scholarly journals Seagrass Condition at Some Small Islands in The Taka Bonerate National Marine Park, South Sulawesi Indonesia

Jurnal Segara ◽  
2021 ◽  
Vol 17 (2) ◽  
pp. 83
Author(s):  
Indarto Happy Supriyadi ◽  
Hendrik Alexander William Cappenberg ◽  
Sam Wouthuyzen ◽  
Muhammad Hafizt ◽  
Susi Rahmawati ◽  
...  

The assessment of seagrass bed condition in Indonesia still refers to the Decree of the State Minister for the Environment (KMNLH) no. 200 of 2004, which considers only one variable, namely the percentage of seagrass cover. To assess the seagrass beds condition to be more in-depth and meaningful, it is necessary to consider the addition of several variables, such as the biotic variables (seagrass species diversity including macroalgae and macro-benthos components) as well as the abiotic variables (reef flat areas and the substrate components). The purpose of this study is to determine the seagrass beds condition in several small islands in the Taka Bonerate National Marine Park by considering the additional analysis using both biotic and abiotic variables as mentioned above. The methodology used in this study is a combination of the use of the standard seagrass transect method, interpretation of satellite imagery related to the seagrass bottom habitat area, and its components on the reef flat of a particular island, as well as weighting and scoring based on those considered additional variables. By applying the criteria in the method, the seagrass bed conditions were then classified into three categories, namely seagrass in good, moderate, and unfavorable conditions, respectively. The results of the total score assessment on several small islands in Taka Bonerate Islands show that the seagrass bed in Latondu Besar Island is in good conditions with the highest score of (316) compared to Tarupa Besar, Jinato, Rajuni Kecil, and Tinabo Besar Islands with an average score of (173). The results of this study indicate that the assessment of seagrass conditions is more meaningful in terms of seagrass ecology than based on seagrass cover alone. However, this study requires a lot of validation for its application in assessing the condition of seagrass beds in other islands in Indonesia.

2008 ◽  
Vol 33 (2) ◽  
pp. 221-224
Author(s):  
Mahatma Lanuru ◽  
Ramdina Fitri

Deposition of suspended sediment was measured with sediment traps in shallow coastal waters colonized by Thallasia dominated seagrass in Pannikiang Island, South Sulawesi (Indonesia). The primary objective of this study was to compare the amounts of sediment deposition inside seagrass beds and in adjacent unvegetated area. The traps were placed in a seagrass bed (Station I, II, and III) and in an adjacent unvegetated area (Station IV) measuring the sediment flux on the seabed. The sediment fluxes due to deposition were significantly higher at stations I and II (P < 0.05) and station III (P < 0.01) than at station IV (unvegetated area). Results of this study suggest that sediment deposition was promoted by dense shoots of seagrass. The study provides quantitative evidence for the importance of seagrass bed as sites of sedimentation of fine particles.  


2021 ◽  
Vol 24 (2) ◽  
pp. 237-246
Author(s):  
Ita Riniatsih ◽  
Ambariyanto Ambariyanto ◽  
Ervia Yudiati

Seagrass bed are one of the ecosistems in shallow waters that can support the biodiversity of marine organisms. Megabenthos as benthic organisms that usually live in association in seagrass beds, have an important role in the food web in their habitat. This study aims to analyse the diversity of megabenthos associated with their habitat characteristics in seagrass waters in Bandengan, Teluk Awur and Panjang Island Jepara. This research was conducted using a descriptive field method, and megabenthos data collecting was carried out using the line transect method. Thr result showed that 158 individuals from 8 species of megabenthos were found (from 2 phyla: Echinodermata and Molluska) from three observation locations. Condition factors that influence the abundance and diversity of megabenthos are the substrat type and seagrass cover.   Padang lamun sebagai salah satu ekosistem di perairan laut dangkal dapat menopang keanekaragaman hayati organisme laut. Megabentos yang termasuk dalam organisme bentik merupakan organisme yang biasa hidup berasosiasi di padang lamun, mempunyai peranan penting dalam jaring-jaring makanan di habitatnya. Penelitian ini bertujuan untuk menganalisa keanekaragaman megabentos dikaitkan dengan karakteristik habitatnya di perairan padang lamun di Bandengan, Teluk Awur dan Pulau Panjang Jepara. Penelitian ini dilakukan dengan metoda deskriptif lapangan, dan pengambilan data megabentos dilakukan dengan metoda line transek. Hasil pengamatan menunjukkan ditemukan 158 individu dari 8 spesies  megabentos (dari 2 filum: Echinodermata dan Molluska) dari ketiga lokasi pengamatan.  Faktor kondisi yang berpengaruh terhadap kelimpahan dan keanekaragaman megabentos adalah jenis substrat dasar dan tutupan lamun.


