Norma Afiati - Academia.edu (original) (raw)

Papers by Norma Afiati

Acta Aquatica, Apr 7, 2023

Osmoregulation is a physiological adjustment mechanism of fish to environmental conditions. Fish ... more Osmoregulation is a physiological adjustment mechanism of fish to environmental conditions. Fish growth performance will reduce when a large amount of energy is redirected for the osmoregulation process. The purpose of this study was to determine the osmotic work level (OWL), osmoregulation pattern, condition factor (K), gonad maturity stages (GMS) and analyze the relationship between OWL with condition factor and GMS of tilapia collected from three floating net cages in Cengklik reservoir, Boyolali. Samples were collected during March-April 2022 followed by some allometric measurements and regression analyses. The OWL of tilapia at the three cages ranged from 4-10 mOsm/L H2O; they performed a hyperosmotic osmoregulation pattern. The condition factor of male and female tilapia were1,86±0,21 and 1,89±0,18. GMS of both male and female tilapia was dominated by GMS IV with a fecundity of 9408±2092.54 eggs. OWL did not reveal a significant effect on condition factors or on the GMS of tilapia (p>0.05). Pearson correlation test showed a weak relationship between OWL with condition factors (r = 0,204) and tilapia GMS (r =-0,001). Therefore, tilapia uses less energy in osmotic work to produce good growth performance because it has more energy for growth, as indicated by the high condition factor (K>1) and domination by fish with GMS IV level of mature gonads.

Pulau Karimunjawa dan Pulau Kemujan merupakan Kawasan dalam Taman Nasional Karimunjawa (TNKJ) yan... more Pulau Karimunjawa dan Pulau Kemujan merupakan Kawasan dalam Taman Nasional Karimunjawa (TNKJ) yang memiliki ekosistem terumbu karang berupa reef flat dan reef slope. Kedua pulau ini seringkali dikunjungi wisatawan, sehingga aktivitas tersebut diperkirakan mempengaruhi kualitas perairannya. Penurunan kualitas perairan menyebabkan perubahan struktur komunitas biota, dalam studi ini ikan karang dan terumbu karang. Berdasarkan alur pemikiran tersebut, maka dilakukan penelitian dengan tujuan mengetahui keanekaragaman, kelimpahan serta hubungan ikan karang dan terumbu karang pada daerah reef flat dan reed slope. Pengambilan data dilaksanakan pada bulan Agustus tahun 2020 di perairan Pulau Karimunjawa (Tanjung Gelam dan Legon Lele) dan Pulau Kemujan (Pulau Sintok dan Batulawang), Kabupaten Jepara, Jawa Tengah. Pengamatan terumbu karang dilakukan dengan menggunakan metode UPT (Underwater Photo Transect) kemudian data diolah menggunakan aplikasi CPCe (Coral Point Count with Excel). Pengamatan ikan karang dilakukan menggunakan metode UVC (Underwater Visual Census). Hasil menunjukkan bahwa kelimpahan karang hidup di lokasi penelitian termasuk kategori sedang hingga sangat baik (24%-77,89%). Indeks keanekaragaman tertinggi terumbu karang ditemukan di Pulau Sintok (2,322) dan terendah di Legon Lele (1,815). Indeks keanekaagaman dan kelimpahan ikan karang tertinggi ditemukan di Pulau Sintok (H' = 3,254 dan 500 ind/150m 2) dengan dominasi famili Pomacentridae, sedangkan terendah ditemukan di Tanjung Gelam (H' = 2,372 dan 123 ind/150m 2). Kelimpahan ikan karang dipengaruhi oleh kondisi terumbu karang sebesar 95,83% (R 2 = 0,9583). Semakin baik kondisi terumbu karang, maka semakin tinggi kelimpahan ikannya. Hasil uji anova menunjukkan nilai F hitung = 54,498 dengan tingkat signifikasi sebesar 0,0034 (α<0,05). Hal ini menunjukkan bahwa data signifikan dan hipotesis diterima.

