scholarly journals Inter-Habitat Variability in Parrotfish Bioerosion Rates and Grazing Pressure on an Indian Ocean Reef Platform

Diversity ◽  
2020 ◽  
Vol 12 (10) ◽  
pp. 381
Author(s):  
Robert T. Yarlett ◽  
Chris T. Perry ◽  
Rod W. Wilson ◽  
Alastair R. Harborne
Keyword(s):  
Indian Ocean ◽  
Physical Structure ◽  
Grazing Pressure ◽  
Species Assemblages ◽  
Bleaching Event ◽  
Ecological Health ◽  
Ecological Functions ◽  
Coral Rubble ◽  
Habitat Variability ◽  
Reef Platform

Parrotfish perform a variety of vital ecological functions on coral reefs, but we have little understanding of how these vary spatially as a result of inter-habitat variability in species assemblages. Here, we examine how two key ecological functions that result from parrotfish feeding, bioerosion and substrate grazing, vary between habitats over a reef scale in the central Maldives. Eight distinct habitats were delineated in early 2015, prior to the 2016 bleaching event, each supporting a unique parrotfish assemblage. Bioerosion rates varied from 0 to 0.84 ± 0.12 kg m−2 yr−1 but were highest in the coral rubble- and Pocillopora spp.-dominated habitat. Grazing pressure also varied markedly between habitats but followed a different inter-habitat pattern from that of bioerosion, with different contributing species. Total parrotfish grazing pressure ranged from 0 to ~264 ± 16% available substrate grazed yr-1 in the branching Acropora spp.-dominated habitat. Despite the importance of these functions in influencing reef-scale physical structure and ecological health, the highest rates occurred over less than 30% of the platform area. The results presented here provide new insights into within-reef variability in parrotfish ecological functions and demonstrate the importance of considering how these interact to influence reef geo-ecology.

scholarly journals The Third Global Coral Bleaching Event on the Marginal Coral Reefs of the Southwestern Indian Ocean and Factors That Contribute to Their Resistance and Resilience

Diversity ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 464
Author(s):  
Sean N. Porter ◽  
Kerry J. Sink ◽  
Michael H. Schleyer
Keyword(s):  
Indian Ocean ◽  
Coral Reefs ◽  
Coral Bleaching ◽  
Bleaching Event ◽  
Thermal Dynamics ◽  
Upwelled Water ◽  
Coral Communities ◽  
Temperature Records ◽  
Southwestern Indian Ocean

Coral reefs reach their southernmost limits in the southwestern Indian Ocean in Maputaland, South Africa. Here, we investigate the recent global coral bleaching event of 2016, the thermal dynamics of these marginal high-latitude reefs and the potential environmental factors regulating the responses of coral communities. Pre-, peak- and post-bleaching surveys of over 9850 coral colonies from 29 genera were undertaken over 3 years across 14 sites spanning 120 km of coastline using point-intercept and visual bleaching index survey methodologies. Bleaching data were related to several environmental variables including temperature, degree heating weeks (DHW), depth, latitude, and upwelling intensity. These reefs have experienced a history of relatively low thermal stress based on DHW. Long-term in situ temperature records nevertheless showed no obvious trend of increase. In situ temperatures also displayed poor relationships, with temperatures predicted by the Representative Concentration Pathway models. Mild coral bleaching with no significant mortality was recorded across sites with taxon-specific bleaching responses evident. Latitude and cumulative daily DHW were significantly related to the bleaching index whereas depth and interactions of depth with latitude and DHW were not. While upwelling of cooler water may offer some refuge to coral communities, especially in the Central and Southern Reef Complexes where it is more pronounced, this may only be transient as the upwelled water may also experience some degree of warming in future, thereby limiting such protection from global warming.