Author(s):  
Riyadi Subur ◽  
Fredinan Yulianda ◽  
Achmad Fahrudin ◽  
Setyo B. Susilo

<p>ABSTRACT</p><p><br />Coral reef, mangrove, and seagrass bed are important ecosystems in coastal areas and small islands which plays critical roles in maintenance of shorelines and lands on small islands. Those ecosystems have mutual relationships in providing effective protection of lands and lives on small islands. The objectives of the research are to calculate, to valuate, and to determine ecological adaptive capacity small islands of Guraici Islands. Field work was carried out at all 17 islands of Guraici Islands, where data collection and calculations of each ecosystem adaptive capacity of coral reef, mangrove and seagrass bed were made. Values of adaptive capacity for each ecosystem are found to range between 0.0 and 1.0 whereas values of the ecological adaptive capacity of every single island in Guraici Islands range between 0.0 and 3.0. The results of this research indicate that all small island ecosystems studied in Guraici Islands can be grouped into three categories of adaptive capacity, they are “medium, low, and very low”. Values of coral reefs adaptive capacity range between 0.0 and 0.58. Values of mangroves adaptive capacity range between 0.0 and 0.51. Values of seagrass beds adaptive capacity range between 0.0 and 0.51. Data analysis made also shows that small island ecological adaptive capacity in Guraici Islands has also belonged to three categories “medium, low, and very low”, where all their adaptive capacity values range between 0.37 and 1.64. Ten islands are in “Medium” category, six islands in “low” category, and one island is in “very low” category.<br />Key words: coral reef, ecological adaptive capacity, mangrove, seagrass</p><p>-------</p><p>ABSTRAK</p><p><br />Terumbu karang (coral reef), mangrove dan padang lamun (seagrass bed), merupakan ekosistem penting di wilayah pesisir dan pulau-pulau kecil yang memegang peranan penting dalam melindungi garis pantai serta daratan pulau kecil. Ekosistem tersebut cukup efektif sebagai pelindung terhadap keselamatan lahan daratan pulau-pulau kecil, dan memiliki keterkaitan dalam melindungi pulau-pulau kecil. Tujuan peneliltian ini adalah menghitung, menilai serta menentukan status kapasitas adaptif ekologi pulau-pulau kecil dalam Gugus Pulau Guraici. Penelitian dilakukan pada 17 pulau yang terdapat dalam Gugus Pulau Guraici, dengan menghitung kapasitas adaptif ekosistem terumbu karang, ekosistem mangrove dan ekosistem lamun. Nilai Kapastias adaptif setiap ekosistem tersebut berkisar 0,0-1,0, sedangkan nilai kapasitas adaptif ekologi pulau berkisar 0,0-3,0. Hasil penelitian ini menunjukkan bahwa seluruh ekosistem pesisir yang diteliti pada pulau-pulau dalam Gugus Pulau Guraici tergolong dalam tiga kategori kapasitas adaptif yaitu “sedang, rendah dan sangat rendah”. Nilai kapasitas adaptif ekosistem terumbu karang berkisar 0,0-0,58.Ekosistem mangrove memiliki nilai kapasitas adaptif berkisar 0,0-0,51, dan ekosistem lamun kapasitas adaptifnya berkisar 0,0-0,59. Hasil analisis juga menunjukkan bahwa kapasitas adaptif ekologi pulau-pulau dalam Gugus Pulau Guraici tergolong kedalam tiga kategori yaitu “sedang, rendah dan sangat rendah”, dengan nilai kapasitas adaptif ekologi yang berkisar 0,37-1,64. Sebanyak sepuluh pulau tergolong memiliki kapasitas adaptif ekologi “sedang’, enam pulau memiliki kapasitas adaptif ekologi berkategori “rendah”, dan satu pulau berkategori kapasitas adaptif ekologi “sangat rendah”.<br />Kata kunci: terumbu karang, kapasitas adaptif ekologis, mangrove, lamun</p>


