scholarly journals Humpback whale song recordings suggest common feeding ground occupation by multiple populations

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Elena Schall ◽  
Karolin Thomisch ◽  
Olaf Boebel ◽  
Gabriele Gerlach ◽  
Sari Mangia Woods ◽  
...  
Keyword(s):  
Southern Ocean ◽  
Behavioral Plasticity ◽  
Prey Availability ◽  
Humpback Whale ◽  
Sea Ice Concentration ◽  
Atlantic Sector ◽  
Feeding Ground ◽  
Breeding Grounds ◽  
Spatio Temporal ◽  
Feeding Grounds

AbstractHumpback whale males are known to sing on their low-latitude breeding grounds, but it is well established that songs are also commonly produced ‘off-season’ on the feeding grounds or during migration. This opens exciting opportunities to investigate migratory aggregations, study humpback whale behavioral plasticity and potentially even assign individual singers to specific breeding grounds. In this study, we analyzed passive acoustic data from 13 recording positions and multiple years (2011–2018) within the Atlantic sector of the Southern Ocean (ASSO). Humpback whale song was detected at nine recording positions in five years. Most songs were recorded in May, austral fall, coinciding with the rapid increase in sea ice concentration at most recording positions. The spatio-temporal pattern in humpback whale singing activity on Southern Ocean feeding grounds is most likely shaped by local prey availability and humpback whale migratory strategies. Furthermore, the comparative analyses of song structures clearly show a differentiation of two song groups, of which one was solely recorded at the western edge of the ASSO and the other song group was recorded throughout the ASSO. This new finding suggests a common feeding ground occupation by multiple humpback whale populations in the ASSO, allowing for cultural and potentially even genetic exchange among populations.

scholarly journals Multi-year presence of humpback whales in the Atlantic sector of the Southern Ocean but not during El Niño

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Elena Schall ◽  
Karolin Thomisch ◽  
Olaf Boebel ◽  
Gabriele Gerlach ◽  
Sari Mangia Woods ◽  
...  
Keyword(s):  
Southern Ocean ◽  
El Niño ◽  
El Nino ◽  
Humpback Whales ◽  
Low Latitude ◽  
Sea Ice Extent ◽  
Atlantic Sector ◽  
Acoustic Data ◽  
Breeding Grounds ◽  
Passive Acoustic

AbstractHumpback whales are thought to undertake annual migrations between their low latitude breeding grounds and high latitude feeding grounds. However, under specific conditions, humpback whales sometimes change their migratory destination or skip migration overall. Here we document the surprising persistent presence of humpback whales in the Atlantic sector of the Southern Ocean during five years (2011, 2012, 2013, 2017, and 2018) using passive acoustic data. However, in the El Niño years 2015 and 2016, humpback whales were virtually absent. Our data show that humpback whales are systematically present in the Atlantic sector of the Southern Ocean and suggest that these whales are particularly sensitive to climate oscillations which have profound effects on winds, sea ice extent, primary production, and especially krill productivity.

scholarly journals Humpback Whale Song on the Southern Ocean Feeding Grounds: Implications for Cultural Transmission

PLoS ONE ◽  
2013 ◽  
Vol 8 (11) ◽  
pp. e79422 ◽  
Author(s):  
Ellen C. Garland ◽  
Jason Gedamke ◽  
Melinda L. Rekdahl ◽  
Michael J. Noad ◽  
Claire Garrigue ◽  
...  
Keyword(s):  
Southern Ocean ◽  
Cultural Transmission ◽  
Humpback Whale ◽  
Feeding Grounds

scholarly journals Large-scale spatial variabilities in the humpback whale acoustic presence in the Atlantic sector of the Southern Ocean

2020 ◽  
Vol 7 (12) ◽  
pp. 201347
Author(s):  
Elena Schall ◽  
Karolin Thomisch ◽  
Olaf Boebel ◽  
Gabriele Gerlach ◽  
Stefanie Spiesecke ◽  
...  
Keyword(s):  
Southern Ocean ◽  
High Latitude ◽  
Large Scale ◽  
Austral Summer ◽  
Humpback Whale ◽  
Humpback Whales ◽  
Stock Management ◽  
Atlantic Sector ◽  
Acoustic Activity ◽  
Passive Acoustic

