A new species of Corallana Dana, 1852 (Crustacea: Isopoda: Corallanidae) from the Andaman Islands, northern Indian Ocean

Corallana mishrai sp. nov. collected from dead mangrove roots at Kodiyaghat, South Andaman, Andaman Islands, India is described and illustrated in detail. Corallana mishrai sp. nov. the first definitive record of the genus from India, is characterized by: frontal lamina with short straight (or very weakly convex) lateral margins and the anterior margin forming a strong acute median point; pleotelson length 0.76 greatest width, posterior margin with 5 robust setae; uropodal exopod 7 times longer than greatest width, extending beyond endopod by one fourth of its length; endopod lateral margin slightly convex with 4 RS and PMS, apex forms a slightly obtuse angle with long simple setae, mesial margin weakly convex with 2 RS and PMS; mandible bidentate; transverse row of 6 tubercles present on pereonite 1 and pleonites 2, 3 and 4 lacking lateral tubercles. The status of the genus and its species are reviewed, and two species are transferred to new combinations: Argathona kulai (Bruce, 1982) comb. nov. and Tachaea bidentata (Jones et al. 1983) comb. nov.

New host record of microhabitat preferences of the Banggai cardinalfish (Pterapogon kauderni) in the introduced habitat in Luwuk waters, Sulawesi

Banggai cardinalfish Pterapogon kauderni is an endemic apogonid fish from Banggai Islands, Central Sulawesi, which is discovered in strong association with black sea urchin (Diadema spp.). These fish also protected themselves from predators associated with sea anemones, hard coral branching, mushroom coral, soft coral, seagrass, and mangrove roots. The Banggai cardinalfish juveniles generally prefer to associate with sea anemones or mushroom corals as microhabitats. However, they are looking for similar microhabitats if they cannot find sea anemones or mushroom coral Heliofungia actiniformis. Microhabitat observation of Banggai cardinalfish was carried out in Luwuk waters, Banggai Regency. The result showed a new host record for juvenile phases of Banggai cardinalfish associated with upside-down jellyfish Cassiopea andromeda as a microhabitat. Further study is needed to represent areas and seasons to get more evidence between the Banggai cardinalfish and jellyfish association concepts.

Mercury Content on Mangrove Roots and Telescopium telescopium in Kao Bay, North Halmahera

The process of extracting gold using mercury (Hg) carried out by Nusa Halmahera Minerals industries (PT. NHM) as well as by the community of illegal gold mining or gold mining without a permit (PETI) that occurs in the mining area of ​​Halmahera Island can have a negative impact on the aquatic environment. This study aims to determine the mercury absorption in mangrove roots of Rhizopora sp and Telescopium telescopium at two different stations. Sampling of mangrove roots was repeated 3 times for each station. Differences in the accumulation of heavy metals Hg in the roots of Rhizophora sp were analyzed using the T-test. The study showed that the concentration of mercury in the roots of Rhizophora sp ranged from 0.016 – 0.026 mg/kg and there were differences in root absorption between Rhizopora sp at station 1 of the Tabobo River mangrove near the PETI disposal and station 2 at the mining industry waste disposal. The concentration of mercury in Telescopium telescopium ranged from 0.08 - 0.15 mg/kg. It is indicates that Telescopium telescopium in Kao Teluk has been contaminated with mercury but is still below the threshold of the quality standard that has been set.

Spatiotemporal Heterogeneity of Mangrove Root Sphere under a Tropical Monsoon Climate in Eastern Thailand

Mangrove ecosystems under tropical monsoon climates experience changes in environmental factors, especially seasonal variations in salinity. These changes might have direct influences on the mangrove root sphere, which plays an important role in carbon dynamics and supports mangrove growth. We aimed to elucidate how the soil properties including salinity and nutrient budget affect the mangrove roots in the wet and dry seasons across the mangrove zonation (Avicennia, Rhizophora, and Xylocarpus zones). This area is in a secondary forest at the Trat River estuary, eastern Thailand. Root mass was observed at 0–10 and 10–20 cm depths across all zones and the living roots were separated into diameter classes. The soil water salinity was measured at a 10 cm depth. We analyzed the nitrogen, phosphorus, and carbon contents in the roots and soil. Spatiotemporal changes occurred due to the vegetation zonation and the variations in salinity and the content of soil available phosphorus that caused different root sphere conditions along the distance from the river. The highest root biomass was found in the riverward Avicennia zone, which was 4.8 times higher than that of the inland Xylocarpus zone in the wet season. The root necromass distribution along the zonation showed an opposite trend to that of biomass. Among seasons, the root size-class proportion differed, with high fine roots observed during the wet season. We confirmed that the root sphere showed both spatial and temporal heterogeneity. Mangrove roots, especially fine roots, interacted with changing salinity, inundation regime, and biological processes evoked by microtopographic gradients as a consequence of mangrove zonation and seasonal rainfall. Our findings indicate how the root sphere differed by specific vegetation structure in this mangrove forest. Therefore, these might provide an ecological perspective for the mangrove rehabilitation plans to facilitate below-ground carbon stock.

