Estimates of Fuegian sprat consumption by humpback whales in the Magellan Strait feeding area as predicted by a bioenergetic model

2021 ◽  
Vol 657 ◽  
pp. 223-239
Author(s):  
J Acevedo ◽  
J Urbán
Keyword(s):  
Fishery Management ◽  
Energy Requirement ◽  
Seasonal Abundance ◽  
Humpback Whales ◽  
Bioenergetic Model ◽  
Marine Predator ◽  
Magellan Strait ◽  
Annual Population ◽  
Feeding Area ◽  
Conservation Plans

Knowing the biomass of prey consumed by a marine predator is a prerequisite for assessing the potential of the predator for competition with fisheries. Here, we estimated the biomass of Fuegian sprat Sprattus fueguensis consumed annually by a small subpopulation of humpback whales Megaptera novaeangliae in the Magellan Strait feeding area. We used a velocity-dependent bioenergetic model that integrates annual energy requirements by sex, age class, and reproductive status, proportion of Fuegian sprat in the diet, and annual population size of whales. The annual energy required in kcal per individual whale was estimated to be 18.88 × 107 for calves, 27.92 × 107 for adults, 30.71 × 107 for pregnant females, and 42.59 × 107 for lactating females. These estimates result in an energy requirement of 19.32 × 109 and 23.41 × 109 for a seasonal abundance of 78 and 96 whales, respectively. Bayesian dietary mixing models predict that Fuegian sprat represented between 27 and 33% of the diet of the whales. This implies that humpback whales remove between 2965 and 3896 t of Fuegian sprat per year during a feeding period of 120 d. However, if estimates are extended to an abundance of 204 humpback whales during the period 2004-2017, the consumption is elevated to 8167-8383 t yr-1. The estimates provided here are useful to apply as input data for consumption by humpback whales in the Fuegian sprat fishery management as well as for conservation plans of this small and vulnerable feeding subpopulation of humpback whales.

scholarly journals A description and summary of the Antarctic Humpback Whale Catalogue

2020 ◽  
pp. 95-99
Author(s):  
Judith Allen ◽  
Carole Carlson ◽  
Peter T. Stevick
Keyword(s):  
South America ◽  
Southern Ocean ◽  
Antarctic Peninsula ◽  
Humpback Whale ◽  
Humpback Whales ◽  
Western Coast ◽  
Long Distance ◽  
Dorsal Fin ◽  
Feeding Area ◽  
The Antarctic

The Antarctic Humpback Whale Catalogue (AHWC) is an international collaborative project investigating movement patterns of humpback whales in the Southern Ocean and corresponding lower latitude waters. The collection contains records contributed by 261 researchers and opportunistic sources. Photographs come from all of the Antarctic management areas, the feeding grounds in southern Chile and also most of the known or suspected low-latitude breeding areas and span more than two decades. This allows comparisons to be made over all of the major regions used by  Southern Hemisphere humpback whales. The fluke, left dorsal fin/flank and right dorsal fin/flank collections represent 3,655, 413 and 407 individual whales respectively. There were 194 individuals resighted in more than one year, and 82 individuals resighted in more than one region. Resightings document movement along the western coast of South America and movement between the Antarctic Peninsula and western coast of South America and Central America. A single individual from Brazil was resighted off South Georgia, representing the first documented link between the Brazilian breeding ground and any feeding area. A second individual from Brazil was resighted off Madagascar, documenting long distance movement of a female between non-adjacent breeding areas. Resightings also include two matches between American Samoa and the Antarctic Peninsula, documenting the first known feeding site for American Somoa and setting a new long distance seasonal migration record. Three matches between Sector V and eastern Australia support earlier evidence provided by Discovery tags. Multiple resightings of individuals in the Antarctic Peninsula during more than one season indicate that humpback whales in this area show some degree of regional feeding area fidelity. The AHWC provides a powerful non-lethal and non-invasive tool for investigating the movements and population structure of the whales utilising the Southern Ocean Sanctuary. Through this methodical, coordinated comparison and maintenance of collections from across the hemisphere, large-scale movement patterns may be examined, both within the Antarctic, and from the Antarctic to breeding grounds at low latitudes.

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

2003 ◽  
Vol 2 (1) ◽  
Author(s):  
M. E. Morete ◽  
R. M. Pace, III ◽  
C. C. A. Martins ◽  
A. C. Freitas ◽  
M. H. Engel
Keyword(s):  
Seasonal Abundance ◽  
Humpback Whales

scholarly journals Exploring the assumptions of multi-stock assessment models for humpback whales (Megaptera novaeangliae) in the Southern Hemisphere: using Breeding Stocks D and E as an example

2020 ◽  
pp. 119-128
Author(s):  
Rebecca Leaper ◽  
Samantha Peel ◽  
David Peel ◽  
Nick Gales
Keyword(s):  
Density Dependence ◽  
Population Model ◽  
Stock Assessment ◽  
Simulated Data ◽  
Megaptera Novaeangliae ◽  
Humpback Whales ◽  
Simulation Approach ◽  
Potential Value ◽  
Simple Simulation ◽  
Feeding Area