2019 ◽  
Vol 2 (1) ◽  
pp. 11-14
Author(s):  
Wahyu Adi

Pulau Kecil Gelasa merupakan daerah yang belum banyak diteliti. Pemetaan ekosistem di pulau kecil dilakukan dengan bantuan citra Advanced Land Observing Satellite (ALOS). Penelitian terdahulu diketahui bahwa ALOS memiliki kemampuan memetakan terumbu karang dan padang lamun di perairan dangkal serta mampu memetakan kerapatan penutupan vegetasi. Metode interpretasi citra menggunakan alogaritma indeks vegetasi pada citra ALOS yaitu NDVI (Normalized Difference Vegetation Index), serta pendekatan Lyzengga untuk mengkoreksi kolom perairan. Hasil penelitian didapatkan luasan Padang Lamun di perairan dangkal 41,99 Ha, luasan Terumbu Karang 125,57 Ha. Hasil NDVI di daratan/ pulau kecil Gelasa untuk Vegetasi Rapat seluas 47,62 Ha; luasan penutupan Vegetasi Sedang 105,86 Ha; dan penutupan Vegetasi Jarang adalah 34,24 Ha.   Small Island Gelasa rarely studied. Mapping ecosystems on small islands with the image of Advanced Land Observing Satellite (ALOS). Previous research has found that ALOS has the ability to map coral reefs and seagrass beds in shallow water, and is able to map vegetation cover density. The method of image interpretation uses the vegetation index algorithm in the ALOS image, NDVI (Normalized Difference Vegetation Index), and the Lyzengga approach to correct the water column. The results of the study were obtained in the area of Seagrass Padang in the shallow waters of 41.99 ha, the area of coral reefs was 125.57 ha. NDVI results on land / small islands Gelasa for dense vegetation of 47.62 ha; area of Medium Vegetation coverage 105.86 Ha; and the coverage of Rare Vegetation is 34.24 Ha.


1989 ◽  
Vol 16 (3) ◽  
pp. 239 ◽  
Author(s):  
H Marsh ◽  
WK Saalfeld

In 1984 and 1985, during surveys designed primarily to census dugongs, six species of sea turtles were counted from the air at an overall sampling intensity of 9% over a total area of 31 288 km2 within the northern sections of the Great Barrier Reef Marine Park. The sea turtles were not identified to species. We attempted to correct sightings for perception bias (the proportion of animals visible in the transect which are missed by observers), and to standardise for availability bias (the.proportion of animals that are invisible due to water turbidity) with survey-specific correction factors. The resultant minimum population estimate in November 1985 was (mean � s.e.) 32 187 � 2532 sea turtles at an overall density of 1.03 � 0.08 km-2, a precision of 8%. We consider this to be a gross underestimate of numbers present. Significant differences between population and density estimates obtained from repeat surveys of the same areas were accounted for by differences in Beaufort sea state and cloud cover. The analysis of covariance data suggested that we had not been successful in standardising all biases. Turtles were widely distributed throughout the Great Barrier Reef lagoon from inshore seagrass beds to mid- and outer-shelf reefs. Highest densities were observed on inshore seagrass beds and on mid-shelf reefs, particularly between Murdoch Island and Cape Melville, and in Princess Charlotte Bay. Maps of density and distribution are given. We discuss the value and limitations of this survey regime for censusing sea turtles.


2018 ◽  
Vol 66 (3) ◽  
pp. 1149 ◽  
Author(s):  
Margarita Loría-Naranjo ◽  
Jimena Samper-Villarreal ◽  
Marylaura Sandoval-Siles ◽  
Jorge Cortés

