scholarly journals Suitability analysis of Tanjung Benoa Waters-Bali for dive tourism

2020 ◽  
Vol 153 ◽  
pp. 01007
Author(s):  
Dwi Budi Wiyanto ◽  
Nuddin Harahab ◽  
Rudianto ◽  
Aida Sartambul
Keyword(s):  
Coral Reef ◽  
Water Depth ◽  
Anthropogenic Activities ◽  
Water Current ◽  
Suitability Analysis ◽  
Coral Fish ◽  
Dive Tourism

This study was aimed to evaluate the suitability of Tanjung Benoa waters for dive tourism. The suitability analysis was carried out using Suitability Tourism Index (STI) method. Water visibility, coral reef coverage, lifeform, coral fish, water depth, and water current were used to analyze the suitability rate. The result showed that Tanjung Benoa waters were categorized as appropriate conditional (STI = 40.74 to 42.59). The less appropriate condition at the location might be caused by the high anthropogenic activities in the land.

scholarly journals Tidal variability of nutrients in a coastal coral reef system influenced by groundwater

2018 ◽  
Vol 15 (4) ◽  
pp. 997-1009 ◽  
Author(s):  
Guizhi Wang ◽  
Shuling Wang ◽  
Zhangyong Wang ◽  
Wenping Jing ◽  
Yi Xu ◽  
...  
Keyword(s):  
Coral Reef ◽  
Water Column ◽  
Water Depth ◽  
Neap Tide ◽  
Groundwater Discharge ◽  
Spring Tide ◽  
Biological Processes ◽  
Reef System ◽  
Nitrite Nitrate ◽  
Coral Reef System

Abstract. To investigate variation in nitrite, nitrate, phosphate, and silicate in a spring–neap tide in a coral reef system influenced by groundwater discharge, we carried out a time-series observation of these nutrients and 228Ra, a tracer of groundwater discharge, in the Luhuitou fringing reef at Sanya Bay in the South China Sea. The maximum 228Ra, 45.3 dpm 100 L−1, appeared at low tide and the minimum, 14.0 dpm 100 L−1, appeared during a flood tide in the spring tide. The activity of 228Ra was significantly correlated with water depth and salinity in the spring–neap tide, reflecting the tidal-pumping feature of groundwater discharge. Concentrations of all nutrients exhibited strong diurnal variation, with a maximum in the amplitude of the diel change for nitrite, nitrate, phosphate, and silicate in the spring tide of 0.46, 1.54, 0.12, and 2.68 µM, respectively. Nitrate and phosphate were negatively correlated with water depth during the spring tide but showed no correlation during the neap tide. Nitrite was positively correlated with water depth in the spring and neap tide due to mixing of nitrite-depleted groundwater and nitrite-rich offshore seawater. They were also significantly correlated with salinity (R2  ≥  0.9 and P < 0.05) at the ebb flow of the spring tide, negative for nitrate and phosphate and positive for nitrite, indicating the mixing of nitrite-depleted, nitrate- and phosphate-rich less saline groundwater and nitrite-rich, nitrate- and phosphate-depleted saline offshore seawater. We quantified variation in oxidized nitrogen (NOx) and phosphate contributed by biological processes based on deviations from mixing lines of these nutrients. During both the spring and neap tide biologically contributed NOx and phosphate were significantly correlated with regression slopes of 4.60 (R2  =  0.16) in the spring tide and 13.4 (R2  =  0.75) in the neap tide, similar to the composition of these nutrients in the water column, 5.43 (R2  =  0.27) and 14.2 (R2  =  0.76), respectively. This similarity indicates that the composition of nutrients in the water column of the reef system was closely related with biological processes during both tidal periods, but the biological influence appeared to be less dominant, as inferred from the less significant correlations (R2  =  0.16) during the spring tide when groundwater discharge was more prominent. Thus, the variability of nutrients in the coral reef system was regulated mainly by biological uptake and release in a spring–neap tide and impacted by mixing of tidally driven groundwater and offshore seawater during spring tide.

scholarly journals Spatiotemporal variability of sedimentary organic matter supply and recycling processes in coral reefs of Tayrona National Natural Park, Colombian Caribbean

