Fluctuations in coral reef fish densities after environmental disturbances on the northern Great Barrier Reef

Global warming is predicted to increase the frequency and or severity of many disturbances including cyclones, storms, and prolonged heatwaves. The coral reef at Lizard Island, part of the Great Barrier Reef, has been recently exposed to a sequence of severe tropical cyclones (i.e., Ita in 2014 and...

Full description

Bibliographic Details
Main Authors: Zegni Triki, Redouan Bshary
Format: Article
Language:English
Published: PeerJ Inc. 2019-04-01
Series:PeerJ
Subjects:
Online Access:https://peerj.com/articles/6720.pdf
_version_ 1797419677861806080
author Zegni Triki
Redouan Bshary
author_facet Zegni Triki
Redouan Bshary
author_sort Zegni Triki
collection DOAJ
description Global warming is predicted to increase the frequency and or severity of many disturbances including cyclones, storms, and prolonged heatwaves. The coral reef at Lizard Island, part of the Great Barrier Reef, has been recently exposed to a sequence of severe tropical cyclones (i.e., Ita in 2014 and Nathan in 2015) and a coral bleaching in the year 2016. Reef fishes are an essential part of the coral reef ecosystem, and their abundance is thus a good marker to estimate the magnitude of such disturbances. Here, we examined whether the recent disturbances at Lizard Island had an impact on the coral reef fish communities. To do this, we examined fish survey data collected before and after the disturbances for potential changes in total fish density post-disturbance. Also, by sorting fish species into 11 functional groups based on their trophic level (i.e., diet), we further explored the density changes within each functional group. Our findings showed an overall decline of 68% in fish density post-disturbance, with a significant density decrease in nine of 11 trophic groups. These nine groups were: browsers, corallivores, detritivores, excavator/scrapers, grazers, macro-invertivores, pisci-invertivores, planktivores, and spongivores. The piscivores, on the other hand, were the only “winners,” wherein their density showed an increase post-disturbance. These changes within functional groups might have a further impact on the trophodynamics of the food web. In summary, our findings provide evidence that the fish assemblage on the reefs around Lizard Island was considerably affected by extreme weather events, leading to changes in the functional composition of the reef fish assemblage.
first_indexed 2024-03-09T06:51:44Z
format Article
id doaj.art-fe4a7b0f940d46018764ae6fa7fdd795
institution Directory Open Access Journal
issn 2167-8359
language English
last_indexed 2024-03-09T06:51:44Z
publishDate 2019-04-01
publisher PeerJ Inc.
record_format Article
series PeerJ
spelling doaj.art-fe4a7b0f940d46018764ae6fa7fdd7952023-12-03T10:27:09ZengPeerJ Inc.PeerJ2167-83592019-04-017e672010.7717/peerj.6720Fluctuations in coral reef fish densities after environmental disturbances on the northern Great Barrier ReefZegni TrikiRedouan BsharyGlobal warming is predicted to increase the frequency and or severity of many disturbances including cyclones, storms, and prolonged heatwaves. The coral reef at Lizard Island, part of the Great Barrier Reef, has been recently exposed to a sequence of severe tropical cyclones (i.e., Ita in 2014 and Nathan in 2015) and a coral bleaching in the year 2016. Reef fishes are an essential part of the coral reef ecosystem, and their abundance is thus a good marker to estimate the magnitude of such disturbances. Here, we examined whether the recent disturbances at Lizard Island had an impact on the coral reef fish communities. To do this, we examined fish survey data collected before and after the disturbances for potential changes in total fish density post-disturbance. Also, by sorting fish species into 11 functional groups based on their trophic level (i.e., diet), we further explored the density changes within each functional group. Our findings showed an overall decline of 68% in fish density post-disturbance, with a significant density decrease in nine of 11 trophic groups. These nine groups were: browsers, corallivores, detritivores, excavator/scrapers, grazers, macro-invertivores, pisci-invertivores, planktivores, and spongivores. The piscivores, on the other hand, were the only “winners,” wherein their density showed an increase post-disturbance. These changes within functional groups might have a further impact on the trophodynamics of the food web. In summary, our findings provide evidence that the fish assemblage on the reefs around Lizard Island was considerably affected by extreme weather events, leading to changes in the functional composition of the reef fish assemblage.https://peerj.com/articles/6720.pdfFish population densityCyclonesFunctional groupsGreat Barrier ReefCoral bleaching
spellingShingle Zegni Triki
Redouan Bshary
Fluctuations in coral reef fish densities after environmental disturbances on the northern Great Barrier Reef
PeerJ
Fish population density
Cyclones
Functional groups
Great Barrier Reef
Coral bleaching
title Fluctuations in coral reef fish densities after environmental disturbances on the northern Great Barrier Reef
title_full Fluctuations in coral reef fish densities after environmental disturbances on the northern Great Barrier Reef
title_fullStr Fluctuations in coral reef fish densities after environmental disturbances on the northern Great Barrier Reef
title_full_unstemmed Fluctuations in coral reef fish densities after environmental disturbances on the northern Great Barrier Reef
title_short Fluctuations in coral reef fish densities after environmental disturbances on the northern Great Barrier Reef
title_sort fluctuations in coral reef fish densities after environmental disturbances on the northern great barrier reef
topic Fish population density
Cyclones
Functional groups
Great Barrier Reef
Coral bleaching
url https://peerj.com/articles/6720.pdf
work_keys_str_mv AT zegnitriki fluctuationsincoralreeffishdensitiesafterenvironmentaldisturbancesonthenortherngreatbarrierreef
AT redouanbshary fluctuationsincoralreeffishdensitiesafterenvironmentaldisturbancesonthenortherngreatbarrierreef