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Mangrove forests serve as a buffer against sedimentation from the mainland into the sea, protect the area from coastal erosion, and prevent seawater intrusion in some ecological types of coastal environments. Additionally, because soil and below-ground biomass retain a significant quantity of carbon, they are essential for carbon sequestration. The current study seeks to estimate the soil organic carbon stock of mangroves associated with natural regeneration, mangrove rehabilitation areas and abandoned shrimp ponds, in Mahakam Delta, East Kalimantan, Indonesia. A 125-meter-long transect line was used to collect data, with three sampling points representing the length of the transect line. Each soil sample was taken at three different depths: 0-50 cm, 50-100 cm, and 100-150 cm. After that, the samples were taken to the laboratory for carbon analysis. The mangrove rehabilitation area had the highest bulk density at 8.64 gr/cm3, followed by natural mangroves along the river border at 7.67 gr/cm3, and abandoned ponds had the lowest at 7.16 gr/cm3. The rehabilitation area had the highest soil carbon stock at 1120 tons/ha, followed by natural mangroves along the riverside at 686 tons/ha and abandoned ponds at 383 tons/ha. In accordance with the study, mangrove rehabilitation regions had larger soil carbon stocks than natural regeneration along the riverside and abandoned ponds. In order to protect the ecologically significant mangrove ecosystem and minimize the effects of climate change, mangrove restoration and rehabilitation are necessary.

The tiger shrimp culture in East Borneo is commonly performed using traditional pond system management. In this work, the objective was to evaluate the application of Boesenbergia pandurata and Solanum ferox extract supplemented as feed additives considering shrimp growth, survival rate, and meat quality culture in a traditional pond. There were three dietary groups that were stocked with 300 shrimp in this study. The shrimp were maintained in a pond, separated with a 3 × 3 m² net. The dietary treatment applied was divided into three types, namely P1, without the extracts; P2, 20 mL kg⁻¹ dietary supplementation; and P3, 30 mL kg⁻¹ dietary supplementation in the diet. The findings revealed that the herb extract influenced the growth rate, feed efficiency, survival rate, and meat quality of the shrimp, mainly the amino and fatty acid contents in the shrimp meat. The 30 mL kg⁻¹ herb extract dose in group 3 showed a higher growth performance and survival rate. In group 3, 98% of the shrimp could survive until the final study period, while 96% of shrimp survived in group 2, and 70% of the shrimp survived in group 1. These findings indicate that the phytoimmune (B. pandurata and S. ferox) extract can be utilized as a feed additive to improve the growth, survival rate, and meat quality of the shrimp.

The mangrove forest ecosystem plays an absorbent and carbon sink to reduce CO2 levels in the atmosphere, including in degraded mangrove areas. This research was conducted precisely on abandoned shrimp ponds in mangrove areas in the Mahakam Delta. Four different locations are locating on Sepatin ponds, ponds, ponds, and ponds Bayur headland. The purpose of this study was to estimate the above-ground carbon stock in abandoned shrimp ponds. Carbon stock measurement methods create a 125 m transect and quadrant divided into six plots at each location. These measurements were conducted on living vegetation and dead wood from felling vegetation. Measurement of above-ground biomass was done by measuring the tree diameter at breast height (1.3 m) on each tree diameter> 5 cm in radius quadrant plot 7 m. Vegetation has a diameter <5 cm categorized in seedling criteria and measured 30 cm from the ground within the quadrant plot radius of 2 m. The vegetation diversity experienced a succession calculated using the diversity index by calculating the dominance index, diversity index, and similarity index of vegetation. While the calculation of above-ground biomass accumulation using allometric equations according to the species. The results showed that vegetation analysis in the fourth study sites obtained a high dominance index value at each location. The study is inversely proportional to the value of diversity and similarity index. The highest total carbon stock at Tanjung Nipah location was 11.599 Mg C. Ha ^-1, followed by Sepatin 6.248 Mg C. Ha ^-1, Benati Dalam 3.579 Mg C. Ha ^-1, and lowest carbon stock at Bayur location 1.460 Mg C. Ha ^-1.

Seftianingrum, R.; Suwasono, R.A.; Sulistioadi, Y.B.; Suhardiman, A., and Diana, R., 2020. Floral composition of the Kayan-Sembakung Delta in North Kalimantan (Indonesia) in different disturbance regimes. Journal of Coastal Research, 36(4), 741–751. Coconut Creek (Florida), ISSN 0749-0208.This paper presents the results of a preliminary study that identify the floral composition of the Kayan-Sembakung Delta in North Kalimantan under different disturbance regimes. The landforms described in the Regional Physical Planning Project for Transmigration in Indonesia land-system map were evaluated to define the mangrove ecosystem boundary. The mangrove ecosystem disturbance levels distinguished by reclassifying the land-cover map of the mangrove ecosystem into four categories, i.e. heavily disturbed mangrove (represented by shrimp ponds abandoned five years ago or less), moderately disturbed mangrove (represented by shrimp ponds abandoned more than five years ago), regrown (secondary) mangrove forest (that may have been logged for wood but did not experience terrain alteration for fishpond development), and relatively undisturbed (primary) mangrove forest. A vegetation survey was conducted in several transects for each of these categories. Basal area, density, species diversity, and abundance of species in each location were calculated to understand the floral composition of the mangrove ecosystem. The study reveals that the mangrove forest in the Simanggaris River has the highest total basal area of 44.50 m2/ha, as well as the highest tree density of 1635 individual/ha, which indicates the most dense and mature remaining mangrove forest followed by the Sikang River near Liago Village with 85.75% of canopy cover. The heavily degraded mangrove ecosystem in Ibus Island has the highest importance value index of 278.89%, with Sonneratia sp. as the dominant species. The Kayan-Sembakung Delta hosts at least six original mangrove species, i.e. Rhizophora apiculata, Osbornia octodonta, Lumnitzera littorea, Avicennia sp, Rhizophora sp, and Sonneratia sp. In addition to the six original mangrove species listed, the inner part of the Kayan Delta also has several forest patches dominated by Nypa fruticans, whereas some parts of the Delta host a mixed vegetation composition between freshwater and brackish water ecosystems.