boat densities over time and the quantity of Fraser River Chinook salmon, the main constituent of orca diet in those regions. Boat densities and the salmon abundance over time were estimated independently. Glucocorticoids in orcas rise when the animal faces psychological tension or starvation. The study found that prey is maximum in August, at which time, boats are most abundant. Conversely, the availability of salmon was minimum in late fall when the level of marine boat traffic was also the least. Glucocorticoid levels were highest in the fall when there was a shortage of prey and maximum during August at the height of availability of food. Similarly, thyroid hormones co-relate to nutritional stress, enabling animals to lower metabolism rates to better conserve declining nutrition. The Southern Resident Killer Whales arrive in the study area in spring after having fed on salmons from early spring spawning on other rivers when their thyroid hormone levels are highest. The hormone levels decline as the animals arrive in the study area, plateau during the time of fish availability and decline further during the period of nutritional scarcity. The toxin analysis was ongoing at the time of publication of research. So far, presence of congeners of the three toxins in whale feces are found to be proportionate to the levels of these chemicals measured in samples of orca flesh during biopsy. The results indicate that restoring the abundance and quality of available prey is an important first measure to restoring orca populations in the area under study. Biodiversity indicator An analysis of feces of two dolphin and one whale species led to the discovery of a new species of Helicobacter, namely Helicobacter cetorum, the bacteria being associated with clinical symptoms and gastritis in the cetaceans. See also Ambergris References External links The 8-year-old who discovered a $65,000 piece of whale poop Biological oceanography Feces Marine biology Whales