Meiofauna in a Potential Deep-Sea Mining Area—Influence of Temporal and Spatial Variability on Small-Scale Abundance Models

In large areas of the Clarion Clipperton Fracture Zone (northeast Pacific), exploration of deep-sea polymetallic nodules as a potential source of high-technology metals is ongoing. Deep-sea mining may have a severe impact on the benthic communities. Here, we investigated meiofauna communities in the abyss at the scale of a prospective mining operation area. Random forest regressions were computed to spatially predict continuous layers of environmental variables as well as the distribution of meiofauna abundance across the area. Significant models could be computed for 26 sediment and polymetallic nodule parameters. Meiofauna abundance, taxon richness and diversity were also modelled, as well as abundance of the taxon Nematoda. Spatial correlation is high if the predictions of meiofauna are either based on bathymetry and backscatter or include sediment and nodule variables; Pearson’s correlation coefficient varies between 0.42 and 0.91. Comparison of differences in meiofauna abundance between different years shows that spatial patterns do change, with an elevated abundance of meiofauna in the eastern part of the study area in 2013. On the spatial scale of a potential mining operation, distribution models prove to be a useful tool to gain insight into both temporal variability and the influence of potential environmental drivers on meiofauna distribution.

Abundance of Meiofauna and Physical-Chemical Parameters as Water Quality Indicator

The zone of Losari Coast is an icon of Makassar city, however increase activity of surrounding communities causes a decrease in the water quality. Meiofauna is an effective benthic organism used as an indicator of water quality. This study assessed the meiofauna abundance and physical-chemical parameters as water quality indicator in the Losari Coast, Makassar. The sampling method in this study was purposive sampling. The resuts showed that total meiofauna abundance identified was 66791 indv.m-2, composed of 12 phylum and 91 species or genera. Stations at the estuary of the Jeneberang and Tallo River are two sites with high level of abundance, this condition allows presence of organic contaminants triggers the high growth of meiofauna in these locations. Dissolved Oxygen is below its supposed level in waters. Acidity, phosphate and nitrate content at some of research stations exceed the threshold of their allowed presence in waters set by Indonesia government. Ostracoda, oligochaeta, polychaeta, tunicata and ciliophora are phylums with a high level of abundance, because the phylum has high adaptability to pollutant. Good water quality is indicated by a variety of biota living in the waters, the range of diversity and uniformity indices shows that meiofauna species are categorized highly diverse and evenly distributed. The dominance index shows that there is no species was dominant, except stations around Losari reclamation project. Temperature, current velocity, depth, brightness, salinity, pH, DO, nitrate-seawater, and phosphate-seawater correlate with meiofauna abundance. The results as a consideration for the management or monitoring of coastal environments.

WATER QUALITY STUDY BASED ON MEIOFAUNA ABUNDANCE AND POLLUTION INDEX IN THE COASTAL ZONE OF LOSARI BEACH, MAKASSAR

The coastal zone of Losari Beach is located in a strategic position and rich in potential coastal resources, but the high density of human activities has decreased the quality of the surrounding waters.This study aimed to examine water quality based on meiofauna abundance and pollution index in the coastal zone of Losari Beach, Makassar. It employed a quantitative descriptive approach with purposive sampling method. The identified total meiofauna abundance was117,176 individuals/m2consisting of 138 species from 13 phyla. Ostracoda, olygochaeta, sarcomastigophora, ciliophora, and polychaetawere phyla with the highest abundance because of their high adaptability to polluted aquatic conditions. Meanwhile, tardigrada and aelosomatidaewere found in very low abundance because both phyla only thrive in pollution-free environments and have a pattern of high migration flow from one habitat to another. As for aelosomatidae, the habitat of its speciesis limitedto brackish or saline waters. A good-quality aquatic environment is a habitat for all benthic organisms and enables their even distribution. It explains the discovery of true and temporary meiofauna with uniform or even compositions in the bottom of the waters. The waters in the coastal zone of Losari Beach are heavily polluted. The stationslocated around the traditional Paotere harbor, hotels, restaurants, Losari Beach Platforms, the waste disposal outlets of Stella Maris Hospital, Fort Rotterdam canals, and Jeneberang River mouthhad very high pollution index. Some of these stations had low meiofauna abundance levels, and the poor water quality in their surroundings was caused by anthropogenic activity. Even though the area around TanjungMerdeka Beach had relatively low pollution index, it was categorized as severely contaminated because the index score was >10.

Analisis Ekologis Meiofauna Sebagai Bioindikator Di Pesisir Pantai Losari, Makassar

The research aims to analyze ecological value of meiofauna as bioindicator in Losari Coast, Makassar. The total meiofauna abundance was 66791 indv/m2, consisted of 12 phylum and 91 species/genus. The stations located at the mouth of the Jeneberang River, Tanjung Merdeka, and the Tallo River are research sites with high levels of abundance, due to the presence of organic contaminants produced by surrounding anthropogenic activity that trigger high growth of meiofauna. ostracoda, oligochaeta, tunicata and ciliophora are the phylum with high levels of abundance compared to other meiofauna, as it that phylum has a high adaptability to the entry of pollutant material in the water. Diversity index and evenness indicates the meioufauna in the Losari Coast categorized by a high level of diversity and evenly distributed. While dominance index indicated that no dominant meifauna species, except at research stations located around the Losari Beach reclamation project. Keywords: Abundance, meiofauna, anthropogenic, Coastal Losari Beach, Makassar