2014 ◽  
Vol 11 (11) ◽  
pp. 2977-2990 ◽  
Author(s):  
E. Bayraktarov ◽  
C. Wild
Keyword(s):  
Organic Matter ◽  
Coral Reef ◽  
Coastal Upwelling ◽  
Sediment Traps ◽  
Sedimentary Organic Matter ◽  
Spatiotemporal Variability ◽  
Water Current ◽  
Labile Organic Matter ◽  
Natural Park ◽  
River Mouths

Abstract. Sediments are fundamental for the function of oligotrophic coral reef ecosystems because they are major places for organic matter recycling. The Tayrona National Natural Park (TNNP, Colombian Caribbean) is located between the population center Santa Marta (>455 000 inhabitants) in the southwest and several river mouths in the east. Here, coral reef sediments experience pronounced changes in environmental conditions due to seasonal coastal upwelling, but knowledge of relevant spatiotemporal effects on organic matter supply to the sediments and recycling processes is not available. Therefore, sediment traps were deployed monthly over 14 months complemented by assessment of sedimentary properties (e.g., porosity, grain size, content of particulate organic matter and pigments) and sedimentary O2 demand (SOD) at water-current-exposed and sheltered sites along distance gradients (12–20 km) to Santa Marta and the eastern river mouths (17–27 km). Findings revealed that seasonal upwelling delivered strong (75–79% of annual supply) pulses of labile organic matter mainly composed of fresh phytoplankton detritus (C : N ratio 6–8) to the seafloor. Sedimentary chlorophyll a contents and SOD increased significantly with decreasing distance to the eastern rivers, but only during upwelling. This suggests sedimentary organic matter supply controlled by nutrient-enriched upwelling waters and riverine runoff rather than by the countercurrent-located city of Santa Marta. Organic matter pulses led to significantly higher SOD (more than 30%) at the water-current-sheltered sites as compared to the exposed sites, ensuing a rapid recycling of the supplied labile organic matter in the permeable silicate reef sands.

scholarly journals Assessing macroinvertebrate communities in relation to environmental variables: the case of Sambandou wetlands, Vhembe Biosphere Reserve

2019 ◽  
Vol 10 (1) ◽  
Author(s):  
Tatenda Dalu ◽  
Rivoningo Chauke
Keyword(s):  
Community Structure ◽  
Water Depth ◽  
Environmental Variables ◽  
Anthropogenic Activities ◽  
Biosphere Reserve ◽  
High Water ◽  
Macroinvertebrate Community ◽  
Macroinvertebrate Communities ◽  
Negative Effect ◽  
Macrophyte Cover

AbstractThe Vhembe Biosphere Reserve, South Africa, contains many wetlands that serve as wildlife habitats and provide vital ecosystem services. Some of the wetlands are continuously being degraded or destroyed by anthropogenic activities causing them to disappear at an alarming rate. Benthic macroinvertebrates are known as good water quality bioindicators and are used to assess aquatic ecosystem health. The current study investigated habitat quality using macroinvertebrate community structure and other biotic variables (i.e. phytoplankton, macrophytes) in relation to environmental variables in the Sambandou wetlands using canonical correspondence analysis (CCA). A total of fifteen macroinvertebrate families were identified over two seasons. The CCA highlighted seven variables, i.e. pH, phosphate concentration, temperature, ammonium, macrophyte cover, conductivity and water depth, which were significant in structuring macroinvertebrate community. Picophytoplankton and microphytoplankton concentrations decreased from winter to summer, whereas nanophytoplankton concentration increased from winter to summer. Thus, the dominance of small-sized phytoplankton indicated nutrient limitation and decreased productivity, whereas winter sites 2 and 3 were dominated by large-celled phytoplankton, highlighting increased productivity. Winter sites were mostly negatively associated with CCA axis 1 and were characterised by high temperature, phosphate and ammonium concentrations, macrophyte cover, pH and conductivity. Summer sites were positively associated with axis 1, being characterised by high water depth and pH levels. The results obtained highlighted that agricultural activities such as cattle grazing and crop farming and sand mining/poaching had a negative effect on macroinvertebrate community structure.

