TOXICITY OF SEA GRASS EXTRACT (Eucheuma cottonii AND Gracillaria sp) TO LARVA Artemia salina

Seaweed is a source of foreign exchange, namely as a main export product and a source of income for coastal communities. Previous research on species Eucheuma cottonii and Gracillaria sp contain bioactive compounds that can be used in medicine, for example as anti-cancer. The purpose of this study was to determine the LC50 value and safe concentration of Artemia salina larvae. The research was conducted at the Chemical Oceanography Laboratory of the Department of Marine Sciences, Faculty of Fisheries and Marine, Riau University in July 2020. The method used in this research is the experimental method. The results of the research on the toxicity of the n-hexane extract of seaweed E. cottonii and Gracillaria sp had bioactivity compounds against A. salina shrimp larvae, indicated by a small LC50 value (<1000 ppm), namely 62.62 ppm for E. cottonii and 83.55. ppm for Gracillaria sp, so it is included in the toxic category. According to research by experts, if the extract or compound tested is less than 1000 ppm, it is considered that there is biological activity. For a safe concentration for the survival of A. salina, 6.262 ppm for E. cottonii and 8.355 ppm for Gracillaria sp.

Standards and practices for reporting plankton and other particle observations from images

This technical manual guides the user through the process of creating a data table for the submission of taxonomic and morphological information for plankton and other particles from images to a repository. Guidance is provided to produce documentation that should accompany the submission of plankton and other particle data to a repository, describes data collection and processing techniques, and outlines the creation of a data file. Field names include scientificName that represents the lowest level taxonomic classification (e.g., genus if not certain of species, family if not certain of genus) and scientificNameID, the unique identifier from a reference database such as the World Register of Marine Species or AlgaeBase. The data table described here includes the field names associatedMedia, scientificName/ scientificNameID for both automated and manual identification, biovolume, area_cross_section, length_representation and width_representation. Additional steps that instruct the user on how to format their data for a submission to the Ocean Biodiversity Information System (OBIS) are also included. Examples of documentation and data files are provided for the user to follow. The documentation requirements and data table format are approved by both NASA’s SeaWiFS Bio-optical Archive and Storage System (SeaBASS) and the National Science Foundation’s Biological and Chemical Oceanography Data Management Office (BCO-DMO).

Benthic Nepheloid Layers along the U.S. GEOTRACES GA03 Transect in the Western North Atlantic: Characterization and Influence on 230Th and 231Pa Cycling

&lt;p&gt;Benthic nepheloid layers (BNLs) are particle-rich layers that can extend over a thousand meter or more above the seafloor and are thought to be produced by the resuspension of fine sediments from strong bottom currents. They can often be subdivided into two sublayers: (i) a lower sublayer in contact with the seabed, where particle concentrations are the largest and which roughly coincides with the bottom mixed layer (BML); and (ii) an upper sublayer in which particle concentration decreases up to a clear water minimum (CWM). Although BNLs have long been recognised in vertical traces of optical instruments lowered to abyssal depths, their influence on ocean biogeochemical cycles &amp;#8211; on the cycling of particle-reactive metals in particular &amp;#8211; remains poorly understood.&lt;/p&gt;&lt;p&gt;In this study, we characterize the BNLs observed between the New England continental shelf and Bermuda and explore their influence on the cycling of &lt;sup&gt;230&lt;/sup&gt;Th and &lt;sup&gt;231&lt;/sup&gt;Pa &amp;#8211; two naturally-occurring particle-reactive radionuclides that have found different applications in chemical oceanography and paleoceanography. To this end, we use concomitant measurements of temperature, salinity, particle concentration derived from light beam transmissometry, and &lt;sup&gt;230&lt;/sup&gt;Th and &lt;sup&gt;231&lt;/sup&gt;Pa activities in the dissolved and particulate fractions, which have been collected along the western segment of the U.S. GEOTRACES GA03 transect. We estimate that the thickness of strong BNLs (particle concentration &gt; 20 &amp;#181;g l&lt;sup&gt;-1&lt;/sup&gt;) varied from about 72 to 1358 m between different deep stations. At all stations, particle concentrations below the CWM were the highest in the BML, whose thickness ranged from 95 to 320 m, and decreased generally with height above the seafloor. A simplified model of particle-radionuclide cycling in the deep water column, which includes a particle source representing sediment resuspension at topographic reliefs and their subsequent lateral transport, is fitted to observed profiles of particle concentration and radionuclide activities at two selected stations. The model can reproduce simultaneously the increase of particle concentration with depth, the low dissolved activities in the BNLs, and the extremely large particulate activities near the bottom. Analysis of &lt;sup&gt;230&lt;/sup&gt;Th and &lt;sup&gt;231&lt;/sup&gt;Pa budgets reveals that the behaviour of both radionuclides in the BNL is fundamentally different from that envisioned in reversible exchange theory. Sensitivity tests with the model suggest that lateral particle sources near continental slopes and similar reliefs can produce significant biases in the paleoceanographic applications of both radionuclides, including the &lt;sup&gt;230&lt;/sup&gt;Th-normalization method and the interpretation of sediment &lt;sup&gt;231&lt;/sup&gt;Pa/&lt;sup&gt;230&lt;/sup&gt;Th records.&lt;/p&gt;