ILMU KELAUTAN: Indonesian Journal of Marine Sciences, 2004

Aktifitas manusia yang terus meningkat di wilayah pesisir, telah menyebabkan terjadinya peningkat... more Aktifitas manusia yang terus meningkat di wilayah pesisir, telah menyebabkan terjadinya peningkatan tekanan lingkungan yang berasal dari berbagai macam sumber pencemaran, antara lain limbah industri, pertanian, transportasi, dan limbah domestik. Salah satu sumber pencemar yang cukup dominan di lingkungan perairan pantai adalah pencemaran akibat limbah domestik. Selama ini yang dipakai untuk mengetahui pencemaran lingkungan oleh limbah domestik adalah menggunakan indikator biologi yaitu bakteri coliform. Namun penggunaan bakteri coliform sebagai indikator pencemaran limbah domestik mempunyai permasalahan antara lain tidak terdeteksinya bakteri coliform tersebut pada perairan pantai, sementara diduga kuat bahwa perairan tersebut tercemar oleh limbah domestik termasuk feces. Oleh karena itu indikator alternatif sangat diperlukan. Salah satu indikator alternatif pencemaran limbah domestik adalah koprostanol, yang mempunyai sifat cukup konservatif, dapat dikuntitatifkan dan dapat dihubungkan dengan sumber pencemar yang spesifik. Namun perlu diingat bahwa di alam, koprostanol mengalami proses degradasi oleh bakteri, sehingga perlu dilakukan penelitian mengenai isolasi dan identifikasi bakteri pendegradasi koprostanol pada lingkungan sungai, muara, dan perairan pantai Banjir Kanal Timur Semarang pada monsun timur. Penelitian dilakukan pada bulan Juli s/d Agustus 2003 pada lingkungan sungai, muara, dan perairan pantai Banjir Kanal Timur Semarang. Isolasi bakteri dari sampel air dan sedimen dilakukan di Laboratorium Mikrobiogenetika, FMIPA Jurusan Biologi UNDIP Semarang dan identifikasi bakteri pendegradasi koprostanol terseleksi dilakukan di Laboratorium Hama dan Penyakit Balai Besar Pengembangan Budidaya Air Payau (BBPBAP) Jepara. Hasil penelitian diperoleh bahwa bakteri pendegradasi koprostanol yang berasal dari lokasi Banjir Kanal Timur Semarang pada berbagai variasi lingkungan dan habitat diperoleh 69 isolat (83,13%) dari 83 isolat yang diuji. Sedangkan hasil identifikasi terhadap 6 isolat terbaik diperoleh 3 (tiga) genus bakteri mampu mendegradasi koprostanol, yaitu Achromobacter, Bacillus, dan Branhamella. Dari 3 genus bakteri pendegradasi koprostanol yang didapatkan, ada 2 (dua) genus yang selama ini belum dilaporkan, yaitu genus Achromobacter, dan Branhamella.

IOP conference series, Jun 1, 2022

Mangrove areas in the northern coast of Jepara Regency have been threatened by coastal erosion an... more Mangrove areas in the northern coast of Jepara Regency have been threatened by coastal erosion and changes in land use since 1980. These areas represent coastal ecosystems with significant ecological, biological, and economic importance. The status of these ecosystems needs to be monitored; the latest condition is important to local authorities. Rate of change in mangrove conditions can be used to forecast the future condition of these coastal areas. This study aims to determine the temporal changes in the area and density of mangrove vegetation in Jepara Regency in 2017 and 2020. This study applied analysis of Sentinel 2-A multitemporal satellite imagery and classification using random forest on the Google Earth Engine platform. It was found that the mangrove area shrank from 103 ha in 2017 to 95 ha in 2020. The vegetations showed that changes in mangrove area in Jepara Regency have decreased in the rare and dense mangrove density types. The density of rare and dense mangroves experienced a decrease in area of 6 and 5 hectares, respectively. No mangroves with dense cover were found in 2020. Meanwhile, mangroves with moderate cover experienced an increase in area of 3 hectares in 2020 compared to last year 2017.

