Imagine the fastest speed you are able to run, now imagine your favorite horror movie villain is chasing you with a chainsaw. This is your VO2 max, or the absolute fastest your body can move.
According to University of Rhode Island professor Dr. Scott McWilliams, a wildlife ecologist and physiologist specializing in migratory birds, Â humans average between 20 and 25 percent of their VO2 max while running a marathon. Birds on the other hand, regularly operate at about 80 percent or more of their VO2 max during migrations. These animals also use fat as their primary source of energy, instead of carbohydrates and proteins like humans.
The Â biological and environmental science program at URI has decided it will hold a series of lectures on a diverse range of subjects to help generate meaningful conversation on the topics. The series kicked off with McWilliams joined by Dr. Bethany Jenkins last week.
Any endurance runner can tell you about “the wall,” where your body runs out of normal fuel types and the begins using fat stored for energy, forcing Â runners to move slower. It takes longer for fat to be metabolized and doing so creates pro-oxidants that damage cells.
Birds combat oxidant damage in their cells by naturally producing more antioxidants and by eating a diet that largely consists of berries during migrations.
“In the system we work in on Block Island, all birds, even if they’re feeding on insects other times of the year, switch to feeding on fruits during their migration and stop over sites,” said McWilliams.
McWilliams studies migratory birds throughout the world and the effect of human activity and construction on them.
“We can use the resource information and then develop maps of where black scoters are expected to be during winter in our neck of the woods,” McWilliams said.
Unlike the Cape Wind Project, the Block Island wind turbines are proposed to be placed off of the coast of the island where the birds spend a large amount of their time. The scoters reside in R.I. in the winter, and scientists like McWilliams fear that the turbines will interfere with the birds natural behavior and habitat.
“We’re essentially addressing if you put a wind-farm here, is it a place that is perhaps going intercept scoters?” McWilliams said.
Another area of research that McWilliams discussed was phenotypic flexibility. He talked about how birds actually shrink their organs while migrating because they change their diet from the high protein of worms and insects to an antioxidant rich berry diet and are eating much less food.
Jenkins discussed the role of nutrients and limiting factors in the ocean on primary production and how it is being effected by human activity.
“These are diatoms, they are the most primary producers in the ocean, they produce every fourth breath of oxygen you breathe,” Jenkins said.
Diatoms are an algae that includes over 100,000 known species. These micro organisms encase themselves in a shell of silica, basically building a glass house around themselves for protection and to allow the sunlight in they need for photosynthesis.
Unlike multicellular organisms, diatoms cannot move around to find food and are subject to using the nutrients present in there surrounding environment. These food sources can range from the naturally occurring to any horrible industrial or toxic waste that comes to mind.
Jenkins and the scientists she works with study the microbes in Narragansett Bay that use nitrogen and how they are affected by the waste that is and has been historically dumped into the bay and other urban estuaries. The excess nitrogen creates the perfect living conditions for the microbes, but the area becomes over populated Â with them fairly quickly. When this happens they start to consume larger amounts of oxygen from the water, especially as they decay.
“You can see from the red,” Jenkins said, motioning to a large portion the map, “that indicates in 2006 where Narraganset Bay, the bottom water was basically zero, in terms of dissolved oxygen.”
When their populations rise too high, some of the algae that produce toxins can start to reach dangerous levels as well. Factors such as these lead to events like when large amounts of fish begin to die and the entire biology for the bay starts to change for the worse.
The environmental series will continue this Friday in the Pharmacy Building auditorium 170 at 3 p.m. The topic is “Ecohydrological controls on phosphorus and nitrogen biogeochemistry,” presented by Dr. Todd Walter from the Department of Biological and Environmental Engineering at Cornell University.