Kedalaman Klorofil Maksimum Selama Musim Peralihan II dan Implikasinya untuk Perikanan Tuna di Laut Banda

The Deep chlorophyll maximum (DCM) in the Banda Sea during the second transitional season (October 2015) was relatively shallow (25 - 64 m) above the mixed layer and far from the base of the euphotic layer or compensation depth. Its presence was identical to the depth of nitraclin injected into the mixed layer as a result of upwelling generated by internal waves. The contribution of these waves to the increase in Banda Sea fertility calculated using ocean color data is 56.87%. This phenomenon is due to the shallow optical depth of the satellite (20-25 m) while high chlorophyll-a concentrations are below. DCM was also associated with the swimming layer of Madidihang (Thunnus albacares) (34 - 68 m) caught with longline gear during the same period

Pemetaan Morfologi Ambang Galala Poka (APG)

The Galala Poka (APG) sill is in the form of an underwater hill located in the narrow waters of the TAD and TAL transition zones. The morphology of APG is important to map because it influences the dynamics of water masses during the tidal period in the TAL and TAD Transitional areas, and can even explain the phenomena of cohesive sediment transport and deposition as well as tidal mixing phenomena that often occur around APG. This research aims to map the topographical profile of the APG seabed and calculate its spatial dimensions.The GIS-based mapping method is used to create an APG seabed topographic model using data compiled from sounding results, digital Navionic Sonar Chart data and digital shipping channel bathymetry data. The trapezoidal rule model is used to calculate the APG dimensions. APG seabed 2D and 3D spatial models mapped with ArcGIS 10.8 and Surfer 23.The results of the analysis found the APG boundaries at coordinates 128.19316 – 128.19829E and 3.66027 – 3.56659S and UTM coordinates 410399.1390 ​​– 410969.1292 mT and 9594764.3000 – 9595384.3000 mU. The topography of APG is generally convex with a flat peak at the center. There are variations in the slope of the seabed, especially on the outer side of the APG. APG volume with a reference depth of 0m (LWS) 1,304,828.05 m3, surface area 151,954.65 m2. At a reference depth of 8m, the APG volume is 20,071.95 m3, the area is 94,887.23 m2. At a reference depth of 10m, the APG volume is 351,296.95 m3, and the surface area is 73,012.06 m2

COASTAL UPWELLING UNDER THE INFLUENCE OF WESTERLY WIND BURST IN THE NORTH OF PAPUA CONTINENT, WESTERN PACIFIC

Coastal upwelling play an important role in biological productivity and the carbon cycle in the ocean. This research aimed to examine the phenomenon of coastal upwelling that occur in the coastal waters north of Papua continent under the influence of Westerly Wind Burst(WWB) prior to the development of El Nino in the Pacific. Data consisted of sea surface temperature, vertical oceanic temperature, ocean color satellite image, wind stress and vector wind speed image, sea surface high, and Nino 3.4 index. Coastal upwelling events in the northern coastal waters of Papua continent occurred in response to westerly winds and westerly wind burst (WWBs) during December to March characterizing by low sea surface temperature (SST) (25 - 28C), negative sea surface high deviation and phytoplankton blooming, except during pre-development of the El Nino 2006/2007 where weak upwelling followed by positive sea surface high deviation. Strong coastal upwelling occurred during two WWBs in December and March1996/1997 with maximum wind speed in March produced a strong El Nino 1997/1998. Upwelling generally occurred along coastal waters of Jayapura to Papua New Guinea with more intensive in coastal waters north of Papua New Guinea indicated by Ekman transport and Ekman layer depth maximum