scholarly journals Kerapatan dan Kelulushidupan pada Rekrutmen Karang Pocillopora damicornis (Density and Survivorship on the Recruitment of the brooding coral Pocillopora damicornis)

2014 ◽  
Vol 19 (3) ◽  
pp. 171 ◽  
Author(s):  
Munasik Munasik ◽  
Suharsono Suharsono ◽  
J Situmorang ◽  
Kamiso H N
Keyword(s):  
Reef Flat ◽  
Side Surface ◽  
Back Reef ◽  
Pocillopora Damicornis ◽  
Lower Side ◽  
Juvenile Corals ◽  
Central Java ◽  
Settlement Plate ◽  
Juvenile Density ◽  
Brooding Coral

Studi rekrutmen karang Pocillopora damicornis telah dilakukan dengan mengamati kerapatan juvenil pada substrat penempelan di dataran terumbu Pulau Panjang, Jepara, Jawa Tengah. Hasil menunjukkan bahwa rekrutmen terjadi sepanjang tahun dan tertinggi pada periode Agustus-Oktober. Laju rekrutmen karang di belakang terumbu (back reef) pada sisi bawah angin (selatan) lebih tinggi daripada di sisi atas angin (utara) Pulau Panjang, tampaknya hal ini berkorelasi dengan kerapatan populasi karang dewasanya. Kerapatan juvenil karang tertinggi pada substrat batu alam terjadi pada sisi bawah permukaan substrat, akan tetapi pertumbuhan juvenil karang tertinggi ditemukan di sisi atas permukaan substrat. Hal ini mengindikasikan bahwa kerapatan juvenil karang berhubungan dengan kelulusan hidup juvenil karang. Semakin tinggi kerapatan juvenil karang P. damicornis maka semakin rendah kelulusan hidup juvenil karang karena terjadinya peningkatan persaingan sesama juvenil karang dan akibat kekurangan cahaya. Kata kunci: rekrutmen, kerapatan, kelulushidupan, karang Pocillopora damicornis Recruitment of the brooding coral Pocillopora damicornis was studied by observing the juvenile density on the settlement plate substrate in reef flat of Panjang Island, Jepara, Central Java. The results show that recruitment occurs throughout the year and the highest in the period from August to October. The rate of recruitment of coral reefs in back reef on the leeward (south) is higher than on the windward (north) of the island, it seems to be correlated with population density of adult corals. The highest density of juvenile corals on natural substrata occurs on the lower side surface of the substrate, but the highest growth of juvenile are found on the upper side surface of the substrate. This indicates that the density of juvenile corals associated with the survival of juvenile corals. The higher density of juvenile corals P. damicornis, the lower the survival of juvenile corals due to an increase in competition among juvenile corals and due to lack of light. Keywords: recruitment, density, survivorship, coral Pocillopora damicornis

scholarly journals TIMING OF LARVAL RELEASE BY REEF CORAL Pocillopora damicornis AT PANJANG ISLAND, CENTRAL JAVA

2018 ◽  
Vol 33 (1) ◽  
pp. 33-39 ◽  
Author(s):  
Munasik ◽  
Suharsono ◽  
J. Situmorang ◽  
H. N. Kamiso
Keyword(s):  
Full Moon ◽  
Reef Coral ◽  
Lunar Cycle ◽  
Tidal Range ◽  
Pocillopora Damicornis ◽  
Larval Release ◽  
Double Peaks ◽  
Central Java ◽  
New Moon ◽  
Peak Release

Monthly larval release by the coral Pocillopora damicornis at Panjang Island, Central Java was investigated. Corals were collected from windward and leeward and maintained in outdoor, flow-trough system to quantify nightly release of larvae. Larval release of the coral occurs every month throughout the year, and its planulation increased during dry monsoon. Monthly planulation occurs from new moon to full moon and possesses in different pattern between single and paired colonies. Planulation in paired colonies occurred in single peak and more synchronized in each colony however single colonies planulated in double peaks and less synchronized in each colony. This study confirmed that planulation period of P. damicornis at Panjang Island over a range of lunar phases with shorter periods of peak release which predominantly controlling by tidal range rather than lunar cycle.

Larval Settlement of Corals in Flowing Water using a Racetrack Flume

2002 ◽  
Vol 36 (1) ◽  
pp. 76-79 ◽  
Author(s):  
S. Harii ◽  
H. Kayanne
Keyword(s):  
Reef Flat ◽  
Marine Invertebrates ◽  
Larval Settlement ◽  
Flow Speed ◽  
Flowing Water ◽  
Pocillopora Damicornis ◽  
Settlement Rate ◽  
Ishigaki Island ◽  
Digitally Controlled ◽  
Flow Speeds

Although the larvae of marine invertebrates settle in currents, few studies have examined settlement under flow. We studied the settlement of two brooding coral larvae with different behavior in a flow using a small racetrack flume made of polycarbonate and acrylic (58 cm long). Flow was generated using a digitally controlled gear-motor-driven paddle wheel. The settlement rates of the larvae, Heliopora coerulea and Pocillopora damicornis, were observed at three flow speeds: 1.6, 4.4, and 9.8 cm/sec, which correspond to the currents at low, mean, and ebb or flood tides, respectively, at Shiraho Reef flat, Ishigaki Island, Japan. The settlement rate of H. coerulea larvae decreased with increasing flow speed (20% at 1.6 cm/sec, 2% at 9.8 cm/sec). In contrast, the settlement rate of P. damicornis larvae was high at all flow speeds (> 50% at all flow speeds). This difference in the larval settlement rates of the two species is in accordance with the current conditions in which the adult corals are distributed.

