The effect of causeway construction on seagrass meadows in the Western Pacific ? a lesson from the ancient city of Nan Madol, Madolenihmw, Pohnpei, FSM

2005 ◽  
Vol 11 (3) ◽  
pp. 212 ◽  
Author(s):  
Rob Coles ◽  
Lel McKenzie ◽  
Stuart Campbell ◽  
Rudi Yoshida ◽  
Ahser Edward ◽  
...  
Keyword(s):  
Algal Species ◽  
Seagrass Species ◽  
Thalassia Hemprichii ◽  
Seagrass Meadows ◽  
Seaward Side ◽  
Algal Abundance ◽  
Seagrass Cover ◽  
Faunal Communities ◽  
Cymodocea Rotundata ◽  
Holothuria Atra

Two seagrass meadow sites were chosen at Nan Madal adjacent to the now permeable remnants of an ancient causeway constructed 500 to 700 years ago: one immedlately on the shoreward side of the causeway, and one immediately on the seaward side. The shoreward site had greater seagrass cover, canopy height, algal abundance, and epiphyte abundance and lower species diversity (both seagrass and macro-algae), as well as muddier sediments than the seaward site. The abundance of associated fauna did not appear to differ between sites, although the composition of the faunal communities was different. On the seaward site, average epiphyte cover was less than onetenth the epiphyte cover of that on the shoreward side. Halimeda species were the most common algae on the seaward side, while on the shoreward side Hypnea species were dominant. Cymodocea rotundata was the dominant seagrass species (54% of seagrass cover) on the seaward site, but was absent on the shoreward site, which was dominated by Thalassia hemprichii (84%) and Enhalus acoroides (16%). There was no difference in salinity between the two sites. Sediments had a higher proportion of fine mud shoreward. The beche-de-mer, Holothuria atra, was common on the seaward side of the causeway, but not on the shoreward side. The causeway is open to water flow at all tide heights and does not appear to influence water height in any way. The effects of even this simple permeable barrier on seagrass meadows are evident and include differences in seagrass species, algal species, and fauna. We discuss the management lesson from this historic location for present-day Pacific island causeway developments.

scholarly journals Community Structure of Seagrass Meadows In Mantehage Island Waters, North Sulawesi

2014 ◽  
Vol 1 (4) ◽  
pp. 177
Author(s):  
Simon I Patty ◽  
Husen Rifai
Keyword(s):  
Diversity Index ◽  
Seagrass Species ◽  
Thalassia Hemprichii ◽  
Seagrass Meadows ◽  
North Sulawesi ◽  
Halophila Ovalis ◽  
Cymodocea Rotundata ◽  
Syringodium Isoetifolium ◽  
Species Composition And Distribution ◽  
Thalassodendron Ciliatum

Research on the structure of seagrass communities in the waters of the island Mantehage was conducted in September 2010. The purpose of this study is to collect data and information on the structure of seagrass communities. Observations includes the identification seagrass species, measuring the number of individual/stand, cover percentage of each type/species on the transect. 6 types of seagrass found, i.e. Enhalus acoroides, Halophila ovalis, Thalassia hemprichii, Thalassodendron ciliatum, Cymodocea rotundata and Syringodium isoetifolium. Seagrass species composition and distribution varies at each location and is dominated by the presence of Thalassia hemprichii (48.14%) with coverage percentage ranges between 15.91% to 35.11%. Diversity index values ranged from 0.79 to 1.69 ; evenness index between 0.57 to 0.94 and the index of dominance between 0.20 to 0.56. In conclusion, the condition of seagrass meadows in Mantehage island is relatively good and can support marine life adequately.Keywords : Structure communities, seagrass, Mantehage Island

DENSITY AND THE COVERAGE OF SEAGRASS ECOSYSTEM IN BAHOI VILLAGE COASTAL WATERS, NOTRH SULAWESI

2017 ◽  
Vol 9 (1) ◽  
pp. 375-383 ◽  
Author(s):  
Muh. Fahruddin ◽  
Fredinan Yulianda ◽  
Isdradjad Setyobudiandi
Keyword(s):  
Coastal Waters ◽  
Seagrass Species ◽  
Reef Habitat ◽  
Thalassia Hemprichii ◽  
Halophila Ovalis ◽  
Seagrass Ecosystem ◽  
Seagrass Cover ◽  
Cymodocea Rotundata ◽  
Syringodium Isoetifolium ◽  
Coral Reef Habitat

