As well as advising local authorities and playing a practical role, returning stranded mammals to the sea and coordinating efforts to remove carcasses, the National Stranding Networks also act as an environmental observer.

Strandings provide a significant source of information about cetacean and pinniped (seals, otters etc.) populations along the Pelagos Sanctuary coastline.

Monitoring strandings, then, provides demographic information on the species studied (cause of death, reproduction, growth) and enables biological samples to be taken, which can be used to identify an individual’s species, age, reproductive status, pollutant concentrations, pathologies, and diet; this information provides an insight into the state of marine mammal populations, their relationship with the ecosystem and, occasionally, the impact of human activities.

Monitoring stranding events gives a lot of benefits:

• Understanding a species: information on some species can only be collected via strandings, as they are rarely seen at sea.
• The distribution of different species: analyzing the geography of strandings provides an insight into cetacean distribution.
• Understanding the biology of different species: genetics of different populations, feeding habits, structures of different populations.
• Understanding causes of death: natural deaths, being captured in nets, ship strikes, pollution monitoring (cetaceans, at the end of the food chain, consume concentrated amounts of pesticides and heavy metals), parasitology, infectious diseases, assessing the risk of diseases that can be transmitted to humans etc.
• Annual mortality monitoring: establishing a mortality index. The Network, in operation for nearly fifty years, has gathered and analyzed information. This made it possible to determine a ‘normal’ mortality index, known as a ‘benchmark’, which can be used to explore the features of particular events and, as a result, alert scientists.
• Other scientific research: biometry, genetics of different populations, whales’ feeding areas, feeding habits studies, determining the cetacean sex ratio, age, anatomy etc. and other information derived from samples.
• And occasionally the successful rescue of living cetaceans!