Syringodium Isoetifolium Research Articles

MORFOMETRIK LAMUN DI ZONA INTERTIDAL PERAIRAN PANTAI DESA ADMINISTRATIF MALAKU KECAMATAN SERAM UTARA KABUPATEN MALUKU TENGAH

Background: Seagrass is an angiosperm flowering plant that can grow well in coastal environments. Seagrass is a one seed plant that has roots, stems, rhizomes, leaves, flowers, fruit and seeds. Differences in substrate type, environmental conditions and nutrient content can influece the existence of seagrass species and their morphometric shapes.This research aims to determine the morphometric of seagrass in the intertidal zone of coastal waters of Malaku Administrative Village, North Seram Sub-district Methods: Sampling used a roaming survey method in the intertidal zone of coastal waters of Malaku Administrative Village. The research data were analyzed descriptively based on the results of species identification, observations and measurements of the segrass morphological structure. Results : The type of seagrass found in the intertidal zone of the coastal waters of the Malaku Administrative village is Cymodocea serulata, Cymodocea rotundata, Halophila ovalis, Halophila minor, Halodule pinifolia, Halodule uninervis, Thalassia hemprichii, and Syringodium isoetifolium. Morphometric forms of seagrass include : Root length ±3cm-16,5cm. Rhizome distance ±1cm–4,5cm. leaf blade length ± 2,4cm-15cm. The shape of the leaf blade is flat, oval, cylindrical, serrated at the tip of the leaf and small in length. Leaf width ±0,2cm-1cm, seagrass stand heigth ± 3-19,3cm. Conclusion: From the research results obtained, it can be concluded that the intertidal zone of the coastal wters of the malaku administrative village are 8 (eigth) types of seagrass and have morphometric structure that vary in size.

Relationship between seagrass community structure and carbon stocks on the coasts of Karimunjawa Marine National Park, Indonesia

The seagrass ecosystem is considered one of the most effective coastal ecosystems in storing carbon. Carbon stock estimation for a certain ecosystem is highly affected by factors such as species diversity and habitat type. This study aims to investigate the relationship between plant community structure and carbon stocks in the seagrass ecosystem using a case study of six coastal sites in Karimunjawa Marine National Park, Indonesia. In this region, eight seagrass species were recorded, i.e., Enhalus acoroides, Thalassia hemprichii, Cymodocea rotundata, Halodule pinifolia, Halophila ovalis, Halophila minor, Syringodium isoetifolium, and Oceana serrulata. From the six study sites, the highest estimated carbon stock was 426.2 Mg C ha−1 (Site 5; Telaga, dominated by E. acoroides). Meanwhile, the lowest estimated carbon stock was 127.4 Mg C ha−1 (Site 4; Koin, dominated by T. hemprichii). The density of E. acoroides was positively correlated with the total seagrass biomass carbon stocks (r = 0.97; p < 0.01), while its dominance was positively correlated with sediment carbon stocks (r = 0.92; p < 0.05) and total seagrass ecosystem carbon stocks (r = 0.92; p < 0.05). Seagrass ecosystems with different community structures showed different carbon storage capacities. Seagrass ecosystems dominated by large-sized species such as E. acoroides showed higher estimated carbon stocks thus suggesting the importance of considering the variability of community structure in managing seagrass ecosystems for carbon sequestration and storage.

Assessment of coral reef connectivity in improved organic carbon storage of seagrass ecosystems in Palk Bay, India

The increase in climate-related extreme events and ecosystem degradation demands consistent and sustainable climate mitigation efforts. Seagrass playing a key role in nature-based carbon sequestration mitigation strategy. Here, we investigated the role of coral reef connectivity in blue carbon dynamics with seagrass meadows with coral reef connectivity (SC areas) and without coral reef connectivity (SG areas) in Palk Bay, India. The high sediment organic carbon was recorded in SC areas (90.26 ± 25.68 Mg org.C/ha) and lower in SG areas (66.96 ± 12.6 Mg org.C/ha). The maximum above-ground biomass (AGB) was recorded in Syringodium isoetifolium (35.43 ± 8.50) in SC areas and the minimum in Halophila ovalis (7.59 ± 0.90) in SG areas, with a similar trend observed in below-ground biomass (BGB). Our findings highlight the importance of coral reefs in enhancing the blue carbon potential of seagrass ecosystems and underscore the need for integrated conservation and restoration strategies for coral reefs and seagrasses.

