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Types and characteristics of sound that produced by fish is a reoresentation to its behavior. Single click in certain characteristics is produced when terapon jorbua was rested, while multiple click that emitted when individual fish was interacted with others. Single frog which had a spectral intensity, frequency and duration that was greater than a single click was a representation to territorial behavior. Multiple frog that produced by individual fish was a representation to suffered attack from the other fish or as a defensive behavior

The clown anemonefish ‘Nemo’ Amphiprion ocellaris is the most popular fish species in the global marine ornamental trade and also its host sea anemones Heteractis magnifica, Stichodactyla gigantea, and Stichodactyla mertensii are traded. However, total catch and the potential impact of exploitation of these target organisms in Spermonde Archipelago, Indonesia, are not known. Therefore, the main objective of this study was to investigate the impact of the fishery on populations of A. ocellaris and its host anemones and how management could be improved. In order to obtain a comprehensive view on the marine ornamental fishery and trade of these species in Spermonde, this study also investigated the socioeconomics of the marine ornamental fishery and the catch records for A. ocellaris and it's host anemones. The study revealed that both, A. ocellaris and sea anemone densities were significantly lower at coral reefs with high exploitation (HE) than at reefs with low exploitation (LE). The total body length and group size of A. ocellaris was also significantly smaller at HE than at HL sites. The yearly amount traded by middlemen is estimated to 140 000 specimens of A. ocellaris and 31 000 anemones. The socioeconomic analysis showed that educational level of marine fishermen family members was low; most of them only finished elementary school. The household income analysis showed that marine ornamental fishery was not the major source of income, covering 13−43% of the expenses, with the exception of one studied island (84%). These findings revealed a considerable negative impact of marine ornamental fishery on the target populations and therefore, the implications for management strategies and conservation are discussed, including fish size restrictions for collectors, marine protected areas and regular monitoring of the amount of trade at middlemen.

The colonisation of hard substrata (HS) by epibenthic megafauna was studied by photographic surveys along the Ardencaple Canyon in the deep western Greenland Sea in 2000. Seven transects at 2,700–3,200 m water depth showed generally low densities of dropstones, sunken wood, and other substrata including anthropogenic material (range: 2–11 HS km−1). Overall, 30 different taxa and morphotypes were found on or associated with HS. While the sea anemone Bathyphellia margaritacea and the pantopod Ascorhynchus abyssi dominated the fauna on the substrate surfaces, a ball-shaped morphotype of uncertain taxonomic origin characterised assemblages marginally associated with HS. Community analysis revealed differences in faunal patterns near the continental rise and towards the deep sea, but diversity and evenness did not differ significantly between the various regions. However, we conclude that dropstones and other hard substrata at the seafloor serve as colonisation islands and thereby generally increase small-scale habitat diversity in polar deep-sea environments.

The Laptev Sea is a high-Arctic epicontinental sea north of Siberia (Russia) that is one of the least understood regions of the world’s ocean. It is characterized by a shallow and broad shelf plateau, high influx of river water, sediments and nutrients during summer, long-lasting sea-ice cover from October to May, and the formation of a narrow flaw-lead polynya off the fast-ice edge during winter. Here, we describe results of a German–Russian research project (1993-present), presenting the distribution patterns and dynamics of its marine flora and fauna, as well as pathways and processes of coupling between sea-ice, water-column and sea-floor biota. Three ecological zones are distinguished along a combined east–west and Lena-impact gradient, differing in the composition of pelagic and benthic communities. In general, high Chl a concentrations in the sediments indicate a tight coupling between sympagic and pelagic primary production and nutrient supply to the benthos throughout the entire Laptev Sea. However, there were pronounced regional differences between the ecological zones in magnitude of primary production and trophic dynamics. Primary production during the ice-free summer was highest in the estuarine zone most strongly influenced by the Lena River (210 mg C m −2 day −1 ). The western and northeastern Laptev Sea yielded 55 and 95 mg C m −2 day −1 , respectively. Moreover, the zones differed in the partitioning of carbon flux between zooplankton and benthic food webs. In the Lena zone zooplankton carbon demand was about 31 mg C m −2 day −1 whereas in the western zone it was 21 mg C m −2 day −1 and in the eastern zone 4 mg C m −2 day −1 . Total benthic carbon demand was 32 mg C m −2 day −1 for the Lena zone, 56 mg C m −2 day −1 in the western zone and 100 mg C m −2 day −1 in the northeastern zone. A carbon budget constructed for the Laptev Sea indicates that (1) a high proportion of primary production is channelled through the benthic trophic web, bypassing the pelagic trophic web, and (2) autochthonous primary production in the northeastern and western Laptev Sea might not be sufficient to fuel both pelagic and benthic secondary production and, hence, input of allochthonous organic carbon is required to balance the overall carbon demand.

