Diversity of macroalgae diversity in the tidal waters

The Tidal waters of Sancang beach are habitats for various marine biota, such as macroalgae. This research aims to find out the diversity of macroalgae species in the tidal waters of Sancang Beach, conducted in February-April 2020. This research uses qualitative methods, sampling techniques using purposive sampling with the help of transect belts. The stations used in the search consist of Station 1 in the Ciporeang area, Station 2 in the Cicukangjambe area, and Station 3 in the Cibako area. Each station has one 100-meter transect belt with a plot size of 1 x 1 meter. Ecological index calculations include diversity index, uniformity index, and dominance index. The results showed that 39 types of macroalgae were found consisting of 10 orders, 18 families, 26 genera with a total macroalgae count of 13324 individuals. The average value of the ecological index obtained includes the diversity index (H') 2.15 with the medium category, the uniformity index (E) 0.26 with the low category, and the dominance index (C) 0.19 with the low category.Keywords: Diversity, macroalgae, sancang beach, tidal waters

Nitrogen Cycling and Mass Balance in the World’s Mangrove Forests

Nitrogen (N) cycling in mangroves is complex, with rapid turnover of low dissolved N concentrations, but slow turnover of particulate N. Most N is stored in soils. The largest sources of N are nearly equal amounts of mangrove and benthic microalgal primary production. Dissolved N fluxes between the forests and tidal waters show net uptake, indicating N conservation. N2-fixation is underestimated as rapid rates measured on tree stems, aboveground roots and cyanobacterial mats cannot currently be accounted for at the whole-forest scale due to their extreme patchiness and the inability to extrapolate beyond a localized area. Net immobilization of NH4+ is the largest ecosystem flux, indicating N retention. Denitrification is the largest loss of N, equating to 35% of total N input. Burial equates to about 29% of total inputs and is the second largest loss of N. Total inputs slightly exceed total outputs, currently suggesting net N balance in mangroves. Mangrove PON export equates to ≈95% of PON export from the world’s tropical rivers, but only 1.5% of the entire world’s river discharge. Mangrove N2O emissions, denitrification, and burial contribute 0.4%, 0.5–2.0% and 6%, respectively, to the global coastal ocean, which are disproportionate to their small worldwide area.

Growth and Population Parameters of Panulirus penicillatus and Panulirus homarus in Labangka Tidal Waters, Indonesia

HighlightUtilization, Growth, and Population of Bullet Tuna (Auxis rochei Risso 1810) in Indian Ocean Southern Sumbawa (2020)Eligibility Status Kawakawa (Euthynnus affinis Cantor, 1849) from Lombok Strait and Indian Ocean Southern Sumbawa (2020)Biological Aspect of Parent Candidate of White-spotted Rabbitfish (Siganus canaliculatus) from Serewe Bay, Lombok Timur District (2020)Study of Sustainability in Management of Malabar Blood Snapper Fisheries in the Indian Ocean Coastal Waters, Sumbawa Regency (2020)Growth Rate and Survivorship of Acropora sp. Fragments that Transplanted on the Artificial Substrate Made from Fly Ash and Bottom Ash (2020)Reproductive Biological Aspect of Panulirus penicillatus in Sumbawa Island Waters, Indonesia (2019)Fisheries Resource Status of Spiny Lobster Panulirus penicillatus in Labangka Waters, South Sumbawa, Indonesia (2019)Growth Rate of Acropora formosa Coral Fragments Transplanted on Different Composition of Faba Kerbstone Artificial Reef (2019)Agribusiness of Edible Jellyfish Crambione mastigophora in Saleh Bay, NTB: Implementation of Sustainable Fisheries (2019)AbstractThe Labangka tidal waters, located south of Sumbawa Regency are the habitat and potential fishing ground for lobsters. The dominant species caught by the Labangka fishermen are the Panulirus penicillatus and P. homarus. Fishing pressure is one of the greatest factor influencing the biological and stock condition of lobsters in Labangka. The aim of this study is to determine the key attributes in growth and population parameters. Some attributes whose values are relatively stable compared to that of 2015, consist of conditional factors such as (old age), growth pattern (hypoallometric), growth coefficient (slow growth), exploitation rate (overexploited), and fishing rate (excessive fishing). While, attributes that have improved are carapace length at first capture (CLc) longer than 50% carapace length of infinity (0.5CL∞) and CL rate (CLc/0.5CL∞) reaching more than 1.00 (CLR > 1.00). In implementing sustainable management of spiny lobster for fishery resources, improvisation is needed in place of catching technologies. One of the recommendation is to add more fishing vessel (Lboat > 17.0 m) equipped with engines that are able to reach potential fishing ground in the west waters of Cemplung beach, Labangka.