The In Vitro Antioxidant and Anti-Inflammatory Activities of Selected Australian Seagrasses.

Recent studies have shown that seagrasses could possess potential applications in the treatment of inflammatory disorders. Five seagrass species (Zostera muelleri, Halodule uninervis, Cymodocea rotundata, Syringodium isoetifolium, and Thalassia hemprichii) from the Great Barrier Reef (QLD, Australia) were thus collected, and their preliminary antioxidant and anti-inflammatory activities were evaluated. From the acetone extracts of five seagrass species subjected to 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging antioxidant assay, the extract of Z. muelleri had the highest activity (half minimal concentration of inhibition (IC50) = 138 µg/mL), with the aerial parts (IC50 = 119 µg/mL) possessing significantly higher antioxidant activity than the roots (IC50 ≥ 500 µg/mL). A human peripheral blood mononuclear cells (PBMCs) assay with bacterial lipopolysaccharide (LPS) activation and LEGENDplex cytokine analysis showed that the aerial extract of Z. muelleri significantly reduced the levels of inflammatory cytokines tumour necrosis factor alpha (TNF-α), interleukin (IL)-1β, and IL-6 by 29%, 74%, and 90%, respectively, relative to the LPS treatment group. The aerial extract was thus fractionated with methanol (MeOH) and hexane fraction, and purification of the MeOH fraction by HPLC led to the isolation of 4-hydroxybenzoic acid (1), luteolin (2), and apigenin (3) as its major constituents. These compounds have been previously shown to reduce levels of TNF-α, IL-1β, and IL-6 and represent some of the major bioactive components of Z. muelleri aerial parts. This investigation represents the first study of the antioxidant and anti-inflammatory properties of Z. muelleri and the first isolation of small molecules from this species. These results highlight the potential for using seagrasses in treating inflammation and the need for further investigation.

Seagrass Community Structure and Ecosystem Carbon Stocks Along the Shoreline of Semujur Island, Bangka Belitung Province, Indonesia

Seagrass meadows serve as vital blue carbon ecosystems, sequestering significant amounts of CO2 and playing a crucial role in climate change mitigation. Semujur Island, located in the Bangka Belitung Province, exemplifies numerous small Indonesian islands boasting extensive seagrass meadows lining their shores. This research seeks to (1) describe the community structure of seagrass on Semujur Island, (2) assess the carbon storage within the seagrass ecosystem, and (3) analyze the relationship between seagrass community structure and carbon reserves across three distinct sites. According to the results of this study, there are eight species of seagrass on Semujur Island, i.e., Cymodocea rotundata, Enhalus acoroides, Halodule uninervis, Halophila ovalis, Oceana serrulata, Syringodium isoetifolium, Thalassia hemprichii, and Thalassodendron ciliatum. Diversity indices varied among sites, ranging from 1.48 to 1.72. Species evenness indices varied between 0.83 and 0.92, while dominance indices varied between 0.20 and 0.28. The highest estimated carbon stock was obtained at the site dominated by the species H. uninervis (75.11 MgC/ha); followed by the site dominated by T. hemprichii (50.55 MgC/ha). The correlation between seagrass community structure, including density and coverage, and carbon stocks demonstrated a moderate positive correlation, with coefficients of 0.430 and 0.528, respectively (p&lt;0.05). This research highlights the significance of integrating ecological dynamics into the management of seagrass ecosystems to enhance climate change mitigation efforts. Additionally, it offers valuable data as a reference for the restoration and conservation of seagrass ecosystems.

Seagrass Meadow Conditions in Coastal Waters of Siwak Bay Central Lombok

Seagrass is a flowering plant thriving in shallow sea waters and estuaries. Seagrass ecosystems are essential in supporting life in shallow seas as primary producers, biota habitats, sediment trappers, and nutrient trappers. Environmental factors affecting seagrass growth include temperature, salinity, pH, and substrate. The study was conducted in March-June 2023. This study aimed to determine the type and condition of seagrass beds in the waters of Siwak Bay. The method used in this study is the quadrant transect method at three research stations. There are seven types of seagrass identified, namely Thalassia hemprichii, Halophila ovalis, Cymodocea rotundata, Cymodocea serrulata, Halodule pinifolia, Halodule uninervis, and Syringodium isoetifolium. The percentage of total seagrass cover is at a value of 37%-61%, indicating that the condition of seagrass beds in the waters of Siwak Bay is included in the unhealthy category. The highest species density found at station III in Halodule pinifolia was 483.5 stands/m², and the lowest was found at stations II and III in Thalassia hemprichii and Cymodocea serrulata with 0 stands/m². The average density value of seagrass beds in the waters of Siwak Bay is very dense. The highest type frequency was found in Cymodocea rotundata, with a value of 2.53. The tallest species diversity and diversity index was found at station II with values of 1.56 and 0.8, respectively. In contrast, the highest dominance index was found at station I, with a value of 0.44.

