Tourists perceptions of Caribbean islands facing environmental threats before the COVID-19 health crisis: Holbox Island and Archipelago of Bocas del Toro.

Knowledge gaps exist in the socio-ecological systems of small touristic islands in Latin America. Understanding tourists' perceptions of their environmental knowledge can help plan actions to prevent natural capital loss necessary for local economies. Tourists' perceptions of a touristic hotspot, Holbox Island, were documented. Surveys demonstrated that tourists are aware of their environmental impacts and are interested in minimizing these. Results were compared with results on Bocas del Toro, Panama. Tourists' perceptions had similarities among sites driven by similarities in tourists' populations with a common geographic origin. Tourists lack site-specific knowledge to steer them towards environmentally conscious decisions in both regions. Findings suggest the need to promote local actions to gain tourists' understanding about their destination and support education programs on island conservation. Addressing these needs can help build resilience to overcome the adverse socio-environmental effects of tourism, environmental disasters, and health crises as COVID-19 on small islands.

Pacific Ocean-wide profile of CYP1A1 expression, stable carbon and nitrogen isotope ratios, and organic contaminant burden in sperm whale skin biopsies.

BACKGROUND: Ocean pollution affects marine organisms and ecosystems as well as humans. The International Oceanographic Commission recommends ocean health monitoring programs to investigate the presence of marine contaminants and the health of threatened species and the use of multiple and early-warning biomarker approaches. OBJECTIVE: We explored the hypothesis that biomarker and contaminant analyses in skin biopsies of the threatened sperm whale (Physeter macrocephalus) could reveal geographical trends in exposure on an oceanwide scale. METHODS: We analyzed cytochrome P450 1A1 (CYP1A1) expression (by immunohistochemistry), stable nitrogen and carbon isotope ratios (as general indicators of trophic position and latitude, respectively), and contaminant burdens in skin biopsies to explore regional trends in the Pacific Ocean. RESULTS: Biomarker analyses revealed significant regional differences within the Pacific Ocean. CYP1A1 expression was highest in whales from the Galapagos, a United Nations Educational, Scientific, and Cultural Organization World Heritage marine reserve, and was lowest in the sampling sites farthest away from continents. We examined the possible influence of the whales' sex, diet, or range and other parameters on regional variation in CYP1A1 expression, but data were inconclusive. In general, CYP1A1 expression was not significantly correlated with contaminant burdens in blubber. However, small sample sizes precluded detailed chemical analyses, and power to detect significant associations was limited. CONCLUSIONS: Our large-scale monitoring study was successful at identifying regional differences in CYP1A1 expression, providing a baseline for this known biomarker of exposure to aryl hydrocarbon receptor agonists. However, we could not identify factors that explained this variation. Future oceanwide CYP1A1 expression profiles in cetacean skin biopsies are warranted and could reveal whether globally distributed chemicals occur at biochemically relevant concentrations on a global basis, which may provide a measure of ocean integrity.

Interfamilial characterization of a region of the ZFX and ZFY genes facilitates sex determination in cetaceans and other mammals.

Sequence polymorphism of homologues ZFX and ZFY, in a 604-base pair exon region, was examined in 10 known males and 10 known females across seven cetacean families and used to design a simple, highly sensitive and widely applicable fluorescent 5' exonuclease assay for gender determination in cetaceans. Multiplex amplification, cloning, and sequencing of these previously uncharacterized regions revealed (i) eight fixed differences between ZFX and ZFY, (ii) 29 variable sites between ZFX and ZFY and (iii) very low interspecific nucleotide diversity for both ZFX and ZFY across all families examined. We developed a 5' exonuclease assay that produces a small (105 bp) polymerase chain reaction (PCR) product from both the X and the Y chromosome orthologs, and used double-labelled fluorescent probes to distinguish between the two genes in a real-time PCR assay that is highly reproducible and sensitive. We demonstrated sex specificity for 33 cetacean species in nine families. Given the availability of conserved primers and sequence information for many mammalian species, this approach to designing sexing assays for a wide range of species is both practical and efficient.