Tenaya Norris

Novel hemotrophic mycoplasma identified in naturally infected California sea lions (Zalophus californianus)

The hemoplasmas are the trivial name for a group of erythrocyte-parasitizing, non-cultivable in vitro bacteria of the genus Mycoplasma that have been described in several mammalian hosts worldwide. This study is the first report of hemoplasmas in marine mammals. EDTA anticoagulated whole blood samples from 137 California sea lions (Zalophus californianus) and 20 northern elephant seals (Mirounga angustirostris) admitted to the Marine Mammal Center (Sausalito, CA; www.marinemammalcenter.org) or live captured in Oregon were collected during 2008. Hemoplasma-specific genomic DNA was detected in blood samples from 12.4% California sea lions tested using PCR. Hemoplasma PCR positive blood specimens also were tested in reverse transcription polymerase chain reaction (RT-PCR) using the hemoplasma-specific primers for the 16S and 23S rRNA genes. The RT-PCR showed the presence the hemoplasmal rRNA, strongly suggesting the presence of potentially viable hemoplasmas in the bloodstream of the animals. BLAST search and phylogenetic analysis of the 16S rRNA sequences of the hemoplasma from California sea lions revealed that the organism is a novel hemoplasma species with only 92.1% of its nucleotide similarity to the 16S rRNA gene of the previously described hemoplasma species of alpacas, Candidatus Mycoplasma haemolamae. Thus, due to low level of genetic similarity of the hemoplasma to other described hemoplasmas and the mammalian host in which the hemoplasma was detected we propose that this novel hemoplasma species has been given the provisional name Candidatus Mycoplasma haemozalophi sp. nov.

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. Toxicoses from harmful algal blooms appear to be increasing. Viral epidemics are most common along the Atlantic U.S. coastline, while bacterial epidemics, especially leptospirosis, are most common along the Pacific coast. Certain protozoal and fungal zoonoses appear to be emerging, such as Toxoplasma gondii in southern sea otters in California, and Cryptococcus gattii in cetaceans in the Pacific Northwest. Disease reports were most common from California where pinniped populations are large, but increased effort also occurs. Anthropogenic trauma remains a large threat to marine mammal health, through direct mortality and indirect chronic disease. Neoplasia cases were under-reported from 2003–2012 when compared to true number of cases, and over-reported in several years due to case duplication. Peer-reviewed literature greatly underestimates the true magnitude of disease in marine mammals as it focuses on novel findings, fails to reflect etiology of multifactorial diseases, rarely reports prevalence rather than simple numbers of cases, and is typically presented years after a disease first occurs. Thus literature cannot guide management actions adequately, nor inform indices of ocean health. A real-time, nationally centralized system for reporting marine mammal disease data is needed to be able to understand how marine mammal diseases are changing with ecosystem changes, and before these animals can truly be considered ‘sentinels of ocean health’.

Initial skill assessment of the California Harmful Algae Risk Mapping (C-HARM) system.

Toxic algal events are an annual burden on aquaculture and coastal ecosystems of California. The threat of domoic acid (DA) toxicity to human and wildlife health is the dominant harmful algal bloom (HAB) concern for the region, leading to a strong focus on prediction and mitigation of these blooms and their toxic effects. This paper describes the initial development of the California Harmful Algae Risk Mapping (C-HARM) system that predicts the spatial likelihood of blooms and dangerous levels of DA using a unique blend of numerical models, ecological forecast models of the target group, Pseudo-nitzschia, and satellite ocean color imagery. Data interpolating empirical orthogonal functions (DINEOF) are applied to ocean color imagery to fill in missing data and then used in a multivariate mode with other modeled variables to forecast biogeochemical parameters. Daily predictions (nowcast and forecast maps) are run routinely at the Central and Northern California Ocean Observing System (CeNCOOS) and posted on its public website. Skill assessment of model output for the nowcast data is restricted to nearshore pixels that overlap with routine pier monitoring of HABs in California from 2014 to 2015. Model lead times are best correlated with DA measured with solid phase adsorption toxin tracking (SPATT) and marine mammal strandings from DA toxicosis, suggesting long-term benefits of the HAB predictions to decision-making. Over the next three years, the C-HARM application system will be incorporated into the NOAA operational HAB forecasting system and HAB Bulletin.

Re-alimentation in harbor seal pups: Effects on the somatotropic axis and growth rate

The metabolic hormones, growth hormone (GH) and insulin-like growth factor (IGF)-I, together with IGF binding proteins (IGFBP), have been well studied in domestic species and are the primary components of the somatotropic axis. This hormone axis is responsive to nutrient intake, associated with growth rate, and accretion of protein and adipose. However, this relationship has not been evaluated in species that rely heavily on adipose stores for survival, such as pinnipeds. The primary objectives of this research were to investigate the response of the somatotropic axis to reduced nutrient intake and re-alimentation in rehabilitated harbor seal pups, and to assess if these hormones are related to nutritional status and growth rate in harbor seals. Stranded harbor seal pups (n=24) arrived at the rehabilitation facility very thin after fasting for several days (nutritional nadir). Throughout rehabilitation nutrient intake increased and pups gained mass and body condition. Concentrations of GH and IGFBP-2 decreased with re-alimentation, while IGF-I and IGFBP-3 concentrations increased. Overall, GH and IGFBP-2 were negatively associated and IGF-I and IGFBP-3 were positively associated with growth rate and increased body condition of harbor sea pups. Further, the magnitude of the growth response was related to the magnitude in response of the somatotropic axis to varied levels of intake. These data suggest that multiple components of the somatotropic axis may be used to assess the energy status of individuals and may also provide information on the level of feed intake that is predictive of growth rate.

Evaluation of the Captive Care and Post-Release Behavior and Survival of Seven Juvenile Female Hawaiian Monk Seals (Monachus schauinslandi)

Extremely poor juvenile survival in the endangered Hawaiian monk seal (Monachus schauinslandi) is primarily caused by prey limitation and continues to drive the population decrease in the Northwestern Hawaiian Islands (NWHI). In 2006-2007, a pilot project was conducted to determine whether temporarily providing nutritional supplementation and protection from predation would enhance the survival of juvenile monk seals. Seven female seals, two of which were rare fraternal twins, were included in the captive care (CC) project. Six weanling seals gained weight commensurate with their duration in captivity, 89 to 297 d, with weight gains of 31 to 143% initial body weight, and were released at Midway Atoll. The seventh seal, a female yearling, died 23 d after being admitted from complications associated with malnutrition and stress. The CC and three control seals were instrumented with satellitelinked GPS dive recorders to monitor post-release behavior and survival as part of an assessment of the project’s success. Satellite tags transmitted between 37 and 311 d. Initially, the CC seals foraged closer to shore, used less of the atoll, and dove to shallower depths ( 60 m and > 4 min). Over the course of several weeks, most of the CC and control seals were foraging in a similar fashion. These results demonstrate that following a brief acclimation period, captive-fed monk seals are capable of foraging normally postrelease. However, none of the CC seals were alive as 2-y-olds, whereas two of the control seals were alive in 2010 as 4-y-olds. Although post-release survival was poor in the current study, with a more suitable release location, an expanded captivefeeding program could be a useful tool to salvage the reproductive potential of Hawaiian monk seals in the future.