scholarly journals Diversity of Coral Fish At Saebus Island, East Java, Indonesia

2018 ◽  
Vol 31 ◽  
pp. 08021
Author(s):  
Siti Fatimah ◽  
Tri Widya Laksana Putra ◽  
Putranto Kondang ◽  
Suratman ◽  
Larossa Gamelia ◽  
...  
Keyword(s):  
Coral Reef ◽  
Diversity Index ◽  
Fish Diversity ◽  
Underwater Visual Census ◽  
Important Place ◽  
Census Methods ◽  
Target Fish ◽  
Coral Reef Ecosystems ◽  
Coral Fish ◽  
Different Depths

Coral reef ecosystem is known as an important place to live various types of fish, where coral conditions will affect the diversity and abundance of the fish. In healthy coral reef ecosystems generally can be found many types of fish with high density. This research aims to investigate the diversity and abundance of coral fishes at Saebus Island, East Java. The observation conducted at 4 stations, according to cardinal point by UVS (underwater visual census) methods with belt transect with the visibility of 2,5 m horizontally, and 5 m vertically. The length of transect was 100 m parallel with coastline, with the area of observation is 500 m2. The censuses were conducted at 2 different depths (3 and 10 m). This study found 70 kinds of coral fish originated form 20 family at all stations. These fishes were from 3 different fish categories i.e. 7 target fishes, 13 indicator fishes, and 50 major fishes. Three different fishes that dominated target fish, indicator fish and major fish were Epinephelus fasciatus, Chaetodon baronessa and Aulostomus chinensis, respectively. There was similar value of fish diversity index at two different depths which were 3.635 and 3,623. While uniformity index at the depth of 3m was 0.153 and at 10m was 0.217, and domination index at the depth of 3m was 0.11 and at 10m was 0.167. These values suggest that diversity of coral fish at Saebus island can be categorized as high diversity.

scholarly journals Confidence Levels, Sensitivity, and the Role of Bathymetry in Coral Reef Remote Sensing

2020 ◽  
Vol 12 (3) ◽  
pp. 496 ◽  
Author(s):  
James A. Goodman ◽  
Mui Lay ◽  
Luis Ramirez ◽  
Susan L. Ustin ◽  
Paul J. Haverkamp
Keyword(s):  
Remote Sensing ◽  
Coral Reef ◽  
Coral Reefs ◽  
Water Depth ◽  
Data Availability ◽  
Sensor Technology ◽  
Internal Quality ◽  
Benthic Habitat ◽  
Model Output ◽  
Confidence Levels

Remote sensing is playing an increasingly important role in the monitoring and management of coastal regions, coral reefs, inland lakes, waterways, and other shallow aquatic environments. Ongoing advances in algorithm development, sensor technology, computing capabilities, and data availability are continuing to improve our ability to accurately derive information on water properties, water depth, benthic habitat composition, and ecosystem health. However, given the physical complexity and inherent variability of the aquatic environment, most of the remote sensing models used to address these challenges require localized input parameters to be effective and are thereby limited in geographic scope. Additionally, since the parameters in these models are interconnected, particularly with respect to bathymetry, errors in deriving one parameter can significantly impact the accuracy of other derived parameters and products. This study utilizes hyperspectral data acquired in Hawaii in 2000–2001 and 2017–2018 using NASA’s Classic Airborne Visible/Infrared Imaging Spectrometer to evaluate performance and sensitivity of a well-established semi-analytical inversion model used in the assessment of coral reefs. Analysis is performed at several modeled spatial resolutions to emulate characteristics of different feasible moderate resolution hyperspectral satellites, and data processing is approached with the objective of developing a generalized, scalable, automated workflow. Accuracy of derived water depth is evaluated using bathymetric lidar data, which serves to both validate model performance and underscore the importance of image quality on achieving optimal model output. Data are then used to perform a sensitivity analysis and develop confidence levels for model validity and accuracy. Analysis indicates that derived benthic reflectance is most sensitive to errors in bathymetry at shallower depths, yet remains significant at all depths. The confidence levels provide a first-order method for internal quality assessment to determine the physical extent of where and to what degree model output is considered valid. Consistent results were found across different study sites and different spatial resolutions, confirming the suitability of the model for deriving water depth in complex coral reef environments, and expanding our ability to achieve automated widespread mapping and monitoring of global coral reefs.

