Evidence map›Paper›PMID 34686699›Full record

ArticleScientific reports2021

Oceanographic anomalies coinciding with humpback whale super-group occurrences in the Southern Benguela.

Subhra Prakash Dey, Marcello Vichi, Giles Fearon, Elisa Seyboth, Ken P Findlay, Jan-Olaf Meynecke, Jasper de Bie, Serena Blyth Lee, Saumik Samanta, Jan-Lukas Menzel Barraqueta and 2 more

Abstract read
In one paragraph

Article in Scientific reports, 2021. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 1 paper.

0numbers the graph read from it
0cells of the map it votes in
1citing papers in PubMed
–field-weighted citation impact
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

1 citing paper in PubMed.

  1. Humpback Whales (Animals : an open access journal from MDPI · 2026
    Review
4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

12 authors.

Subhra Prakash DeyDepartment of Oceanography, University of Cape Town, Rondebosch, 7701, South Africa. subhra.dey@uct.ac.za.
Marcello VichiDepartment of Oceanography, University of Cape Town, Rondebosch, 7701, South Africa. marcello.vichi@uct.ac.za.
Giles FearonDepartment of Oceanography, University of Cape Town, Rondebosch, 7701, South Africa.
Elisa SeybothCentre for Sustainable Oceans, Faculty of Applied Sciences, Cape Peninsula University of Technology, Cape Town, South Africa.
Ken P FindlayCentre for Sustainable Oceans, Faculty of Applied Sciences, Cape Peninsula University of Technology, Cape Town, South Africa.
Jan-Olaf MeyneckeGriffith Climate Change Response Program, Griffith University, Southport, Qld, Australia.
Jasper de BieGriffith Climate Change Response Program, Griffith University, Southport, Qld, Australia.
Serena Blyth LeeGriffith Climate Change Response Program, Griffith University, Southport, Qld, Australia.
Saumik SamantaEarth Sciences, Stellenbosch University, Cape Town, South Africa.
Jan-Lukas Menzel BarraquetaEarth Sciences, Stellenbosch University, Cape Town, South Africa.
Alakendra N RoychoudhuryEarth Sciences, Stellenbosch University, Cape Town, South Africa.
Brendan MackeyGriffith Climate Change Response Program, Griffith University, Southport, Qld, Australia.

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

Seasonal feeding behaviour of humpback whales (Megaptera novaeangliae) has been observed in the coastal waters of the Southern Benguela where the species has been observed forming super-groups during the austral spring in recent years since 2011. Super-groups are unprecedented densely-packed aggregations of between 20 and 200 individuals in low-latitude waters and their occurrences indicate possible changes in feeding behaviour of the species. We accessed published data on super-groups occurrence in the study area in 2011, 2014 and 2015, and investigated oceanographic drivers that support prey availability in this region. We found that enhanced primary production is a necessary but not sufficient condition for super-groups to occur. Positive chlorophyll anomalies occurring one month prior to the super-group occurrences were identified, but only a concurrent significantly reduced water volume export from the region throughout October were conducive to the aggregations in the specific years. Hydrodynamic model results attributed the anomalous decreased volume export to the strength and orientation of the Goodhope Jet and associated eddy activity. The combination of random enhanced primary production typical of the region and emerging anomalous conditions of reduced water export in October since 2011 resulted in favourable food availability leading to the unique humpback whale aggregations. The novelty of this grouping behaviour is indicative of the lack of such oceanographic conditions in the past. Given the recency of the events, it is difficult to attribute this reduction in ocean transport to climatic regime shifts, and the origin should be likely investigated in the distant water mass interaction with the greater Agulhas system rather than in local intensifications of the upwelling conditions. A positive trend in the humpback whale population abundance points to the need to monitor the exposure of the species to the changing climate conditions.

Identifiers

PMID34686699
PMCPMC8536746

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Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.