Physical seagrass ecosystem damage have been reported in various regions in Indonesia. Seagrass ecosystem damage is caused by human activity such as trampling seagrass and boats that muddy the waters and reduced the density and seagrass cover. This study aims to provide information about the density and the coverage of seagrass. The method used in this research is the transect method measuring 50x50 cm squared at three different locations by considering coastal ecosystems Bahoi village that already exist. Station 1 is near to mangrove habitat, station 2 is right on seagrass habitats, and station 3 is near to coral reef habitat. The results indicated there is six seagrass species that found in the Bahoi village which is Enhalus acoroides, Thalassia hemprichii, Cymodocea rotundata, Syringodium isoetifolium, Halophila ovalis, and Halodule uninervis. The density and seagrass cover is shows that the station 1 has the highest density and seagrass cover percentage compared with the other stations. The highest density of seagrass species located in station 1 with 955 individuals/m2, and the lowest was located at station 3 with 699 individuals/m2. While the highest cover percentage is located at station 1 with 270% and the lowest located at station 3 with 229%. Keyword: seagrass ecosystem, density, coverage, Bahoi

scholarly journals DENSITY AND THE COVERAGE OF SEAGRASS ECOSYSTEM IN BAHOI VILLAGE COASTAL WATERS, NOTRH SULAWESI

2017 ◽  
Vol 9 (1) ◽  
pp. 375
Author(s):  
Muh. Fahruddin ◽  
Fredinan Yulianda ◽  
Isdradjad Setyobudiandi
Keyword(s):  
Coastal Waters ◽  
Seagrass Species ◽  
Reef Habitat ◽  
Thalassia Hemprichii ◽  
Halophila Ovalis ◽  
Seagrass Ecosystem ◽  
Seagrass Cover ◽  
Cymodocea Rotundata ◽  
Syringodium Isoetifolium ◽  
Coral Reef Habitat

<p><em>Physical seagrass ecosystem damage have been reported in various regions in Indonesia. Seagrass ecosystem damage is caused by human activity such as trampling seagrass and boats that muddy the waters and reduced the density and seagrass cover. This study aims to provide information about the density and the coverage of seagrass. The method used in this research is the transect method measuring 50x50 cm squared at three different locations by considering coastal ecosystems Bahoi village that already exist. Station 1 is near to mangrove habitat, station 2 is right on seagrass habitats, and station 3 is near to coral reef habitat. The results indicated there is six seagrass species that found in the Bahoi village which is Enhalus acoroides, Thalassia hemprichii, Cymodocea rotundata, Syringodium isoetifolium, Halophila ovalis, and Halodule uninervis. The density and seagrass cover is shows that the station 1 has the highest density and seagrass cover percentage compared with the other stations. The highest density of seagrass species located in station 1 with 955 individuals/m<sup>2</sup>, and the lowest was located at station 3 with 699 individuals/m<sup>2</sup>. While the highest cover percentage is located at station 1 with 270% and the lowest located at station 3 with 229%.</em></p><p><em> </em></p><p><strong><em>Keyword: </em></strong><em>seagrass ecosystem, density, coverage, Bahoi</em></p>

scholarly journals Kondisi dan Keanekaragaman Jenis Lamun di Perairan Pulau Serangan, Provinsi Bali

2018 ◽  
Vol 5 (1) ◽  
pp. 131
Author(s):  
Luh Gede Manik Radzena Martha ◽  
Pande Gde Sasmita Julyantoro ◽  
Alfi Hermawati Waskita Sari
Keyword(s):  
Water Quality ◽  
Diversity Index ◽  
Good Condition ◽  
Quality Parameters ◽  
Seagrass Species ◽  
Thalassia Hemprichii ◽  
Halophila Ovalis ◽  
Cymodocea Rotundata ◽  
Index Value ◽  
Seagrass Coverage