scholarly journals Coral Reef Drag Coefficients – Water Depth Dependence

2017 ◽  
Vol 47 (5) ◽  
pp. 1061-1075 ◽  
Author(s):  
S. J. Lentz ◽  
K. A. Davis ◽  
J. H. Churchill ◽  
T. M. DeCarlo
Keyword(s):  
Coral Reef ◽  
Coral Reefs ◽  
Drag Coefficient ◽  
Water Depth ◽  
Open Channel ◽  
Momentum Balance ◽  
Laboratory Studies ◽  
Drag Coefficients ◽  
Significant Term ◽  
The Cross

AbstractA major challenge in modeling the circulation over coral reefs is uncertainty in the drag coefficient because existing estimates span two orders of magnitude. Current and pressure measurements from five coral reefs are used to estimate drag coefficients based on depth-average flow, assuming a balance between the cross-reef pressure gradient and the bottom stress. At two sites wind stress is a significant term in the cross-reef momentum balance and is included in estimating the drag coefficient. For the five coral reef sites and a previous laboratory study, estimated drag coefficients increase as the water depth decreases consistent with open channel flow theory. For example, for a typical coral reef hydrodynamic roughness of 5 cm, observational estimates, and the theory indicate that the drag coefficient decreases from 0.4 in 20 cm of water to 0.005 in 10 m of water. Synthesis of results from the new field observations with estimates from previous field and laboratory studies indicate that coral reef drag coefficients range from 0.2 to 0.005 and hydrodynamic roughnesses generally range from 2 to 8 cm. While coral reef drag coefficients depend on factors such as physical roughness and surface waves, a substantial fraction of the scatter in estimates of coral reef drag coefficients is due to variations in water depth.

scholarly journals KONDISI TERUMBU KARANG PULAU MANTEHAGE KABUPATEN MINAHASA UTARA PROVINSI SULAWESI UTARA

2019 ◽  
Vol 7 (3) ◽  
pp. 208
Author(s):  
Ardy Kase ◽  
Indri Manembu ◽  
Joshian Schaduw
Keyword(s):  
Coral Reef ◽  
Coral Reefs ◽  
Anthropogenic Activities ◽  
Good Condition ◽  
Digital Camera ◽  
Health Conditions ◽  
Point Count ◽  
Lack Of Information ◽  
Reef Health ◽  
Moderate Condition

Coral reefs are coastal ecosystems with the highest level of diversity. Corals are invertebrates that are included in the Phylum Coelenterata (hollow animal) or Cnidaria. Whereas coral reefs are a collection of millions of polyps. Natural phenomena and various anthropogenic activities threaten the health and presence of Mantehage Island coral reefs and the lack of information about the health conditions of coral reefs on Mantehage Island. The purpose of this study is to determine the condition of coral reefs andto  provide baselines data on Mantehage Island. Data collection was done by using UPT  method (Underwater Photo Transect). Underwater Photo Transect carried out by underwater shooting using a digital camera that was shielded (housing). Image analysis were done using the CPCe software (Coral Point Count with Excel extensions). The results of coral reef health conditions at four stations on Mantehage Island shows, coral reef cover at each station as follows, station 1 (one) 53.00% were in good condition, station 2 (two) 25.40% were in a moderate condition, station 3 (three) 16.49% were in poor condition, and station 4 (four) 42.07% were in a moderate condition. From the four stations, the condition of Mantehage Island's coral reefs were in the moderate category with a percentage of 34.24%.Keywords:. Mantehage Island, Terumbu Karang, UPT, CPCe

scholarly journals Persepsi Masyarakat tentang Terumbu Karang di Kepulauan Seribu

