Many small cetacean, sirenian, and pinniped species aggregate in groups of large or variable size. Accurate estimation of group sizes is essential for estimating the abundance and distribution of these species, but is challenging as individuals are highly mobile and only partially visible. We developed a Bayesian approach for estimating group sizes using wide‐angle aerial photographic or video imagery. Our approach accounts fo...

The Bristol Bay stock of beluga whales ( Delphinapterus leucas ) is genetically distinct and resides in Bristol Bay year‐round. We estimated the abundance of this population using genetic mark‐recapture, whereby genetic markers from skin biopsies, collected between 2002 and 2011, were used to identify individuals. We identified 516 individual belugas in two inner bays, 468 from Kvichak Bay and 48 from Nushagak Bay, and recaptu...

At least five populations (stocks) of beluga whales ( Delphinapterus leucas ) are thought to winter in the Being Sea, including the Bristol Bay, Eastern Bering Sea (Norton Sound), Anadyr, Eastern Chukchi Sea, and Eastern Beaufort Sea (Mackenzie) populations. Belugas from each population have been tagged with satellite‐linked transmitters, allowing us to describe their winter (January–March) distribution. The objectives of this...

We describe the annual distribution of beluga whales ( Delphinapterus leucas ) in Bristol Bay, Alaska, using data from 31 satellite‐linked transmitters during 2002–2011. Bristol Bay has one of the largest and best studied Pacific salmon ( Oncorhynchus spp.) fisheries in the world, allowing us to link the seasonal distribution of belugas to that of salmon. During salmon migrations, beluga movements were restricted to river entr...

Counts of migrating whales depend on accurate sightings data. In this study, teams of shore‐based observers independently tracked whale pods during the southbound migration of gray whales ( Eschrichtius robustus ) while a routine (“standard watch”) census was underway. A comparison of sighting records showed that time and location accuracy was limited to 45 s, 3° (magnetic) horizontally, and 0.0057° (0.2 reticles) vertically....