Seagrass Enhalus Acoroides Research Articles

Impact of water turbidity to Seagrass (Enhalus acoroides) morphology

Seagrass meadows provide a range of important ecosystem functions that can be influenced by both natural and anthropogenic pressures. One water quality that important for seagrass growth and survival is turbidity. A study to observe impacts of high turbidity to seagrass morphometry was conducted in two islands i.e., Sabutung and Bangko-Bangkoang of Pangkep Regency. These two islands are influenced by sediment load from several rivers in Pangkep Regency. Water column turbidity impacts seagrass by reducing the quantity and quality of light available for photosynthesis. However, dense population of seagrass Enhalus acoroides was found buried under turbidity regimes in both Islands. Some seagrass morphological characteristics such as leaf sheath length, leaf length and width, rhizome diameter and internode length were varied among locations. This suggested that seagrass developed morphological plasticity in responding to reduced light. Seagrass may establish morphological acclimatization to respond to the minimum light availability.

Spatial and Structural Factors Shape Seagrass-Associated Bacterial Communities in Singapore and Peninsular Malaysia

Plant-microbe relationships play critical roles in the functioning and health of terrestrial plants, but little is known about this relationship in marine angiosperms such as seagrasses. Here, we investigated the microbial communities associated with the seagrass Enhalus acoroides throughout Singapore and Peninsular Malaysia. At each sampling location we collected 10 individual and unconnected plants. Each plant was subsequently broken down into leaves, roots, and rhizomes. In addition to living plant parts a sediment sample was taken in close proximity to each. Using high throughput 16S rRNA gene amplicon sequencing we characterised the bacterial communities associated with each plant part and the associated sediment sample. Results indicate geographic structuring of bacterial communities, with a significant pattern of distance decay suggesting dispersal limitation is a contributing factor to the differences we see in bacterial community structure. Bacterial communities can be further differentiated by the function of the collected sample (leaf, root, and rhizome), and we identified a number of microbial indicator species that are associated with each plant part. Further analysis revealed the presence of several microbial taxa that have previously been identified as indicators of “unhealthy” or “stressed” seagrass meadows. This study addresses a current scientific gap related to the characterisation of seagrass microbiomes, and provides a foundation on which future studies can build, particularly those in the Southeast Asian seagrass biodiversity hotspot.

Environmental Factors for Holothuria scabra Sea Cucumber Cultivation

Sea cucumber cultivation is an alternative to anticipate the continuity of production due to overfishing. Maintenance environmental factors are important factors to consider in sea cucumber cultivation. A suitable location really supports the success of sea cucumber cultivation. This study aims to identify the main habitat and indicators in determining a suitable location for cultivation of Holothuria scabra. The study was located in the intertidal zone of the Watuar village seagrass ecosystem during May 2020 to October 2020. The results showed that the location of the Watuar village seagrass beds was suitable to be developed as a sea cucumber cultivation location with three main indicators, namely 35 cm depth (at low tide) and 195 cm (at the highest tide), the condition of the seagrass vegetation is moderate and is the natural habitat of H. scabra with the dominance of the seagrass Enhalus acoroides, Cymodocea rotundata, Cymodocea serrulata, Thalassia hemprecchii with moderate density and the bottom substrate is muddy sand with particle size 100 µm of 96.7%.

Rising Temperature Is a More Important Driver Than Increasing Carbon Dioxide Concentrations in the Trait Responses of Enhalus acoroides Seedlings

Increasing temperature and CO2 concentration are among the most important factors affecting marine ecosystems under climate change. We investigated the morphological, biochemical, and physiological trait responses of seedlings of the tropical seagrass Enhalus acoroides under experimental conditions. Trait responses were greater under temperature effects than increasing CO2 concentration. Seedlings under rising temperatures showed enhanced leaf growth, lower leaf nutrient content, and stimulated down-regulating mechanisms in terms of photo-physiology. Increasing CO2 concentrations did not show any significant effects independently. There was a significant interaction for some of the trait responses considered, such as leaf number and carbon content in the roots, and trends of higher starch concentrations in the leaves and lower rETRmax under combined enriched CO2 and high temperature, even though none of these interactions were synergistic. Understanding the single and interactive trait responses of seagrass seedlings to increasing temperature and CO2 concentration is of importance to determine the relative responses of early life stages of seagrasses, which may differ from adult plants, in order to form a more holistic view of seagrass ecosystem health under climate change.

