Southern Hemisphere Humpback Whales Research Articles

Cytochrome P450 isozyme protein verified in the skin of southern hemisphere humpback whales (Megaptera novaeangliae): Implications for biochemical biomarker assessment

Large mysticete whales represent a unique challenge for chemical risk assessment. Few epidemiological investigations are possible due to the low incidence of adult stranding events. Similarly their often extreme life-history adaptations of prolonged migration and fasting challenge exposure assumptions. Molecular biomarkers offer the potential to complement information yielded through tissue chemical analysis, as well as providing evidence of a molecular response to chemical exposure. In this study we confirm the presence of cytochrome P450 reductase (CPR) and cytochrome P450 isoenzyme 1A1 (CYP1A1) in epidermal tissue of southern hemisphere humpback whales (Megaptera novaeangliae). The detection of CYP1A1 in the integument of the humpback whale affords the opportunity for further quantitative non-destructive investigations of enzyme activity as a function of chemical stress.

Return movement of a humpback whale between the Antarctic Peninsula and American Samoa: a seasonal migration record

ESR Endangered Species Research Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsSpecials ESR 13:117-121 (2011) - DOI: https://doi.org/10.3354/esr00328 NOTE Return movement of a humpback whale between the Antarctic Peninsula and American Samoa: a seasonal migration record Jooke Robbins1,*, Luciano Dalla Rosa2,3,4, Judith M. Allen5, David K. Mattila6, Eduardo R. Secchi2,4, Ari S. Friedlaender7, Peter T. Stevick5, Douglas P. Nowacek7,8, Debbie Steel9 1Provincetown Center for Coastal Studies, 5 Holway Avenue, Provincetown, Massachusetts 02657, USA 2Projeto Baleias/Brazilian Antarctic Program, Museu Oceanográfico ‘Prof. Eliézer C. Rios’, FURG, Rio Grande, RS 96200-970, Brazil 3Department of Zoology and Marine Mammal Research Unit, University of British Columbia, Room 247, AERL, 2202 Main Mall, Vancouver, British Columbia V6T 1Z4, Canada 4Laboratório de Tartarugas e Mamíferos Marinhos/Instituto de Oceanografia, Universidade Federal do Rio Grande-FURG, Cx.P. 474, Rio Grande, RS 96201-900, Brazil 5Antarctic Humpback Whale Catalog, Allied Whale, College of the Atlantic, Bar Harbor, Maine 04609, USA 6Hawaiian Islands Humpback Whale National Marine Sanctuary, 726 S. Kihei Road, Kihei, Hawaii 96753, USA 7Nicholas School of the Environment, and 8Pratt School of Engineering, Duke University Marine Laboratory, 135 Duke Marine Lab Rd., Beaufort, North Carolina 28516, USA 9Marine Mammal Institute, Oregon State University, 2030 SE Marine Science Drive, Newport, Oregon 97366, USA *Email: jrobbins@coastalstudies.org ABSTRACT: Humpback whales Megaptera novaeangliae are seasonal migrants that mate and calve at low latitudes and feed at mid- to high latitudes. Connections between most Southern Hemisphere breeding and feeding areas are not well understood, but are critical for assessing stock structure and human impacts. Photo-identification was performed to identify the feeding grounds of an Endangered sub-population that breeds in the central South Pacific Ocean (CSP). Identification photographs were obtained from 159 ind. at American Samoa and compared to 3508 Southern Hemisphere humpback whales in the Antarctic Humpback Whale Catalogue (AHWC), including 1352 from Antarctic feeding grounds. Two individuals from American Samoa were seen on 3 occasions at the Antarctic Peninsula. This is the first known feeding site for American Samoa and one of few reliably identified for the CSP. AHWC #2950 was confirmed to have undertaken a round-trip movement of no less than 18840 km, spanning 108 longitudinal degrees. This represents the largest mammalian migration known to date and a departure from historical assumptions about CSP migratory patterns. The frequency, causes, and fitness implications of such movements have yet to be determined. However, distance is the only known extrinsic barrier to humpback whale movement within oceans, and so maximum individual range is 1 factor potentially affecting population exchange and colonization of new habitats. The movement documented here may place this Endangered sub-population at risk if conservation efforts are relaxed in unidentified parts of its range. Yet, the ability of humpback whales to undertake such extensive movements may have also contributed to the apparent recovery of some populations versus other historically exploited whale species. KEY WORDS: Migration · Humpback whale · Photo-ID · Spatial distribution · Conservation Full text in pdf format PreviousNextCite this article as: Robbins J, Dalla Rosa L, Allen JM, Mattila DK and others (2011) Return movement of a humpback whale between the Antarctic Peninsula and American Samoa: a seasonal migration record. Endang Species Res 13:117-121. https://doi.org/10.3354/esr00328 Export citation RSS - Facebook - Tweet - linkedIn Cited by Published in ESR Vol. 13, No. 2. Online publication date: January 27, 2011 Print ISSN: 1863-5407; Online ISSN: 1613-4796 Copyright © 2011 Inter-Research.

