scholarly journals CORAL REEF CONDITION IN RELATION TO CORAL REEF FISH ABUNDANCES BEFORE MASS BLEACHING EVENT IN SIMEULUE ISLANDS, ACEH

2019 ◽  
Vol 25 (2) ◽  
pp. 64
Author(s):  
Ulung Jantama Wisha ◽  
Koko Ondara ◽  
Wisnu Arya Gemilang ◽  
Guntur Adhi Rahmawan ◽  
Ruzana Dhiauddin ◽  
...  
Keyword(s):  
Coral Reef ◽  
Reef Fish ◽  
Coral Reef Fish ◽  
Bleaching Event ◽  
West Part ◽  
Aceh Province ◽  
The Indian Ocean ◽  
Fish Abundances ◽  
Mass Bleaching Event ◽  
Mass Bleaching

Bordered with the Indian Ocean, Simeulue Islands is one of the outermost islands in Indonesia located in the west part of Aceh Province. Simeulue waters are productive areas due to the unpolluted condition yet and great of biomass. Three regions were particularly observed, those are Simeuluecut, Ganting, and Labuhan Bajau. In those areas, the existing marine tourism activities might influence the coral reef ecosystem studied. This study aimed to evaluate the condition of coral and coral reef fish in those three particular regions before mass bleaching event in 2016 triggered by ENSO. Point Intercept Transect (PIT) method was employed to record the percentage cover of coral, species diversity, and coral reef fish. Ganting waters was a moderate ecosystem area whith the percentage coverage was up to 45.62%. However, in Simeuluecut and Labuhan Bajau waters, the coral reef communities were excellent with coral percentage coverage reached 83.12% and 81.25 %, respectively. The highest  abundance genera of coral reef fish was observed in Simueluecut waters. This condition was changed oppositely in 2016 when mass bleaching threatened Simeulue waters due to temperature anomaly triggered by ENSO phenomenon. The temperature increases almost 3oC for 6 months that undoubtedly induced bleaching that about 50% of coral colonies were dramatically declined in coral coverage and coral recruitment. 

scholarly journals Year-round high abundances of the world’s smallest marine vertebrate (Schindleria) in the Red Sea and worldwide associations with lunar phases

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Vanessa Robitzch ◽  
Victor Molina-Valdivia ◽  
Jaiber J. Solano-Iguaran ◽  
Mauricio F. Landaeta ◽  
Michael L. Berumen
Keyword(s):  
Coral Reef ◽  
Reef Fish ◽  
Red Sea ◽  
Coral Reef Fish ◽  
Seasonal Temperature ◽  
Global Trends ◽  
Lunar Phases ◽  
Spatial Differences ◽  
New Moon ◽  
Reproductive Cycles

AbstractVery little is known about the ecology and biology of the smallest marine vertebrates, fishes in the genus Schindleria. Even though over half of named Schindleria species have been identified in the Red Sea, the collection of only very few specimens has been documented. Here, we assessed abundance patterns of nearly two thousand Red Sea long dorsal fin (LDF) adults and found evidence for putative seasonal and spatial differences, likely related to differing habitat and environmental conditions. The highest abundances were outside local seasonal temperature extremes and decoupled from peaks of coral reef fish recruitment. We also found evidence for global trends in abundances related to lunar cycles using our Red Sea data and that from a recently published large collection of specimens from the DANA Expedition (1928–1930). The abundance of adult LDF Schindleria in relation to lunar phases differed significantly, with most Schindleria caught outside the full moon, and mostly during the new moon in the Red Sea and the 3rd quarter moon in the DANA collection. We further suggest that the abundances of Schindleria at coral reefs may be related to reproductive cycles and that these cycles may be timed with the moon as back-calculations of hatch dates from otoliths from the Red Sea significantly resulted after the new moon, making Schindleria the fastest-lived coral reef fish with the shortest generation times. Schindleria could be the most numerous coral reef fish in the world, for which we encourage increased research.

scholarly journals Impact of cyclones on hard coral and metapopulation structure, connectivity and genetic diversity of coral reef fish

Coral Reefs ◽  
2021 ◽  
Author(s):  
Gabriele Gerlach ◽  
Philipp Kraemer ◽  
Peggy Weist ◽  
Laura Eickelmann ◽  
Michael J. Kingsford
Keyword(s):  
Genetic Diversity ◽  
Coral Reef ◽  
Genetic Structure ◽  
Reef Fish ◽  
Coral Reef Fish ◽  
Population Genetic Study ◽  
Hard Coral ◽  
Great Loss ◽  
Metapopulation Structure ◽  
The Impact

AbstractCyclones have one of the greatest effects on the biodiversity of coral reefs and the associated species. But it is unknown how stochastic alterations in habitat structure influence metapopulation structure, connectivity and genetic diversity. From 1993 to 2018, the reefs of the Capricorn Bunker Reef group in the southern part of the Great Barrier Reef were impacted by three tropical cyclones including cyclone Hamish (2009, category 5). This resulted in substantial loss of live habitat-forming coral and coral reef fish communities. Within 6–8 years after cyclones had devastated, live hard corals recovered by 50–60%. We show the relationship between hard coral cover and the abundance of the neon damselfish (Pomacentrus coelestis), the first fish colonizing destroyed reefs. We present the first long-term (2008–2015 years corresponding to 16–24 generations of P. coelestis) population genetic study to understand the impact of cyclones on the meta-population structure, connectivity and genetic diversity of the neon damselfish. After the cyclone, we observed the largest change in the genetic structure at reef populations compared to other years. Simultaneously, allelic richness of genetic microsatellite markers dropped indicating a great loss of genetic diversity, which increased again in subsequent years. Over years, metapopulation dynamics were characterized by high connectivity among fish populations associated with the Capricorn Bunker reefs (2200 km2); however, despite high exchange, genetic patchiness was observed with annual strong genetic divergence between populations among reefs. Some broad similarities in the genetic structure in 2015 could be explained by dispersal from a source reef and the related expansion of local populations. This study has shown that alternating cyclone-driven changes and subsequent recovery phases of coral habitat can greatly influence patterns of reef fish connectivity. The frequency of disturbances determines abundance of fish and genetic diversity within species.

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