Southern Hemisphere humpback whales ( Megaptera novaeangliae ) inhabit a wide variety of ecosystems including both low- and high-latitude areas. Understanding the habitat selection of humpback whale populations is key for humpback whale stock management and general ecosystem management. In the Atlantic sector of the Southern Ocean ( ASSO ), the investigation of baleen whale distribution by sighting surveys is temporally restricted to the austral summer. The implementation of autonomous passive acoustic monitoring, in turn, allows the study of vocal baleen whales year-round. This study describes the results of analysing passive acoustic data spanning 12 recording positions throughout the ASSO applying a combination of automatic and manual analysis methods to register humpback whale acoustic activity. Humpback whales were present at nine recording positions with higher acoustic activities towards lower latitudes and the eastern and western edges of the ASSO . During all months, except December (the month with the fewest recordings), humpback whale acoustic activity was registered in the ASSO . The acoustic presence of humpback whales at various locations in the ASSO confirms previous observations that part of the population remains in high-latitude waters beyond austral summer, presumably to feed. The spatial and temporal extent of humpback whale presence in the ASSO suggests that this area may be used by multiple humpback whale breeding populations as a feeding ground.

scholarly journals New insights into prime Southern Ocean forage grounds for thriving Western Australian humpback whales

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Sophie Bestley ◽  
Virginia Andrews-Goff ◽  
Esmee van Wijk ◽  
Stephen R. Rintoul ◽  
Michael C. Double ◽  
...  
Keyword(s):  
Southern Ocean ◽  
Humpback Whale ◽  
Humpback Whales ◽  
Western Boundary ◽  
Boundary Current ◽  
Austral Spring ◽  
Partial Explanation ◽  
Migration Pathways ◽  
Western Australian ◽  
Feeding Grounds

Abstract Humpback whale populations migrate extensively between winter breeding grounds and summer feeding grounds, however known links to remote Antarctic feeding grounds remain limited in many cases. New satellite tracks detail humpback whale migration pathways from Western Australia into the Southern Ocean. These highlight a focal feeding area during austral spring and early summer at the southern Kerguelen plateau, in a western boundary current where a sharp northward turn and retroflection of ocean fronts occurs along the eastern plateau edge. The topographic steering of oceanographic features here likely supports a predictable, productive and persistent forage ground. The spatial distribution of whaling catches and Discovery era mark-recaptures confirms the importance of this region to Western Australian humpback whales since at least historical times. Movement modelling discriminates sex-related behaviours, with females moving faster during both transit and resident periods, which may be a consequence of size or indicate differential energetic requirements. Relatively short and directed migratory pathways overall, together with high-quality, reliable forage resources may provide a partial explanation for the ongoing strong recovery demonstrated by this population. The combination of new oceanographic information and movement data provides enhanced understanding of important biological processes, which are relevant within the context of the current spatial management and conservation efforts in the Southern Ocean.

scholarly journals The Southern Ocean Exchange: porous boundaries between humpback whale breeding populations in southern polar waters

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
M. C. C. Marcondes ◽  
T. Cheeseman ◽  
J. A. Jackson ◽  
A. S. Friedlaender ◽  
L. Pallin ◽  
...  
Keyword(s):  
Southern Ocean ◽  
High Latitude ◽  
Prey Availability ◽  
Humpback Whale ◽  
Humpback Whales ◽  
West Antarctic ◽  
Breeding Populations ◽  
Commercial Whaling ◽  
Feeding Area ◽  
New Evidence

AbstractHumpback whales (Megaptera novaeangliae) are a cosmopolitan species and perform long annual migrations between low-latitude breeding areas and high-latitude feeding areas. Their breeding populations appear to be spatially and genetically segregated due to long-term, maternally inherited fidelity to natal breeding areas. In the Southern Hemisphere, some humpback whale breeding populations mix in Southern Ocean waters in summer, but very little movement between Pacific and Atlantic waters has been identified to date, suggesting these waters constituted an oceanic boundary between genetically distinct populations. Here, we present new evidence of summer co-occurrence in the West Antarctic Peninsula feeding area of two recovering humpback whale breeding populations from the Atlantic (Brazil) and Pacific (Central and South America). As humpback whale populations recover, observations like this point to the need to revise our perceptions of boundaries between stocks, particularly on high latitude feeding grounds. We suggest that this “Southern Ocean Exchange” may become more frequent as populations recover from commercial whaling and climate change modifies environmental dynamics and humpback whale prey availability.