ISSR and RAPD primers selection for assessing genetic diversity of Enhalusacoroides (L.f.) Royle

Inter Simple Sequence Repeat (ISSR) and Random Amplified Polymorphic DNA (RAPD) are common PCR-based molecular markers used to study genetic diversity both between and within species. One of important steps in ISSR and RAPD analyses is primer selection to obtain bright PCR products. The aim of this study was to select ISSR and RAPD primers that produced scorable fragments of PCR product for genetic diversity evaluation of seagrass Enhalusacoroides (L.f.) Royle. The study also aimed to compare ISSR and RAPD technique in producing informative fragments. Enhalusacoroides is one seagrass species widely distributed in Indonesia. Seagrass samples were collected from Sanur Coastal Water and from Nusa Dua Coastal Water. DNA was extracted using CTAB method. Ten ISSR primers and eight RAPD primers were tested. Results showed that RAPD was more informative than ISSR. Among ten ISSR primers, only four primers resulted in scorable fragments in all samples, and only one among those primers gave polymorphic pattern. As many as 15 fragments have resulted from three ISSR primers and only 1 fragment was polymorphic. All RAPD primers produced scorable products, and three primers resulted in polymorphic fragments. A total of 42 RAPD fragments were produced and 4 from them were polymorphic fragments

Phytochemical Analysis and in vitro Antibacterial Activities of Seagrass Enhalus acoroides against Staphylococcus aureus

Several studies of marine bioactive compounds have been carried out using seagrass. Enhalus acoroides is a type of seagrass that has bioactive compounds including alkaloids, flavonoids, tannins, steroids, and saponins that have potential as an antibacteria. The aim of study is to investigate the phytochemical compound contained in the crude extract of Enhalus acoroides and its antibacterial activities of Enhalus acoroides against Staphylococcus aureus. The seagrass was collected, washed, dried, grind and exposed to extraction by vacum rotary evaporator at temperature of 40°C and was analyzed for their phytoconstituents. Further, the crude extract was tested against pathogenic bacterial at different concentrations using disc diffusion method to determine the effect of bioactive compounds in E. acoroides to bacteria. In the present study, qualitative test of phytochemical from ethanol extract of Enhalus acoroides leaves contained phytochemical compound of alkaloids, flavonoids, tannins, steroids and saponins, while the extract of roots contained all of compounds except saponins. Based on research can be concluded, that Enhalus acoroides also has antibacterial activity against Staphylococcus aureus that showed by the presence of inhibition zone. The present finding suggests that the extract of seagrass Enhalus acoroides can be used an antibacterial agent from marine.

PERTUMBUHAN LAMUN HASIL TRANSPLANTASI Enhalus Acorides DI PADANG LAMUN TELUK AMAHAI

The condition of seagrass beds in Amahai Bay is relatively fertile, with a fairly high and wide density. Enhalus acoroides was chosen as a type of seagrass used for transplants in this study because Enhalus acoroides was quite abundant in the waters of Amahai Bay. Seed availability is one of the factors that need to be considered in the transplant business. There are several points in the waters of Amahai Bay where seagrass conditions do not grow evenly. Many fishermen who do fishing activities in the seagrass area inadvertently damage the ecosystem in the seagrass beds in that location. Under these conditions, it is important to do seagrass transplants so that the seagrass ecosystem is not increasingly damaged due to many human activities or natural factors. This experimental field research was carried out comparing the growth of transplanted seagrass Enhalus acoroides using the anchored sprig method. Determination of the location of the study carried out by the method of purposive random sampling. The research station in the waters of the village of Amahai at the substrate location of the muddy sand bottom with a depth of 0.85-1.5m. The station is divided into 3 observation points, with each location given 3 plots of 1x1m size with a transplant of 16 stands in each plot. The highest leaf growth rate for transplanted seagrass is at station 2, which is 3.76 mm.hr-1 on young leaves and 1.86 mm.day-1 for old leaves. And there is a difference in the speed of growth between the growth of natural seagrass and transplanted seagrass. The difference in transplantation stations has a very significant effect on the growth of seagrass leaves.