The viability of seagrass ecosystems for supporting dugong recovery in Kenya

Seagrasses are the primary source of food for dugongs and a good indicator of marine ecosys- tem health. The East African dugong (Dugong dugon) population is listed as critically endan- gered under the IUCN Red List. This study aimed to document the status of seagrass beds and evaluate their potential for supporting dugong recovery in Kenya. A cross-sectional survey was conducted in December 2016 to March 2017, with data gathered through desktop reviews, inter- views, beach surveys and aerial surveys. Seven seagrass species were found at sampled sites, namely Syringodium isoetifolium, Thalassodendron ciliatum, Halophila ovalis, Zostera capensis, Thal- assia hemprichii, Cymodocea serrulata, and Halodule uninervis. Halodule and Halophila seagrass spe- cies are important in the diet of dugongs. Two dugongs were sighted during the aerial survey. The spread of sea urchins, unplanned infrastructure development, Illegal, Unreported and Unregulated fishing, and boat anchors negatively affected seagrass ecosystems and hence dugong distribution in Kenya.

Seagrasses produce most of the soil blue carbon in three Maldivian islands

Blue carbon is fast garnering international interest for its disproportionate contribution to global carbon stocks. However, our understanding of the size of these blue carbon stocks, as well as the provenance of carbon that is stored within them, is still poor. This is especially pertinent for many small-island nations that may have substantial blue carbon ecosystems that are poorly studied. Here, we present a preliminary assessment of blue carbon from three islands in the Maldives. The higher purpose of this research was to assess the feasibility of using blue carbon to help offset carbon emissions associated with Maldivian tourism, the largest Maldivian industry with one of the highest destination-based carbon footprints, globally. We used stable isotope mixing models to identify how habitats contributed to carbon found in sediments, and Loss on Ignition (LoI) to determine carbon content. We found that for the three surveyed islands, seagrasses (Thalassia hemprichii, Thalassodendron ciliatum, Halodule pinofilia, Syringodium isoetifolium, and Cymodocea rotundata) were the main contributors to sediment blue carbon (55 – 72%) while mangroves had the lowest contribution (9 – 44%). Surprisingly, screw pine (Pandanus spp.), a relative of palm trees found across many of these islands, contributed over a quarter of the carbon found in sediments. Organic carbon content (‘blue carbon’) was 6.8 ± 0.3 SE % and 393 ± 29 tonnes ha-1 for mangrove soils, and 2.5 ± 0.2% and 167 ± 20 tonnes ha-1 for seagrasses, which is slightly higher than global averages. While preliminary, our results highlight the importance of seagrasses as carbon sources in Maldivian blue carbon ecosystems, and the possible role that palms such as screw pines may have in supplementing this. Further research on Maldivian blue carbon ecosystems is needed to: 1) map current ecosystem extent and opportunities for additionality through conservation and restoration; 2) determine carbon sequestration rates; and 3) investigate options and feasibility for tourism-related blue carbon crediting. Overall, the opportunity for blue carbon in the Maldives is promising, but the state of knowledge is very limited.

Impact of ship-way channel dredging on a seagrass community in the Gulf of Carpentaria, Australia

