in South American fur seals (Arctocephalus australis), demonstrating it can infect related species. Northern fur seals (NFS, Callorhinus ursinus) are sympatric with CSL, and copulation between these species has been observed; yet, there are no reports of urogenital carcinoma in NFS.

Proteomic analysis of cerebrospinal fluid in California sea lions (Zalophus californianus) with domoic acid toxicosis identifies proteins associated with neurodegeneration.

Proteomic studies including marine mammals are rare, largely due to the lack of fully sequenced genomes. This has hampered the application of these techniques toward biomarker discovery efforts for monitoring of health and disease in these animals. We conducted a pilot label-free LC-MS/MS study to profile and compare the cerebrospinal fluid from California sea lions with domoic acid toxicosis (DAT) and without DAT.

PHARMACOKINETICS OF TRAMADOL HYDROCHLORIDE AND ITS METABOLITE O-DESMETHYLTRAMADOL FOLLOWING A SINGLE, ORALLY ADMINISTERED DOSE IN CALIFORNIA SEA LIONS (ZALOPHUS CALIFORNIANUS).

Tramadol is a synthetic, centrally acting, opiate-like analgesic that is structurally related to codeine and morphine. The objective of this study was to determine the pharmacokinetics of tramadol hydrochloride and its major active metabolite O-desmethyltramadol (M1) in the California sea lion (Zalophus californianus). A single dose of tramadol was administered orally in fish at 2 mg/kg to a total of 15 wild California sea lions admitted for rehabilitation.

LAPAROSCOPIC GASTROPEXY FOR CORRECTION OF A HIATAL HERNIA IN A NORTHERN ELEPHANT SEAL (MIROUNGA ANGUSTIROSTRIS).

A female northern elephant seal (Mirounga angustirostris) weaned pup presented with malnutrition. During rehabilitation, the seal developed regurgitation and reduced lung sounds on auscultation. Radiographs and endoscopy performed under sedation suggested a diaphragmatic hernia.

Common cancer in a wild animal: the California sea lion (Zalophus californianus) as an emerging model for carcinogenesis.

Naturally occurring cancers in non-laboratory species have great potential in helping to decipher the often complex causes of neoplasia. Wild animal models could add substantially to our understanding of carcinogenesis, particularly of genetic and environmental interactions, but they are currently underutilized. Studying neoplasia in wild animals is difficult and especially challenging in marine mammals owing to their inaccessibility, lack of exposure history, and ethical, logistical and legal limits on experimentation.

Proteomic Analysis of Plasma from California Sea Lions (Zalophus californianus) Reveals Apolipoprotein E as a Candidate Biomarker of Chronic Domoic Acid Toxicosis.

Domoic acid toxicosis (DAT) in California sea lions (Zalophus californianus) is caused by exposure to the marine biotoxin domoic acid and has been linked to massive stranding events and mortality. Diagnosis is based on clinical signs in addition to the presence of domoic acid in body fluids. Chronic DAT further is characterized by reoccurring seizures progressing to status epilepticus.

Blood and Hair Mercury Concentrations in the Pacific Harbor Seal (Phoca vitulina richardii) Pup: Associations with Neurodevelopmental Outcomes.

Monomethylmercury (MeHg(+)) is an environmental pollutant, which at sufficiently high exposures, has induced neurotoxicosis in several animal species, including humans. Adverse neurological effects due to gestational exposure are of particular concern as MeHg(+) readily crosses the blood-brain and placental barriers. The degree to which environmental concentrations in marine prey affect free-living piscivorous wildlife, however, remains largely undetermined.

Phylogenomic characterization of California sea lion adenovirus-1.

Significant adenoviral diversity has been found in humans, but in domestic and wild animals the number of identified viruses is lower. Here we present the complete genome of a recently discovered mastadenovirus, California sea lion adenovirus 1 (CSLAdV-1) isolated from California sea lions (Zalophus californianus), an important pathogen associated with hepatitis in pinnipeds. The genome of this virus has the typical mastadenoviral structure with some notable differences at the carboxy-terminal end, including a dUTPase that does not cluster with other mastadenoviral dUTPases, and a fiber that shows similarity to a trans-sialidase of Trypanosoma cruzi and choline-binding protein A (CbpA) of Streptococcus pneumoniae.

Coccidioidomycosis and other systemic mycoses of marine mammals stranding along the central California, USA coast: 1998-2012.

A wide range of systemic mycoses have been reported from captive and wild marine mammals from North America. Examples include regionally endemic pathogens such as Coccidioides and Blastomyces spp., and novel pathogens like Cryptococcus gattii, which appear may have been introduced to North America by humans.