2006 ◽  
Vol 7 (1) ◽  
pp. 27-45
Author(s):  
Farma Mangunsong
Keyword(s):  
Coral Reef ◽  
Natural Resources ◽  
Good Condition ◽  
Reef Coral ◽  
Economic Benefits ◽  
Strong Impact ◽  
Income Source ◽  
Significant Relationships ◽  
High Dependency ◽  
Coral Fish

Kepulauan Seribu has rich natural resources in the form of coral reef coral fish, and other ocean Now which interact with each other. Resident of Kepulauan Seribu has a high dependency on these natural resources. The existence of coral reef has a strong impact on fisheries since the number offish and other biota will be high when the coral reef is in good condition. Nelayan tangkap konsumsi is one of the job types which strongly affected by the existence of coral reef Fishermen get economic benefits in the form of job and income source. Not only fishermen, all the residents also get benefits in the form of protein source, income source, and also job field from the existence of coral reef Nevertheless, based on the research done by the experts, the condition of the coral reef in Kepulauan Seribu tends to get worse because of human and natural factors. The purpose of this study is to reveal the Kepulauan Seribu residence perception of the coral reef condition and factors affect this perception. Rased on regression results, place of residency, age, education, length of stay, major sauce of household income, and condition of coral reef at the nearest island have significant relationships with the people's perception.  

scholarly journals KELIMPAHAN IKAN KARANG PADA KAWASAN TERUMBU BUATAN DI PERAIRAN RATATOTOK SULAWESI UTARA

2015 ◽  
Vol 6 (1) ◽  
pp. 55 ◽  
Author(s):  
Indri Manembu ◽  
L.A Adrianto ◽  
D Bengen ◽  
F Yulinda
Keyword(s):  
Coral Reef ◽  
Species Composition ◽  
Reef Fishes ◽  
Coral Reef Fishes ◽  
Sea Surface ◽  
Artificial Reefs ◽  
Line Transect ◽  
Visual Census ◽  
Coral Fish ◽  
Reef Ecosystem

Ekosistemterumbu karangmerupakan salah satu potensi sumberdaya laut yang sangat penting bagi kehidupan manusia. Potensi sumberdaya ikan karang di perairan Indonesia perlu diketahui agar dapat dikembangkan sebagai salah satu aset dalamkegiatan pariwisata bahari. Penelitian yang dilakukan tahun 2009-2011 bertujuan untuk mengetahui kelimpahan dan komposisi jenis ikan karang pada kawasan terumbu buatan di perairan Ratatotok. Metode line transect dan sensus visual pada perairan seluas 250M2 digunakan untuk mengetahui kelimpahan ikan karang dengan keragaman jenis pada masing-masing stasiun pengamatan pada kedalaman 10 meter. Hasil penelitian telah teridentifikasi sebanyak 116 spesies ikan pada terumbu buatan Stasiun 1 (daerah Teluk Buyat); 112 spesies pada terumbu buatan Stasiun 2 (daerah Tanjung) dan pada terumbu alami di Stasiun 3 (daerah Ratatotok) sebanyak 88 spesies. Kelimpahan ikan pada kawasan terumbu buatan lebih tinggi pada kisaran 24-28 spesies daripada karang alami. Kelimpahan spesies ikan dari famili Pomacentridae mendominasi ketiga stasiun pengamatan dengan 19 spesies dan yang paling sedikit dari famili Anomalopidae yang hanya ditemukan 1 spesies.Coral reef ecosystem is one of important natural resources in tropical waters. It has some coral reef fishes, species of corals and others biota that have several most interesting ecotourism extraction scientific and educational objects. The aim of this study is to determine the abundance of coral fish composition surrounded in artificial reefs area in Ratatotok waters. This study was done during 2009 to 2011by using the visual census and line transect methods within area of 250 M2 to observe the species composition and diversitas of coral fishes founded in three sites at the depth of 10 m from sea surface. The results showed that there were 116 species in Site 1(Buyat bay); 112 species in Site 2 (Tanjung) and 88 species of coral reef fishes in Site 3 (Ratatotok). Fishes of Pomacentridae were found 19 species in all locations. Only one species fish of Anomalopidae was found.

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