Serangan Island is one of the tourism destinations in Bali which is administratively belong to the municipality of Denpasar. Tourism development near with the segrass habitat cause the segrass ecosystem being degraded in the waters of Serangan Island. This study was aimed to determine the diversity and conditions of seagrass species which were observed from the density and percentage of seagrass coverage and to examine the effect of water quality on the percentage of seagrass coverage. This research was conducted from February to March 2017 on Serangan Island using quantitative descriptive method. Sampling was conducted at three stations by taking data and samples of seagrass, measuring water quality (temperature, salinity, pH, turbidity, substrate observation) and analyze of nitrates and phosphates content. Seven types of seagrass species were found i.e. Enhalus acoroides, Thalassia hemprichii, Cymodocea rotundata, Halophila ovalis, Halodule pinifolia, Syringodium isoetifolium, and Thalassodendron ciliatum. The study showed that the diversity index value was in the medium category. The density of seagrass was classified as very tight (condition scale of 5). The highest density was found on Cymodocea rotundata spesies at station I about 777 ind/m2. The highest percentage of seagrass coverage (79,55%) was found in station I which classified as good condition, while station II and station III were classified as damaged condition with value 13.65% and 20,79% respectively. Finally, the water quality parameters have relatively low effect to seagrass coverage percentage.

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 Seagrass Vegetation Analysis on The Coast of Hadirin and Batu Lawang Beach Karimunjawa National Park

el–Hayah ◽  
2020 ◽  
Vol 7 (3) ◽  
Author(s):  
Muhammad Asmuni Hasyim ◽  
Muhammad Ainul Yaqin ◽  
M. Bahrul Ulum ◽  
Berry Fakhry Hanifa ◽  
Teguh Cahyono
Keyword(s):  
National Park ◽  
Dominant Species ◽  
Exploratory Research ◽  
Seagrass Species ◽  
Vegetation Analysis ◽  
Thalassia Hemprichii ◽  
Seagrass Cover ◽  
Syringodium Isoetifolium ◽  
Thalassodendron Ciliatum ◽  
Cymodocea Serrulata

The purpose of this study was to determine the structure and condition of seagrass communities  in the waters of hadirin Beach and Batu lawang karimunjawa. national park. This exploratory research used descriptive qualitative methods, each study location is divided into two transects. Data identified at SPTN Office 1 Kemujan Karimunjawa National Park. The results of the study were six species of seagrass, namely: Holodule uninervise, Thalassodendron ciliatum, Halophila minor, Syringodium isoetifolium, Thalassia hemprichii and Cymodocea serrulata. The percentage of seagrass cover namely Holodule uninervise is 38.04 %. Thalassodendron ciliatum of 6.25%, Halophila minor of 29.56%, Syringodium isoetifolium of 31.25%, Thalassia hemprichii at 14.21% and Cymodocea serrulata to 16.9%. The highest density of seagrass species in Hadirin Beach is from the Uninervise holodule species 72.30%, with 858 stands on the first transect and 54.66% on the second transect with 253 stands. Whereas for the highest Batu Lawang Beach is the species of Thalassia hemprichii 51.1% with 162 stands, on the first transect and 44.9% with 114 stands. The substrate has the type of sandy clay and coral fragments. Holodule uninervise is the most dominant species found on the beach of Hadirin meanwhile Thalassia hemprichi is the most dominant species in Batu Lawang.

scholarly journals MODELLING, SIMULATION AND VISUALIZATION OF A MULTISPECIFIC PHILIPPINE SEAGRASS MEADOW

2019 ◽  
Vol XLII-4/W19 ◽  
pp. 77-82
Author(s):  
V. P. Bongolan ◽  
G. M. Torres ◽  
J. E. Branzuela
Keyword(s):  
Clonal Growth ◽  
Seagrass Meadow ◽  
Light Attenuation ◽  
Thalassia Hemprichii ◽  
Diffusion Limited Aggregation ◽  
Seagrass Meadows ◽  
Branching Angle ◽  
Coexisting Species ◽  
Cymodocea Rotundata ◽  
Model Features

Abstract. Seagrass meadows are constantly under threat from natural and man-made stresses due to its shallow existence in the coastal environment. Restoration and preservation of seagrasses by means of rehabilitation or transplanting strategies is possible, but the studies have been limited. An agent-based model of a mixed Philippine seagrass meadow is presented. Three species were used for testing: Enhalus acoroides, Thalassia hemprichii, and Cymodocea rotundata. The model features parameter-based clonal growth of seagrass species, recruitment of new seagrass apices through basic flowering/seeding, and a crowding logic for multiple coexisting species in a single meadow. Seagrass clonal growth is modeled using a modified Diffusion-Limited Aggregation (DLA) model. Each species has a preconfigured set of parameters for clonal growth including rhizome elongation, branching rate, vertical elongation rate, rhizome branching angle and shoot age. Seed recruitment is applied through occasional flowering/seeding events configurable per species. We developed a simple three-species competition model which controls the growth and direct competition effects based on a configurable population size and comparison radius. Upon further calibration and validation, the model would enable more accurate long-term predictions for different rehabilitation and transplanting strategies of mixed seagrass meadows. Further improvements can also be implemented, particularly taking into account the environmental variables within the meadows such as light attenuation and salinity, among other factors.