Seagrass beds are an important ecosystem on the Caribbean coast of Costa Rica. At Cahuita National Park (CNP) a seagrass bed at Perezoso has been monitored continually since 1999 within the CARICOMP program. Thalassia testudinum is the dominant seagrass species, in some cases mixed with Syringodium filiforme. The results from the 2009 to 2015 monitoring period are presented here, and contrasted with data before 2009. Total (above and below ground tissue) mean biomass of T. testudinum was higher (1 255.4 ± 146.0 gm-2) than biomass before 2009, with an increasing tendency. However, productivity (1.5±0.59 gm-2d-1) and turnover rate (4.3 ± 1.22 %d-1) were lower than previous monitoring periods. In this period, mean leaf area diminished considerably (4.9 ± 2.30 m2), but leaf area index (LAI) increased (1.9 ± 0.80 m2leafm-2) in comparison to prior monitoring. Productivity, density, turnover rate, LAI and biomass showed intra-annual variations; while mean biomass of T. testudinum did not vary significantly among years. No correlations were found between water salinity, temperature and clarity with seagrass measurements. However, most seagrass parameters were strongly correlated with precipitation. These results highlight the effect of external environmental agents acting on the ecosystem. CNP presents a long-term stable seagrass meadow. However, there are indirect signals, such as high biomass and above-ground biomass proportion, along with low productivity and LAI, which point to a nutrient increment in Perezoso’s seagrass bed. To continue protecting this seagrass bed, it is necessary to improve monitoring methods, and seagrass beds should be included in national conservation policies and monitoring programs.


2020 ◽  
Vol 4 (1) ◽  
pp. 6-13
Author(s):  
Sing Lui Lo ◽  
Tzuen Kiat Yap ◽  
Cheng Ann Chen ◽  
Teruaki Yoshida

A comparison of zooplankton abundance and community in the seagrass and non-seagrass areas of Limau-limauan and Bak- Bak waters within the newly established Tun Mustapha Marine Park was made during 15-17 May 2017. Samples were collected via horizontal tow of a 140 μm plankton net. Environmental variables (temperature, salinity, DO, pH, turbidity) showed no significant differences among the study sites. However, zooplankton showed increasing abundance from non-seagrass, seagrass edge, to seagrass areas at Limau-limauan, while abundance values were comparable among the stations at Bak-bak. Overall zooplankton abundance was significantly higher at the seagrass areas relative to the non-seagrass station at Limau-limauan (p < 0.005), while no statistical difference was found at Bak-Bak (p < 0.21). Mean canopy height was 3-fold higher (p < 0.001) at Limau-limauan than Bak-Bak, suggesting the importance of seagrass bed structural complexity in habitat preference for zooplankton. Cluster analysis revealed the zooplankton community from the seagrass area at Limau-limauan was different from that at seagrass edge and non-seagrass areas, which may be attributed to the influence of seagrass meadows in forming characteristic zooplankton compositions. Marked differences in zooplankton composition and abundance even in close vicinity of sites suggest the importance of local small-scale variations in seagrass habitats in shaping the zooplankton community.


PeerJ ◽  
2015 ◽  
Vol 3 ◽  
pp. e1280 ◽  
Author(s):  
Atsushi Nanami

The present study examined pair formation, spatial pattern of home range and spatial variation in density, size and social status of blotched foxfaceSiganus unimaculatus(family Siganidae) on an Okinawan coral reef. Of 32 pairs sampled for sexing, 31 (96.9%) were heterosexual and showed size-assortative pairing. Developed ovaries were found in April and July, whereas oocytes were immature in August, September and February. Heterosexual pairing was found in both reproductive and non-reproductive periods. Home range size tended to be positively related to fork length (FL). The degree of home range overlap for same size class pairs was smaller than that for different size class pairs. The intraspecific behavior when two pairs approached each other was categorized as ‘attack,’ ‘agonistic display’ and ‘no interactions,’ and the frequency of agonistic behaviors (“attack” or “agonistic display”) was significantly greater than “no interactions.” Underwater observations at a seagrass bed, a rocky reef flat and a sheltered reef slope revealed that the mean FL was significantly smaller at the sheltered reef slope (4–13 cm) than at the rocky reef flat (>13 cm). No individuals were found in the seagrass bed. Most individuals less than 6 cm FL were solitary, whereas most individuals over 7 cm FL were paired. Density was significantly greater on the sheltered reef slope than on the rocky reef flat.


