American Alligators

Alligators are a great example of a ‘sentinel species’ for human health because they are top predators, and do not migrate (usually stay within 5 miles of their “territory”), and are thus a record of the effects of both past and ongoing contamination.

Starting in July of 2018, our team began sampling alligators at many locations up and down the Cape Fear River and outside of the Cape Fear watershed. To date we have sampled from > 90 alligators.


Gather current data on the American alligator population across NC, and compare that data to ongoing studies of coastal NC.  The initial studies will involve the collection of tissue and blood/urine samples from adult and juvenile alligators.  These samples will be:

  • analyzed to determine levels of contaminants for comparison with animals sampled in different areas of NC
  • used to determine health status through analysis of blood chemistry and other biomarkers
  • coupled with future satellite tracking data to establish land use patterns of alligators that will ensure a data-driven approaches for conservation of alligators in NC

Photo by Alan Cradick

We use an active capture method for American Alligators. This involves a barbless treble hook on the end of a fishing line or kevlar rope to bring the animal close enough to snare it with a dog pole. From there, we get control of the head, close and secure the jaws, and place a towel over the eyes to keep the animal calm. Once that is done, a quick blood sample is taken along with measurements of the body. Finally, we tag the animal with permanent scute markings and a PIT (passive RIFD) tag like is used on dogs and cats. This allows any member of our team or the North Carolina Wildlife Resources Commission to track the animal if it is captured again. Before we release the animal we paint it with a harmless wax based cattle paint so that we know if we've captured the animal recently, even from a distance.

This method has been developed over many years, several states, and a couple of continents to maximize safety for the animal, our team, and any onlookers.