scholarly journals Community structure and condition of seagrass meadows in Ayau Islands, Raja Ampat Regency

2020 ◽  
Vol 45 (1) ◽  
pp. 13-24
Author(s):  
Andri Irawan ◽  
Muhammad Hafizt ◽  
Udhi Eko Hernawan
Keyword(s):  
Community Structure ◽  
Environmental Parameters ◽  
Water Clarity ◽  
Well Being ◽  
Common Species ◽  
Thalassia Hemprichii ◽  
Seagrass Meadows ◽  
Halophila Ovalis ◽  
Seagrass Cover ◽  
Baseline Information

Seagrass meadows are an important component of coastal ecosystems, providing many ecosystem services beneficial for human well-being. Basic information about seagrass meadows in Indonesia is relatively limited, particularly in the eastern part of Indonesia, such as the remote Ayau Islands in Raja Ampat. In this paper, we reported the community structure and condition of seagrass meadows in Ayau Islands surveyed during Nusa Manggala Expedition in November 2018. We conducted the seagrass survey using quadrat transect method at five locations, i.e. Reni, Rutum, Abidon, Kanober, and Dorehkar. In the survey, we assessed parameters of community structure, including habitat extent, species composition, seagrass cover, seagrass density, macroalgae and epiphyte cover. We also recorded environmental parameters, i.e. substrate types, water clarity, salinity, water temperature, and nutrient (phosphate and nitrate). Our study showed that seagrass meadows in Ayau Islands are multispecies meadows, composed of two to five species. In overall, five species recorded in Ayau Islands are Cymodocea rotundata, Enhalus acoroides, Halodule pinifolia, Halophila ovalis, and Thalassia hemprichii. The most common species is T. hemprichii as it can be found in all locations. Meadows in Reni, Rutum, and Dorehkar are in a healthy condition, while in Abidon and Kanober are in less healthy condition. This information is of significance as baseline information needed for seagrass conservation planning.

scholarly journals The Inventory of Seagrasses in Marine Field Station of Faculty of Fisheries and Marine Science in Subdistrict of East Likupang District North Minahasa

2018 ◽  
Vol 6 (2) ◽  
pp. 38
Author(s):  
Stevani Rawung ◽  
Ferdinand F Tilaar ◽  
Ari B Rondonuwu
Keyword(s):  
Seagrass Species ◽  
Thalassia Hemprichii ◽  
Field Station ◽  
Enhalus Acoroides ◽  
Halophila Ovalis ◽  
Halodule Uninervis ◽  
Cymodocea Rotundata ◽  
Syringodium Isoetifolium ◽  
Random Survey ◽  
Cymodocea Serrulata

This study was conducted in Marine Field Station of Faculty of Fisheries and Science of Sam Ratulangi University, Sub-district of East Likupang, North Minahasa. This study aims to identified the seagrasses in the water of Marine Field Station. The benefits of this study are for the database of seagrasses ecosystem management and comparative for other studies. The Observation and data collection was using random survey technic by analyzed the areas to collecting all the seagrass species found. Furthermore, the seagrass samples were categorised into each species. The result showed the amount of seagrass species in Marine Field Station are 8 species from 6 genera and 2 families: Cymodocea rotundata, Cymodocea serrulata, Halodule uninervis, Syringodium isoetifolium, Thalassia hemprichii, Enhalus acoroides,  Halophila ovalis, dan Halophila minor.Keyword: Inventory, Seagrass, Marine Field Station ABSTRAKPenelitian dilakukan di perairan Marine Field Station Fakultas Perikanan dan Ilmu Kelautan Unsrat Kecamatan Likupang Timur Kabupatan Minahasa  Utara. Tujuan penelitian  untuk mengidentifikasi lamun yang ada di Perairan Marine Field station. Manfaat penelitian dapat menjadi data pengelolaan ekosistem padang lamun dan dapat menjadi perbandingan untuk penelitian-penelitian selanjutnya. Pengamatan dan pengambilan sampel menggunakan teknik survei jelajah, yaitu dengan menjelajahi wilayah pengamatan sambil mencari semua spesies lamun. Lamun yang diambil adalah semua jenis yang ditemui. Selanjutnya, sampel lamun dikelompokan berdasarkan spesies. Hasil pengamatan menunjukkan jumlah spesies lamun pada lokasi penelitian di Perairan Marine Field Station adalah 8 spesies dari 6 genera dan 2 famili yaitu, Cymodocea rotundata, Cymodocea serrulata, Halodule uninervis, Syringodium isoetifolium, Thalassia hemprichii, Enhalus acoroides,  Halophila ovalis, dan Halophila minor. Kata kunci: Inventarisasi, Lamun, Marine Field Station