Swarming benthic crustaceans in the Bering and Chukchi seas and their relation to geographic patterns in gray whale feeding

1989 ◽  
Vol 67 (6) ◽  
pp. 1531-1542 ◽  
Author(s):  
Stacy L. Kim ◽  
John S. Oliver
Keyword(s):  
Bering Sea ◽  
Baja California ◽  
Prey Availability ◽  
Chukchi Sea ◽  
Gray Whale ◽  
Life Stages ◽  
Gray Whales ◽  
Feeding Ground ◽  
Geographic Patterns ◽  
Feeding Grounds

Swarming benthic crustaceans were widespread in the Chukchi and Bering seas. Swarms differed in their geographic extent, local biomass, and life stages of swarming individuals and thus in their availability to feeding gray whales (Eschrichtius robustus). Immature amphipods apparently swarmed for dispersal, whereas cumaceans probably swarmed for mating. All life stages of the hyperbenthic mysids occurred above the sea floor. Although the geographic spread of mysid swarms and shrimp communities was much greater than for the amphipod and cumacean swarms, the latter swarmed in denser patches to produce higher local biomass. Crustacean swarms are important in describing the geographic patterns of gray whale feeding from the Chukchi Sea to Baja California, including the primary, secondary, and tertiary feeding grounds. The primary feeding ground is in the southern Chukchi Sea and especially the northern Bering Sea, where gray whales suck infaunal amphipods from fine sand, producing an extensive record of feeding excavations. The primary feeding ground is divided into a relatively deep zone (> 20 m), where tube-dwelling ampeliscid amphipods are the major prey, and a shallow zone (< 20 m), where burrowing pontoporeid amphipods dominate. The secondary feeding ground is in the southern Bering Sea along the eastern Alaska Peninsula and adjacent Alaskan mainland where shrimp and mysids are the major prey. The tertiary feeding ground is at the periphery of the primary and secondary feeding grounds in Alaskan waters and south of the Bering Sea where there is a general decrease in the availability of prey and their use by gray whales from Canada to Baja California. The tertiary prey communities include swarms of amphipods, cumaceans, and mysids as well as infaunal polychaete worms, but mysids are used the most by whales. The primary gray whale feeding ground was much smaller during low sea levels when the extensive Beringian Platform was exposed to air. This shallow shelf is a unique habitat that presently harbors the largest ampeliscid amphipod community in the world. At low sea level, swarming crustaceans like those sampled in the present study may have been equally or more important to gray whales than infaunal prey. These historical changes in prey availability may account for the catholic diet of the gray whale.

scholarly journals Humpback Whale (Megaptera novaeangliae) Song on a Subarctic Feeding Ground

2021 ◽  
Vol 8 ◽  
Author(s):  
Saskia C. Martin ◽  
Ana S. Aniceto ◽  
Heidi Ahonen ◽  
Geir Pedersen ◽  
Ulf Lindstrøm
Keyword(s):  
Cultural Transmission ◽  
Humpback Whale ◽  
Megaptera Novaeangliae ◽  
Humpback Whales ◽  
Low Latitude ◽  
Feeding Ground ◽  
The North ◽  
Singing Behavior ◽  
Breeding Grounds ◽  
Singing Activity