There is potential value in exploring multi-stock models to address situations where humpback stocks are mixing. However, sensitivity to the assumptions underlying these models has yet to be fully explored. Using a simple simulation approach, the assumptions of a population model that allows for mixing of humpback whale (Megaptera novaeangliae) stocks D and E on feeding areas has been explored by relaxing the assumptions of the original Johnston and Butterworth model in a number of plausible ways. First the ability of the model to estimate parameters was checked for a situation where simulated data are generated from an underlying model of exactly the same form for which the actual values of these parameters are known (Scenario 1). Then the ability of the model to estimate these parameters when alternative forms and assumptions were used for the underlying model generating the data was investigated. Specifically, stocks were allowed to mix non-uniformly across each feeding area and catch was non-uniformly distributed across each feeding area (Scenario 2). The consequences of density dependence implemented on feeding rather than breeding areas (Scenario 3) were also examined. The original mixing model was robust to alternate mixing and catch allocation scenarios in all but one of the simulations, but when density dependence acted at the level of the feeding rather than the breeding areas, the model produced estimates that were quite different from the underlying population. It is recommend that the inclusion of density dependence on feeding areas in models that allow for mixing of whales on these grounds be investigated further.

Trophic role of the humpback whale (Megaptera novaeangliae) in the feeding area of Magellan Strait, Chile

2020 ◽  
Vol 109 ◽  
pp. 105796 ◽  
Author(s):  
Daniela Haro ◽  
Pablo Sabat ◽  
Francisco Arreguín-Sánchez ◽  
Sergio Neira ◽  
Juan Carlos Hernández-Padilla
Keyword(s):  
Humpback Whale ◽  
Megaptera Novaeangliae ◽  
Magellan Strait ◽  
Feeding Area ◽  
Trophic Role

scholarly journals ‘Megapclicks’: acoustic click trains and buzzes produced during night-time foraging of humpback whales ( Megaptera novaeangliae )

2007 ◽  
Vol 3 (5) ◽  
pp. 467-470 ◽  
Author(s):  
Alison K Stimpert ◽  
David N Wiley ◽  
Whitlow W.L Au ◽  
Mark P Johnson ◽  
Roland Arsenault
Keyword(s):  
Megaptera Novaeangliae ◽  
Humpback Whales ◽  
Baleen Whale ◽  
Night Time ◽  
Baleen Whales ◽  
Acoustic Behaviour ◽  
Suction Cup ◽  
Form Part ◽  
Acoustic Tags ◽  
Feeding Area

Humpback whales ( Megaptera novaeangliae ) exhibit a variety of foraging behaviours, but neither they nor any baleen whale are known to produce broadband clicks in association with feeding, as do many odontocetes. We recorded underwater behaviour of humpback whales in a northwest Atlantic feeding area using suction-cup attached, multi-sensor, acoustic tags (DTAGs). Here we describe the first recordings of click production associated with underwater lunges from baleen whales. Recordings of over 34 000 ‘megapclicks’ from two whales indicated relatively low received levels at the tag (between 143 and 154 dB re 1 μPa pp), most energy below 2 kHz, and interclick intervals often decreasing towards the end of click trains to form a buzz. All clicks were recorded during night-time hours. Sharp body rolls also occurred at the end of click bouts containing buzzes, suggesting feeding events. This acoustic behaviour seems to form part of a night-time feeding tactic for humpbacks and also expands the known acoustic repertoire of baleen whales in general.

First evidence of interchange of humpback whales (Megaptera novaeangliae) between the Magellan Strait and Antarctic Peninsula feeding grounds

Polar Biology ◽  
2021 ◽  
Vol 44 (3) ◽  
pp. 613-619
Author(s):  
Jorge Acevedo ◽  
Juan Capella ◽  
Ted Cheeseman ◽  
Cole C. Monnahan ◽  
Ken Southerland ◽  
...  
Keyword(s):  
Antarctic Peninsula ◽  
Megaptera Novaeangliae ◽  
Humpback Whales ◽  
Magellan Strait ◽  
Feeding Grounds

Population trends for humpback whales (Megaptera novaeangliae) foraging in the Francisco Coloane Coastal‐Marine Protected Area, Magellan Strait, Chile

2019 ◽  
Vol 35 (4) ◽  
pp. 1212-1231 ◽  
Author(s):  
Cole C. Monnahan ◽  
Jorge Acevedo ◽  
A. Noble Hendrix ◽  
Scott Gende ◽  
Anelio Aguayo‐Lobo ◽  
...  
Keyword(s):  
Protected Area ◽  
Marine Protected Area ◽  
Megaptera Novaeangliae ◽  
Population Trends ◽  
Humpback Whales ◽  
Magellan Strait ◽  
Coastal Marine

Trophic Ecology of Humpback Whales (Megaptera novaeangliae) in the Magellan Strait as Indicated by Carbon and Nitrogen Stable Isotopes

2016 ◽  
Vol 42 (2) ◽  
pp. 233-243 ◽  
Author(s):  
Daniela Haro ◽  
Luciana Riccialdelli ◽  
Jorge Acevedo ◽  
Anelio Aguayo-Lobo ◽  
Américo Montiel
Keyword(s):  
Stable Isotopes ◽  
Trophic Ecology ◽  
Megaptera Novaeangliae ◽  
Humpback Whales ◽  
Nitrogen Stable Isotopes ◽  
Carbon And Nitrogen ◽  
Magellan Strait

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.

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