Utilization of natural materials sourced from the sea is very promising. These natural ingredients can function as antibacterials that are useful in a number of fields. This study aims to explore the extract of sea cucumber Phylloporus sp. as an antibacterial agent for Vibrio alginoliticus and Vibrio harveyi. The diffusion method was carried out with three treatments of sea cucumber extract starting at doses of 500, 1000 and 1500 mg/L with three replications for each treatment. Positive control was antibiotic Chloramphenicol 100 mg/ml (0.01%) and negative control with dimethylsulfoxide (DMSO) 10%. The test results showed that sea cucumber extract was able to inhibit both types of bacteria, visible from the inhibition zone formed. In Vibrio alginoliticus bacteria, the average inhibition zone formed was 0.433 ± 0.0288. In bacteria, Vibrio harveyii was inhibited by sea cucumber extract with an average inhibition zone of 0.516 ± 0.104. Inhibition zone of sea cucumber extract Phylloporus sp. lower than Chloramphenicol which is a commercial antibacterial.

Plankton has been considered an important live diet for various marine species including spiny lobster larvae. Thus, studying the diversity and abundance of plankton taxa in the natural settlement habitat of spiny lobster larvae might reveal alternative live diets for the larvae. The study was conducted in Tawang Bay, an important habitat for spiny lobsters in East Java, Indonesia. Plankton ysed using eDNA metabarcoding and highthroughput sequencing. Of the collected samples, 26 phyla, 40 classes, 54 orders, 75 families, 85 genera, and 97 species were identified. Further analysis indicated that the diversity index was considered moderate as the value was 2.16, while the uniformity and dominance indices were 0.22 and 0.24, respectively, which indicates that there is no dominant plankton species in Tawang Bay., Oithona simplex , Oithona sp., Pseudodiaptomus euryhalinus , Calocalanus pavo, and Calocalanus minutus are potential live diets for larvae of aquaculture species including lobster and therefore should be further studied.

Catching is one way to get Short necked-clam so the demand also increases. The gonadosomatic index (GSI) of short necked-clam is a study to maintain the availability of short-necked-clam in waters. Another thing that can be obtained from this study is to know its relation to the ecological status (quality of water, substrate, and the abundance of plankton) in the waters of Sedati, Indonesia. The strategy utilized in deciding the choose point is based on the purposive inspecting strategy did some time recently with attempting to take samples at a few point within the range of brief necked-clam angling ground. To decide the relationship of the environmental status with GSI used regression, and correlation is further illustrated by descriptive statistical analysis. Based on the regression analysis, water quality has a relationship to the gonadosomatic index of short-necked clam either directly with a value of -0.1278 or through nutrients that are worth 0.6813. While the nutrient has a relationship to the gonadosomatic index of -0.99583 and substrate of 0.2525. The results showed ecological status that correlates most strongly is plankton abundance of 94.39% (very strong) but negative correlated, with dissolved oxygen of 83.92% (very strong) and with the temperature of 62,98% (strong).