Port construction at McArthur River Mine in the western Gulf of Carpentaria, Australia, required the dredging of an access channel through a prolific seagrass community. A 4 km by 60 m channel dredged to 5 m depth removed 18.95ha of intertidal and shallow subtidal seagrass. Dredge spoil was pumped onshore to settle in multiple ponds before the decant water returned to the gulf. Quantitative surveys of the seagrass community surrounding the channel using a Before After Control Impact Repeated measures (BACIR) experiment were conducted to investigate the effect of the channel construction on the seagrass community.Nine seagrass species were found during the surveys, but not all species were found in each of the impact or control sectors at all times. Syringodium isoetifolium (Ascherson) Dandy and Cymodocea serrulata (R.Brown) Ascherson and Magnus were the most common and extensive seagrasses (occurring mid- and offshore), while Halophila ovalis (R.Brown) Hook and Halodule uninervis (Forsskal) Ascherson were also abundant (occurring inshore). Twenty-five months after the completion of dredging no significant impact of channel dredging was identified: neither a retreat of seagrasses from the channel, a decline in seagrass cover, nor a reduction in biomass or shoot density. The sediment particle size distribution in the impact sector did not change. Changes in seagrass abundance were detected, but they were consistent in both the impact and control sectors (5–24 km distant from the dredged channel). During both pre- and all post-dredging surveys, seagrasses were found at about 80% of sites (range 79%–84%) in the impact sector (>300 sites). Dredge spoil was pumped onshore, then contained and settled in bunded ponds. Decant water was free of sediment. Sedimentation, elevated turbidity and light attenuation in the vicinity of the operating dredge was minimal and had no deleterious effect on the seagrass community.

Seagrass Aboveground Carbon Stock Mapping using PlanetScope SuperDove Imagery in Nemberala, Rote Island, East Nusa Tenggara

Seagrass ecosystem is natural objects that can be used to adapt and mitigate climate change through blue carbon sequestration. There are 16 seagrass species in Indonesia and the high diversity of these species supports the high potential of carbon that can be absorbed and stored. This study aimed to develop a general equation to estimate seagrass aboveground carbon stock (AGC) from the percent cover (PC), and to map seagrass AGC using PlanetScope imagery in Nemberala, Rote Island. Nemberala has very diverse seagrass species such as Enhalus acoroides (Ea), Cymodocea rotundata (Cr), Halophila ovalis (Ho), Syringodium isoetifolium (Si), Thalassodendron ciliatum (Tc) and Thalassia hemprichii (Th). The results of laboratory analysis to obtain the value of carbon stocks using the Loss on Ignition method from each species were 0.016, 0.004, 0.001, 0.002, 0.001, and 0.0001 (gC/leaf) for Ea, Th, Cr, Si, Tc, and Ho, respectively. The general equation for predicting AGC from PC is SeagrassAGC = (0.051*SeagrassPC) – 0.635 with r of 0.61 and R2 of 0.36. This formula will be applied to convert field seagrass PC data to AGC, which will then be used to train and test the accuracy of seagrass AGC mapping based on PlanetScope SuperDove 8 bands image.

Spatial diversity and habitat characteristics of seagrass meadows with management recommendations in the Andaman and Nicobar Islands, India

The Andaman and Nicobar Islands, India, a geographically remote region, harbor a diverse island ecosystem. Limited exploration has hindered our understanding of marine floral biodiversity in this area. To address this gap, we investigated seagrass meadows in the Andaman and Nicobar Islands to understand their spatial distribution, species composition, and habitat characteristics. We assessed 66 seagrass meadows, including 32 newly discovered ones, filling data gaps in the region’s seagrass coldspots. Seagrasses were found across a wide range of depths, with the majority occurring in shallow subtidal waters (&amp;lt; 8 m). Large-sized species such as Thalassia hemprichii, Enhalus acoroides, Cymodocea rotundata, Cymodocea serrulata, and Syringodium isoetifolium dominated the littoral and shallow subtidal zones, while smaller species such as Halophila spp. and Halodule spp. exhibited broader depth distributions. H. beccarii and H. decipiens were strictly intertidal and subtidal species, respectively. Water depth significantly influenced seagrass occurrence (p &amp;lt; 0.0001), cover (β = -0.2759; SE = 0.02471; p &amp;lt; 0.0001), shoot densities (β = -0.3556; SE = 0.1231; p = 0.005), and biomass (β = -0.3526; SE = 0.1159; p = 0.003). Sand availability emerged as the second significant predictor of seagrass distribution, cover, and biomass (p values &amp;lt; 2e-16, &amp;lt; 2e-16, and 0.01, respectively). Habitat heterogeneity decreased with increasing water depth, and seagrass species exhibited strong preferences for specific substrata, resulting in spatial niche partitioning. Our study provides novel insights into the seagrass spatial diversity, habitat characteristics, and seagrass-environment relationship in the Andaman and Nicobar Islands. Further, it highlights the importance of water depth, habitat characteristics, and substratum heterogeneity in seagrass distribution and growth. Lastly, our findings imply that any change to the benthic profile of the meadows will influence the seagrass species distribution and growth. Understanding these factors is crucial for seagrass conservation and management in the region, aiding the development of targeted strategies to protect these valuable marine habitats and associated biodiversity.

