Abstrak AbstractHeavy metalsiron(Fe) is anessentialheavy metalswhose presencein a certain amountis neededby living organisms, but inexcessiveamountscan causetoxic effects.The aims of the research is to analyze the heavy metals coccentration and the pollution level of Fe in water, sediment, and green mussels (Perna viridis) at Tanjung Emas Semarang. This research was conducted from 7 November and 7 December 2013 using the Atomic Absorption Spectrophotometry (AAS) and research methodswithdescriptive. The results showed that the waters of the Tanjung Emas is still in the stage of heavy metals contaminated iron (Fe). Sediment and green mussels (Perna viridis)already indicated heavy metal contaminatediron. However, variations inenvironmental factorssuch astemperature, salinity, pH, flow velocity an dsediment types also providean important contributionto heavy metal contentof iron(Fe).

Segara Anakan merupakan laguna yang terletak di selatan Pulau Jawa tepatnya di perbatasan antara Jawa Barat dengan Jawa Tengah. Kawasan Segara Anakan merupakan tempat bertemunya sungai besar, sehingga mengalami perubahan penurunan kualitas perairan berupa penyempitan dan pedangkalan akibat proses sedimentasi yang tinggi. Hal ini dikhawatirkan dapat mengakibatkan menurunnya kualitas perairan yang dapat mengganggu pertumbuhan fitoplankton di perairan. Fitoplankton merupakan parameter biologi yang dapat dijadikan bioindikator untuk mengevaluasi kualitas dan tingkat kesuburan suatu perairan. Kondisi tentang lingkungan perairan diperkirakan berubah sepanjang waktu, maka perlu penelitian fitoplankton, untuk mengetahui tingkat kesuburan perairannya. Tujuan dari penelitian ini adalah untuk mengetahui komposisi dan kelimpahan fitoplankton di Laguna Segara Anakan, Cilacap. Penelitian ini menggunakan metode deskriptif eksploratif dengan pengambilan data menggunakan purposive sampling method. Hasil menunjukkan ditemukan 34 genera yaitu Kelas Bacillariophyceae (21 genera), Kelas Cyanophyceae (4 genera), Dinophyceae (6 genera), Chlorophyceae (2 genera), dan Euglenophyceae (1 genus). Kelimpahan fitoplankton berkisar antara 12.945,8-38.194,1 sel/liter. Indeks Keanekaragaman termasuk kategori sedang dengan nilai berkisar 1,60 - 2,32. Indeks keseragaman termasuk kategori sedang hingga tinggi, dengan nilai berkisar 0,59 - 0,81. Indeks dominansi berkisar antara 0,18 - 0,44. menunjukkan bahwa tidak ada genus yang mendominasi. Segara Anakan is a lagoon located in the south of Java Island precisely on the border between West Java and Central Java. Segara Anakan area is the place where the big river meets. Water quality decrease because of narrowing the lagoon due to the high sedimentation process. This may affect the presence of phytoplankton in the water. The quality and the fertility level of aquatic can be evaluated through the phytoplankton existence since phytoplankton is used as a biological indicator for the marine environment. The condition of the aquatic environment is expected to change over time, so it is necessary to study phytoplankton. The purpose of this research is to know about the composition and abundance of phytoplankton in Segara Anakan Lagoon, Cilacap. This research used the descriptive explorative method by data sampling using purposive sampling method. The study showed 34 genera of Bacillariophyceae (21 genera), Cyanophyceae (4 genera), Dinophyceae (6 genera), Chlorophyceae (2 genera), and Euglenophyceae (1 genus). The abundance of phytoplankton ranging from 12.945,8-38.194,1 cells/liter. The Diversity Index is a medium category with values ranging from 1.60 to 2.32. The evenness index is moderate to high, with values ranging from 0.59 to 0.81. The Dominant index ranges from 0.18 to 0.44. The value indicates the category of no dominating genus.