Marine Ecotourism Potential in Unggeh Island Tapanuli Tengah Regency, North Sumatra, Indonesia

Highlight Calculated and assested the percentage of live coral coverIdentified reef fishes and calculated fish abundanceMeasured physical and chemical oceanography parameter Analyzed carrying capacity and suitability of Unggeh Island for tourism utilization especially marine diving and snorkeling.AbstractUnggeh Island located in the administration of the Village Sitardas Badiri District, Central Tapanuli Regency into a marine tourism area. The development of marine ecotourism Unggeh Island is an alternative to the economic improvement of so- ciety. This study aims to assess the potential of coral reef ecosystem in the form of percentage of life form coral, coral species and species and abundance of reef fish found in Unggeh Island waters of Central Tapanuli Regency and to analyze the suitability of coral reef ecosystem in Unggeh Island for tourism utilization es- pecially marine diving and snorkeling. Coral reef community data collection was done by using SCUBA divers equipment, in identifying The coral community used underwater photo transect (UPT) method, while coral fish diversity was observed by underwater visual census (UVC) method. Physical and chemical oceanography parameter data such as temperature, salinity, pH, current, transparency and DO are performed at each observation station. The survey results of coral reef observation at four stations showed different results. Percentage of live coral cover of station 1 to 4 were 25.40 %, 12.33%, 28.53%, and 25.53 respectively. Therefore, reef fishes found 36 species that consist of ten families and 423 individual fishes. The results showed that Unggeh Island was suitable (S2) for diving and snorkeling activities, with the carrying capacity was 3.054 persons/day.

Pathways of ocean heat towards Pine Island and Thwaites grounding lines

&lt;p&gt;In the Amundsen Sea, modified Circumpolar Deep Water (mCDW) intrudes into ice shelf cavities, causing high ice shelf melting near the ice sheet grounding lines, accelerating ice flow, and controlling the pace of future Antarctic contributions to global sea level. The pathways of mCDW towards grounding lines are crucial as they directly control the heat reaching the ice. A realistic representation of mCDW circulation, however, remains challenging due to the sparsity of in-situ observations and the difficulty of ocean models to reproduce the available observations. In this study, we use an unprecedentedly high-resolution (200 m horizontal and 10 m vertical grid spacing) ocean model that resolves shelf-sea and sub-ice-shelf environments inqualitative agreement with existing observations during austral summer conditions. We demonstrate that the waters reaching the Pine Island and Thwaites grounding lines follow specific, topographically-constrained routes, all passing through a relatively small area located around 104&amp;#186;W and 74.3&amp;#186;S. The temporal and spatial variabilities of ice shelf melt rates are dominantly controlled by the sub-ice shelf ocean current. Our findings highlight the importance of accurate and high-resolution ocean bathymetry and subglacial topography for determining mCDW pathways and ice shelf melt rates.&amp;#160;&lt;/p&gt;&lt;p&gt;&lt;br&gt;We also briefly introduce our various existing model outputs focusing on the Amundsen Sea and demonstrate how to access these model outputs, plot some basic variables, and create animations. We hope that these model output can be utilized for many different aspects of oceanographic researches including observational planning, data analysis for physical, biological and chemical oceanography, and boundary conditions for ocean and ice sheet models.&amp;#160;&lt;/p&gt;&lt;p&gt;&amp;#160;&lt;/p&gt;

The Ability of biofilter sponge demospongiae class with various forms of growth towards the turbidity and total suspended solid

The sponge is an invertebrate animal from phylum porifera that lives permanently and filters out what is in the water column. The sponge has various forms of growth, including massive, branching, and submissive. Each form of growth is indicated to have different filtering abilities, so this research needs to be done. This study aims to determine whether the ability to filter (biofilter) Turbidity and Total Suspended Solid sponge depends on the form of growth (Massive, Submassive, and Branching). This research was conducted from September to October 2016. Taking sponges in the waters of Barranglompo Island, testing was carried out at the Hatchery Marine Station at Hasanuddin University, Barranglompo Island and measurements of water quality parameters were carried out at the Chemical Oceanography Laboratory, Department of Marine Sciences, Faculty of Marine and Fisheries, Hasanuddin University. The acclimatization process needs to be done to adapt the sponge before being given treatment. Each aquarium is filled with seawater that has been mixed with sediments as much as 0.17 mg/l. Then each form of sponge growth is put into an aquarium with the same body volume of 500 cm3 and sees the ability to filter it for 10 hours and 24 hours. After that, water samples were taken at each aquarium to measure turbidity parameters, Total Suspended Solid, and Total Organic Materials. The results showed that at 10 hours and 24 hours the sponge with submassive growth forms filtered more particles in the water column than massive and branching growth forms, while sponge with branching growth forms run into stress and death after filtering for 24 hours.Keywords: growth pattern, biofilter, sediment, sponge.