Assessment of blue carbon in seagrass meadows in Pulicat Lake, Andhra Pradesh, India

Coastal ecosystems such as seagrass, mangroves and saltmarshes sequester and store large quantities of carbon in the soil. Carbon sequestration potential of four seagrass species Halophila ovalis, Halodule pinifolia, Syringodium isoetifolium and Halodule uninervis in Pulicat Lake, Andhra Pradesh, India was assessed. The mean seagrass biomass within the seagrass beds in the lake ranged from 1.43 ± 0.06 to 2.01 ± 0.12 Mg/ ha and the total blue carbon storage in the seagrass meadows ranged from 0.49 ± 0.15 to 9.52 ± 0.15 Mg C ha−1 while stored carbon in the sediment ranged from 1.29 ± 0.04 to 11.94 ± 0.15 Mg C ha−1. Regression analysis showed a considerable correlation between seagrass carbon and sediment carbon. Among the environmental parameters analyzed, pH showed significant correlation with seagrass biomass and sediment carbon (P < 0.05). The present study demonstrates the carbon sequestration potential of seagrass ecosystem in the Pulicat Lake.

Diversity of Seagrass Along Two Coast Line Villages in The Regency of Biak Numfor: A Comparative Study

The Biodiversity Assessment of Seagrass Ecosystem in Orwer and Ambroben Waters, Biak Numfor Regency, Papua Province is very important for a baseline study of the ecosystem health of seagrass beds. The ecological function of seagrass ecosystems is to stabilize the seabed, provide food and habitat for other marine life, and maintain water quality. The research conducted aims to (1) determine the types of seagrasses, density, and percentage of seagrass cover in Orwer and Ambroben waters, and (2) find out the characteristics of aquatic environmental parameters that play an important role in determining the health status of seagrass meadow ecosystems. Based on the results of the research has been found as many as four types of seagrasses are in Orwer waters, namely Halodule pinifolia, Cymodocea rotundata, Thalassia hemprichii, and Halophila ovalis. In Ambroben waters have been found as many as 7 types of seagrass, namely Halodule pinifolia, Halodule uninervis, Cymodocea rotundata, Syringodium isoetifolium, Enhalus acoroides, Thalassia hemprichii and Halophila ovalis. The average density per seagrass species in Orwer waters is higher (2101 ind/m2) compared to Ambroben waters (1553 ind/m2). The percentage of seagrass ecosystem cover in Orwer is higher (94.44%) than in Ambroben waters (91.53%). The characteristics of aquatic health indicators for seagrass ecosystems in Orwer and Ambroben waters show almost the same range of values, namely temperatures ranging from 29.47-29.97, salinity 33.27-33.97 oo/oo, and pH 7.57-8.46, the dissolved oxygen parameter shows different values between the two waters. Oxygen levels in Orwer waters are 10.47-14.37 mg / L, while Oxygen levels in Ambroben waters are 7.47-11.10 mg / L. Based on these results, it shows that both waters are still included in the category of healthy waters and meet the quality standard criteria for life requirements for seagrass ecosystems.

Species preference for seagrass restoration using vertical distribution model in Tidung Island, Indonesia

Tidung Island is one of the small inhabited islands and a tourist destination that allows the degradation of seagrass meadow and requires physical restoration using transplantation techniques. The seagrass species’ preference suitability needs to assess with this island for this case. This study aims to provide information on species that are possible to choose in seagrass transplantation based on their growth zones. The number of seagrass species, depths, and types of substrates was taken using seagrasswatch guideline by line transects along the coast to the reef slope with 10% plot intervals from the total length of the transect. Seagrass growth is divided into three zones: near the coast (back), middle, and near the reef slope (front). Enhalus acoroides, Cymodocea rotundata, and Thalassia hemprichii were found in almost all zones. Halophila ovalis, Halophila minor, and Halodule uninervis were distributed in the middle to front zone, while Syringodium isoetifolium was only in the middle zone. These findings suggest that transplant areas with high anthropogenic disturbances can use Enhalus acoroides and Thalassia hemprichii because they have the persistent trait. Meanwhile, the areas with low anthropogenic disturbance and low nutrients can use Halophila spp. and Halodule spp., because they can grow shoots and recover quickly.

