Seaweed Kaphapicus alvarezii is very popular in cultivation because it has high economic value and has quite large development potential in Ruguk Village, Ketapang District, South Lampung Regency. Water quality is a factor that influences the growth of seaweed, including the Kaphapicus alvarezii type, both physical and chemical water quality. This research aims to determine the condition of water quality in the seaweed cultivation area of Ruguk Village, Ketapang District, South Lampung Regency, meets the optimal living conditions for cultivating Kaphapicus alvarezii seaweed. This research is a type of descriptive research with a survey method carried out by taking water samples at seaweed cultivation locations and measuring the increase in seaweed growth every week for 4 weeks. The parameters observed in this research were the physical and chemical parameters of the water quality of the seaweed rearing media at the research location which consisted of temperature, brightness, current, pH, salinity, dissolved oxygen (DO), and phosphate and relative growth of the seaweed. Based on the results of observations during the research, it can be concluded that the water quality conditions, both physical and chemical water quality in the seaweed cultivation area in Ruguk Village, Ketapang District, South Lampung Regency, are in accordance with the standard quality requirements for the growth of Kaphapicus alvarezii seaweed, namely temperature 29.1-30.2⁰C, brightness 0,8-1.5 m, current strength 0.20-0.37m/sec, depth 0.8–1.5 m, pH 7.5-8.17, salinity 26-30 ppt, DO of 4.6-7.2 ppm, nitrate 0.2-0.92 mg/L and phosphate of 0.258-0.711 mg /L

Mangroves are vegetation communities that generally grow along the coastline and provide many functions ranging from ecological functions as habitats and economic functions as areas of utilization for humans. In the waters of Batu Licin Village there is an open mangrove area after bauxite mining, therefore it is necessary to conduct research on the level of density and mangrove regeneration seen from the presence of seedlings, saplings, and mangrove trees. This research was conducted in October 2024 in the waters of Kampung Batu Licin East Bintan, the method used in this study is purposive sampling which considers the area around the post-bauxite mine and the area that is still natural. By calculating mangrove density and analyzing the level of regeneration. At the research site found 8 types of mangroves such as Avicenia lanata, Bruguiera gymnorrhiza, Bruguiera cylindrica, Rhizhopora apiculata, Ceriops tagal, Rhizophora mucronata, Xylocarpus granatum, and Sonneratia alba. The density of mangrove seedlings on open land (post bauxite mine) has a high value with a value of 84,000 ind/ha, saplings with a value of 4,960 ind/ha, and trees with a value of 1,310 ind/ha are in the medium category. While on natural land for seedling density with a value of 54,000 ind/ha, at the stake level with a value of 5,240 ind/ha, and trees 1,760 ind/ha are in the very dense category. For the level of regeneration in the two areas is equally good because the presence of seedlings is more than saplings and saplings are more than trees.

This study aims to identify the habitat characteristics and distribution patterns of the antique ark Anadara antiquata in the waters of Senggarang Besar, Tanjungpinang City. The research was conducted from July to September 2024. The research process included site surveys, field data collection, sample analysis, data processing, data analysis, and preparation of the final report. Sampling points were determined using purposive sampling at three observation stations. Antique ark samples were collected using the sweep area method at each station, with an observed area of 10 x 10 meters. The results showed that antique ark in Senggarang Besar prefer habitats with high organic content, relatively lower water temperatures within the optimal range (around 29.83°C), stable salinity (around 30 ppt), and low but still safe levels of dissolved oxygen (around 5.17 mg/L), with these characteristics being most evident at Station I. The distribution pattern analysis showed that all stations had an index of dispersion (Ip) value greater than 0.5, indicating a clumped distribution pattern of the antique ark population in the study area.