Groundwater discharge is known to transport nutrients into estuaries at several locations around ... more Groundwater discharge is known to transport nutrients into estuaries at several locations around the world. However, few studies report groundwater-associated nutrient fluxes from tropical developing regions such as Southeast Asia, even though this area shows the strongest human modifications in the coastal zone worldwide. We investigated groundwater nutrient flux into two streams and estuaries (Awur and Sekumbu Bay) in the urban area of Jepara, Indonesia, and its relation with the land usage surrounding the estuaries.We found that average concentrations of NO3, NH4, and PO4 in Jepara's aquifer reached 145 µM, 68 µM, and 14 µM, respectively, and our results indicate that these were mainly originated from untreated sewage, agriculture, and manure input. Approximately 2200 ton N per year and 380 ton P per year were removed in the soil and aquifer before the nutrients were discharged into the river. The total groundwater discharge into the river and estuary was estimated to 461 × 103 m**3/day, or up to 42% of the river discharge. Discharge of groundwater-associated NO3 (72 × 103 mol/day), NH4 (34 × 103 mol/day), PO4 (5 × 103 mol/day), and additional surface runoff may contribute to eutrophication and a decrease of nearshore surface water quality. Nutrient concentrations in groundwater, river, and coastal seawater in the Jepara region are similar to those found in major urban areas in Southeast Asia, e.g. Manila and Bangkok, even though Jepara has smaller size and population. Thus, our results indicate that medium populated cities with highly modified regional land use can contribute a significant amount of nutrient discharge in the coastal area and should be included in global assessments of nutrient budget calculation.

IOP Conference Series: Earth and Environmental Science, 2021

Mining in the world consists of modern and traditional mining. Various studies have discussed how... more Mining in the world consists of modern and traditional mining. Various studies have discussed how field workers were precarious at being exposed to Covid-19 in modern mining. Many studies discuss ways of modern mines overcoming Covid-19, but discussion of research related to the impacts of Covid-19 on traditional mining has not been carried out. This study addressed the effect of the Covid-19 pandemic on traditional oil mining in Wonocolo, Bojonegoro Regency. This work is a descriptive study using observation and in-depth interviews and reviewing secondary data related to conventional mining activities. The results showed that the Covid-19 pandemic has an indirect effect on traditional oil mining activities in Wonocolo. The pandemic caused a decrease in demand, a drop in selling prices, lower production, and temporary closure of wells in Wonocolo traditional mining. In contrast, Covid-19 did not directly affect miners’ activities since the miners believed that Covid-19 could not inf...

Management of Aquatic Resources Journal, Dec 19, 2018

Perairan Morosari merupakan kawasan pesisir yang memiliki dinamika tinggi akibat dari adanya obje... more Perairan Morosari merupakan kawasan pesisir yang memiliki dinamika tinggi akibat dari adanya objek wisata bahari, dimana akan berpengaruh pada struktur komunitas sumberdaya perikanan, salah satu diantaranya adalah larva ikan yang ada diperairan tersebut. Larva ikan merupakan fase massa kritis dimulai bagi ikan, dimana pembentukan organ tubuh belum terbentuk secara sempurna. Penelitian ini bertujuan untuk mengetahui jenis dan kelimpahan larva ikan berdasarkan pasang surut yang terdapat di perairan sekitar lokasi wisata bahari Dukuh Morosari Desa Bedono, Kabupaten Demak. Penelitian dilaksanakan pada bulan Juli 2017. Metode penelitian yang digunakan adalah survei dengan penentuan titik sampling secara purposive yang dilakukan di 6 stasiun baik pada saat pasang dan surut. Hasil yang diperoleh menunjukkan bahwa jumlah larva ikan yang tertangkap sebanyak 1156 ind/600m 3 terdiri dari 8 famili yakni: Ambassidae (551 ind/600m 3), Belonidae (33 ind/600m 3), Engraulidae (118 ind/600m 3), Gobiidae (8 ind/600m 3), Lutjanidae (7 ind/600m 3), Mugilidae (130 ind/600m 3), Nemipteridae (206 ind/600m 3), Oryziatidae (103 ind/600m 3). Larva famili Ambassidae merupakan larva yang paling banyak tertangkap, sedangkan larva yang tertangkap dengan jumlah paling sedikit ialah famili Lutjanidae. Hasil uji Independent-Sample T test ialah tidak terdapat perbedaan yang signifikan antara kelimpahan larva ikan saat pasang dan surut pada setiap stasiun maupun setiap pengulangan. Jumlah larva ikan pada saat pasang 613 ind/600m 3 dan pada saat surut 543 ind/600m 3 .

