Paula A. Olson

Southwest Fisheries Science Center · Marine Mammal and Turtle Division

The sub‐Antarctic waters of South Georgia Island (Islas Georgias del Sur, SG/IG) are a regularly visited feeding ground for southern right whales ( Eubalaena australis , SRW) in the southwest Atlantic. Satellite telemetry and photo‐identification records were compared to better understand the role of SG/IG in the SRW migratory network. We present t...

Most knowledge on the biology and ecology of the spectacled porpoise (Phocoena dioptrica) has been obtained from stranded specimens, with less than fifteen confirmed sightings in the sea. Published photographs of live animals in their natural environment are also very rare. In this study, 28 live sightings are summarised, from Antarctic and sub Ant...

During three surveys in the austral summers of 2013, 2015, 2019, data on Antarctic blue whale blow rates, dive times, swim speeds, and broadscale movements were collected using video photogrammetric tracking and intra-voyage photo-identification. A total of 24.4 hours of video observations were suitable for blow interval or movement analysis. Simil...

In 2018, it was estimated that fewer than 20 of Mexico’s endemic vaquita porpoise Phocoena sinus remained, and the species was declining by 47% yr ⁻¹ . Entanglement in gillnets is the sole threat to the species, and since the last population size estimate, gillnetting has increased in the small area where most vaquitas remain—a 12 × 24 km area in t...

The estuaries and tidal rivers of the Gulf of Maine have rarely been surveyed systematically for marine mammals. We report here on three years of survey data, 2017 to 2019. This study employed a shipboard visual line-transect methodology study design, collecting data on marine mammals in the lower Piscataqua River, which is confluent with the Gulf...

Photo-identification studies of transient killer whales (Orcinus orca) off western North America have primarily been conducted in the coastal inland waterways of Washington State, British Columbia, and southeastern Alaska. Less is known about transient killer whales along the outer coast and offshore waters of Oregon and central and northern Califo...

The west coast (WC) transient killer whale (Orcinus orca) sub-population range throughout the inland waterways of Washington, British Columbia, and Southeast Alaska; as a result these whales have been extensively studied. Transient killer whales encountered off the Central Coast of California were once considered part of the WC sub-population, but...

Blue whales Balaenoptera musculus at South Georgia were heavily exploited during 20 th century industrial whaling, to the point of local near-extirpation. Although legal whaling for blue whales ceased in the 1960s, and there were indications of blue whale recovery across the wider Southern Ocean area, blue whales were seldom seen in South Georgia w...

t has long been assumed that all of the blue whales caught at South Georgia were Antarctic blue whales (Balaenoptera musculus intermedia). Recently re-evaluated catch data, genetic and acoustic studies have suggested that Chilean blue whales (Balaenoptera musculus subsp.) may occasionally, if infrequently, occur at South Georgia, but this has yet t...

Over 170,000 whales were killed in the sub-Antarctic waters of South Georgia (Islas Georgias del Sur, SG, South Atlantic) from 1904 to 1965. In recent decades, whales are regular summer visitors, with the southern right whale (Eubalaena australis) and humpback whale (Megaptera novaeangliea) most commonly reported. A 23-day cetacean survey was condu...

We model the presence of rare Antarctic blue whales (Balaenoptera musculus intermedia) in relation to the swarm characteristics of their main prey species, Antarctic krill (Euphausia superba). A combination of visual observations and recent advances in passive acoustic technology were used to locate Antarctic blue whales, whilst simultaneously usin...

Species conservation depends on robust population assessment. Data on population abundance, distribution, and connectivity are critical for effective management, especially as baseline information for newly documented populations. We describe a pygmy blue whale Balaen - optera musculus brevicauda population in New Zealand waters with year-round pre...

Between 28 January and 10 February 2018, the National Institute of Water and Atmospheric Research and collaborators conducted a voyage to attach satellite tracking devices to pygmy blue whales in the Taranaki region of New Zealand. The aim of this voyage was to examine the movement and habitat utilization of pygmy blue whales in New Zealand waters....

A blue whale foraging ground was recently documented in the South Taranaki Bight (STB) region of New Zealand (NZ), yet blue whales remain listed as ‘Migrant’ under the NZ threat classification system due to minimal knowledge of their ecology and population. We collected relevant data to fill pressing knowledge gaps, leading us to hypothesize that b...

Since 2012, we have investigated a newly documented group of blue whales (Balaenoptera musculus sp.) in the New Zealand region. Field research has focused on multi-disciplinary data collection regarding the ecology of blue whales occurring in the South Taranaki Bight (STB) region of New Zealand (40.15 S, 173.30 W). The STB region incurs significant...