Mitochondrial DNA diversity of the Southwestern Atlantic humpback whale (Megaptera novaeangliae) breeding area off Brazil, and the potential connections to Antarctic feeding areas

In the Southwestern Atlantic Ocean, humpback whales migrate every winter to the Brazilian coast for breeding and calving in the Abrolhos Bank. This breeding stock represents the remnants of a larger population heavily exploited during the beginning of the 20th century. Despite its relevance to conservation efforts, the degree of current genetic variation and the migratory relationship with Antarctic feeding areas for this population are still largely unknown. To examine these questions, we sequenced ∼400 bp of the mitochondrial DNA control region from samples taken off the Brazilian coast (n = 171) and near the Antarctic Peninsula (n = 77). The genetic variability of the Brazilian humpback whale breeding population was high and similar to that found in other Southern Hemisphere breeding grounds. Phylogenetic analysis suggested the existence of a new mitochondrial clade that exists at low frequency among Southern Hemisphere populations. Direct comparison between the Brazilian and the Colombia breeding populations and the Antarctic Peninsula feeding population showed no genetic differentiation between this feeding region and the Colombian breeding area or between feeding Areas I and II near the Antarctic Peninsula. In contrast, these populations were genetically distinct from the Brazilian population. Two humpback whales sampled off South Georgia Islands, in the Scotia Sea, shared identical haplotypes to whales from Brazil. Our results, supported by photo-identification and satellite telemetry data, suggest that the main feeding area of the Southern Hemisphere humpback whale population is likely to be located near the South Georgia/South Sandwich Islands area and not in the Antarctic Peninsula.

A Case For Killing Humpback Whales?

AbstractDuring the austral summer of 2007/08, hunting of Southern Hemisphere (SH) humpback whales will recommence after almost half a century of protection. The stated rationale for this hunt, by the Government of Japan (GoJ), is to gather important scientific information for use in management. If the scientific need were defensible, and the proponents had accommodated reasonable conservation concerns, then criticisms of the hunt would be limited to philosophical issues. This is not the case. The program’s research objectives are unlikely to be achieved by lethal methods and do not address the principal research needs for SH humpback whales identified by the International Whaling Commission (IWC).

Southern Hemisphere humpback whales wintering off Central America: insights from water temperature into the longest mammalian migration

We report on a wintering area off the Pacific coast of Central America for humpback whales (Megaptera novaeangliae) migrating from feeding areas off Antarctica. We document seven individuals, including a mother/calf pair, that made this migration (approx. 8300km), the longest movement undertaken by any mammal. Whales were observed as far north as 11 degrees N off Costa Rica, in an area also used by a boreal population during the opposite winter season, resulting in unique spatial overlap between Northern and Southern Hemisphere populations. The occurrence of such a northerly wintering area is coincident with the development of an equatorial tongue of cold water in the eastern South Pacific, a pattern that is repeated in the eastern South Atlantic. A survey of location and water temperature at the wintering areas worldwide indicates that they are found in warm waters (21.1-28.3 degrees C), irrespective of latitude. We contend that while availability of suitable reproductive habitat in the wintering areas is important at the fine scale, water temperature influences whale distribution at the basin scale. Calf development in warm water may lead to larger adult size and increased reproductive success, a strategy that supports the energy conservation hypothesis as a reason for migration.