Impacts of the 2014–2017 global bleaching event on a protected remote atoll in the Western Indian Ocean

Coral Reefs ◽  
2019 ◽  
Vol 39 (1) ◽  
pp. 15-26 ◽  
Author(s):  
Julia M. B. Cerutti ◽  
April J. Burt ◽  
Philip Haupt ◽  
Nancy Bunbury ◽  
Peter J. Mumby ◽  
...  
Keyword(s):  
Indian Ocean ◽  
Western Indian Ocean ◽  
Bleaching Event

scholarly journals The extent and intensity of the 1998 mass bleaching event on the reefs of Mauritius, Indian Ocean

2002 ◽  
Vol 2002 (4) ◽  
pp. 43-52 ◽  
Author(s):  
Ruby Moothien Pillay ◽  
Hiroaki Terashima ◽  
Hiroyuki Kawasaki
Keyword(s):  
Indian Ocean ◽  
Bleaching Event ◽  
Mass Bleaching Event ◽  
Mass Bleaching

Participatory reporting of the 2016 bleaching event in the Western Indian Ocean

Coral Reefs ◽  
2019 ◽  
Vol 39 (1) ◽  
pp. 1-11 ◽  
Author(s):  
Mishal Gudka ◽  
David Obura ◽  
James Mbugua ◽  
Said Ahamada ◽  
Ulli Kloiber ◽  
...  
Keyword(s):  
Indian Ocean ◽  
Western Indian Ocean ◽  
Bleaching Event

scholarly journals Altered tropical seascapes influence patterns of fish assemblage and ecological functions in the Western Indian Ocean

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
D. H. Chacin ◽  
C. D. Stallings ◽  
M. Eggertsen ◽  
C. Åkerlund ◽  
C. Halling ◽  
...  
Keyword(s):  
Indian Ocean ◽  
Fish Assemblage ◽  
Western Indian Ocean ◽  
Ecological Functions

scholarly journals Bacterial and Fungal Diversity in Sediment and Water Column From the Abyssal Regions of the Indian Ocean

2021 ◽  
Vol 8 ◽  
Author(s):  
Natasha Maria Barnes ◽  
Samir R. Damare ◽  
Belle Damodara Shenoy
Keyword(s):  
Next Generation Sequencing ◽  
Indian Ocean ◽  
Microbial Diversity ◽  
Microbial Communities ◽  
Water Column ◽  
Deep Sea ◽  
Fungal Diversity ◽  
Ecological Functions ◽  
The Indian Ocean ◽  
Generation Sequencing

The deep sea is the largest environment on Earth, comprising important resources of commercial interest. It is composed of a wide variety of ecosystems, which is home to often unique organisms that are yet to be described. The deep-sea is one of the least studied environments, where research is strongly linked to technological access and advances. With the recent advances in the next-generation sequencing and bioinformatics tools, there is an enhanced understanding of microbial diversity and ecological functions in deep sea. Multidisciplinary programs are being undertaken to investigate into microbial communities in diverse marine environments. As compared to other Oceans, the deeper parts of Indian Ocean are still poorly sampled and studied for bacterial, and more so fungal diversity. The studies reporting usage of modern sequencing tools to describe uncultured microbial diversity have seen a rise in numbers in the last decade. In this review, we summarize the important findings of research works carried on bacterial and fungal diversity from the abyssal regions of the Indian Ocean and provide our views on possible future paths.

scholarly journals Distribution of modern coccolithophore assemblages in the southwest Indian Ocean off southern Africa

1987 ◽  
Vol 6 (1) ◽  
pp. 49-56 ◽  
Author(s):  
Peter J. J. Friedinger ◽  
Amos Winter
Keyword(s):  
Indian Ocean ◽  
Regional Distribution ◽  
Species Assemblages ◽  
Seasonal Fluctuations ◽  
Southwest Indian Ocean ◽  
Agulhas Current ◽  
Surface Water Samples ◽  
Gephyrocapsa Oceanica ◽  
Scanning Electron ◽  
Stable Feature

Abstract. Living coccolithophore assemblages were investigated in 35 surface water samples taken from the Natal Valley (southwest Indian Ocean) in January and November, 1983 and February, 1984. Fifty-nine species were recognised using a scanning electron microscope (S.E.M.). Cluster analysis revealed four different species assemblages dominated by Emiliania huxleyi, Umbilicosphaera hulburtiana, Umbellosphaera tenuis and Gephyrocapsa oceanica. Significant differences in species composition between the sampling periods are attributed to seasonal fluctuations. The regional distribution of the assemblages reflects two different océanographic regimes: 1) The Agulhas Current, which is a nearly stable feature and 2) the area of the Agulhas Return Current, characterised by rapidly changing hydrographic and ecological conditions.

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