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The coral reefs of Panjang Island, Jepara have been under pressure both by natural factors and by human (anthropogenic) activities, which have resulted in the degradation coral reef area. Research on changes in coral reefs is needed, but the constraints are time, cost, and labor. Remote sensing interpretation of satellite image data is an alternative to determine changes in the area of coral reefs. The use of multitemporal image data can be applied to analyze changes that occur, in this study using four Landsat image data with the acquisition of 2001,2005, 2010, and 2019. The purpose of this study was to determine changes in the area of coral reefs in Panjang Island for the period 2001-2019. The research material used is Landsat 7 and Landsat 8 imagery. The research method is a survey method with a multispectral classification of the maximum possibilities for extracting coral reef cover data from multitemporal images that have been corrected geometrically and radiometrically. A field survey (ground check) was conducted to determine the percentage mapping accuracy. Data on coral reef cover were overlaid to obtain the results of changes in the area of coral reefs for the period 2001-2019. The results showed that the coral reefs in Panjang Island had undergone extensive changes, namely: The area of living coral reefs decreased to 64,34%, with a change rate of 0.17 HaYear-1from 2001-2019. In 2001, the distribution of live coral reefs was seen on the northeast, east, south, and west sides of Panjang Island then reduced coral reefs area, finally left on the northeast and south sides of the island in 2019. Terumbu karang di Pulau Panjang ,Jepara telah mengalami tekanan baik oleh peristiwa alam maupun oleh aktivitas manusia (antropogenik), yang menyebabkan terjadinya degradasi luasan areal. Penelitian tentang perubahan luas terumbu karang sangat diperlukan, namun kendaalanya adalah waktu lama, biaya serta tenaga yang banyak. Penginderaan jauh interpretasi data citra satelit adalah salah satu alternatif guna mengetahui perubahan luas terumbu karang.Pemanfaatan data citra multitemporal dapat diterapkan untuk menganalisis perubahan yang terjadi, dalam penelitian ini menggunakan empat data citra landsat dengan akuisisi tahun 2001,2005, 2010 dan 2019. Tujuan penelitian ini adalah untuk mengetahui perubahan luas terumbu karang di perairan Pulau Panjang perode tahun 2001-2019. Materi Penelitian yang dipergunakan adalah citra Landsat 7 dan Landsat 8.Metode penelitian adalah metode survei dengan klasifikasi multispektral dari kemungkinan maksimum untuk ekstraksi data tutupan terumbu karang dari citra multitemporal yang telah dikoreksi secara geometris dan radiometrik.survei lapangan (ground check) dilakukan untuk mengetahui persentase akurasi pemetaan. Data luas tutupan terumbu karang dioverlay guna mendapatkan hasil perubahaan luas terumbu karang periode tahun 2001-2019. Hasil penelitian menunjukan bahwa Terumbu karang di Pulau Panjang telah mengalami perubahan luas yaitu 64,34% dengan laju penurunan sebesar 0,17 HaTh-1dari Tahun 2001-2019. Pada tahun 2001 sebaran terumbu karang hidup terlihat di sisi timur laut, timur, selatan dan dan barat dari Pulau Panjang, kemudian semakin mengecil areanya, hingga tersisa pada sebelah sisi timur laut dan selatan pulau saja pada tahun 2019.

Coral reefs currently are suffered from natural factors along with increasing anthropogenic activity. Panjang Island, a small reef island located in Jepara Regency, may also be experiencing such conditions. Therefore, this work was aimed to observe the condition of the coral cover of Panjang Island. Line intercept transect was applied to survey the coral cover and mortality index from fourteen stations. Insitu data consisted of the bottom substrate composition of the reefs and the physical parameters of the sea. The secondary data, i.e. coral reef area maps from 2001 to 2019 were taken from Landsat Image 7 and 8, data of wind were obtained from www.ogimet.com, while tidal data were collected from BMKG. The bathymetry was determined from the Geospatial Information Agency data, salinity global analysis forecast Phy 001.024 (CMEMS). Sea surface temperature (SST), and chlorophyll-a distribution were analyzed using ENVI software. The result showed that Panjang Island has a poor to the moderate condition of hard coral. Two out of six categories of abiotic and dead coral were found to be high. The mortality index of coral was in the high category (average 0.52). During research periods the sea waters were characterized by high sea surface temperature (29.34-30.94°C), chlorophyll-a was also tended to be high (0-2.65 mg.m-3), and an average of salinity was high 32 ‰. The weak currents came to all sides of the island, therefore the coral reef was not exposed to extreme currents. The waves came from the east, then the energy decreases after being blocked by coral reefs on the eastern side of the island, so that coral reefs in the northeast and south sides were safer to be exposed. The results suggest that hydrodynamic ecology directly or indirectly affected the percentage of coral cover and mortality index at the reefs of Panjang Island.

