scholarly journals Observations on the behaviour of the dugong (Dugong dugon Müller, 1776) from waters of the Lease Islands, eastern Indonesia

1997 ◽  
Vol 67 (1) ◽  
pp. 71-77 ◽  
Author(s):  
H.H. de Iongh ◽  
B. Bierhuizen ◽  
B. van Orden
Keyword(s):  
Feeding Ecology ◽  
Coastal Waters ◽  
Small Population ◽  
Seagrass Meadows ◽  
Eastern Indonesia ◽  
Halophila Ovalis ◽  
Scuba Divers ◽  
Halodule Uninervis

A small population of dugongs was discovered in coastal waters of the Lease islands in eastern Indonesia. Studies on behaviour and feeding ecology revealed information on the interaction with seagrass meadows, modes of surfacing and submergence times and behaviour in the presence of scuba divers. Regular concentrated feeding was observed in a grazing sward at a subtidal monospecific Halophila ovalis meadow, confirming earlier observations of regular recropping by dugongs of grazing swards, covered by monospecific Halodule uninervis, inside an intertidal multi-species meadow.

Impact of Dugong grazing and turtle cropping on tropical seagrass communities

1999 ◽  
Vol 5 (4) ◽  
pp. 277 ◽  
Author(s):  
Lemnuel Aragones ◽  
Helene Marsh
Keyword(s):  
Grazing Intensity ◽  
Biomass Productivity ◽  
Chelonia Mydas ◽  
Mixed Species ◽  
Seagrass Meadows ◽  
Halophila Ovalis ◽  
Halodule Uninervis ◽  
Cymodocea Rotundata ◽  
Time Frames ◽  
The Impact

The impact of grazing by two megaherbivores, the Dugong Dugong dugon and the Green Turtle Chelonia mydas on the community structure of intertidal seagrasses was investigated experimentally over two time frames (shorterterm: 1?4 months; longer-term: 10 and 13 months), at three levels of grazing intensity (leaf cropping, light grazing, intensive grazing), at two seagrass meadows in tropical Queensland, Australia: (1) a mixed species bed of Zostera capricorni, Halophila ovalis, Halodule uninervis, Cymodocea rotundata and Cymodocea serrulata, and (2) a monospecific bed of Halodule uninervis, From the perspective of the megaherbivores, grazing improved the structure and dynamics of the tropical seagrass communities by altering their biomass, volume of detritus, net aboveground biomass productivity and the species composition of the mixed-species bed, Recovery from grazing disturbance occurred after several months to a year.

PEMETAAN SEBARAN PADANG LAMUN MENGGUNAKAN CITRA SATELIT LANDSAT 8 DI KEPULAUAN TANIMBAR KABUPATEN MALUKU TENGGARA BARAT PROVINSI MALUKU

2019 ◽  
Vol 3 ◽  
pp. 871
Author(s):  
Desita Anggraeni ◽  
M. Nurkholis Fauzi ◽  
Christian Novia Ngesti H.
Keyword(s):  
Landsat 8 ◽  
Surface Reflectance ◽  
Halophila Ovalis ◽  
Halodule Uninervis ◽  
Gap Data

Padang lamun merupakan habitat penting pesisir yang memiliki peran kunci dalam ekosistem pesisir. Kawasan ini merupakan area asuhan bagi ikan-ikan kecil, udang, persembunyian biota dari predatornya, pendaur zat hara, serta penyerap nutrien dari limpasan air laut yang dapat membantu menstabilkan sedimen dan kejernihan air. Kepulauan Tanimbar merupakan salah satu lokasi di Provinsi Maluku dengan potensi sebaran lamun yang cukup luas, namun informasi mengenai sebaran lamun di kawasan ini tidak terdata dengan baik. Teknologi penginderaan jauh merupakan salah satu alternatif untuk mengisi gap data di area yang luas dan sulit dijangkau, termasuk untuk memetakan sebaran lamun di Kepulauan Tanimbar. Penelitian ini bertujuan untuk menyediakan data dasar sebaran dan luas habitat lamun di pesisir Kepulauan Tanimbar. Metode yang digunakan adalah analisis citra penginderaan jauh Landsat 8, menerapkan penajaman citra untuk perairan dangkal menggunakan algoritma Lyzenga. Citra Landsat yang digunakan Landsat Surface Reflectance liputan path/row 106/65 dan 106/66 tahun perekaman 2017. Pengambilan data lapangan dilakukan pada tanggal 1-10 November 2017. Metode pengambilan data lamun dilakukan menggunakan metode seagrass watch . Hasil pengolahan citra menunjukkan lamun terdistribusi merata di seluruh pesisir Kepulauan Tanimbar dengan luas total 5.615,63 hektar dengan tutupan terpadat di sekitar Pulau Seira. Hasil survei lapangan menunjukkan tutupan lamun terpadat dijumpai di Formusan dengan tutupan lamun rata-rata 95%. Kondisi lamun paling baik berada di daerah Sabal, didukung kondisi air yang sangat jernih dengan substrat utama pasir. Berdasarkan hasil pengamatan lapangan, jenis lamun yang ditemukan antara lain: E n h alu s a c o r oid e s , T h ala s sia h e m p ric hii, C y m o d o c e a s e r r ula t a , C y m o d o c e a rotundata, Syringodi um isoetifolium, Halodule uninervis, Halophila ovalis, dan Halophila minor .

