BIOTURBATOR SEBAGAI PEREKAYASA EKOSISTEM DI PESISIR DAN LAUTAN

A bioturbator is a biota that can change sediment either directly or indirectly through stirring particles and/or moving water. Changes in the sediment affect the resources that will affect the existence of other organisms. This paper aims to explain bioturbators and their roles as ecosystem engineers in coastal and marine environments. Bioturbators are classified into two main groups, namely reworking organisms and burrow ventilation organisms. Bioturbator affects the biogeochemistry of sediment and the sediment physical structure, both of which cause the formation of new habitats that can be used by other organisms. This, in turn, will affect the structure of the benthic community. It is necessary to understand how bioturbators work and how big their effect is so that they can be used for habitat conservation and restoration in the future.

KONDISI TERUMBU KARANG DI PERAIRAN PULAU BATU BILIS, BUNGURAN UTARA, KABUPATEN NATUNA

The purpose of this study was to determine the type of coral life forms and cover percentages on Batu Bilis Island. This research was conducted by purposive sampling method, where the determination of the 3 (three) research locations in this study were based on coral location observations and map images. The study results show there are 9 (nine) types of coral life forms in Location 1 dominated by 13.47% of Coral Massive (CM), 7 (seven) types of coral life forms in Location 2 dominated by 17.13% of Acropora encrusting (ACE), and 13 types of coral life forms in Location 3 dominated by 28.90% of Coral Massive (CM). The coral cover percentages are 40.90% of the medium category in Location 1, 31.60% of the medium category in Location 2, and 53.90% of the good category in Location 3. The condition of environmental parameters in Batu Bilis Island was considered good for coral reefs.

PROFIL VERTIKAL DAN HORIZONTAL PARAMETER SALINITAS, DHL, DAN TDS BERDASARKAN VARIASI MUSIMAN DI ESTUARI SUNGAI CITARUM

Salinity, electrical conductivity (EC), and Total Dissolved Solid (TDS) are parameters that pose an important role in the distributions of environmental pollution substances in the estuary. The difference in salinity, EC, and TDS concentration vertically (based on the depth in the water column) and horizontally (based on the distance from the estuary mouth) will affect the process of pollutant’s transportation and transformation in the estuary. On the other hand, seasonal variations will also affect parameters. Therefore, the information related to the vertical and horizontal profiles of salinity and other parameters based on seasonal variations is necessary to study. The purpose of this study is to analyze the vertical profile and horizontal-vertical of salinity, EC, and TDS concentrations during the rainy season and dry season in the estuary of Citarum River. This research was conducted in April 2018 (rainy season) and August 2018 (dry season) when the low tide. The measurement of salinity, EC, and TDS was directly conducted in the field using a conductivity meter. The results show that the concentration level of salinity, EC, and TDS showed a vertical and horizontal difference in the estuary of the Citarum River. In addition, there are differences in the concentration of salinity, electrical conductivity, TDS in the rainy season and dry season in the estuary of the Citarum River. The level of TDS has a linear relationship between salinity and electrical conductivity, with a value of R2 >95%.

KONDISI TERUMBU KARANG DI KAWASAN WISATA PULAU BOKORI, KENDARI, PROVINSI SULAWESI TENGGARA

Bokori Island has been a tourist destination managed by the Tourism Office of the Southeast Sulawesi Provincial since 2014. The location is close to the city center, making this island visited by many tourists. In addition to the beauty of the island, it is also necessary to maintain the beauty of coral reefs as objects for underwater recreation. The study was conducted on 24–25 July 2019 at three sites of observation. The research purpose was to determine the condition of coral reefs of the island, which is used as a tourist destination. The result indicates that the condition of coral reefs is categorized good by having coral cover about 50.67%. The dominant coral at the island is the foliose coral (CF) group with percent cover about 22%, followed by coral branching (CB) 10%, Acropora tabulate (ACT) 8.57%, mushroom coral (CMR) 6%, encrusting coral (CE) 2% and massive coral (CM) 1.33%. The dominant type of substrate was dead coral with algae (DCA) about 37.3%, and the damage due to explosion could still be seen in the location. The current condition of coral needs to be maintained and improved supervision so that live coral can improve so that the function to support underwater tourism can be achieved.

SPESIASI DAN BIOGEOGRAFI IKAN DI KAWASAN SEGITIGA TERUMBU KARANG

The coral triangle is a region with the highest hotspot of fish biodiversity in the world. Factors to explain biodiversity in the coral triangle are varied widely. Factors as well as biogeography and speciation in evolutionary processes would explain the richness of fish species. The species formation theory in fish (speciation) is divided into allopatric, sympatric, and parapatric speciations. Biogeographically, the reason of what causes high biodiversity in the coral triangle area is divided into several models, namely: the center of origin, the center of overlap, the center of accumulation, the center of survival/refugia, and the mid domain effect/null model. This article will discuss the role and contribution of each mode/hypothesis in explaining coral triangle areas' biodiversity hotspots to provide information for biodiversity conservation of reef fishes in the future.