Analisis Kandungan Merkuri (Hg) dan Kadar Klorofil Lamun Enhalus Acoroides Di Perairan Marlosso dan Nametek Kabupaten Buru Provinsi Maluku

Seagrass is a type of vegetation that is able to live and develop well in coastal areas and is a habitat for several types of marine animals,such as sea cucumbers, sea urchins, starfish and sea urchins. Seagrass is an organism that is susceptible to pollution of the coastal environment such as mercury (Hg) so that it has an impact on the chlorophyll content of seagrass leaves. This study aims to determine the content of heavy metal Hg and its relationship with the chlorophyll content of seagrass Enhalus acoroides in the waters of Marlosso and Nametek in Buru District Maluku Province. The study was conducted in May 2018 and laboratory analysis was conducted in June 2018. Samples were taken at two stations namely Nametek Beach and Muos Sungai Marlosso. The results showed that the content of heavy metal Hg in roots> rhizoma> seagrass leaves. The content of heavy metals and seagrass chlorophyll content has a negative correlation where the Hg metal has a correlation of (r = - 0.97) and indicates that the higher the content of heavy metals will reduce the seagrass chlorophyll content

Short Communication: Restoration of seagrass Enhalus acoroides using a combination of generative and vegetative techniques

Abstract. Ambo-Rappe R, La Nafie YA, Syafiuddin, Limbong SR, Asriani N, Handayani NT, Lisdayanti E. 2019. Short Communication: Restoration of seagrass Enhalus acoroides using a combination of generative and vegetative techniques. Biodiversitas 20: 3358-3363. Seagrass areas have been declining in extent worldwide, with associated loss in seagrass ecosystem functions and services. Seagrass restoration is important to mitigate, halt and reverse such declines and their consequences. Generative propagation has benefits in terms of genetic biodiversity, however, survival of seagrass seedlings has often been poor especially in high energy environments. Terrestrial restoration often uses shade trees to protect vulnerable seedlings. This study aimed to evaluate the feasibility of a similar approach in the marine environment, using adult plants to protect seedlings of the tropical seagrass Enhalus acoroides (L.f.) Royle. Enhalus seeds taken from a donor bed were germinated and grown into seedlings, then planted in a location with high hydrodynamic exposure at three different densities (high, medium, and low). Adult Enhalus transplants were co-planted to provide three levels of protection: fifty (high), ten (medium), and none (no protection). Results showed that high-density seedling co-planting with high protection from adult transplants had significantly (p< 0.05) higher six-month survival rate compared to the other treatments. Our results indicate that, even in high energy environments, co-planting seedlings with adult transplants may combine the advantages of generative and vegetative propagation methods, promoting greater short-term effectiveness in terms of seedlings survival and growth in the restored seagrass meadows.

First record of the seagrass-boring shipworm Zachsia sp. (Bivalve: Teredinidae) in natural and transplanted Enhalus acoroides (Hydrocharitaceae) rhizomes in tropical Southwest Pacific

Seagrass ecosystems are under threat worldwide. Seagrass transplantation is one restoration approach which is has been tried with uneven success. While transplantation methods and oceanographic parameters have been investigated in attempts to understand the factors affecting transplant survival rate and seagrass transplantation success, little attention has been paid to the possible impact of pests. We observed borer molluscs in a seagrass Enhalus acoroides both from natural bed and transplant area. This is thought to be the first record from Indonesian waters of these bivalve molluscs of the genus Zachsia, family Teredinidae, the only mollusc genus known to bore into seagrass rhizomes. In a further eleven E. acoroides shoots (average length 10.5cm) we found between one and four calcareous burrows 2mm to 5mm in diameter inside the rhizome. Further research is required to determine the species present and its distribution in Indonesian waters as well as the true ecological impact of Zachsia sp. on seagrasses.