Feeding ecology of Japanese Spanish mackerel (Scomberomorus niphonius) along the eastern coastal waters of China

2021 ◽  
Vol 40 (8) ◽  
pp. 98-107
Author(s):  
Haozhi Sui ◽  
Ying Xue ◽  
Yunkai Li ◽  
Binduo Xu ◽  
Chongliang Zhang ◽  
...  
Keyword(s):  
Feeding Ecology ◽  
Coastal Waters ◽  
Spanish Mackerel ◽  
Scomberomorus Niphonius

scholarly journals Monitoring oyster culture rafts and seagrass meadows in Nagatsura-ura Lagoon, Sanriku Coast, Japan before and after the 2011 tsunami by remote sensing: their recoveries implying the sustainable development of coastal waters

PeerJ ◽  
2021 ◽  
Vol 9 ◽  
pp. e10727
Author(s):  
Hiroki Murata ◽  
Motoyuki Hara ◽  
Chinatsu Yonezawa ◽  
Teruhisa Komatsu
Keyword(s):  
Remote Sensing ◽  
Sustainable Development ◽  
Coastal Waters ◽  
Coastal Ecosystems ◽  
Oyster Culture ◽  
Sanriku Coast ◽  
The Sustainable Development ◽  
Seagrass Meadows ◽  
Before And After ◽  
Aquaculture Management

Background Coastal ecosystems are blue infrastructures that support coastal resources and also aquaculture. Seagrass meadows, one of coastal ecosystems, provide substrates for epiphytic diatoms, which are food resources for cultured filter feeder organisms. Highly intensive coastal aquaculture degrades coastal environments to decrease seagrass meadows. Therefore, efficient aquaculture management and conservation of seagrass meadows are necessary for the sustainable development of coastal waters. In ria-type bays, non-feeding aquaculture of filter feeders such as oysters, scallops, and ascidians are actively practiced along the Sanriku Coast, Japan. Before the 2011 Great East Japan Earthquake, the over-deployment of oyster culture facilities polluted the bottom environment and formed an hypoxic bottom water layer due to the organic excrements from cultured oysters. The tsunami in 2011 devastated the aquaculture facilities and seagrass meadows along the Sanriku Coast. We mapped the oyster culture rafts and seagrass meadows in Nagatsura-ura Lagoon, Sanriku Coast before and after the tsunami and monitored those and environments after the tsunami by field surveys. Methods We conducted field surveys and monitored the environmental parameters in Nagatsura-ura Lagoon every month since 2014. We used high-resolution satellite remote sensing images to map oyster culture rafts and seagrass meadows at irregular time intervals from 2006 to 2019 in order to assess their distribution. In 2019, we also used an unmanned aerial vehicle to analyze the spatial variability of the position and the number of ropes suspending oyster clumps beneath the rafts. Results In 2013, the number and distribution of the oyster culture rafts had been completely restored to the pre-tsunami conditions. The mean area of culture raft increased after the tsunami, and ropes suspending oyster clumps attached to a raft in wider space. Experienced local fishermen also developed a method to attach less ropes to a raft, which was applied to half of the oyster culture rafts to improve oyster growth. The area of seagrass meadows has been expanding since 2013. Although the lagoon had experienced frequent oyster mass mortality events in summer before the tsunami, these events have not occurred since 2011. The 2011 earthquake and tsunami deepened the sill depth and widened the entrance to enhance water exchange and improve water quality in the lagoon. These changes brought the expansion of seagrass meadows and reduction of mass mortality events to allow sustainable oyster culture in the lagoon. Mapping and monitoring of seagrass meadows and aquaculture facilities via satellite remote sensing can provide clear visualization of their temporal changes. This can in turn facilitate effective aquaculture management and conservation of coastal ecosystems, which are crucial for the sustainable development of coastal waters.