The mangrove ecosystem is a plant that is closely related to water. Mangroves have an important role in preserving aquatic ecosystems, beaches and even land areas. The important role of mangroves in these waters will of course be directly related to the health condition of mangroves in an ecosystem. Mangrove health is an integral part of sustainable management of mangrove ecosystems. The research carried out on the mangrove ecosystem in the Sei Nyirih water area aims to determine the Mangrove Health Index, Community Structure and Important Value Index. This research method uses Purposive Sampling at three stations with three plots at each station. The results of the research in the Sei Nyirih mangrove area were divided into three categories, namely the Tree Category, Sapling Category and Seedling Category with the types found namely Rhizopora apiculata, Bruguiera gymnorhiza, Xylocarpus granatum, Schyphipora hysrophylacea, Ceriops tagal and Lumnitzera littorea. The Importance Value Index is dominated by the Rhizopora apiculata type in the Tree and Sapling Category, while in the Seedling Category it is the Xylocarpus granatum type. Then the Mangrove Health Index (MHI) obtained from the MonMang V 2.0 Application Station 1 with an average of 67.34% or in the Excellent category, Station 2 with an average of 66.57% or in the Moderate category and Station 3 with an average of 67.62% or in the Excellent category. Meanwhile, the Mangrove Health Index uses Excel Station 1 with an average of 76.07% or in the Excellent category, Station 2 with an average of 74.96% or in the Excellent category and Station 3 with an average of 78.62% or in the Excellent category.

Keter Island, located in Tembeling Tanjung Village, Bintan Regency, harbors a diverse mangrove ecosystem, predominantly composed of Rhizophora species. This study aimed to assess mangrove density at the tree level, evaluate vegetation cover, and determine the ecological status of the mangrove ecosystem based on its level of degradation. Field surveys were conducted to obtain an overview of ecosystem conditions, followed by systematic random sampling at sites within Tembeling waters where mangroves are distributed. The results indicate that mangrove tree density falls within the medium category, while canopy cover is classified as very dense with good ecological quality. Overall, the mangrove ecosystem on Keter Island is categorized as moderate, although it still displays favorable ecological characteristics. These findings suggest that while the mangrove ecosystem remains in a medium condition, degradation is ongoing, thereby necessitating further research and rehabilitation efforts. Given the vital role of mangroves in sustaining the ecological balance of small islands, direct monitoring and intervention by relevant authorities are essential to reduce degradation and ensure the long-term sustainability of the mangrove forest on Keter Island.

Mantis shrimp (Lysiosquillina maculata Fabricus, 1793) is a type of marine crustacean that has high nutritional content, especially protein, so it is quite in demand by the international community as a consumption ingredient. Mantis shrimp is an interesting species because it has true economic and ecological value. The development of mantis shrimp fisheries in the Tanakeke Islands and Kanalo Islands can provide broad benefits, both in terms of economy and social. Ecosystem Approach to Fisheries Management is here to realize fisheries management that balances socio-economic aspects and the utilization of fish resources fairly, with knowledge, information, and uncertainty regarding biotic, abiotic components, and human interactions in aquatic ecosystems to realize integrated, comprehensive, and sustainable fisheries management. This study aims to examine the capture of mantis shrimp Based on EAFM in the Fishing Technique Domain. This study is classified as mixed methods according to the indicators set for the Fishing Technique domain, namely the frequency of violations over the past five years; Catching; area of fishing area, and duration of fishing; legal documents of the fishing fleet; and fishing vessel crew certificates. The selection of research respondents was based on purposive sampling. The condition of the mantis shrimp fishery according to the Ecosystem Approach to Fisheries Management (EAFM) approach shows an aggregate value of 290 which produces a Domain value of 93.55. This value is included in the model category with a Dark Green flag, which indicates that the implementation of EAFM is at a very good level.

Seaweed possesses the potential to serve as a functional food or supplement, being nutrient-dense and a source of food and medicine due to its abundance of minerals, vitamins, and antioxidants. In Indonesia, seaweed is extensively utilized due to its advantageous properties for multiple industries, including agriculture, animal husbandry, pharmaceuticals, chemicals, and medicine. This study seeks to discover a specific component of sea grape (Caulerpa racemosa), which is prevalent in the waters of Lohia Village, Lohia District, Muna Regency, Southeast Sulawesi. The composition of sea grape (Caulerpa racemosa) was analyzed utilizing an X-ray Fluorescence Spectrometer (XRF) due to its capacity to detect nearly all minerals in a single measurement. The study's findings indicated that sea grapes (Caulerpa racemosa) at stations 1, 2, and 3 contained Chlorine (Cl), Calcium (Ca), Potassium (K), and Bromine (Br), along with several trace elements including Iron (Fe), Phosphorus (P), Strontium (Sr), Silicon (Si), and Titanium (Ti) in minor quantities. At stations 4, 5, and 6, sea grapes (Caulerpa racemosa) predominantly exhibited Chlorine (Cl), Potassium (K), and Magnesium (Mg), whereas Calcium (Ca) and Bromine (Br) were present in lesser quantities. Despite the considerable benefits of sea grapes (Caulerpa racemosa) for humans, caution is imperative in their use. Sea grapes (Caulerpa racemosa) possess the capacity to absorb minerals and bioaccumulate heavy metals from seawater, resulting in the presence of trace elements.