Mass Settlement and Post-Settlement Mortality of Epinephelus Merra (Pisces: Serranidae) On Réunion Coral Reefs

1998 ◽  
Vol 78 (1) ◽  
pp. 307-319 ◽  
Author(s):  
Yves Letourneur ◽  
Pascale Chabanet ◽  
Laurent Vigliola ◽  
Mireille Harmelin-Vivien
Keyword(s):  
Indian Ocean ◽  
Coral Reefs ◽  
Reef Flat ◽  
Western Indian Ocean ◽  
Back Reef ◽  
Major Event ◽  
Population Densities ◽  
Per Capita ◽  
New Moon ◽  
Settlement Event

An unusual mass settlement event of the grouper Epinephelus merra occurred on the fringing coral reefs of Reunion Island (south-western Indian Ocean) in April 1994. This major event coincided with stormy conditions associated with the new moon period. The abundance of new settlers was surveyed for 45 days following settlement on both the reef flat and the back reef area of the coral reefs of St Gilles, La Saline and St Leu. Mean densities of settlers were higher on reef flats (maximum 474 ind/20 m2 at La Saline) than on back reef areas (maximum 156 ind/20 m2 at La Saline). Seven weeks later, densities of settled E. merra had drastically decreased, and did not differ with site and zone (18.5 ind/20 m2). Percentages of post-settlement mortality at that period ranged from 85 to 88% in back reef areas and from 93 to 95% on reef flats. A strong correlation between density of recruits and per capita mortality suggests density-dependent early post-settlement mortality for E. merra. The limitation of food resources and shelters, perhaps combined with an increase of diseases due to high population densities of settlers, was probably the main cause of mortality just after the mass settlement. Predation by reef fish, including cannibalism between settlers, is probably responsible for most subsequent mortality.

scholarly journals Signatures of Adaptation and Acclimatization to Reef Flat and Slope Habitats in the Coral Pocillopora damicornis

2021 ◽  
Vol 8 ◽  
Author(s):  
Shelby R. Marhoefer ◽  
Kyall R. Zenger ◽  
Jan M. Strugnell ◽  
Murray Logan ◽  
Madeleine J. H. van Oppen ◽  
...  
Keyword(s):  
Weight Gain ◽  
Heat Tolerance ◽  
Environmental Conditions ◽  
Reef Flat ◽  
Average Weight ◽  
Transplant Experiment ◽  
Pocillopora Damicornis ◽  
Partial Mortality ◽  
Algal Symbiont ◽  
Outlier Loci

Strong population-by-habitat interactions across environmental gradients arise from genetic adaptation or acclimatization and represents phenotypic variation required for populations to respond to changing environmental conditions. As such, patterns of adaptation and acclimatization of reef-building corals are integral to predictions of the future of coral reefs under climate warming. The common brooding coral, Pocillopora damicornis, exhibits extensive differences in host genetic and microbial symbiont community composition between depth habitats at Heron Island in the southern Great Barrier Reef, Australia. An 18-month reciprocal field transplant experiment was undertaken to examine the environmental and genetic drivers behind variation in survival, weight gain, heat tolerance and algal symbiont community between the reef flat and slope habitats. We observed population-by-habitat interactions for in situ partial mortality and weight gain, where trait-related fitness of natives was greater than transplants in most cases, consistent with local adaptation. On average, flat colonies transplanted to the slope had a relatively low partial mortality but minimal weight gain, whereas slope colonies transplanted to the flat had relatively high partial mortality and average weight gain. Experimental heat tolerance was always higher in colonies sourced from the flat, but increased when slope colonies were transplanted to the flat, providing evidence of acclimatization in these colonies. The performance of certain slope to flat transplants may have been driven by each colony’s algal symbiont (Symbiodiniaceae) community, and flat variants were observed in a small number of slope colonies that either had a fixed flat composition before transplantation or shuffled after transplantation. Host genotypes of previously identified genetic outlier loci could not predict survival following transplantation, possibly because of low sample size and/or polygenic basis to the traits examined. Local environmental conditions and Symbiodiniaceae composition may provide insight into the adaptive potential to changing environmental conditions.

scholarly journals A Study of the Maximum Momentum Flux in the Solitary Wave Run-Up Zone over Back-Reef Slopes Based on a Boussinesq Model

2019 ◽  
Vol 7 (4) ◽  
pp. 109 ◽  
Author(s):  
Liu ◽  
Shao ◽  
Ning
Keyword(s):  
Solitary Wave ◽  
Momentum Flux ◽  
Reef Flat ◽  
Slope Angle ◽  
Shock Capturing ◽  
Wave Transformation ◽  
Back Reef ◽  
Boussinesq Model ◽  
Fringing Reefs ◽  
Run Up