scholarly journals New Records of Seagrass Flora in Air Bangis West Sumatera

2012 ◽  
Vol 13 (1) ◽  
pp. 77
Author(s):  
Eni Kamal ◽  
Japar Sidik Bujang ◽  
Muta Hara Zakaria
Keyword(s):  
Coral Reefs ◽  
West Coast ◽  
Coastal Waters ◽  
New Record ◽  
New Records ◽  
Thalassia Hemprichii ◽  
Habitat Characteristic ◽  
Halodule Uninervis ◽  
Width Measurements ◽  
Shallow Coastal Waters

Seagrasses in the Air Bangis Archipelago, west coast of Sumatra were found growing in sandy muddy substratesof the shallow coastal waters at depth of 0.3-2.5 m, dominated by degraded coral reefs around the off-shoreislands. Two species; Enhalus acoroides (L.f) Royle and Thalassia hemprichii (Ehrenb) Aschers were observed atPulau Unggas, Pulau Pasir Panjang and Teluk Tapang. Halodule uninervis (Forssk) Aschers was observed in twolocations; Pasir Panjang and Teluk Tapang. The occurrence of this species is unknown previously and therefore itis a new flora record for Sumatra. With this new record, Sumatra has six species of seagrasses, contributing tohalf of total number of seagrasses occurring in Indonesia. According to leaf width measurements, two morphologicalvariants (narrow and wide leaved) can be distinguished for Halodule uninervis. In addition, descriptions of thespecies and their habitat characteristic are provided.

scholarly journals Pemetaan Kondisi Lamun di Perairan Sekitar Pulau Lepar Kabupaten Bangka Selatan

2019 ◽  
Vol 2 (2) ◽  
pp. 83-86
Author(s):  
Suci Puspita Sari
Keyword(s):  
Thalassia Hemprichii ◽  
Enhalus Acoroides ◽  
Halophila Ovalis ◽  
Halodule Uninervis ◽  
Cymodocea Rotundata ◽  
Cymodocea Serrulata

Status mengenai kondisi ekosistem lamun di perairan Bangka Selatan diperlukan untuk menentukan terjadinya indikasi kerusakan lamun sebagai akibat dari aktifitas penambangan timah di wilayah pesisir. Kondisi kesehatan lamun dianalisis melalui kerapatan dan tutupan lamun sehingga dapat diketahui kondisinya.  Metode yang digunakan untuk memantau kondisi lamun pada penelitian ini adalah pemanfaatan teknologi Penginderaan Jauh dan Sistem Informasi Geografis (SIG), menggunakan algoritma Depth Invariant Index (DII). Distribusi lamun berdasarkan hasil pengolahan data citra Landsat tahun 2017 menunjukkan bahwa padang lamun di perairan Bangka Selatan seluas 4066,7 Ha. Spesies yang ditemukan dari 7 titik sampling, yaitu Enhalus acoroides, Thalassia hemprichii, Halophila ovalis, Cymodocea serrulata, Halodule uninervis, dan Cymodocea rotundata. Kondisi padang lamunnya secara umum termasuk dalam kategori “Miskin”.  

scholarly journals STRUKTUR KOMUNITAS IKAN PADA EKOSISTEM LAMUN DI PANTAI PUDING KABUPATEN BANGKA SELATAN

2018 ◽  
Vol 12 (2) ◽  
pp. 35-44
Author(s):  
Sania Prisilia ◽  
Wahyu Adi ◽  
Arief Febrianto
Keyword(s):  
Strong Relationship ◽  
Data Retrieval ◽  
Line Transect ◽  
Thalassia Hemprichii ◽  
Seagrass Meadows ◽  
Gill Net ◽  
Seagrass Ecosystems ◽  
Halodule Uninervis ◽  
Relationship Of ◽  
Seagrass Density