Male humpback whales (Megaptera novaeangliae) are known to produce long complex sequences of structured vocalizations called song. Singing behavior has traditionally been associated with low latitude breeding grounds but is increasingly reported outside these areas. This study provides the first report of humpback whale songs in the subarctic waters of Northern Norway using a long-term bottom-moored hydrophone. Data processed included the months January–June 2018 and December 2018–January 2019. Out of 189 days with recordings, humpback whale singing was heard on 79 days. Singing was first detected beginning of January 2018 with a peak in February and was heard until mid-April. No singing activity was found during the summer months and was heard again in December 2018, continuing over January 2019. A total of 131 song sessions, including 35 full sessions, were identified throughout the study period. The longest and shortest complete sessions lasted 815 and 13 min, respectively. The results confirm that singing can be heard over several months in winter and spring on a high latitude feeding ground. This provides additional evidence to the growing literature that singing is not an explicit behavior confined to low latitude breeding grounds. The peak of song occurrence in February appears to coincide with the reproductive cycle of humpback whales. Finally, this study indicates that song occurrence on a subarctic feeding ground likely aids the cultural transmission for the North Atlantic humpback whale population.

scholarly journals DASSO: a data assimilation system for the Southern Ocean that utilizes both sea-ice concentration and thickness observations

2021 ◽  
pp. 1-6
Author(s):  
Hao Luo ◽  
Qinghua Yang ◽  
Longjiang Mu ◽  
Xiangshan Tian-Kunze ◽  
Lars Nerger ◽  
...  
Keyword(s):  
Data Assimilation ◽  
Southern Ocean ◽  
Sea Ice ◽  
Coupled Model ◽  
Sea Ice Concentration ◽  
Model Free ◽  
Antarctic Sea Ice ◽  
Ice Concentration ◽  
Data Assimilation System ◽  
Assimilation System

Abstract To improve Antarctic sea-ice simulations and estimations, an ensemble-based Data Assimilation System for the Southern Ocean (DASSO) was developed based on a regional sea ice–ocean coupled model, which assimilates sea-ice thickness (SIT) together with sea-ice concentration (SIC) derived from satellites. To validate the performance of DASSO, experiments were conducted from 15 April to 14 October 2016. Generally, assimilating SIC and SIT can suppress the overestimation of sea ice in the model-free run. Besides considering uncertainties in the operational atmospheric forcing data, a covariance inflation procedure in data assimilation further improves the simulation of Antarctic sea ice, especially SIT. The results demonstrate the effectiveness of assimilating sea-ice observations in reconstructing the state of Antarctic sea ice, but also highlight the necessity of more reasonable error estimation for the background as well as the observation.

scholarly journals Ventilation of the abyss in the Atlantic sector of the Southern Ocean

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Camille Hayatte Akhoudas ◽  
Jean-Baptiste Sallée ◽  
F. Alexander Haumann ◽  
Michael P. Meredith ◽  
Alberto Naveira Garabato ◽  
...  
Keyword(s):  
Southern Ocean ◽  
Bottom Water ◽  
Climate Models ◽  
Deep Ocean ◽  
Analytical Framework ◽  
Weddell Sea ◽  
Global Ocean ◽  
Shelf Water ◽  
Antarctic Bottom Water ◽  
Atlantic Sector

AbstractThe Atlantic sector of the Southern Ocean is the world’s main production site of Antarctic Bottom Water, a water-mass that is ventilated at the ocean surface before sinking and entraining older water-masses—ultimately replenishing the abyssal global ocean. In recent decades, numerous attempts at estimating the rates of ventilation and overturning of Antarctic Bottom Water in this region have led to a strikingly broad range of results, with water transport-based calculations (8.4–9.7 Sv) yielding larger rates than tracer-based estimates (3.7–4.9 Sv). Here, we reconcile these conflicting views by integrating transport- and tracer-based estimates within a common analytical framework, in which bottom water formation processes are explicitly quantified. We show that the layer of Antarctic Bottom Water denser than 28.36 kg m$$^{-3}$$ - 3 $$\gamma _{n}$$ γ n is exported northward at a rate of 8.4 ± 0.7 Sv, composed of 4.5 ± 0.3 Sv of well-ventilated Dense Shelf Water, and 3.9 ± 0.5 Sv of old Circumpolar Deep Water entrained into cascading plumes. The majority, but not all, of the Dense Shelf Water (3.4 ± 0.6 Sv) is generated on the continental shelves of the Weddell Sea. Only 55% of AABW exported from the region is well ventilated and thus draws down heat and carbon into the deep ocean. Our findings unify traditionally contrasting views of Antarctic Bottom Water production in the Atlantic sector, and define a baseline, process-discerning target for its realistic representation in climate models.

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