Metal pollution becomes a problem that is very threatening to marine ecosystems. This is because heavy metals difficult be destroyed and will accumulate in the water. This study aims to determine the content of chromium (Cr) in Water, Sediment and green mussels (Perna viridis) and know the maximum limit weekly consumption and the feasibility of the Green Shellfish consumption. Samples were taken in January 2016 for Trimulyo waters. Research using descriptive methods. Sampling was done by purposive sampling method. Heavy metal content analysis using AAS. MTI Value (Maximum Tolerable Intact) is calculated by the formula MWI / Ct to determine the value of the maximum limit of consumption of green mussels per week. The results showed the content of chromium (Cr) in water in Trimulyo waters of <0.003 mg / L, the content of chromium (Cr) in the sediments ranged from 20.49 to 45.78 mg / kg. The content of heavy metals Chromium (Cr) in Green Mussels ranged from <0.01 to 0.20 mg / kg. Maximum weight intake of green mussels are safe for consumption of water Trimulyo per week for women with an average body weight of 45 kg for metal Chromium (Cr) is 13.27 ± 4.78 kg per week. As for males with an average weight of 60 kg of 17.68 ± 6.37 kg per week. According to the Minister of Environment Decree 51 of 2004 Trimulyo water conditions have not categorized the heavy metal contaminated Chromium (Cr). The content of heavy metals chromium (Cr) in the sediments are well below the standards set by NOAA (National Oceanic and Atmospheric Administration) of 1999. As for the heavy metal content of chromium (Cr) in the Green Mussel showed that the clams in these waters has not been contaminated by heavy metals Chromium (Cr) according to the quality standard by the Food adulteration (metallic Contamination) Hong Kong in 1997. Keywords : Chromium (Cr), Water, Sediment, Perna viridis, Trimulyo Pencemaran logam menjadi suatu masalah yang sangat mengancam bagi ekosistem laut. Hal ini diduga karena logam berat susah hancur dan akan terakumulasi di perairan. Penelitian ini bertujuan untuk mengetahui kandungan Kromium (Cr) dalam Air, Sedimen dan Kerang Hijau (Perna viridis) serta mengetahui batas maksimum konsumsi mingguan dan tingkat kelayakan konsumsi Kerang Hijau. Sampel diambil pada Bulan Januari 2016 di perairan Trimulyo. Penelitian menggunakan metode deskriptif. Pengambilan sampel dilakukan secara Purposive Sampling Method. Analisis kandungan logam berat menggunakan AAS. Nilai MTI (Maximum Tolerable Intact) dihitung dengan rumus MWI/Ct untuk mengetahui nilai batas maksimum konsumsi Kerang Hijau per minggu. Hasil penelitian menunjukkan kandungan Kromium (Cr) dalam air di perairan Trimulyo sebesar <0,003 mg/L, kandungan Kromium (Cr) pada sedimen berkisar antara 20,49 – 45,78 mg/kg. Kandungan logam berat Kromium (Cr) pada Kerang Hijau berkisar antara <0,01 – 0,20 mg/kg. Berat Maksimal asupan Kerang Hijau yang aman dikonsumsi dari perairan Trimulyo per minggu untuk wanita dengan berat badan rata-rata 45 kg untuk logam Kromium (Cr) adalah 13,27±4,78 kg per minggu. Sedangkan untuk laki-laki dengan berat badan rata-rata 60 kg sebesar 17,68±6,37 kg per minggu. Menurut Keputusan Menteri Lingkungan Hidup No.51 Tahun 2004 kondisi perairan Trimulyo dikategorikan belum tercemar logam berat Kromium (Cr). Kandungan logam berat Kromium (Cr) pada sedimen berada di bawah baku mutu yang ditetapkan oleh NOAA (National Oceanic and Atmospheric Administration) Tahun 1999. Sedangkan untuk kandungan logam berat Kromium (Cr) pada Kerang Hijau menunjukkan bahwa kerang di perairan tersebut belum tercemar oleh logam berat Kromium (Cr) sesuai dengan baku mutu oleh Food Adulteration (Metalic Contamination) Hong Kong Tahun 1997. Kata kunci : Kromium (Cr), Air, Sedimen, Perna viridis, Trimulyo

