Analysis of marine debris and mangrove forest density in Purnama village, Dumai city, Riau province

Mangrove ecosystems naturally function as trap of waste produced from anthropogenic activities including marine debris. This study aims to analyze marine debris and density of mangrove forests in the Purnama Village. The survey research method was carried out in two stations: Station I (Estuary of Sungai Masjid) and Station II (coastal waters of the Unri Marine Station), which was held from April to July 2021. Marine debris was collected in five plots in a quadrant transect measuring 100 x 50 meter. Identification results of mangrove species in Station I found 3 species of mangrove (Xylocarpus granatum, Rhizophora apiculata and Bruguiera gymnorriza), while at Station II found 3 species of mangroves (Rhizophora apiculata, Xylocarpus granatum and Avecennia alba). This research results obtained the release of marine debris at Station II is more than that of Station I. While in Station II there are 172 items (marine debris density of 0.172 item/m2), weight of marine debris 12.665 grams/m2 and mangrove density 2222 individu/ha (category very close). At Station I there are 35 items (the density of marine debris is 0.035 item/m2), the total weight of marine debris is 3.194 grams/m2 and the density of mangroves is 1678 individu/ha (category very close).

Köyceğiz-Dalyan Lagün Ekosistemi Kefal Populasyonlarının Büyüme Performans İndeksleri

As it is common in tropical and temperate zones, mullet species constitute the most important fish species caught along the coast and estuaries of Turkey. In terms of ecology, tourism and and fish productivity (52 kg/ha), Koycegiz-Dalyan Lagoon Ecosystem (KDLES) is the most important lagoon, with a 5500 ha surface area, is the Mediterranean Coast of Turkey. In the dalyan (barrier fish trap) systems; approximately 225 tons (80-405 tons) of mullets are caught to obtain 5 tons of dried fish eggs per year. Seventy percent of fish production in the lagoon is composed of mullets. The mullet samples were collected monthly between October 1992 and September 1994 from eight stations (one of them is a marine station) by trammel nets. The ages were determined using by scales anda ge composition varied form 0 to 6 ages. Species composition of 1159 sampled individuals were proportionally determined as Mugil cephalus 45%, Liza aurata 35%, Liza saliens 14%, Liza ramada 12%, Chelon labrasus 6%. The growth performance indices calculated from von Bertalanffy growth parameters using by all individuals for the M. cephalus, L. aurata, L. saliens, L. ramada and C. labrasus were determined as 2.957, 2.866, 2.692 and 2.719, respectively. The highest growth performance index was calculated for M. cephalus. The growth performance indeces of mullet species in Köyceğiz-Dalyan Lagoon Ecosystem were found around the world averages.

Improving Keeping for Octopuses by Testing Different Escape-Proof Designs on Tanks for “Big Blue Octopus” (Octopus cyanea)

Octopus cyanea has a wide range of natural distribution and is interesting for scientific research. However, unlike Octopus vulgaris, the species is poorly studied, and few data exist on best practices for keeping them. One of the most common reasons for losing octopuses in human care is their ability to escape from holding tanks. Adult Octopus cyanea (n = 33) were locally collected in Okinawa throughout the year. All animals were housed at the laboratory facilities at the Marine Station of the Okinawa institute of Science and Technology. Animals were kept in a flow-through saltwater system in three different types of holding tanks ranging from 550 L to 600 L tanks or in 2000 L tanks, all with an environment enriched with clay pots or natural rocks as dens. They were fed a daily diet of dead fish or live or dead crustaceans ad libitum. To characterize the effectiveness of different keeping conditions, we compared escape attempts and non-natural deaths during the animals’ time under human care. We found that two types of tanks, the 600 L transparent acrylic glass tanks with weighted lids and the 2000 L tanks with synthetic grass lined walls, had significantly fewer escapes than the 550 L tanks.

COMMUNITY STRUCTURE OF PHYTOPLANKTON AND CHLOROPHYLL-α CONCENTRATION IN THE SUNGAI MESJID VILLAGE DUMAI RIAU PROVINCE

The research was conducted in December 2019 at Sungai Mesjid Village Dumai Riau Province. This study aims were to know the condition of water quality, know the structure of the phytoplankton community, know the concentration of chlorophyll-a and know the effect between chlorophyll-a concentration and phytoplankton abundance in waters. The method used in this study was a survey method. The research location is divided into 3 station points namely Bangsal Aceh, Marine Station and Jalan Dermaga. The results showed that the quality of waters classified as oligotrophic waters. Phytoplankton found in this study consisted of 4 classes and 12 species of phytoplankton and the abundance of phytoplankton has a range between 195.57 - 244.33 ind./l. Diversity index (H') ranges from 1.2951 - 2.1705, dominance index (D) ranges from 0.24 to 0.46 and uniformity index (E) ranges from 0.7825 to 0.9551. The chlorophyll-a concentration in waters of Sungai Mesjid Village in Dumai ranged from 0.0025 to 0.0210 mg/L. Phytoplankton abundance and chlorophyll-a concentration has a moderate effect, wherewith increasing chlorophyll-a concentration, phytoplankton abundance will also increase

MOLECULAR IDENTIFICATION OF PROTEOLITIC BACTERIA FROM MANGROVE SEDIMENT IN DUMAI MARINE STATION

Proteolytic bacteria have an important role in the degradation of complex compounds to a simple compounds by the enzyme proteases. Sediment in the mangrove ecosystem of Dumai Marine Station may contain the bacteria. This research aims to identify the proteolytic bacteria of mangrove sediments molecularly and to examine the antagonism of pathogenic bacteria. The method used in this research was a survey. The results obtained 10 bacterial isolates (AZ1, AZ2, AZ3, AZ4, AZ6, AZ10, AZ11, AZ15, AZ18, and AZ20). Identification using 16S rRNA analysis revealed that 3 isolates showed different results, namely AZ2 had a similarity to Bacillus proteolyticus with strain MCCC 1A00365, AZ6 had a similarity to the bacteria Bacillus monlinensis with strain BL4-6 and AZ20 had similarity to the bacterium Bacillus toyonensis with strain MCCC 1A00365 BCT-7112. Three of the 10 isolates that had the highest inhibition against pathogens. Isolates AZ2 shovued inhibition zone against Pseudomonas aeruginosa with a diameter of 9.65 mm, AZ6 shovued inhibition zone against Escherichia coli bacteria with a diameter of 5.18 mm, and AZ20 shovued inhibition zone against Vibrio alginolyticus bacteria with a diameter of 4, 01 mm.

John Robertson Henderson (1863–1925): Scotland, India and anomuran taxonomy

John Robertson Henderson was born in Scotland and educated at the University of Edinburgh, where he qualified as a doctor. His interest in marine natural history was fostered at the Scottish Marine Station for Scientific Research at Granton (near Edinburgh) where his focus on anomuran crustaceans emerged, to the extent that he was eventually invited to compile the anomuran volume of the Challenger expedition reports. He left Scotland for India in autumn 1885 to take up the Chair of Zoology at Madras Christian College, shortly after its establishment. He continued working on crustacean taxonomy, producing substantial contributions to the field; returning to Scotland in retirement in 1919. The apparent absence of communication with Alfred William Alcock, a surgeon-naturalist with overlapping interests in India, is highlighted but not resolved.