Empu Rancak coastal waters in Karanggondang village, Mlonggo District is one of the coral reef ecosystem location in coastal area of Jepara Regency. Following the growth of culinary and Marine tourism bring the need for monitoring the condition of coral reefs so that such activity does not provide ecological impacts against the condition of coral reefs. The method used to assess the condition of coral reefs is Line Intercept Transect which done by percentage calculation of living coral coverage. The research results shows that the condition of the coral reefs in a depth of 3 metres found coral cover percentage of 4.5%, while at a depth of 6 meters found coral cover percentage of 9.7%. From this result indicates the coral reefs in critical condition，however the high biodiversity and dominance index value is presumed that these coral reefs was in good condition. It`s showed by the high percentage of coral die either at a depth of 3 metres (95.54%) or at a depth of 6 meters(90.30%). The diversity of species of coral were found at a depth of 3 meters consist of 6 genus, they are: Goniastrea sp., Favia sp., Galaxea sp., Porites, Acropora sp. and Montipora sp., whereas at a depth of 6 meters were found more species of coral diversity for at least 11 genus, they are: Acropora sp., Favites sp., Echinopora sp., Goniastrea sp. Symphyllia agaricia sp, Favia sp., Goniopora sp., Porites sp., Montipora sp., Platygyra sp., and Montastrea sp. The condition of coral reefs cover which relatively critical are caused by decreasing the quality of waters ecology that caused by sedimentation rate and runoff processes of land activity, high waves in northwest monsoon and the growth of culinary tourism as well as marine tourism in Empu Rancak coastal waters gradually worsen the condition of coral reefs. Perairan pantai Empu Rancak desa Karanggondang, Kecamatan Mlonggo merupakan salah satu lokasi ekosistem terumbu karang yang berada pesisir di kabupaten Jepara. Dengan berkembangnya aktivitas wisata kuliner serta wisata bahari, maka perlu dilakukan pemantauan kondisi terumbu karang agar kegiatan tersebut tidak tidak memberikan dampak ekologi terhadap kondisi terumbu karang. Metode yang dipergunakan untuk menilai kondisi terumbu karang adalah dengan metode perhitungan persentase penutupan karang hidup menggunakan Line Intercept Transect. Hasil penelitian menunjukan bahwa Kondisi terumbu karang di kedalaman 3 meter ditemukan prosentasi tutupan karang sebesar 4,5 %, sedangkan pada kedalaman 6 meter ditemukan prosentase tutupan karang sebesar 9,7 %, maka kondisi terumbu karang di perairan pantai empu rancak Mlonggo, dalam kondisi buruk sekali, namun tingginya keanekaragaman dan nilai indeks dominasi, maka diduga bahwa terumbu karang dilokasi penelitian pernah dalam kondisi baik sebelumnya. Hal ini ditunjukan dengan tingginya prosentase karang mati baik pada kedalaman 3 meter (95,54 %) maupun pada kedalaman 6 meter (90,30 %). Keanekaragaman jenis karang yang ditemukan pada kedalaman 3 meter terdiri atas 6 genus yaitu : GoniastreaSp., Favia Sp., Galaxea Sp., Porites Sp., Acropora Sp.,dan Montipora Sp.,sedangkan pada kedalaman 6 meter ditemukan keanekaraamanan jenis karang yang lebih banyak (11 genus), yaitu : Acropora sp., Favites sp., Echinopora sp., Goniastrea sp., Symphyllia agaricia, Favia sp., Goniopora sp., Porites sp., Montipora sp., Platygyra sp. ,dan Montastrea sp. Kondisi tutupan terumbu karang yang relatif buruk sekali diduga diakibatkan oleh menurunnya kualitas ekologi perairan yang diakibatkan oleh oleh tekanan laju sedimentasi serta proses run off dari aktivitas didaratan, tingginya paparan gelombang pada saat musim barat serta berkembangnya wisata kuliner serta wisata bahari di perairan Pantai Empu rancak yang memperburuk kondisi terumbu karang.