Management of Aquatic Resources Journal, Dec 19, 2018

Permasalahan sediaan air di kawasan pesisir sangat kompleks sesuai dengan ragam peruntukan sepert... more Permasalahan sediaan air di kawasan pesisir sangat kompleks sesuai dengan ragam peruntukan seperti halnya di Desa Pesantren dan Desa Mojo. Penelusuran tentang kualitas air untuk ragam peruntukan sangat penting dalam meningkatkan kualitas sosial dan ekonomi masyarakat. Tujuan penelitian adalah untuk mengkaji kelayakan sumber daya air untuk beberapa peruntukan dan menganalisis variabel penurun kualitas air di kawasan pesisir. Penelitian didasarkan kepada metode survei dan dilaksanakan pada bulan Mei 2017 di Desa Pesantren dan Desa Mojo, Ulujami, Pemalang. Pengambilan sampel mengacu pada metode purposive sampling di 3 lokasi sungai, 2 lokasi sumur, 1 lokasi sawah, serta 2 lokasi tambak. Variabel yang diukur adalah bau, warna, rasa, suhu, TDS, kekeruhan air, debit sungai, kesadahan, pH, amonia, nitrit, nitrat, Cd, dan Pb. Mutu air dievaluasi berdasarkan Indeks Pencemaran (IP) sesuai KEPMEN LH No.115 Tahun 2003 dan PP No.82 Tahun 2001. Hasil penelitian menunjukkan bahwa tambak, sawah, dan sungai dinyatakan tidak memenuhi kelayakan air, dengan status tambak 1 yang terletak cukup jauh dari laut telah tercemar berat (IP= 21,17), tambak 2 yang terletak dekat dengan laut memiliki status tercemar sedang (IP= 8,18), sawah yang terletak cukup jauh dari laut dinyatakan tercemar ringan (IP= 3,88), sungai 1 yang letaknya kearah kawasan hulu tergolong tercemar ringan (IP= 3,14), sungai 2 yang terletak di tengah dan dekat dengan cabang Sungai Comal telah tercemar sedang (IP= 5,12), sungai 3 yang letaknya dekat dengan laut yaitu tercemar ringan (IP= 4,99), sedangkan mutu air sumur 1 dan 2 yang terletak di kawasan pemukiman cukup jauh dari laut dinyatakan layak karena masih memenuhi baku mutu (IP= 0,91 dan 0,85). Warna, kekeruhan air, amonia, TDS, logam Pb dan Cd merupakan variabel penurun kualitas air di tambak, sawah, sungai dan sumur. Warna, kekeruhan air, amonia, dan TDS kemungkinan besar berasal dari sisa pakan ikan di tambak dan pupuk di sawah yang tidak terserap oleh padi, sedangkan logam Pb dan Cd dalam penelitian ini kemungkinan berasal dari limbah domestik di kawasan hulu yang terbawa oleh Sungai Comal.

Science of The Total Environment, Jun 1, 2018

Groundwater discharges 106,000 mol d −1 of DIN and 5000 mol d −1 of DIP to the river. • Land use ... more Groundwater discharges 106,000 mol d −1 of DIN and 5000 mol d −1 of DIP to the river. • Land use and environmental infrastructure correlates with nutrient dynamics. • Medium populated cities can contribute to nutrient flux comparable with megacities.

SAINTEK PERIKANAN : Indonesian Journal of Fisheries Science and Technology, Feb 14, 2019

Populasi alamiah penyu di Indonesia terus menurun 20-30% per tahun terutama lebih disebabkan oleh... more Populasi alamiah penyu di Indonesia terus menurun 20-30% per tahun terutama lebih disebabkan oleh faktor manusia dibandingkan dengan faktor alam dan predator. Beberapa di antara teknik penyelamatan untuk pelestarian penyu antara lain melalui penetasan di sarang semi-alami, perlindungan translokasi habitat (konservasi in-situ), penegakan hukum, penyuluhan dan pemberdayaan masyarakat sekitar. Di sarang semi-alami jenis pakan yang tepat pada saat pemeliharaan awal tukik sebelum dilepas ke laut akan mempengaruhi kelulus-hidupan mereka. Padahal, sampai saat ini jenis pakan yang tepat untuk tukik belum banyak diketahui. Penelitian ini menggunakan tiga 3 perlakuan pakan (Sardinella lemuru 100%; Sargassum filipendula 100%; campuran S. lemuru dan S. filipendula 50:50%), analisis data enggunakan Rancangan Acak Lengkap (RAL) dengan 3 pengulangan. Secara statistik, diketahui bahwa tiap perlakuan pakan menghasilkan perbedaan pada variabel panjang, lebar karapas dan bobot tukik. Berdasarkan analisis alometri tukik E.imbricata selama penelitian, dihasilkan konstanta b <  antar perlakuan yang menunjukkan bahwa pertumbuhan bersifat alometri negatif pada variabel panjang karapas dan bobot tubuh serta panjang dan lebar karapas; kecuali pada hubungan panjang dan lebar karapas tukik dengan pakan S. lemuru.