Seagrass-associated fungal communities show distance decay of similarity that has implications for seagrass management and restoration.

Marine fungal biodiversity remains vastly understudied, and even less is known of their biogeography and the processes responsible for driving these distributions in marine environments. We investigated the fungal communities associated with the seagrass Enhalus acoroides collected from Singapore and Peninsular Malaysia to test the hypothesis that fungal communities are homogeneous throughout the study area. Seagrass samples were separated into different structures (leaves, roots, and rhizomes), and a sediment sample was collected next to each plant. Amplicon sequencing of the fungal internal transcribed spacer 1 and subsequent analysis revealed significant differences in fungal communities collected from different locations and different structures. We show a significant pattern of distance decay, with samples collected close to each other having more similar fungal communities in comparison with those that are more distant, indicating dispersal limitations and/or differences in habitat type are contributing to the observed biogeographic patterns. These results add to our understanding of the seagrass ecosystem in an understudied region of the world that is also the global epicenter of seagrass diversity. This work has implications for seagrass management and conservation initiatives, and we recommend that fungal community composition be a consideration for any seagrass transplant or restoration programme.

Two novel diterpenes from the stems and leaves of tropical seagrass Enhalus acoroides in the South China sea

Two novel diterpenes Enhoidin A (1) and Enhoidin B (2) featuring an unusual gibberellane skeleton were isolated from the stems and leaves of Enhalus acoroides. Their structures were elucidated on the basis of spectroscopic analysis including 1D and 2D NMR techniques and HR-ESI-MS. This is the first time that this type of lactone ring between C-18 and C-20 has been found among gibberellanes from the tropical seagrasses. Evaluation of the all compounds for cytotoxicity against four human cancer cell lines (MCF-7, HCT-116, HepG-2 and HeLa), and showed moderate cytotoxic activities.

Growth Inhibition of Phaeocystis Globosa Induced by Luteolin-7-O-glucuronide from Seagrass Enhalus acoroides.

Enhalus acoroides (E. acoroides) is one of the most common species in seagrass meadows. Based on the application of allelochemicals from aquatic plants to inhibit harmful algal blooms (HABs), we used E. acoroides aqueous extract against harmful algae species Phaeocystis globosa (P. globosa). The results showed that E. acoroides aqueous extract could significantly inhibited the growth of P. globosa, decrease the chlorophyll-a content and photosynthetic efficiency (Fv/Fm) values of P. globosa, followed by vacuolization, plasmolysis, and the destruction of organelles. Twelve types of major chemical constituents were identified in E. acoroides aqueous extracts by ultraperformance liquid chromatography-high resolution mass spectrometry (UPLC-HRMS), including six flavonoids, two homocyclic peptides, two long-chain aliphatic amides, one tannin, and one nitrogen heterocyclic compound. Flavonoids were the characteristic chemical constituents of E. acoroides aqueous extract. Furthermore, the antialgal activity of luteolin-7-O-glucuronide (68.125 μg/mL in 8 g/L E. acoroides aqueous extract) was assessed. The EC50–96 h value was 34.29 μg/mL. In conclusion, the results revealed that luteolin 7-O-glucuronide was one of the antialgal compounds of E. acoroides aqueous extract, with potential application as novel algaecide.

Uji Kandungan Logam Berat Pb Dan Hg Pada Air, Sedimen Dan Lamun (Enhalus acoroides) Di Perairan Teluk Kayeli Kabupaten Buru Provinsi Maluku

The difference in accumulation of lead and mercury heavy metals in water, sediments and seagrass organs Enhalus acoroides (roots, rhizomes and leaves) is found in the waters of Kayeli Bay, Buru Island, Maluku Province. Samples were taken from ten observed station (Kayeli River Estuary, Suket River Estuary, Anahoni River Estuary, Waelata I Estuary, Waelata River Estuary II, Waeapo River Estuary, Sanleko River Estuary, Marlosso River Estuary, Nametek Beach and Jikumerasa Beach). Pb and Hg were analyzed using Atomic Absorption Spectrophotometer. The content of Pb and Hg in sediments is higher than in water. The highest Pb and Hg content is found in the roots then in the rhizoma and leaves (roots> rhizoma> leaves). Seagrass Enhalus acoroides is one of the living organisms that can be used as a bio-indicator of the level of heavy metal pollution in the aquatic environment.
 Key Words: Enhalus acoroides, Pb, Hg, Bioakumulasi, Bioindicator