Rembang Regency could be named as Salt City because they have very high production after Pati Regency. Along the road of Juwana (Pati) - Rembang, salt pond could be seen as square salt sea equipped with windmill to take the sea water from the channel into the pond and is processed into salt. Although salt localproduction is sufficient enough for raw material of industry, therefore best practical technology it is needed. The objective of present work are to improve directly the process of salt production and basic technique for diversiificatio of salt production, i.e. salt and bittern. The result of present works as follows. Getrape type salt pond is applied, where young water embankment is located upstream and the down to seed pond 1, 2, 3, then distributed to cristalization pan. Seawater is taken through primary dykes to pump at elevation of 1.5 m, so still full of water during high tide. On cristalization pan (size of 200 m2) sea water will be settled during 7–10 days until its cristalized. Salt cristal was located under bittern solution could be scrap and collected in collection point. The left-after bittern of 29–30° Be could be flowed back into seed pan uo be collected in bitter collection point.

Ikan Kerapu merupakan salah satu ikan unggulan yang ditargetkan sebagai komoditi eksport Indonesia. Usaha budidayanya saat ini sangat terganggu dengan tingginya mortalitas pada stadia larva. Usaha untuk mengatasi masalah tersebut adalah dengan menggunakan obat seperti antibiotik yang ternyata tidak membuahkan hasil maksimal tetapi justru menimbulkan resistensi beberapa jenis bakteria. Salah satu aspek yang belum pernah dilihat dalam rangka mengatasi masalah ini adalah dengan mengusahakan percepatan pertumbuhan pada stadia larva sehingga akan lebih mampu menghindari dari beberapa penyebab mortalitas. Salah satu sumber energi yang terdapat dalam perairan namun dalam jumlah yang tidak besar adalah dissolved organic matter (DOM). Penelitian ini ditekankan untuk melihat kemampuan larva ikan Kerapu dalam memanfaatkan DOM (digunakan asam amino terlarut ;ATT) yang terdapat di air laut. Sebanyak 16 (enam belas) jenis asam amino yang terdiri dari tiga klas yakni neutral, basic, dan acidic digunakan dalam penelitian ini. Sedangkan larva ikan Kerapu yang digunakan berumur 2 hari. Hasil penelitian menunjukkan bahwa larva ikan Kerapu menyerap seluruh jenis asam amino baik neutral, basic, dan acidic. Namun jenis asam amino yang diserap adalah glutamat, histidin, lisin, serin, metionin, tritopan dan iso leusin. Sedangkan yang paling banyak diserap oleh larva ikan ini adalah lisin. Hal yang menarik dalam penelitian ini adalah terdapat beberapa jenis asam amino yang diduga justru dikeluarkan oleh larva ikan tersebut yakni glysin, alanin, tyrosin, valin, phenil alanin dan leusin. Penyerapan beberapa jenis asam amino ini diduga dimanfaatkan oleh larva ikan Kerapu dalam proses pertumbuhannya. Kata kunci : asam amino terlarut, larva, Kerapu Macan, Epinephelus fuscoguttatus Kerapu (grouper fish) is known as an important and highly economic value fish and a good candidate for major export commodity for Indonesia. However, there is an important problem faced by its cultivation i.e. high mortality rate at larva stage. Many different efforts have been done to overcome this problem mainly by using drugs and antibiotics, which have caused another problem i.e. bacteria resitance. One aspect that has not been widely investigated is by increasing its growth rate so that the larvae will have the ability to avoid mortality, such as by utilising dissolved organic matter (DOM) which naturally occur in the environment. This research investigates the question whether Kerapu fish larvae have the ability to absorb DOM (in this case disolved free amino acids; DAA) as well as the preference and the rate of absorbsion. There were 16 species of DAA used in this experiment which consist of three classes i.e. neutral, basic, and acidic. Two days old larvae were used in the experimant. The results showed that Kerapu larvae absorbed all classes of amino acids, although not all amino acids given being absorbed but only glutamine, histidine, lysin, serine, triptophan, metionine and iso leusine. While the most absorbed amino acids was lysine. One interesting results showed that the larvae secrete several amino acids i.e. glysine, alanine, tyrosine, valine, phenil alanine and leusine. The absorbsion and secretion of amino acids were possibly related to its metabolic processes within the larvae in relation to growth processes. Keywords: dissolved free amino acids, DAA, larvae, Kerapu, Epinephelus fuscoguttatus