There has been very little previous research on Indo-Pacific humpback dolphins (Sousa chinensis) in the Beibu Gulf of southern China. Here, we report on the population size, habitat and ecology, threats, and overall conservation status of this putative population. 'Population size' was estimated based on photo-identification mark/recapture analysis...

Eight blue whales were photo-identified from coastal waters around New Zealand in 2015: seven from the South Island and one from Raoul Island (of the Kermadec Islands). Our collection of New Zealand blue whale photo-identifications now totals 38 individuals (27 left sides, 25 right sides). The 2015 photos were compared to one another and to 31 iden...

Identification photographs of individual Antarctic blue whales were collected from multiple sources, 1991-2016, and compiled into the Antarctic Blue Whale Catalogue. Sources include the IWC IDCR/SOWER cruises, IWC-SORP voyages, the Institute of Cetacean Research, and naturalists and collegial scientists working in the Antarctic region. This year, s...

Blue whales are infrequently reported from New Zealand and their taxonomic status is unclear. Here we present new information on the residency, external morphology, and habitat use of blue whales encountered in New Zealand waters. Thirty-one blue whales were photo-identified around the North and South Islands of New Zealand from 2004-2014 in seven...

Blue whales (Balaenoptera musculus) were among the most intensively exploited species of whales in the world. As a consequence of this intense exploitation, blue whale sightings off the coast of Chile were uncommon by the end of the 20th century. In 2004, a feeding and nursing ground was reported in southern Chile (SCh). With the aim to investigate...

Since its near extirpation during the period of industrial whaling in the early and mid 20th century, the once common Antarctic blue whale Balaenoptera musculus intermedia remains extremely rare. While annual systematic surveys around Antarctica from 1978 to 2009 recorded only 216 visual encounters of this species, their loud and distinctive calls...

Previous underwater recordings made in New Zealand have identified a complex sequence of low frequency sounds that have been attributed to blue whales based on similarity to blue whale songs in other areas. Recordings of sounds with these characteristics were made opportunistically during the Southern Ocean Research Partnership's recent Antarctic B...

Movements of Antarctic blue whales on their summer foraging grounds have been described using data from the Discovery marking program, photo identification studies and acoustic recordings. However, these techniques are unable to provide a continuous time-series of actual movements, instead inferring movement from two (or more) known locations at tw...

Observations of killer whales (Orcinus orca) during a survey off East Antarctica, 82°–95°E revealed previously undescribed variations in pigmentation and group associations. During the survey 24 killer whale groups were sighted south of 60°S and classified, when possible, to Types A, B, or C based on their external morphology. Sufficient observatio...

Studies have shown that killer whale (Orcinus orca) communities in high latitudes regularly comprise assemblages of sympatric ‘ecotypes’—forms that differ in morphology, behavior, and prey preferences. Although they can appear superficially similar, recent genetic evidence suggests that breeding is assortative among ecotypes within individual commu...

Photographs of blue whales have been collected during annual IWC IDCR/SOWER cruises since 1987-1988. The archiving and analysis of these photographs has been undertaken to aid in the assessment of Southern Hemisphere blue whales. Over 23,000 photographs were obtained from all six IWC Management Areas during cruises from 1987-1988 to 2008-2009. 16 y...

The vaquita (Phocoena sinus) is the most endangered species of cetacean in the world, with an estimated global population of less than 150 individuals. The species is listed as Critically Endangered by the IUCN, and is on the U.S. and Mexican endangered species lists. It is expected that the population will dwindle to extinction if management solut...

Photographs of blue whales have been collected during annual IWC IDCR/SOWER surveys since 1987-1988. The archiving and analysis of these photographs has been undertaken to aid in the assessment of Southern Hemisphere blue whales. Over 22,000 photographs were obtained from all six IWC Management Areas during 20 Antarctic research cruises through 200...

Distribution and prevalence of the phoretic barnacle Xenobalanus on cetacean species are reported for 22 cetaceans in the eastern tropical Pacific Ocean (21 million km2). Four cetacean species are newly reported hosts for Xenobalanus: Bryde's whale (Balaenoptera edeni), long-beaked common dolphin (Delphinus capensis), humpback whale (Megaptera nova...

We conducted the 30 th annual IWC-SOWER (formerly IDCR) Cruise in the eastern part of Antarctic Area IV aboard the Japanese Research Vessel Shonan Maru No.2. The cruise departed Fremantle, Australia on 24 December 2007 and returned to Benoa, Bali, Indonesia on 26 February 2008. The cruise had three main objectives: 1) survey waters outside the pack...

Over 21,000 identification photographs of blue whales were collected during 19 IWC IDCR/SOWER Antarctic cruises conducted from 1987-1988 to 2007-2008. Archiving and analysis of these photographs has been undertaken at SWFSC to aid in the assessment of Southern Hemisphere blue whales. Photographs were obtained from all six IWC Management Areas and r...