Experimental Investigation of Wave Attenuation Using a Hybrid of Polymer-Made Artificial Xbloc Wall and Mangrove Root Models

Rising sea levels, strong wave currents and destructive human activities put coastal areas at risk of erosion and potential flooding. Several countermeasures have been introduced—both artificial and natural—to tackle the issue. This study investigated the effectiveness of the use of hybrid polymer-made artificial Xbloc walls and mangrove root models for protection against water waves. One Xbloc wall was made up of three Xbloc units stacked on top of each other and joined together using water-resistant tape. The artificial models were designed using SolidWorks and AutoCAD software, 3D printed, laser cut and then superglued. The experiment was conducted at Nottingham Trent University Laboratory with a varying combination of single/multiple Xbloc walls and mangrove root models. The change in the wavelength, height, celerity and period was observed for six different model arrangements. The results revealed a successful decrease in the celerity, height and wavelength, as well as the elongation of the wave period (one cycle time). The hybrid arrangement of one Xbloc wall and two mangrove roots provided the best protection, reducing the wavelength, celerity and height by 5.50%, 26.46% and 58.97%, respectively, and also delaying the wave period by 28.34%. The lowest attenuation in the entire wave parameters stated was observed for the arrangement containing only one set of mangrove roots model. Therefore, the wave attenuation using the combined action of 3D printed polymer-made Xbloc walls and mangrove roots was better, because it facilitated the dissipation of wave energy to a greater degree compared to the use of only Xbloc walls or mangrove roots separately.

Keanekaragaman Jenis Plankton pada Akar dan Perairan Sekitar Mangrove Desa Lembar Selatan, Kabupaten Lombok Barat

The mangrove ecosystem is one of the ecosystems in the estuary area that is unique and very sensitive to environmental changes. The large number of aquaculture businesses around Cemare Hamlet, West Lombok Regency have resulted in many mangrove areas being converted into pond cultivation locations. This will have an impact on the life of mangrove ecosystems such as plankton. This study aims to determine the abundance of plankton species around the mangrove area of ??Dusun Cemare, Sheet Selatan Village, West Lombok Regency. The research was conducted in May-October 2019 using a purposive sampling method by determining 7 stations to represent water conditions. Plankton analysis using the Lackey drop microtranscting method. The results showed that the mangrove ecosystem in Dusun Cemare was composed of 4 types, namely: Rhizophora sp., Avicenia sp., Bruguiera sp., And Soneratia sp. The plankton community in mangrove waters is composed of 13 types, while the abundance of plankton species (periphyton) attached to the mangrove roots consists of 6 types. The composition of plankton species which tends to be high indicates that the mangrove waters of Dusun Cemare are still feasible to sustain the survival of the associated biota in it.

Mangrove roots model suggest an optimal porosity to prevent erosion

Mangrove swamps are extremely productive ecosystems providing many ecological services in coastal regions. The hydrodynamic interactions of mangrove roots and water flow have been proposed as a key element to mitigate erosion. Several studies reveal that precise prediction of the morphological evolution of coastal areas, in the face of global warming and the consequent sea-level rise, requires an understanding of interactions between root porosity (the fraction of the volume of void space over the total volume), water flows, and sediment transport. Water flows around the mangrove prop roots create a complex energetic process that mixes up sediments and generates a depositional region posterior to the roots. In this work, we investigated the boundary layer behind permeable arrays of cylinders (patch) that represent the mangrove roots to explore the impact of patch porosity on the onset of sediment transport. The flow measurements were performed in a vertical plane along the water depth downstream of the mangrove root models. A high-resolution Particle Image Velocimetry (PIV) was used in a flume to observe the impact of porosity on the mean flow, velocity derivatives, skin friction coefficient, and production of turbulent kinetic energy for Reynolds number of 2500 (based on patch diameter length-scale). Here, we proposed a predictive model for critical velocity for incipient motion that takes into account the mangrove roots porosity and the near-bed turbulence effect. It is found that the patch with the $$\phi =47\%$$ ϕ = 47 % porosity, has the maximum critical velocity over which the sediment transport initiates. We found the optimum porosity has the minimum sediment erosion and creates negative vorticity sources near the bed that increases the critical velocity. This signifies an optimum porosity for the onset of sediment transport consistent with the porosity of mangroves in nature. The phenomenological model is elucidated based on an analysis of the vorticity evolution equation for viscous incompressible flows. For the optimum porous patch, a sink of vorticity was formed which yielded to lower the near-bed turbulence and vorticity. The minimum velocity fluctuations were sufficient to initiate the boundary layer transition, however, the viscous dissipation dominated the turbulence production to obstruct the sediment transport. This work identified the pivotal role of mangrove root porosity in sediment transport in terms of velocity and its derivatives in wall-bounded flows. Our work also provides insight into the sediment transport and erosion processes that govern the evolution of the shapes of shorelines.

THE ROLES OF ARBUSCULAR MYCORRHIZAE IN SUPPORTING THE MANGROVE GROWTH

The current study aims to determinate the potential of Arbuscular mycorrhizae in supporting the mangrove growth, the role of Arbuscular mycorrhizae on the improvement of mangrove growth in terms of its colonization level with the mangrove roots, the mangrove ability of Arbuscular mycorrhizae in the way of supporting the rehabilitation of mangroves, and giving the recommendation to the local government related to the potential of mycorrhizal fungi in rehabilitating the degraded magrove areas living in the coastal areas of Kwandang, North Gorontalo regency. Moreover, this study used a descriptive qualitative analysis method using ex-post-facto approach. To collect the data, it used a pruposive sampling on rhizosfer and mangrove roots in order to observe the spore density, the diversity and the mycorrhizal colonization. The results of this study show that the ability of Arbuscular mycorrhizae in supporting the mangrove growth is categorized in the high level. It can be seen from the spora density. On average in research location, the number of the spores that were successfully isolated is 42 spores/ 100 grams of soil. Arbuscular mycorrhizae has a role in the way of increasing the mangrove growth. This can be seen from the high percentage of colonization with mangrove roots whereas 57,87%.