Gastropods Species Associated with Seagrass Ecosystems in Pasir Putih, Manokwari

Gastropods are one of the classes of mollusks that associate well with seagrass ecosystems. The waters of Pasir Putih are included in a coastal area where many types of gastropods are found in seagrass ecosystems. However, not all types of gastropods in seagrass beds in this region are well known. For this reason, this study aims to determine the types of gastropods associated with seagrass ecosystems in the waters of Pasir Putih, Manokwari. But specifically the objectives of this study are divided into 3, knowing the types of gastropods, seagrass species and the association of gastropods with seagrass in Pasir Putih Waters, Manokwari. In sampling, the quadratic transect method was used, drawn perpendicularly from the shore towards the shore. Physical parameters of water chemistry were observed in situ, this data collection method used was descriptive method. Based on the results of the identification that has been done, that there are 115 individuals, 42 species and 15 families that exist in the White Sand Waters, Manokwari. Four seagrass species were found, namely Cymodocea rotundata, Halodule pinifolia, Halophila ovalis, and Syringodium isoetifolium.

Relationship between seasonal seagrass growth and egg case dynamics of the oval squid (Sepioteuthis lessoniana Férussac in Lesson, 1832) in the coastal waters of the Ryukyu Archipelago

The oval squid (Sepioteuthis lessoniana Férussac in Lesson, 1832 often lays eggs on seaweed in coastal waters. However, in the coastal waters of the Ryukyu Archipelago, Japan, it specifically lays its eggs on seagrass, a behavior also observed in mainland Japan. Spawning dynamics in relation to seagrass growth have not been previously documented, and it remains unclear why oval squids specifically select seagrass as a spawning substrate. Therefore, we conducted a field survey to investigate the seasonal growth of seagrass communities (total area of 2,400 m2) and determine the abundance of egg cases deposited by oval squid on seagrass. Seasonal quadrat monitoring was conducted in the coastal waters of central Okinawa Island, Ryukyu Archipelago, Japan, from 2018 to 2020. Seagrass (Thalassia hemprichii (Ehrenberg) Ascherson, 1871 and Syringodium isoetifolium (Ascherson) Dandy, 1939) increased in length and coverage area from late June and peaked in late August; thereafter, the seagrass gradually withered. Furthermore, oval squid eggs, each containing 1–3 ova, were deposited on seagrass from mid-July 2018 and late June 2020, and the largest numbers were deposited in mid-August 2018 and late July 2020. The number of eggs laid on the seagrass gradually decreased until late September 2018, when they were no longer observed. However, in 2020, the number of eggs spawned decreased, followed by an increase between August and September, and eggs were no longer found in mid-October. The function of the seagrass community as a specific spawning substrate and nursery ground for hatched juvenile oval squid is also emphasized.

Distribution of Seagrass in North Sulawesi: A Review

Seagrasses are crucial coastal ecosystems that provide a multitude of ecological and economic benefits. The distribution of seagrass meadows plays a pivotal role in maintaining marine biodiversity, supporting fisheries, and contributing to carbon sequestration. Seagrass meadow ecosystems are important in the coastal environment. This ecosystem functions ecologically in the water as a habitat for various species of marine life, and has the ability to bind soil and sediment and dampen waves so that it helps protect the coast from erosion and storms. Seagrass ecosystems play a role in nutrient circulation, carbon storage, and play an important role in climate change mitigation. In addition, these ecosystems can potentially serve as a source of antioxidant compounds and bioindicators of aquatic environmental health. The coast of North Sulawesi has the potential for the existence of this ecosystem so it is necessary to assess the potential of seagrasses that are important in the coast of North Sulawesi Province. There are reportedly 10 seagrass species that have been identified in coastal North Sulawesi, consisting of Hydrocharitaceae and Cymodoceaceae families, namely Enhalus acoroides, Thalassia hemprichii, Halophila ovalis, Syringodium isoetifolium, Halodule uninervis, Cymodocea serrulata, Cymodocea rotundata, Thalassodendron ciliatum, Halophila spinulosa, and Halodule Pinifolia. Keywords: Seagrass, North Sulawesi, Bioindicator, ecosystem

Diversity of Seagrass Species in The Conservation Area of The Sawu Sea Marine National Park (TNP)

