The Assessment of Biological and Pollution Index of Estuaries Around Port of Tanjung Emas Semarang

Estuary is a place of accumulation of the population’s actitivites produced by domestic, industry or agriculture. This research was conducted to three of estuary of the rivers around the waters of Port of Tanjung Emas Semarang (PTES). They were estuaries of Baru river, Banjir Kanal Timur (BKT) and Siangker in west monsoon from October to December 2015. The purpose of this research was to analyze pollution index, the abundance of microorganisms either phytoplankton or zooplankton, the content of heavy metal in sediment and sea water, biological index that included diversity (H), uniformity (e), dominance (D), Saprobik Index (SI), and the Total of Saprobik Index (TSI) in the waters either HTL (High Tide Level) or LTL (Low Tide Level). The concentration of heavy metal in both sea water and sediments were analyzed by using Atomic Absorption Spectrophotometer (AAS). The result obtained from 12 parameters which were tested showed that the three waters can be categorized at heavily polluted condition at each value from 12.52 to 24.98. The concentration of heavy metal at sea water during HTW and LTW ranging from Cd is around 0.033 and 0. 048 mg/kg, Cu 0.047 and 0.07 mg/kg, Pb 0.48 and 0.71 mg/kg, and Zn 0.043 and 0.057 mg/kg. The saprobity value index based on the existence of phytoplankton or zooplankton was ranging of Oligosaprobik at low pollution or has not been polluted yet.


Introduction
Coastal areas and river estuaries are susceptible area of pollution from upstream. Pollution in the river estuary area is caused by frequent activity by both domestic and shipping industries in the region [1].
Kali Baru river estuaries located in the Port of Tanjung Emas Semarang (PTES), beside the domestic pollution from upstream, port activities such as shipyards, power plants, ship activities in the region have affected the estuary. Banjir Kanal Timur estuary is an area that is also close to PTES waters and a fishing area where the water quality is influenced by fishing activities and discharges from domestic households in the area. Siangker Estuary is a river estuary located in the west side of PTES close to the airport that will affected to the river estuary. The purpose of this research is to analyze the value of Kali Baru river estuary pollution, BKT (Banjir Kanal Timur) and Siangker in terms of diversity (H '), uniformity (e), dominance (D), Saprobik Index (SI) and Total Saprobik Index (TSI) in both phytoplankton and zooplankton at HTL (High Tide Level) and LTL (Low Tide Level). Analysing the heavy metal concentrations Cu, Cd, Pb and Zn in both seawater and sediment. The last calculation of the pollution index on the territorial waters

Material and Methods
The research was conducted at the coastal estuaries around the Port of Tanjung Emas Port Semarang (PTES) in 3 areas with 3 research station, 1 st station (estuary Kali Baru ), 2 nd station (estuary Banjir Kanal Timur) and 3 rd station (estuary Siangker). Research conducted from October to December 2015.
(3) Where e = (Index of evenness or stability), Hmax = log 2 S = 3.3219 log10S, S = the number of taxa in a community. To know the dominance of certain types in the waters can be used Simpson dominance index, where, SI = saprobic coefficient (-3 to In which: IPj = index of pollution for j Ci = parameter of consentration of water quality i Lij = parameter of quality which submitted in quality j water M = maximum R = average There are 4 IP (Index Pollution) class with score 0≤IP≤1.0 fullfilled quality standard, 1.0≤IP≤5.0 slightly polluted, 5.0≤IP≤10 moderately polluted and IP≥10 status of the water heavily polluted. The observed parameter consist of 12 parameters, there are turbidity, pH, sulfida, phenol, DO, BOD5, PO4 (phosphat), nitrat , metal Cd, Cu, Pb and Zn.

Results and Discussion
The mean average concentration of heavy metal under sea water at three estuaries when LTL is bigger than when its HTL, but for Cu concentration when LTL smaller than when its HTL.  Saprobity Index (SI) value is when it's HTL or LTL close to similar of the three estuary. Meanwhile TSI value at three estuary get several difference in which when it's HTL the value will be bigger compared when it's LTL (Table 1.). At three estuaries, the value of saprobity counted as oligosaprobic waters, in which slightly polluted or haven't polluted [3]. Pleurosygma sp Pleurosygma sp.
Cyanophycea 31 Anabaenopsis sp. The zooplankton biodiversity index in October at HTL ranged from 1.92 and 2.26 while at LTL ranged from 1.13 and 2.22 indicating that Kali Baru estuary and BKT were slightly polluted while the Siangker estuary was slightly polluted. The uniformity index (e) shows that the species condition is abundant except for the LTL condition at the Kali Baru estuary. The dominant index on the three river estuaries indicates the absence of a species dominance in these waters (Figure 4). The Acartian genus dominates on three estuaries compared to Microstella sp. and Trocophora sp.
Where the abundance of zooplankton is more at the Kali Baru estuary than in other waters. Crustacean class is more dominant than other classes, where in that class found 21 species of genus while in class Ciliata only found 13 genus while class Cirripida least found (Table 3). Undinopsis sp.
Branchiiolaria sp. Diversity value in Kali Baru estuary at HTL or LTL show that biota community is not stable or heavily polluted while at another water area is`slightly polluted to moderate. These things seen at the value of homogeneity at Kali Baru estuary which is equally relative of homogeneity while for another estuary teritory low species homogeneity is occured. Ecological pressure is occured at Kali Baru estuary rather than other water in BKT and Siangker because domination value that close to one. This thing is because of the pressure form domestic waste and shipyard around the estuary ( Figure 5).

Figure 5. Indeks value H', e dan D phytoplankton in November 2015 in three estuaries around PTES
Saprobity water condition is in oligosaprobik condition or slightly polluted or haven't polluted at all except at HTL at BKT is in condition β-mesosaprobik which is polluted condition at low to medium level (Table 4). In November there is amount of class that fewer than in the earlier month at west season, there are only three classes which are Baciilariophyceae, Dinophyceae, Chrysophyceae dan Cyanophycea. Skeletonema genus is still dominating followed by Synedra sp. and the last is Thallassiothrix sp. and Pyrocystis sp. (Table 5).        The pollution contamination index on the three river estuaries shows highly polluted conditions where the BKT and Siangker estuaries are higher at HTLwhile at LTL at the estuary of the BKT river having the highest value (Table 11).