Sediments sampled during summers 1999–2002 with the German ice-breaker RV “ Polarstern ” were analyzed to estimate benthic microbial activity and biomass of the smallest sediment-inhabiting organisms (size range: bacteria to meiofauna) along a channel system in the deep western Greenland Sea at about 75°N. Biochemical investigations were expanded by direct counts of bacteria and meiofaunal organisms, including foraminiferans. A total of 36 stations was sampled along the Ardencaple Canyon, extending over 200 km in north-easterly direction from the Greenland continental rise towards the central Greenland Basin. Stations were grouped in defined regions, generally with sampling sites inside the canyon plus accompanying sites on the northern and southern levees. An additional eight stations were sampled along a depth transect crossing the Greenland continental margin and traversing the channel in its midsection. All parameters investigated confirmed no differences between stations within the channel compared to stations on the levees, opposing the hypothesis that the Ardencaple Canyon displays a major pathway for suspension-driven shelf drainage flows. However, investigations showed some general trends in the data: parameters indicating food availability at the seafloor and total microbial biomass generally decreased with increasing water depth and distance from the Eastern Greenland continental margin. Along the depth transect crossing the Greenland margin both parameters exhibited increased values at deep stations on the continental rise. The position of these stations coincides with the position of the ice edge during sampling in summer 2000. Increased food availability and microbial biomass in the sediments most probably reflect raised levels of primary productivity and enhanced sedimentation in the marginal ice zone, thereby pointing to a close pelago-benthic coupling. Bacterial activities in the sediments showed a different picture with generally increasing values with increasing distance from the continental margin, which could probably be explained by a change in bacterial assemblages.

Species composition, abundance, biomass and spatial distribution pattern of brittle star assemblages of the Kolbeinsey Ridge, north of Iceland, were investigated by analysing seafloor photographs and epibenthic sled catches. Sampling was conducted in July 1992 along a 34 km long cross-ridge transect at 67°55′N in depths ranging from 830 to 1100 m. Five brittle star species were found. Only one species, Ophiocten gracilis, occurred with densities of more than 1 ind m−2. Both ridge slopes were characterized by soft bottom habitats, the ophiuroid distribution, however, revealed differences between slopes. Generally, brittle star densities were significantly higher on the eastern slope. There, the highest mean abundance per station of O. gracilis was 497 ind m−2. Except for one station, a distinct patchiness on the 100 m-scale was obvious in the spatial distribution of O. gracilis. Small settling stages with disc diameters 4 mm were most abundant. Our findings reflect a cross-ridge gradient in terms of hydrographic regime and, hence, probably pattern of food supply for the benthos.

Russian and German scientists have investigated the extreme environmental system in and around the Laptev Sea in the Siberian Arctic. For the first time a major comprehensive research program combining the efforts of several projects addressed both oceanic and terrestrial processes, and their consequences for marine and terrestrial biota, landscape evolution as well as land-ocean interactions. The primary scientific goal of the multidisciplinary program was to decipher past climate variations and their impact on contemporary environmental changes. Extensive studies of the atmosphere, sea ice, water column, and sea-floor on the Laptev Sea Shelf, as well as of the vegetation, soil development, carbon cycle, permafrost behaviour and lake hydrology, and sedimentation on Taymyr Peninsula and Severnaya Zemlya Archipelago were performed during the past years under a framework of joint research activities. They included land and marine expeditions during spring (melting), summer (ice free), and autumn (freezing) seasons. The close bilateral cooperation between many institutions in Russia and Germany succeeded in drawing a picture of important processes shaping the marine and terrestrial environment in northern Central Siberia in Late Quaternary time. The success of the projects, which ended in late 1997, resulted in the definition and establishment of a new major research effort which will concentrate on establishing a better understanding of the paleoclimatic and paleoenvironmental record of the area. This is important because it allows to be able to judge rates and extremes of potential future environmental changes.