2018 ◽  
Vol 4 (1) ◽  
Author(s):  
Muhammad Banda Selamat ◽  
Mahatma Lanuru ◽  
Amir Hamzah Muhiddin

Coral reefs and seagrass are natural fortress for small islands from waves and ocean currents. The spatial distribution of these benthic substrate should be known and monitored regularly. This study aims were to map existing benthic substrates on the reef flat of Bontosua Island, determine the spatial composition and develop index ratio. Benthic substrates were surveyed using geotagging technique. Their distribution were estimate using Quickbird image that was rectified and classified using ISOcluster method and validate by 240 selected photos. The seagrass were surveyed at 8 stasions to record percent cover and species composition. Depth profiles were track along 10 reef flat line segment. Bontosua Island has an elongated shape from South to Northwest. This study had produced a benthic substrate distribution map with thematic accuracy 76%. Total area able to map were 54.2 hectares. About 43% benthic substrates at Bontosua were mixture of coral rubble, seagrass and algae, 20% was mixture of rubble and algae, 16% dominated by seagrass, 13% mixture of sand and seagrass and 8% substrate were dominated by live coral. There were eight seagrass species found with average percent cover 37.2 ± 12.5 percent. The spatial ratio of live coral, seagrass and mixed substrate for West side reef flat was 2:20:49 and 1:9:9 for East side. This indicate that the distribution of benthic substrates on the West side is much wider than on the East side. This approach potentially applied to study the relationship between benthic substrate composition and the deformation of small islands.


2019 ◽  
Vol 22 (1) ◽  
pp. 42
Author(s):  
Sarah Nabilla ◽  
Retno Hartati ◽  
Ria Azizah Tri Nuraini

The availability of nutrients in seagrass beds can act as growth limiting factors. Absorption of nutrients in the water column is carried out by the leaves while the absorption of nutrients from the sediment is carried out by the roots but does not rule out the transport of nutrients by the roots will also arrive at the leaves of the seagrass. If the nutrient requirement is not met properly, then the growth will be disrupted. Like the difference in distribution and density of seagrass itself. Nutrient concentrations in waters vary. Nitrate and phosphate levels in the waters are strongly influenced by sources of organic material from outside/land (allochthonous) or from the water itself (autocthonous). This research was conducted with the aim of nothing: to determine the relationship between nutrient content (nitrate and phosphate) in sediment to seagrass cover in Teluk Awur and Pantai Blebak, JeparaData collection of seagrass and sediment was carried out on March 2018 in the waters of Teluk Awur and Blebak Beach, Kabupaten Jepara. Type identification, density, and coverage are carried out at the research location. Nitrate and phosphate analysis in sediments is carried out in Laboratorium Pengujian dan Peralatan. Based on the results of research that has been carried out, it can be concluded that there is a very strong positive relationship between nutrients and seagrass closure in the two research locations, each of which is 0.955 (91.1%) in Teluk Awur waters and 0.962 (92.6%) in Blebak Beach.Ketersediaan nutrien di perairan padang lamun dapat berperan sebagai faktor pembatas pertumbuhan. Penyerapan nutrien pada lamun pada kolom air dilakukan oleh daun sedangkan penyerapan nutrien dari sedimen dilakukan oleh akar namun tidak menutup kemungkinan pengangkutan nutrien oleh akar juga akan sampai pada bagian daun. Jika kebutuhan nutrien tidak terpenuhi dengan baik, maka pertumbuhannya mengalami gangguan. Seperti perbedaan sebaran dan kepadatan lamun itu sendiri. Konsentrasi nutrien di perairan bervariasi. Kadar nitrat dan fosfat di perairan sangat dipengaruhi oleh sumber bahan organik yang berasal dari luar/ daratan (allochthonous) maupun dari dalam perairan itu sendiri (autocthonous). Penelitian ini dilakukan dengan tujuan: untuk mengetahui hubungan antara kandungan nutrien (nitrat dan fosfat) pada sedimen terhadap tutupan lamun di Teluk Awur dan Pantai Blebak, Jepara. Identifikasi jenis, kepadatan dan penutupan dilakukan pada lokasi penelitian. Analisa nitrat dan fosfat dalam sedimen dilakukan di Laboratorium Pengujian dan Peralatan. Berdasarkan hasil penelitian yang telah dilakukan dapat di ambil kesimpulan bahwa terdapat hubungan sangat kuat positif antara nutrien dengan penutupan lamun pada dua lokasi penelitian, nilainya masing-masing sebesar 0,955 (91,1%) di Perairan Teluk Awur dan 0,962 (92,6%) di Pantai Blebak.


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