Jurnal pengelolaan sumberdaya alam dan lingkungan, Aug 12, 2021

Global nitrogen pollution in the aquatic environment has been increased mostly due to the disposa... more Global nitrogen pollution in the aquatic environment has been increased mostly due to the disposal of organic wastewater from human activities. Chronic disposal of nitrogen compounds into the waters caused eutrophication and death of aquatic organisms. The process of reducing nitrogen in wastewater can be carried out economically and efficiently using nitrifying-denitrifying bacteria. Besides that, another environmentally friendly technology that can also be used is bioremediation using microalgae such as Chlorella sp. The synergistic relationship between bacteria and microalgae has a better performance in reducing nitrogen compounds in organic wastewater. This study aims to determine the rate of nitrification, changes in nitrate concentrations, and the effect of differences in treatments and time on changes in nitrate levels in organic wastewater. This study was conducted from July to August 2020 was an experimental laboratory using a randomized block design. Organic wastewater samples were taken from Lake Rawa Pening Central Java. The results showed the highest nitrification rate was performed by treatment C (a combination of probiotics and Chlorella sp.) of 0.2 mg NH4-N l-1.hour-1, followed by treatment B (Chlorella sp.), D (control), and A (probiotics) of 0.169, 0.009 and 0.008 mg NH4-N l-1.hour-1, respectively. The highest percentage change in nitrate levels during the study was treatment C (1 874%), B (1 664%), D (200%), and A (175%), respectively. The analysis of variance and the DMRT test showed that there were differences between treatments and times of changes in nitrate levels (pvalue <0.05), with the highest average change in nitrate levels found in treatment C.

Management of Aquatic Resources Journal, Mar 9, 2018

is one of the largest river owned by the city of Semarang. The river has a main function as drain... more is one of the largest river owned by the city of Semarang. The river has a main function as drainage system and flood control of the city. Several streams flowing into the East Banjir Kanal River and end at the estuary. As estuary accommodates all loads from the river, therefore, the trophic status of waters in particular for East Banjir Kanal River needs to be evaluated in the context of environmental management and utilization of natural resources.

Berkala perikanan terubuk, Jul 25, 2021

Aacl Bioflux, 2020

Potential stock of fish larvae is an indicator of the sustainability of fisheries resources in co... more Potential stock of fish larvae is an indicator of the sustainability of fisheries resources in coastal waters. Various types of human activities cause waste either in the form of domestic or industrial waste, that have a role in reducing the number of species and number of fish larvae stock in natural environments. The west coast region of Demak Regency has the potential of mangroves and estuaries as a function of the ecosystem for the protection and the growth of several species of fish larvae. The purpose of the study was to determine the composition, abundance, and distribution of fish larvae in the waters of the west coast of Demak. Sampling locations were situated on the west coast of Demak, namely in Sri Wulan, Bedono, and Timbulsloko seawater. The study was conducted in May 2018 and sampling was conducted three times. Each sampling period took place 14 days apart and was carried out in estuarine habitats, around mangrove forests and abraded coastline. Salinity, seawater temperature, current, pH, dissolved oxygen, nitrates, nitrites, H2S and seawater transparency were analyzed. The study had found 13 genera of fish larvae, namely Ambasis,

Journal of Coastal Zone Management, 2007

The reproductive cycles of male and female Anadara granosa and Anadara antiquata which have been ... more The reproductive cycles of male and female Anadara granosa and Anadara antiquata which have been studied and compared by histological techniques showed great anatomical similarity. Gametogenesis is associated with a system of follicle cells which break down as the gametes approach maturity. The arrangement of follicle cells is characteristics of the sex. In the female, gametogonia are peripheral to the follicle cells, whilst in the male they are interstitial. The process of spermatogenesis parallel the classical vertebrate pattern, i.e. successive layers of spermatogenic cells (spermatogonia, primary and secondary spermatocytes, spermatids, and spermatozoa) occurring more or less regularly in succession toward the centre of the follicle. The diameter of the maximum size oocytes is 75µm for A. granosa and 65µm for A. antiquata. Spawning in both A. granosa and A. antiquata is progressing gradually throughout the year as indicated by the availability of various stages of oogonia and spermatogonia; for which the highest number of oogonia were those of 25-40µm diameter. The histological study indicated that both species are iteroparous with planktotrophic type of development, yet performing a short period of pelagic life (ca 1 month).