The Sawu Sea is an important habitat for dolphins, dugongs, manta rays and turtles. Sabu Island is one of the locations included in the Sawu Marine National Park area with considerable seagrass potential. The purpose of this study was to determine the health condition and community structure of seagrass on Sabu Island. This study used line transect, square transect, and random transect methods. The results of observations found 8 species, the most common types of seagrass were Thalassia hemprichii, Cymodocea rotundata, Halodule uninervis, Halophila ovalis, and Syringodium isoetifolium. A type of seagrass that is rarely found is Cymodocea serrulate which is only found in Loborai. The highest species density at Bodae station is Halodule unservices, and the lowest at Bodae station is Enhalus acoroides. The diversity index of seagrass species at the three stations is included in the low species diversity category. Seagrass species uniformity index is included in the medium community category. The dominance index of seagrass species at 3 stations is in the low dominance category. The highest coverage was Halodule uninervis with a value of 42.74% and the lowest was Enhalus acoroides with a value of 0.69%. The extent of seagrass cover at each of the Bodae, Laborai, and Keliha locations is 69.09%, 62%, and 66%, respectively. The highest Importance Value Index was found in Halodule uniservis, namely 138.00%, 30.55%, 96.80%, and the lowest was in Cymodocea serrulate. Overall the health condition of the seagrass beds at the observation location is included in the healthy category.

Potential transformation of seagrass (Syringodium isoetifolium) into a bioactive food ingredient using different extraction techniques

Background: Syringodium isoetifolium is a seagrass that grows abundantly in Indonesian territorial waters and has been known to be of high significance not only for the seawater ecosystem, but also for human beings (as food, nutritional and pharmaceutical products). In this study, the bioactive constituent of Syringodium isoetifolium was extracted using several different techniques to recover a maximum yield. Methods: Extraction was carried out by conventional and non-conventional (Microwave-assisted extraction, ultrasound-assisted extraction-bath system, and ultrasound-assisted extraction- (UAE) probe system) techniques with green solvents (water, 50% ethanol, and 100% ethanol). Results: As a result, 50% ethanol and water extracts exhibited a significantly higher yield. Total phenol content was significantly higher for 50% ethanol extract. Different extraction techniques (using 50% ethanol solvent) showed that the UAE-probe was the best technique since it yielded the highest total phenol (17.37 ± 2.16 mg GAE/g) and the richest bioactive compounds (Choline, betaine, 3,5-di-tert-butyl-4-hydroxybenzoic acid, 7-Hydroxycoumarine, 4-Methoxycinnamic acid, Zearalenone, Caffeic acid, Levalbuterol, Phloretin, Dihydrocaffeic acid, Quercetin-3β-D-glucoside and Quercetin). Interestingly, choline was the most abundant compound in the extract obtained with different extraction techniques. In this in silico assay, choline from seagrass extract was shown as an anti-inflammatory. The interaction pathway of the choline compound with receptors (TNF-α, IL-1β, and IL6) had a higher binding affinity value than the inhibitor-receptor interaction (i.e. -3.4, -3.0, and -2.8 kcal/mol). The cytotoxicity test on TIG-1 cells showed that the extract did not have a toxic effect on them. Conclusions: These findings support the potential use of Syringodium isoetifolium as a bioactive food ingredient.

Comparative acute toxicity study of Syringodium isoetifolium on aquatic and rodent experimental animals

This study was intended to assess the acute toxicity of hydroalcoholic leaf exact of Syringodium isoetifolium seagrass on brine shrimp, zebrafish and Wistar albino rats. The extract of different concentrations were used for brine shrimp (0.01-5 mg/ml in propylene glycerol/Tween 80/ water (4:1:4), zebrafish (12.5, 25, 50, 100, 200, 400 mg/ml), and female albino Wistar rat (500, 1000, 2000, 2500 and 5000 mg/kg) study. The control group received distilled water and the studies were carried out as per the OECD guidelines. The experimental subjects were observed individually for the first 24 hours, with special attention given during the first four hours, thereafter for a prescribed duration. The results of brine shrimp exhibited increased mortality with increasing concentration of the extract. Maximum mortality occurred at 1000 µg/ml and the least mortalities happened at 1 µg/ml concentration. Whereas no mortality and physical damage were identified in the zebrafish and Wistar albino rats irrespective of the concentration. The study revealed that the extract was found to be a toxic effect on brine shrimp due to the poor elimination of cytotoxic substances from the body at high concentrations and elimination freely at low concentrations. No toxicity was exerted on other study subjects.