HUBUNGAN KANDUNGAN NITRAT TERHADAP PERTUMBUHAN LAMUN (Enhalus acoroides) DI PESISIR PANTAI NEGERI SULI KECAMATAN SALAHUTU KABUPATEN MALUKU TENGAH

Background: Seagrass (Enhalus acoroides) is a type of seagrass that has the largest size, leaf strands can reach sizes> 1m. This type grows in shallow waters to a depth of 4 meters, on the basis of sand, mud sand or mud. The purpose of this study was to determine the relationship of nitrate content to the growth of seagrass (Enhalus acoroides) on the coast of Suli Village Salahutu District, Central Maluku Regency.
 Method: The type of research used in this study was descriptive to determine the relationship of nitrate content to growth of seagrass Enhalus acoroides on the coast of Suli State Salahutu District, Central Maluku Regency. The study was conducted on February 1-15, 2018.
 Results: This study showed that each transect had different growths of seagrass length, namely on transect 1, seagrass growth, reaching an average of 1.05, transect 2 averaging 1.01, while on transect 3 seagrass growth reached 1 average. , 35. Transect 3 has a greater growth rate than transect 1 and transect 2 while transect 2 has a lower growth rate than transect 1 and transect 3, while the results of the measurement of the average nitrate level on all transects are the same namely at transect 1 of 0.020 mg / l, transect 2 is 0.010 mg / l and transect 3 is 0.210 mg / l.
 Conclusion: Oligtrofic waters have nitrate levels between 0-5 mg / l, mesotrophic waters have nitrate levels between 1-5 mg / l, and eutrophic waters have nitrate levels ranging from 5-50 mg / l.

Fine-scale genetic structure and flowering output of the seagrass Enhalus acoroides undergoing disturbance.

Seagrass are under great stress in the tropical coast of Asia, where Enhalus acoroides is frequently the dominant species with a large food web. Here, we investigate the question of the fine‐scale genetic structure of this ecologically important foundation species, subject to severe anthropogenic disturbance in China. The genetic structure will illuminate potential mechanisms for population dynamics and sustainability, which are critical for preservation of biodiversity and for decision‐making in management and restoration. We evaluated the fine‐scale spatial genetic structure (SGS) and flowering output of E. acoroides, and indirectly estimated the relative importance of sexual versus asexual reproduction for population persistence using spatial autocorrelation analysis. Results reveal high clonal diversity for this species, as predicted from its high sexual reproduction output. The stronger Sp statistic at the ramet‐level compared with genet‐level indicates that clonality increases the SGS pattern for E. acoroides. Significant SGS at the genet‐level may be explained by the aggregated dispersal of seed/pollen cohorts. The estimated gene dispersal variance suggests that dispersal mediated by sexual reproduction is more important than clonal growth in this study area. The ongoing anthropogenic disturbance will negatively affect the mating pattern and the SGS patterns in the future due to massive death of shoots, and less frequency of sexual reproduction.

Influence of seaweed farming on the growth of the seagrass Enhalus acoroides

The goal of this research was to analyse the influence of seaweed farming on the growth of the seagrass Enhalus acoroides, as well as the relationship between seagrass growth and environmental parameters. The research was carried out at Karampuang Island, Mamuju District, Sulawesi Barat Province, Indonesia, from August to November 2017. Data were collected from three plots (frames) in seagrass areas with seaweed farming (treatment plots) and 3 plots (frames) in seagrass areas without seaweed farming (control plots). The growth of E. acoroides was measured through sampling 10 plants (3 leaves per plant) in each plot. The selected leaves were marked and the new growth measured at fortnightly intervals using a ruler with a precision of 1mm. Average growth rates were calculated, and the Student t-test was applied to the difference in average growth rates. The absolute growth and growth rates of E. acoroides did not differ significantly between the treatment and control plots. Highest and lowest growth rates were recorded during the fourth and sixth fortnightly observations, respectively. Principal Component Analysis (PCA) showed clear temporal differentiation of E. acoroides leaf growth based on measurement timing, but did not differentiate between (separate) the treatment and control plots. The highest growth rates were associated with elevated levels of nitrate (NO3) and total organic carbon (TOC) in the water column, with relatively low seawater temperatures.

