Dynamics of fish diversity across an environmental gradient in the Seribu Islands reefs off Jakarta

Madduppa HH, Subhan B, Suparyani E, Siregar AM, Arafat D, Tarigan SA, Alimuddin, Khairudi D, Rahmawati F, Bramandito A. 2013. Dynamics of fish diversity across an environmental gradient in the Seribu Islands reefs off Jakarta. Biodiversitas 14: 17-24. The reefs of Seribu Islands have been affected by multitude of anthropogenic pressures. However, the biodiversity of reef fishes across the archipelago linked to environmental condition is poorly known. This study aimed to investigate the biodiversity and the trophic level of fish communities across the archipelago. The study on reef fish communities was conducted on 33 reef sites associated with islands or shoal randomly chosen from each zone along environmental gradients from the inshore water nearest of Jakarta Bay to the offshore water of the outer islands. The study sites represented each sub-districts within the archipelago, namely Pari, Tidung, Panggang, Kelapa, and Harapan. A total of 46,263 individual fishes were counted, belonging to 216 species and 29 families. The multivariate analysis of fish abundance using the Bray Curtis similarity index and non-metric multidimensional scaling (MDS) clearly showed the clustering of sub-districts, near and far from Jakarta Bay. The results showed that the sub-districts can be clustered into three groups. Group one consists of one sub-district (Pari) located in the southern part of the Seribu Islands near Jakarta Bay. Group two consists of three sub-districts (Tidung, Panggang, Kelapa) located in mid of the archipelago. The third group consists of one sub-district (Harapan) located in the northern part of the Seribu Islands. Based on species richness and fish diversity indices, the sub-districts can be clustered into two groups (1 = Pari and Tidung, 2 = Panggang Kelapa, Harapan). However, levels of similarities among sub-districts varied. The fish community in sub-district of Pari was dominated by carnivorous, omnivorous and herbivorous fishes, while those in the rest of sub-districts were dominated by omnivorous and carnivorous fishes. The present study results showed that the biodiversity of reef fishes across the Seribu Islands seemed to be linked to the environmental conditions

PENGARUH CAHAYA TERHADAP TINGKAT KELANGSUNGAN HIDUP DAN PERTUMBUHAN KARANG LUNAK LOBOPHYTUM STRICTUM (OCTOCORALIA: ALCYONACEA) HASIL TRANSPLANTASI PADA SISTEM RESIRKULASI

The current research was conducted to investigate the effect of light on growth of soft coral Lobophytum strictum. This species was transplanted and reared in two different ponds, uncovered pond (with light penetration) and covered pond (no light penetration. A total of 16 coral fragments was placed on each pond. Both, the survival rate and the growth rate were significantly different on the effect of light (P<0.05). The soft coral on the uncovered pond was survive up to 12 weeks (100%), followed with increased length (from 5,95 to 10,04 cm) and width (from 5,27 to 6,84 cm) of the transplanted coral fragments. Conversely, the soft coral in the covered ponds showed survival rate of 62,5% (up to 8th week), with decreased length (from 8,25 to 5,25 cm) and width (from 9,14 to 4,86 cm) of each fragments during the period of study.Penelitian yang dilakukan untuk mengetahui pengaruh cahaya terhadap pertumbuhan karang lunak Lobophytum strictum hasil transplantasi dilakukan dengan pemeliharaan karang lunak pada dua buah kolam, yaitu kolam terbuka (cahaya) dan kolam tertutup (tanpa cahaya). Pada masing-masing kolam ditempatkan 16 fragmen karang lunak yang sudah ditransplantasikan. Kelangsungan hidup dan pertumbuhan karang lunak berbeda signifikan antar perlakuan cahaya (P<0,05). Karang lunak yang dipelihara di kolam terbuka mampu bertahan hidup 100% (12 minggu), dengan disertai peningkatan panjang (5,95-10,04 cm)  dan lebar (5,27-6,84 cm) fragmen karang. Hal yang berbeda ditunjukkan karang lunak yang dipelihara di kolam tertutup, hanya mampu bertahan hidup hingga minggu ke-8 (62,5%). Hal ini disertai dengan penurunan panjang (8,25-5,25 cm) dan lebar (9,14-4,86 cm) fragmen setiap minggunya

Will the Increasing of Anthropogenic Pressures Reduce the Biopotential Value of Sponges?

Production of bioactive compounds from marine benthic organisms is suggested to relate ecologically with environment. However, anthropogenic pressures cause a considerable damage to coral reefs environment. This research aimed to define the pattern sponges biopotential values at the increasing of anthropogenic pressures to coral reef environment. Three representative sponges were selected (Theonella sp., Hyrtios sp., and Niphates sp.) and study had been conducted in Hoga Island, Indonesia, to define the relationship between seawater variables (DO, pH, phosphate, and ammonia ions), sponges spatial competition, and their bioactivity level (Brine Shrimp Lethality Test). The study showed anthropogenic pressures affect the reef environment, as abiotic cover was increased and eutrophication was detected at the site closer to the run-off domesticated area. Statistical multivariate analyses revealed sponges spatial competition was significantly different (P<0.05) between groups of high, moderate, and low bioactivity level. Abiotic cover was detected as the major factor (36.19%) contributed to the differences and also the most discriminant factor distinguishing sponges spatial competition in the groups of bioactivity level (93.91%). These results showed the increasing anthropogenic pressures may result in a higher abiotic area and may directly be a consequence to the lower production of bioactive compounds in sponges

Concentration of fish serum albumin (FSA) in the aqueous extract of Indonesian Perciformes fishes’ muscle tissue

<div><p>Fish serum albumin (FSA) is an aquatic resource that has potential to be developed as nutraceutical. Therefore, research was undertaken to assess albumin levels in the aqueous extract of muscle tissue of several Perciformes commonly available at a local fish market in Indonesia. Three random replicates for each of 17 Perciformes species were collected and assessed for their FSA content by application of a reversed-phase (C4) HPLC analytical method. Results of these analyses showed that the albumin concentration of the extracts was in the range 3.49–12.61 g/L, and that they varied significantly (<i>P</i> < 0.05) between species and families. This finding may mean that FSA levels are species and family dependent, something that could be investigated in future studies. As fishes from the family Scrombidae showed the highest concentration (12.61 g/L) of FSA, they would likely have the most value as a source for production of albumin-based nutritional and/or clinical products.</p></div