Seagrass has an important role for marine environment as a primary producer also as constituent and ecosystems habitats that support the life on coral reefs and mangrove or coastal. This research is aimed to identify the seagrass species and to undertand thier density and coverage. This research was conducted on June-August 2016 at Ujung Piring waters, Jepara. The research used descriptive method. Sampling was conducted on five stations, where each station performed five repetitions. The seagrasses found in research sites were identified and counted for their density and coverage. Seawater quality parameter were measured in situ. Sediment were take for grain size analysis to undertand their characteristic. The research showed that during the study period there were four species of seagrasses i.e. Enhalus acoroides, Thalasia hemprichii, Cymodocea Rotundata, and Syringodium isoetifolium. Overall this study indicate the highest and lowest density found in Thalassia hemprichii  (33,87 and 4,35 stands/m²).  E. acoroides had highest coverage (48,67%) while the lowest (8,71%) was T. hemprichii. There were variation in density and covarage of seagrass species due to water quality and showed uneven distribution of the seagrass species in that area.  Keywords : Enhalus acoroides,  Thalasia hemprichii, Cymodocea rotundata, dan Syringodium isoetifolium, variasi komposisi, Lamun memiliki peranan penting bagi kehidupan di laut sebagai produsen primer serta penyusun habitat dan ekosistem yang menyangga kehidupan di terumbu karang dan mangrove atau daratan pantai. Penelitian ini bertujuan untuk mengidentifikasi jenis-jenis lamun dan variasi kerapatan dan penutupannya di perairan Ujung Piring, Kabupaten Jepara. Penelitian ini dilakukan pada bulan Juni–Agustus 2016 di perairan Ujung Piring Jepara. Metode yang digunakan dalam penelitian ini adalah metode deskriptif. Pengambilan sampel dilakukan pada lima stasiun, dimana setiap  stasiun dilakukan lima kali pengulangan. Lamun diidentifikasi di lokasi penelitian, dihitung kerapatannya dan penutupannya. Pengukuran kualitas perairan dilakukan in situ, sedangkan sedimen diambil untuk dianalisa butiran untuk mengetahui karakteristik sedimennya. Hasil penelitian ini menunjukkan selama periode penelitian terdapat 4 jenis lamun, yaitu Enhalus acoroides,  Thalasia hemprichii, Cymodocea rotundata, dan Syringodium isoetifolium. Kerapatan tertinggi dan terendah ditemukan pada Thalassia hemprichii yaitu 33,87 dan 4,35 tegakan/m².  Persentase penutupan tertinggi ditemukan pada E. acoroides dengan nilai 48,67% dan yang terendah 8,71% oleh T. hemprichii. Terdapat variasi komposisi dan kerapatan berdasarkan waktu pengamatan, hal ini menunjukkan adanya pengaruh lingkungan dan tidak terjadi persebaran lamun yang merata pada daerah tersebut. Kata Kunci :  Enhalus acoroides,  Thalasia hemprichii, Cymodocea rotundata, dan Syringodium isoetifolium, variasi komposisi.

Indonesia has been known to have a high diversity of sea cucumber, but data and information are mostly on high-economic-value species. Sea cucumber living in soft-bottom substrates is less studied and unexploited. Wulan estuary located in the Demak Regency of Central Java was experiencing high sedimentation, which was consisted of fine material, and acted as a habitat for many macrozoobenthos, amongst others sea cucumbers. The objective of the present research was to identify the species of sea cucumber in the soft bottom of the Wulan estuary. The collection of sea cucumber specimens was done using a dredge. A total of 132 specimens were collected, examined, and identified through their morphological characters. The holothuroids found in the soft-bottom of the Wulan estuary represent five genera (Acaudina, Colochirus, Holothuria, Paracaudina, Phyllophorus,) in four families (Caudinidae, Cucumariidae, Holothuriidae, and Phyllophoridae) belonging to three orders (Molpadida, Dendrochirotida, and Aspidochirotida). The species were Acaudina sp., A. molpadioides, Colochirus quadrangularis, Holothuria cf. impatiens, Paracaudina sp., Paracaudina chilensis, P. australis, and Phyllophorus spiculata. A. molpadioides is presented as the most frequently found species. Although sea cucumber found in the Wulan estuary has not been exploited, it still needs to be managed to sustain its population.