Mangrove ecosystems play a crucial role both ecologically and economically. However, in Bintan Regency, their area has significantly declined due to development activities. This research aims to determine the productivity of the mangrove ecosystem in Busung Village, Bintan Regency, following the implementation of HKm. The study was conducted from April to May 2025 using a purposive sampling method with three observation stations, each consisting of three plots. Observations were made on litter production, decomposition, and mangrove crabs (Scylla sp.) parameters. Litter samples were collected using three 1×1 meter litter traps per plot, while decomposition was measured using litter bags, and mangrove crab samples were collected using foldable traps. Data correlation analysis between parameters was performed using Pearson correlation heatmaps and Principal Component Analysis (PCA). The results show that litter production in the Busung Village mangrove ecosystem was dominated by leaf components (19.51 g dry weight/m² /10 days), with an average total production of 84.74 g dry weight/m²/10 days. Correlation analysis across the three stations indicated that mangrove crabs play a role in regulating mangrove litter productivity through their fragmentation/shredding activities, with varying influences depending on the level of human activity and environmental conditions. In areas with minimal activity (Station 1), an increase in crab density and weight significantly reduced the amount of litter. In fishing areas (Station 2), a healthy nutrient cycle was observed with positive correlations between parameters, while crabs controlled litter stock through consumption and fragmentation. In aquaculture areas (Station 3), the productive environment supported crab growth, although litter availability had less direct impact on the crabs.

Swimming crab shell waste is a fishery byproduct that has the potential to pollute the environment if not utilized properly. One alternative utilization is to process it into chitosan, which is then formulated into liquid fertilizer. This study aimed to determine the effect of chitosan concentration based on swimming crab shells on the chemical properties of liquid fertilizer. The study was conducted from February to March 2025. Chitosan and liquid fertilizer production was conducted at the Fishery Products Biochemistry Laboratory, Pangkep State Agricultural Polytechnic. The method used was an experimental laboratory with a Completely Randomized Design (CRD), with three treatments and three replications, with chitosan concentrations of 2%, 4%, and 6%. Data were analyzed using One-Way ANOVA and the W-Tukey HSD test. If the assumption of homogeneity of variance was not met, Welch ANOVA with the Games-Howell test was used to determine differences in effects between treatments. The results showed that the treatment had a significant effect (P<0.05) on most of the chemical properties of liquid fertilizer. The chemical properties of pH were (2.90 3.00 3.23), C-organic were (1.08% 2.72% 4.21%), macronutrients N + P₂O₅ + K₂O were (0.76% 0.64% 1.19%). In conclusion, increasing the concentration of chitosan improves the chemical properties of liquid fertilizer, so that crab shell chitosan has the potential as a material for liquid organic fertilizer formulation.

Food is very important as a source of nutrient for the body every day. Currently, the trend of fast food is increasingly attracting people’s interest without considering the nutrional content in it. Gyoza is a fast food similar to dimsum that has a savory and taste in the from of jiozia. Modification of gyoza filling using male mackerel (Rastrelliger kanaguarta) and Kappaphycus alvrezii seaweed is made as an alternative to healthy fast food. This study aims to determine the characteristic of the chemical and sensory quality of male mackerel gyoza (Rastrelliger kanaguarta) fortifed with Kappaphycus alvarezii seaweed. This research method was carried out in March-June 2025 using the experimental laboratory method with three treatments and repetitions for chemical test. The addition of Kappaphycus alvarezii seaweed to the nutrition of male mackerel gyoza had a significant effect (p<0.005) based on the ANOVA test, highest protein content in sample A without seaweed 19.97%, the highest iodine content in sample C fortified with 20 grams of seaweed 20.06 µg/g, the highest fiber content sample C fortified with 20 grams of seaweed with a result of 9.55%.