scholarly journals KAJIAN KOMUNITAS EKOSISTEM LAMUN DI SEMENANJUNG TARABITAN KECAMATAN LIKUPANG BARAT KABUPATEN MINAHASA UTARA

2021 ◽  
Vol 9 (2) ◽  
pp. 24
Author(s):  
Risandi D Sitaba ◽  
Carolus P Paruntu ◽  
Billy Theodorus Wagey
Keyword(s):  
Species Composition ◽  
Percent Cover ◽  
Seagrass Beds ◽  
Seagrass Species ◽  
Thalassia Hemprichii ◽  
Enhalus Acoroides ◽  
Halophila Ovalis ◽  
Halodule Uninervis ◽  
Cymodocea Rotundata ◽  
Syringodium Isoetifolium

This research was conducted in the waters of Tarabitan Peninsula, West Likupang North Minahasa using quadants transect method. The purpose of this study was to determine the community structure of seagrass found in that waters as initial information for sustainable management seagrass ecosystem . Field observation was conducted to identify the seagrass species, number of individuals/shoots, percent cover for each type of seagrass in those plotting quadrants. The result of this study documented 6 types of seagrass namely, Enhalus acoroides, Thalassia hemprichii, Cymodocea rotundata, Syringodium isoetifolium, Halophila ovalis and Halodule uninervis. The species composition and distribution of seagrass were varied and was dominated by Thalassia hemprichii was the most dominant seagrass species with a relative density of 55.55%, a relative frequency of 33.67%, 39.92% relative cover, an important value index of 129.03%, a diversity index of 1.30 belonging to this condition, moderate, the uniformity index of 0.72 is classified as high and the dominance index of 0.2 is classified as low. Based on Minister of Environment Decree Republic Indonesia No. 200 of 2004 concerning the status of seagrass beds, the condition of the seagrass beds in the waters of Tarabitan Village is classified as rich / healthy with a cover value of ≥ 60. Keywords : Seagrass Community, Species Composition,  distribution, Tarabitan Peninsula           Penelitian ini dilakukan di perairan Semenanjung Tarabitan Likupang Barat Minahasa Utara dengan menggunakan metode transek kuadran. Tujuan penelitian ini adalah untuk mengetahui struktur komunitas lamun yang terdapat di perairan tersebut sebagai informasi awal untuk pengelolaan lamun secara berkelanjutan. Pengamatan lapangan dilakukan untuk mengidentifikasi jenis lamun, jumlah individu/tegakan, persentase tutupan tiap jenis lamun pada tiap kuadran. Hasil penelitian ini mendokumentasikan 6 jenis lamun yaitu Enhalus acoroides, Thalassia hemprichii, Cymodocea rotundata, Syringodium isoetifolium, Halophila ovalis dan Halodule uninervis. Komposisi jenis dan sebaran lamun bervariasi dan didominasi oleh jenis lamun Thalassia hemprichii merupakan jenis lamun yang paling dominan dengan kerapatan relatif 55,55%, frekuensi relatif 33,67%, tutupan relatif 39,92%, indeks nilai penting 129,03%, indeks keanekaragaman 1,30 tergolong dalam kondisi sedang, indeks keseragaman 0,72 tergolong tinggi dan indeks dominansi 0,2 tergolong rendah. Berdasarkan Keputusan Menteri Lingkungan Hidup Nomor 200 Tahun 2004, kondisi padang lamun di perairan Desa Tarabitan tergolong kaya / sehat dengan nilai tutupan ≥ 60.Kata Kunci: Komunitas Lamun, Komposisi Jenis, Distribusi, Semenanjung Tarabitan

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