Marine heatwaves and the collapse of marginal North Atlantic kelp forests
Authors: K Filbee-Dexter
C N Narvaez
J Thormar
K M Norderhaug
S Fredriksen
C J Feehan
S P Grace
T Wernberg
Journal: Scientific Reports (2020)
Discipline: Multidisciplinary
Keywords: Extreme climatic events; marine heatwaves; population dynamics; ecologically important species; warm range edge kelp forests
Affiliations: Institute of Marine Research, Nye Flødevigveien 20, 4817, His, Norway. ., UWA Oceans Institute and School of Biological Sciences, The University of Western Australia, Perth, Australia. ., Institute of Marine Research, Nye Flødevigveien 20, 4817, His, Norway., UWA Oceans Institute and School of Biological Sciences, The University of Western Australia, Perth, Australia., Department of Biology and Werth Center for Coastal and Marine Studies, Southern Connecticut State University, New Haven, CT, 06515, USA., Department of Biosciences, University of Oslo, Blindern, PO Box 1066, 0316, Oslo, Norway., Department of Biology, Villanova University, Villanova, PA, 19085, USA., Department of Biology, Montclair State University, Montclair, NJ, 07043, USA.

Abstract:  Extreme climatic events including marine heatwaves (MHWs) are becoming more frequent and severe in the Anthropocene. However, our understanding of how these events affect population dynamics of ecologically important species is limited, in part because extreme events are rare and difficult to predict. Here, we quantified the occurrence and severity of MHWs over 60 years in warm range edge kelp forests on both sides of the North Atlantic. The cumulative annual intensity of MHWs increased two- to four-fold during this period, coinciding with the disappearance of kelps. We experimentally demonstrated a relationship between strong and severe 2018 heatwaves and high kelp mortality in both regions. Patterns of kelp mortality were strongly linked to maximum temperature anomalies, which crossed lethal thresholds in both regions. Translocation and tagging experiments revealed similar kelp mortality rates on reefs dominated by healthy kelp forests and degraded sediment-laden algal 'turfs', indicating equal vulnerability to extreme events. These results suggest a mechanistic link between MHWs and broad-scale kelp loss, and highlight how warming can make ecosystem boundaries unstable, forcing shifts to undesirable ecosystem states under episodically extreme climatic conditions. 

Retracted: No

PubPeer comments:
 I am totally surprised how the peer review was done for this paper. In the foot note it is written that Peer review under responsibility of Transdisciplinary University, Bangalore. Does it mean that the peer review was done internally? This review is written on pure speculations without any patient data. Apparently, these speculations are wrong as the infection rates and death have significantly increased in India at the moment. If clinicians involved in this review would have tried to treat COVID-19 patients with these speculations on herbs - many would have survived or would not have infected. I sincerely hope that elsevier withdraw this review as the speculations are wrong - proven by the real data in India. Please don t make such invalid speculations - we do not know whether they work or not and i would urge the authors to stop using COVID-19 publication strategy to publish  unproven ideas. If the authors have patient data to prove their speculations, please update the review with real data. I have read seen (through video) such speculations which were picked up by the media in India and lay people believed that such remedies would work. Apparently, that belief may be one of the causes of high COVID-19 infection rates and death. People are dying - such assumptions should really stop. ,