Satellite-monitored movements of humpback whales Megaptera novaeangliae in the Southwest Atlantic Ocean

Southern Hemisphere humpback whales Megaptera novaeangliae migrate from wintering grounds in tropical latitudes to feeding areas in the Antarctic Ocean. It has been hypo- thesized that the population wintering off eastern South America migrates to feeding grounds near the Antarctic Peninsula (ca. 65° S, 60° W) and/or South Georgia (54° 20' S, 36° 40' W), but direct evi- dence to support this has never been presented. Between 19 and 28 October 2003, 11 humpback whales (7 females and 4 males) were instrumented with satellite transmitters off Brazil (ca. 18° 30' S, 39° 30' W) to investigate their movements and migratory destinations. Mean tracking time for the whales was 39.6 d (range = 5 to 205 d) and mean distance travelled was 1673 km per whale (range = 60 to 7258 km). Movements on the wintering ground showed marked individual variation. Departure dates from the Brazilian coast ranged from late October to late December. Whales migrated south through oceanic waters at an average heading of 170° and travelled a relatively direct, linear path from wintering to feeding grounds. Two whales were tracked to feeding grounds in offshore areas near South Georgia and in the South Sandwich Islands (58° S, 26° W) after a 40 to 60 d long migration. Historical catches and current sighting information support these migratory routes and destinations. This study is the first to describe the movements of humpback whales in the western South Atlantic Ocean.

Indexing seasonal abundance of humpback whales around Abrolhos Archipelago, Bahia, Brazil

The waters surrounding Abrolhos Archipelago, Brazil, serve as one of several winter grounds for southern-hemisphere humpback whales ( Megaptera novaeangliae ). Development of tourism in this region has caused concern over disturbance effects to breeding and nursing whales. To document the chronology of humpback abundance around Abrolhos, three years of visual-scan data obtained during July through November 1998-2000 were analyzed. During 1-hour scans, observers visually tracked all groups within 9.3km and nearly 360° around a land-based theodolite station to determine group size, composition and behavior. Including only groups of known size, hourly counts (n=462) of adult and calf humpback whales ranged from 0-31 and 0-9, respectively. Group size could not be determined for 255 of 2146 groups observed. Humpback whale abundance was seasonal: there were few in early July when surveys began, peaked in early September, and then gradually declined to zero by late November. Based on Poisson regression, the annual chronology of whale occupancy was relatively invariant. Peak counts averaged about 15 adult whales per hour. Although no evidence was found that the timing of peak counts varied, peak abundance varied among years, and more whales were seen during morning than afternoon. The mean number of adults per group did not vary over time (year, day of year, or time of day), but the likelihood of group size being indeterminate varied predictably. Thus, indices of abundance could be adjusted by assuming that the size of indeterminate groups equals mean group size. Calf abundance varied with adult abundance, and the proportion of groups with calves increased from July through November. The high frequency of groups containing a calf (49.8%) within 9.3km of the Abrolhos Archipelago demonstrated the importance of this area for calves, and proper management is recommended.

Migration redefined? Seasonality, movements and group composition of humpback whales Megaptera novaeangliae off the west coast of South Africa

The migration of Southern Hemisphere humpback whales Megaptera novaeangliae between their feeding and breeding areas has thus far been considered a highly predictable and seasonal event. However, previous observations on the humpbacks that pass through the nearshore waters of the west coast of South Africa have revealed deviations from the behaviour and seasonality expected during a typical migration. This ‘anomaly’ is hypothesised to be associated with prey availability in the region. Shore-based observations between July 2001 and February 2003 from North Head, Saldanha Bay, in the Western Cape province, yielded relative abundances that again did not support a classical migration pattern, with the highest sighting rates from mid-spring through summer. Movement parameters (actual swimming speed, direction and linearity) of humpback groups tracked by theodolite showed mid-spring to be a turning point in their behaviour, after which we observed a significant reduction in actual swimming speed, an increase in ‘non-directional’ movement, and a distribution farther from shore than in other seasons. Additional data on group composition and sex collected between 1993 and 2008 showed a significantly female-biased sex ratio during mid-spring, the first such recorded for any region. Direct observation of feeding on crustacean prey during spring and summer further supports the notion that humpbacks may have more flexible foraging habits than previously appreciated, and that the southern Benguela upwelling region may function as an important feeding area for these whales.