This photodocumentation strengthens the reliability of our data. Volunteers mark dead birds by clipping their wings or toes to prevent recounting them on future surveys. When dead marine mammals are found, volunteers notify the Marine Mammal Stranding Network, which often sends personnel to collect skeletal parts or tissue samples. For example, lab analysis of some Beach Watch tar ball samples has shown that they are of non-coastal California origins. Because contamination can interfere with lab analysis and make results indefensible in court, volunteers must adhere strictly to OSPR protocols, such as using special gloves and containers.
Volunteers also look for oil on dead specimens, and collect oiled feather samples.
They do not collect fresh oil, which is toxic, unless they have the appropriate training. It is useful to do a survey right before oil hits a beach. Baseline data such as rates of dead birds washing up, bird oiling rates, tar ball fingerprinting, and tar ball deposition rates are very useful in the event of an oil spill. Over time, beach monitors become intimately familiar with their areas and become local experts. They will know if a lagoon or river mouth is open or closed on their beach, what's the easiest access to an area of the beach, whether nest sites are active, and which part of the beach is the collection zone where dead things wash up.