Carbon Cycling in the World’s Mangrove Ecosystems Revisited: Significance of Non-Steady State Diagenesis and Subsurface Linkages between the Forest Floor and the Coastal Ocean

Carbon cycling within the deep mangrove forest floor is unique compared to other marine ecosystems with organic carbon input, mineralization, burial, and advective and groundwater export pathways being in non-steady-state, often oscillating in synchrony with tides, plant uptake, and release/uptake via roots and other edaphic factors in a highly dynamic and harsh environment. Rates of soil organic carbon (CORG) mineralization and belowground CORG stocks are high, with rapid diagenesis throughout the deep (>1 m) soil horizon. Pocketed with cracks, fissures, extensive roots, burrows, tubes, and drainage channels through which tidal waters percolate and drain, the forest floor sustains non-steady-state diagenesis of the soil CORG, in which decomposition processes at the soil surface are distinct from those in deeper soils. Aerobic respiration occurs within the upper 2 mm of the soil surface and within biogenic structures. On average, carbon respiration across the surface soil-air/water interface (104 mmol C m−2 d−1) equates to only 25% of the total carbon mineralized within the entire soil horizon, as nearly all respired carbon (569 mmol C m−2 d−1) is released in a dissolved form via advective porewater exchange and/or lateral transport and subsurface tidal pumping to adjacent tidal waters. A carbon budget for the world’s mangrove ecosystems indicates that subsurface respiration is the second-largest respiratory flux after canopy respiration. Dissolved carbon release is sufficient to oversaturate water-column pCO2, causing tropical coastal waters to be a source of CO2 to the atmosphere. Mangrove dissolved inorganic carbon (DIC) discharge contributes nearly 60% of DIC and 27% of dissolved organic carbon (DOC) discharge from the world’s low latitude rivers to the tropical coastal ocean. Mangroves inhabit only 0.3% of the global coastal ocean area but contribute 55% of air-sea exchange, 14% of CORG burial, 28% of DIC export, and 13% of DOC + particulate organic matter (POC) export from the world’s coastal wetlands and estuaries to the atmosphere and global coastal ocean.

Research on Chemical Leakage Based on Three-dimensional Soluble Contaminant Diffusion Model

The leakage and diffusion of pollutants are important issues affecting waters. This paper studies the diffusion of soluble pollutants in water. Based on the three-dimensional hydrodynamic model, a three-dimensional soluble pollutant diffusion model was established and validated. The validation results show that the discrete form of the transport equation used in this model must maintain monotonic properties, and otherwise the model calculation cannot converge. Taking Tianjin Nangang as a representative river section, the cognitive experiment on methanol leakage was carried out to predict the variation characteristics of chemical leakage and diffusion over time in Nangang. The model can be used for chemical leakage and diffusion prediction simulations of other pollutants, and can be used for calculations in runoff and tidal waters.

STUDI KOMUNITAS GASTROPODA DI PERAIRAN PASANG SURUT DESA HUTUMURI KECAMATAN LEITIMUR SELATAN KOTA AMBON

Background: Ecologically, gastropods have an important role to control the population of macroalgae in coral reefs, and economically the snail shell can be used as a source of income for people, especially coastal communities. Method: The method used is a quadratic linear transect method that is placed perpendicular to the coastline with a combination of plots on the transect line. Data analysis included species composition, diversity, dominance, and evenness of gastropod species. Results: The results of the study were 1549 gastropod individuals consisting of 46 species of 23 genera, 17 families, 2 subclasses and 4 orders. In general, the diversity and abundance of gastropods in the coastal tidal waters of the hutumuri village are relatively moderate and the species dominance is evenly distributed. Conclusion: Which consists of 46 species, 21 genera, 17 families and 4 orders. Ecological parameters of the gastropod community in the tidal waters of Hutumuri Village are density value (0.97 ind/m2), abundance value (12.867 in/m) important value (0.2590), diversity value (3.0468), dominance value (0,1445), the value of harmony (0.8010). Dominant index value (D) (0.1445) indicates no species dominance. The diversity pattern of gastropod species in the tidal waters of Hutumuri Village is having a uniform distribution pattern.

Cephalopod Nervous System Organization

Over 700 species of cephalopods live in the Earth’s waters, occupying almost every marine zone, from the benthic deep to the open ocean to tidal waters. The greatly varied forms and charismatic behaviors of these animals have long fascinated humans. Cephalopods are short-lived, highly mobile predators with sophisticated brains that are the largest among the invertebrates. While cephalopod brains share a similar anatomical organization, the nervous systems of coleoids (octopus, squid, cuttlefish) and nautiloids all display important lineage-specific neural adaptations. The octopus brain, for example, has for its arms a well-developed tactile learning and memory system that is vestigial in, or absent from, that of other cephalopods. The unique anatomy of the squid giant fiber system enables rapid escape in the event of capture. The brain of the nautilus comprises fewer lobes than its coleoid counterparts, but contains olfactory system structures and circuits not yet identified in other cephalopods.