Seagrass beds have a variety of roles in fish life, which can be used as nurseries, as a place for feeding ground, and for areas to seek protection. This study aims to analyze the structure of fish communities and seagrass communities and analyze the relationship of fish abundance with seagrass ecosystems. This research was conducted in March 2018 on the beach of Puding Air Banten II, Pasir Putih Village, Tukak Sadai District, Bangka Selatan Regency. Line transect method for seagrass data collection and fish data retrieval using fixed gill nets (gill net). The results of the study found that the total number of individual fish as much as 409 ind / m2 consisted of 25 species. The highest abundance of fish found in Station I with Ambassis interrupta species as many as 241 ind / m2. There were six types of seagrass found on the coast of Puding, namely Enhalus acoroides, Thalassia hemprichii, Halodule uninervis, Halophila spinulosa, Halophila decipiens and Cymodocea serrulata. The highest seagrass density was found at Station I with the seagrass Halodule uninervis species of 2541 ind / m2. Correlation coefficient analysis shows that the abundance of fish with seagrass density has a significant value of 0.956 which is classified as having a very strong relationship. Fish have higher abundance with seagrass meadows which vegetate with mangroves

Mapping seagrass cost-effectively in the Coral Triangle: Sabah, Malaysia as a case study

2015 ◽  
Vol 21 (2) ◽  
pp. 113 ◽  
Author(s):  
Leela Rajamani ◽  
Helene Marsh
Keyword(s):  
Cost Effective ◽  
Human Populations ◽  
Coral Triangle ◽  
Thalassia Hemprichii ◽  
Seagrass Meadows ◽  
Green Turtles ◽  
Halophila Ovalis ◽  
Seagrass Mapping ◽  
Cymodocea Rotundata ◽  
Syringodium Isoetifolium

Knowledge of the distribution and relative abundance of seagrass communities in the Coral Triangle is limited, despite their global significance and the vital ecosystem services they perform for local human populations, threatened species such as dugongs and green turtles, as well as the role of being a globally significant carbon stock. To address this gap and investigate cost-effective methods in data-poor regions, we conducted seagrass mapping near two islands off the coast of Sabah in Malaysia: Banggi Island (7°15′N, 117°12′E) and Mantanani Island (6°43′N, 116°21′E). We used a staged approach that included: (1) interview surveys, (2) manta tow and spot surveys, and (3) comprehensive transect surveys. Approximately 415 ha and 112 ha of seagrass meadows were mapped off Banggi Island and Mantanani Island respectively. We found 10 species of seagrasses from two families: Halophila ovalis, Halodule uninervis (broad and thin leaf varieties), Thalassia hemprichii, Cymodocea rotundata, Halophila decipiens, Halophila spinulosa, Cymodocea serrulata, Syringodium isoetifolium, Enhalus acoroides and Halophila sp. nov. Our methodology proved cost-effective and the resultant information should be relevant to conservation planners.

scholarly journals COMMUNITY STRUCTURE OF SEAWEED AT COASTAL AREA OF HARUKU ISLAND, CENTRAL MOLLUCAS PROVINCE

2015 ◽  
Vol 7 (1) ◽  
Author(s):  
Saleh Papalia
Keyword(s):  
Coastal Waters ◽  
Coastal Area ◽  
Severe Damage ◽  
Habitat Condition ◽  
Dead Coral ◽  
Coral Rubble ◽  
Study Region ◽  
Transect Line ◽  
Halodule Uninervis ◽  
Macro Algae

The study of seaweed biodiversity was conducted in Ory, Pelaw, Kailolo, and Waimital coatal waters of Haruku island in 2011.  The purposes or this study were to determine the density and biodiversity of makroalgae in the coastal waters of the Haruku island. Data collection were conducted in June-September 2011 with square transect line method. The results showed that in the coastal area of Kailolo exhibited the highest value in density and biodiversity of macroalgae in the study regions with 47 species from 31 genera consisting  of 21 species of red algae, 14 species of green algae and 13 species of brown algae. Gracilaria, Acanthophora, Sargassum, Turbinaria, Caulerpa, and Halimeda were the most dominance in the region. The highest biomass of macroalga found in the Kailolo coastal waters was due to its relatively good habitat contidion consisting of dead coral rubble, sand, coral live with seagrass vegetation dominated by Thalasia hemprizii and Halodule uninervis. Meanwhile, habitat condition at the other locations had suffered a severe damage and dominated by dead coral. Environmental conditions in the study region  were within the limits of decent support for the growth of macro algae. Keywords: Macroalgae, diversity, biodiversity, substrat, Haruku island

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