SENYAWA PENCEMAR ORGANIK YANG PERSISTEN (POPs): PENGERTIAN, JENIS, KARAKTERISTIK, DAN PERKEMBANGANNYA DI INDONESIA

Persistent organic pollutants (POPs) have been identified as representing a serious threat to the marine environment and received formal attention by nations worldwide including Indonesia as one of the signatories and ratified countries for the Stockholm Convention. Due to their emerging issues, the study of POPs at all aspects is needed. Therefore, this paper attempts to review characteristics and toxicological properties of POPs, the current status of POPs National Implementation Plans (NIPs) in Indonesia, and propose future directions of POPs study in Indonesia from basic research such as monitoring of POPs distribution in Indonesian seas to applied research for example study of POPs alternative compounds.

WILL FISH DISAPPEAR BY 2048?

In 2006, a tumult arose in the world of fisheries. A controversial paper titled “Impacts of biodiversity loss on ocean ecosystem services” by Worm et al. (2006) was published in Science. The paper was sensational since it alluded to a prediction that global populations of marine fish (finfish and invertebrates) will be 100% collapsed by 2048. The paper was written by a group of marine ecologists and economists in which Boris Worm from Dalhousie University Canada led the authorship. After the paper was published, the issue of fish disappearance in 2048 became hot topics in the world’s mass media. In fact, the Worm et al. paper triggered the debates among researchers. Over time the debates heated up. Surprisingly, a reconciliation took place in 2009, marked by a collaboration between Worm’s team and his critics, writing another paper in Science. The present essay reaffirms the invalidity of the global collapse prediction in 2048 as revealed by many researchers. It is also shown that the Worm et al. paper did not state that all fish will disappear and through the joint paper in 2009, Worm and colleagues have indirectly rectified the prediction already.

ASPEK BIO-EKOLOGI DAN PEMANFAATAN KERANG MARGA ANADARA (MOLLUSCA: BIVALVIA: ARCIDAE)

One of various shellfish in Indonesia waters that has high economic value is genus Anadara, especially as an edible marine species. Anadara is traditionally known in the trade as blood cockles. There are approximately 100 species of blood cockles in subfamily Anadarinae, the largest member of family Arcidae. Systematic of Anadarinae still does not provide certainty until now, including because there are many variations between species. Anadara, and Arcidae, in general, is one of the most abundant families of mollusc in tropical waters, and spread out in almost all of the coastal waters and found in the basis of subsystems. Its growth will be better on soft mud substrate than sandy mud substrate. Blood cockles are known as a filter feeder that feeds using gills on plankton, especially on phytoplankton. The demand for blood cockles is increasing, thus encouraging production efforts that do not only rely on harvesting from nature but through cultivation also that has been done in several places in Indonesia, such as in Sumatra and Java. This paper discussed taxonomy and classification, morphology and anatomy, habitat and distribution, reproduction and aquaculture, diet and feeding habit, and economic value of blood cockles.

ASPEK BIOLOGI UBUR-UBUR API, Physalia physalis (LINNAEUS, 1758)

Physalia physalis is one of the jellyfish believed to be responsible for a significant proportion of jellyfish attack cases in the world. As one of the most dangerous members of the Cnidarian in the sea, P. physalis has a sting that can paralyze their prey. To humans, the sting can cause cardiotoxic, neurotoxic, musculartoxic, and hemolytic effects. P. physalis has different biological characteristics than most organisms. For example, an individual of P. physalis actually is a colony consisting of four groups of individuals who have different structures and functions. The arrangement of the colony has a complex structure and shows a polymorphism. P. physalis is a pleustonic organism because they live on the surface of the water. P. physalis still leaves many mysteries to scientists. For example, the life cycle of a P. physalis is not yet fully known. Besides, the diversity of P. physalis also still leaves questions among scientists. Some believe that P. physalis is monotypic, while others suspect there is cryptic diversity. Therefore, the study of P. physalis is very interesting, especially under the issue of climate change. Many scientists believe that jellyfish get benefit from increasing sea temperatures, so the population is predicted to increase. The high population of P. physalis threatens the sustainability of fish stocks in the ocean, mainly due to P. physalis are productive predators of fish larvae. This paper aims to provide information on the biological aspects of P. physalis, which are still limited in Indonesia.

KAJIAN RISIKO KESEHATAN MANUSIA TERKAIT KONSUMSI MAKANAN LAUT (SEAFOOD) YANG TERCEMAR LOGAM

Consuming contaminated seafood can be potentially harmful for human health, especially for coastal communities. For this reason, a health risk assessment is very important to determine the safe limit for consuming seafood. Several stages in this assessment are; (i) direct comparison with the standard/maximum limit of heavy metal concentration determined by each country or international organization, (ii) determination of the maximum amount of seafood that can be consumed by adults per week, (iii) determination of the Estimated Daily Intake (EDI), and (iv) determination of the Target Hazard Quotient (THQ) of each metal and the Total Hazard Index (HI) for the combined metals.