This study utilized a shock-capturing Boussinesq model FUNWAVE-TVD to investigate the maximum momentum flux in the solitary wave run-up zone over back-reef slopes. Validation results of the present model were compared to the previous version of FUNWAVE using the eddy viscosity breaking model to demonstrate the advantages of the shock-capturing method in predicting the breaking solitary wave transformation and run-up over fringing reefs. A series of numerical experiments was designed comprehensively and performed then to obtain a new formulation for the envelope of the spatial distribution of the maximum momentum flux within the solitary wave run-up zone over back-reef beaches, which is different from the one used over uniformly-sloping beaches. Finally, the effects of the variation of reef parameters (i.e., the fore-reef slope angle, reef flat width, and water depth over the reef flat) on the maximum momentum flux at the initial shoreline were investigated to better understand the role of fringing reefs in the mitigation of tsunami hazard.

scholarly journals Seabird-Derived Nutrients Supply Modulates the Trophic Strategies of Mixotrophic Corals

2022 ◽  
Vol 8 ◽  
Author(s):  
Martin Thibault ◽  
Fanny Houlbreque ◽  
Nicolas N. Duprey ◽  
Noémie Choisnard ◽  
David P. Gillikin ◽  
...  
Keyword(s):  
Coral Reef ◽  
Resource Sharing ◽  
Reef Flat ◽  
Nitrogen Isotope ◽  
Nutrient Supply ◽  
Global Changes ◽  
Pocillopora Damicornis ◽  
Sw Pacific ◽  
Island Communities ◽  
Coral Reef Ecosystems

The ability of corals to modulate their nutrition strategy in response to variable nutrient supply remains poorly understood, limiting our understanding of energy flow in coral reef ecosystems and thus our comprehension of their resilience to global changes. We used a naturally occurring nutrient gradient along the reef flat of two seabird-inhabited islets in the SW Pacific to characterize spatiotemporal fluctuations in coastal nutrient availability, and how it modulates the trophic response of the mixotrophic coral Pocillopora damicornis. The clear gradients in dissolved [NOx] and δ15N values of macroalgae and both P. damicornis tissues and symbionts observed along the reef flat during the dry and the rainy season revealed that seabird-derived-N is supplied year-round to the reef flat. Yet, nitrogen isotope values of macroalgae show that the seabirds’ effect on coral reefs varies with sites and seasons. Metrics derived from the SIBER framework revealed that coral nutrition seasonally favored autotrophy when exposed to higher seabird guano concentrations and at inshore stations, while heterotrophy dominated in corals less exposed to seabird-derived nutrient supply. P. Damicornis is therefore able to cope with large changes in nitrogen supply induced by seabird island communities by switching between autotrophy and heterotrophy. These results shed light on the flexibility of resource sharing within the coral-algae symbiosis and highlight the importance of seabird populations to the functioning of coral reef ecosystems.

scholarly journals Elevated Temperature Alters the Lunar Timing of Planulation in the Brooding Coral Pocillopora damicornis

PLoS ONE ◽  
2014 ◽  
Vol 9 (10) ◽  
pp. e107906 ◽  
Author(s):  
Camerron M. Crowder ◽  
Wei-Lo Liang ◽  
Virginia M. Weis ◽  
Tung-Yung Fan
Keyword(s):  
Elevated Temperature ◽  
Pocillopora Damicornis ◽  
Brooding Coral

Experimental Investigation on Granite Cutting by Means of Diamond Frame Saw

2021 ◽  
Author(s):  
Junjie Wu ◽  
Jinsheng Zhang ◽  
Heng Zhang ◽  
Peiyu Dong ◽  
Congsen Ouyang ◽  
...  
Keyword(s):  
Experimental Investigation ◽  
Wear Resistance ◽  
Wear Rate ◽  
Cutting Forces ◽  
Side Surface ◽  
Cutting Performance ◽  
Feed Speed ◽  
Average Thickness ◽  
Lower Side ◽  
The Mean

Abstract A great quantity of granite sawing experiments was carried out to explore the cutting performance offrame sawing machine with the horizontal reciprocating cutting mode.A model of average thickness of cutting chip was established, and characteristics of cutting forces were analyzed. The mechanism of wear was revealed by analyzing the width of the saw kerf and the wear morphology of the diamond segments. The results showed that the wear resistance and the cutting forces ncrease as the feed speed. The cutting forces change abruptly at the reversing point during granite cutting. At the same time, the proportion of macro-fractured and pulled-out particles and the mean wear rate of segments increase with the feed speed, and the mean protrusion height of the grits is less than 100 μm. The width of the saw kerf is gradually reduced as the sawing progresses, forming an inverted cone with a large upper side and a small lower side. Besides, the studies found that the wear of the segments remains consistent in two directions. The prominent phenomenon of the diamond particles on the side surface is more obvious as the feed speed increases.The research can provide certain data support for granite cutting, and lay the foundation for the subsequent optimization of the structure and equipment.

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