Observations on the female flowers and fruiting of Tape Grass Enhalus acoroides from South Andaman Islands, India

Documenting phenologic events is crucial in obtaining deeper insights into the life cycle of seagrasses. We documented and compared the flowering and fruiting of the seagrass Enhalus acoroides from multispecies seagrass meadows at two sites, Henry Lawrence and Tarmugli islands located inside the marine national parks in South Andaman Islands. At these two locations, the average density of shoots ranged between 30.9/m2 and 18.16/m2, fruits between 5/m2 and 2.33/m2, and flowers between 6.7/m2 and 3.83/m2, whereas the mean length of the peduncles ranged from 40.59cm at Henry Lawrence to 32.44cm at Tarmugli Island. We observed significant differences between the densities of shoots and fruits and peduncle lengths in the two sites. The density of flowers, however, did not vary significantly. These observations of fruiting and flowering in E. acoroides establish an important reproductive stage in the life cycle of the species and open avenues for further seagrass research in the Andaman Islands. We describe the findings and emphasize on the need to establish a long-term phenology monitoring program for E. acoroides in the Andaman Archipelago.

POTENSI EKOSISTEM PADANG LAMUN DI KAWASAN WISATA BAHARI GUGUSAN PULAU PARI, DKI JAKARTA

Marine Tourism Area at Pari Island cluster has a variety of ecosystems, one of them is the seagrass ecosystem. Seagrass is one of the coastal and marine resources, which has the potential to be developed as a resource for tourist attraction in the marine tourism area of Pari Islands. Purpose this study is to describe seagrass conditions, is it worthed to be used as a tourist attraction by conducting field research of species composition, distribution, percent cover at marine tourism territory Pari Islands, DKI Jakarta. The study was conducted from April-May 2017 with the descriptive method, where this method is done by describing or describe seagrass conditions. Survey and field data acquisition carried out in Pari Islands at 10 stations using the quadrant transect method. Based on field observation, in the field was found 5 species of seagrass species Cymodocea rotundata, Enhalus acoroides, Halophila ovalis, Syringodium isoetifolium and Thalassia hemprichii that can be a potential attraction for marine tourism. The results of calculations percent cover of seagrass shows that the highest percent cover was at station 9 with total percent was 76,2 %, while the lowest percent cover was at station 2, amounting to 20,4 %.
 Keywords: Marine Tourism, Pari Islands, Seagrass Beds

Population genetic structure of the threatened tropical seagrass Enhalus acoroides in Hainan Island, China

Knowledge of the genetic structure of ecologically important species provides insight into population dynamics and persistence, which is important for decisions concerning ecosystem conservation and management. Seagrass ecosystems are being degraded in China due to coastal anthropogenic disturbances like eutrophication and pollution, but their genetic ecology is still poorly understood. In this study, we collected Enhalus acoroides samples from three lagoons and five offshore open-water sites along the east coast of Hainan Island to investigate its genetic diversity and structure using ten microsatellite loci. A total of 66 alleles were found, and the genetic diversity indices (i.e. mean number of alleles per locus, allelic richness and heterozygosity) varied among the eight populations. Assignment tests showed that the E. acoroides populations consists of three genetic clusters. Impeded gene flow among lagoonal populations was found, while connectivity existed among the open-water populations. This pattern seemed to be shaped by geographic isolation and ocean currents. Based on the genetic contribution analysis, we recommended that the E. acoroides populations at Tielugang and Gangdong need protection priority given they contribute higher genetic diversity, but are currently high risk populations under threats of pollution and physical disturbance.