In the wild, California sea lions (Zalophus californianus) are exposed to a wide variety of sensory information, which cannot be replicated in captive environments. Therefore, unique procedures are necessary for maintaining physiological and psychological health in nonhuman animals in captivity. The effects of introducing natural scents to captive enclosures have been investigated in a variety of species, yet they have not been examined in marine mammals. This project explored the behavioral effect of scent added to the environment, with the goal of improving the welfare of sea lions in captivity. Two scent types were introduced: (a) natural scents, found in their native environment, and (b) non-natural scents, not found in their native environment. This study examined not only scent enrichment but also the possible evolutionary underpinnings of pinniped olfaction. Scent enrichment was found to significantly impact sea lion behavior as demonstrated by a reduction in pattern swimming, an increase in habitat utilization, and a reduction in stereotypical behavior. However, there were no differences in behavior between natural and non-natural scent conditions.

The impact of the intestinal and fecal microbiome on animal health has received considerable attention in recent years and has direct implications for the veterinary and wildlife rehabilitation fields. To examine the effects of rehabilitation on the microbiome in Kemp’s ridley sea turtlesLepidochelys kempii, fecal samples from 30 incidentally captured juveniles were collected during rehabilitation. Samples were analyzed to determine alpha- (α) and beta- (β) diversity as well as the taxonomic abundance of the fecal microbiota during rehabilitation and in response to treatment with antibiotics. The fecal microbial communities of animals housed in rehabilitation for a ‘short-term’ stay (samples collected 0-9 d post-capture) were compared with ‘long-term’ (samples collected 10+ d post-capture) and ‘treated’ groups (samples collected from turtles that had received antibiotic medication). Results of this study indicate that the most dominant phylum in fecal samples wasBacteroidetes(relative abundance, 45.44 ± 5.92% [SD]), followed byFirmicutes(26.62 ± 1.58%),Fusobacteria(19.49 ± 9.07%), andProteobacteria(7.39 ± 1.84%). Similarly, at the family level,Fusobacteriaceae(28.36 ± 17.75%),Tannerellaceae(15.41 ± 10.50%),Bacteroidaceae(14.58 ± 8.48%), andRuminococcaceae(11.49 ± 3.47%) were the most abundant. Our results indicated that both antibiotic-treated and long-term rehabilitated turtles demonstrated a significant decrease in β-diversity when compared to short-term rehabilitated turtles. Our results likewise showed that the length of time turtles spent in rehabilitation was negatively correlated with α- and β-diversity. This study demonstrates the importance of a judicious use of antibiotics during the rehabilitation process and emphasizes the importance of limiting the length of hospital stays for sick and injured sea turtles as much as possible.

Preclinical studies have shown that chronic alcohol abuse leads to alterations in the gastrointestinal microbiota that are associated with behavior changes, physiological alterations, and immunological effects. However, such studies have been limited in their ability to evaluate the direct effects of alcohol-associated dysbiosis. To address this, we developed a humanized alcohol-microbiota mouse model to systematically evaluate the immunological effects of chronic alcohol abuse mediated by intestinal dysbiosis. Germ-free mice were colonized with human fecal microbiota from individuals with high and low Alcohol Use Disorders Identification Test (AUDIT) scores and bred to produce human alcohol-associated microbiota or human control-microbiota F1 progenies. F1 offspring colonized with fecal microbiota from individuals with high AUDIT scores had increased susceptibility to Klebsiella pneumoniae and Streptococcus pneumoniae pneumonia, as determined by increased mortality rates, pulmonary bacterial burden, and post-infection lung damage. These findings highlight the importance of considering both the direct effects of alcohol and alcohol-induced dysbiosis when investigating the mechanisms behind alcohol-related disorders and treatment strategies.

Estimating population parameters such as survival and population growth is critical for the monitoring of at-risk populations of marine mammals. We conducted monthly boat-based photo-identification surveys in the Mississippi Sound and eastern Louisiana waters during January 2011–June 2015 to assess the status of the Mississippi Sound, Lake Borgne, and Bay Boudreau Tursiops truncatus (Common Bottlenose Dolphin) stock. Using the resulting mark–recapture data, we estimated the survival and population growth rates using a reverse capture–recapture method. The estimated monthly survival probability over this period of time was 0.969 (95% CI: 0.964–0.974). The final monthly population growth rate was then estimated to be 1.005 (95% CI: 0.998–1.013), which suggests a relatively stable population.