Biodiversitas, Apr 10, 2022

Amorphophallus variabilis Blume is a member of the genus Amorphophallus which is known as a wild ... more Amorphophallus variabilis Blume is a member of the genus Amorphophallus which is known as a wild plant that lives in forests, including Central Java, Indonesia. This plant has a high diversity but its existence is neglected and is rarely used by the community. This study aims to introduce A. variabilis through the inherent biological characteristics of the species, local the community's knowledge, ecological functions and the threat of extinction. Data on biological characteristics covering morphological characters were obtained from field observations, while data on anatomy were obtained by making semi-permanent preparations using a modified Ruzin method. Data on community's knowledge were obtained by conducting semi-structural interviews. The results showed that its morphological and ecological characters were very similar to other members of Amorphophallus, but with a very wide variety of patterns on the petiole. The anatomical structure of the leaf blade has a dorsiventral type consisting of several layers, namely a thin cuticle layer, flat upper epidermis, palisade mesophyll, spongy mesophyll, vascular tissue and lower epidermis. The tissue that composes the petiole consists of the epidermis, hypodermis, collenchyma supporting tissue, vascular bundles and secretory cells, while the tuber consists of periderm, cortex, vascular bundles, and pith tissue. This species has almost the same potential as Amorphophallus mueleri Blume which was previously known to have economic and medicinal values. However, the community's knowledge about the A. variabialis is still poor, resulting in neglect of this species that possibly causes its extinction and may have an impact on the ecological balance.

Jurnal Kelautan Tropis, Feb 12, 2021

Octopus laqueus was first discovered not long ago in 2005 in the Ryuku Islands, Japan. Its geogra... more Octopus laqueus was first discovered not long ago in 2005 in the Ryuku Islands, Japan. Its geographical distribution and molecular identification are therefore still rarely. Nucleotide sequences based on mt-DNA COI for O. laqueus that have been uploaded in the GenBank until before this study was carried out were only six sequences. Since DNA barcoding of mt-DNA COI has some advantageous characteristics, this study aimed to analyse the genetic difference of Indonesian O. laqueus to the data available in the GenBank. Samples were collected in 2019-2020 from Karimunjawa (n=16) and Bangka-Belitung (n=2). The mt-DNA COI was extracted using 10% chelex methods, PCR amplified using Folmer's primer and sequenced in Sanger methods. Pairwise alignment and genetic distance were carried out in MEGA-X, whereas the phylogenetic tree was reconstructed using Bayesian methods. BLAST identification resulted in 685 bp with a range of 92,07-99,24 percentages of identity. The genetic mean pair-wise distances within-clade were 0,002 and 0,006, whilst the distance between the clade was 0.0883. Combining the suggestion with the ITF current, it is concluded that O. laqueus taken from Karimunjawa raised from the same species as those in Malaysia (MN711655) and Japan (AB302176). Specimens from Bangka-Belitung were suggested came from different species, as they were separated into the second clade by 8.83%. One single sample from Japan (AB430543) which laid outside the two clades by 11.63%-11.38% was also suggested to represent a different species. Overall, this study opens to various further studies on O. laqueus using other loci of genetic markers.

Acta Aquatica, Apr 7, 2023

Osmoregulation is a physiological adjustment mechanism of fish to environmental conditions. Fish ... more Osmoregulation is a physiological adjustment mechanism of fish to environmental conditions. Fish growth performance will reduce when a large amount of energy is redirected for the osmoregulation process. The purpose of this study was to determine the osmotic work level (OWL), osmoregulation pattern, condition factor (K), gonad maturity stages (GMS) and analyze the relationship between OWL with condition factor and GMS of tilapia collected from three floating net cages in Cengklik reservoir, Boyolali. Samples were collected during March-April 2022 followed by some allometric measurements and regression analyses. The OWL of tilapia at the three cages ranged from 4-10 mOsm/L H2O; they performed a hyperosmotic osmoregulation pattern. The condition factor of male and female tilapia were1,86±0,21 and 1,89±0,18. GMS of both male and female tilapia was dominated by GMS IV with a fecundity of 9408±2092.54 eggs. OWL did not reveal a significant effect on condition factors or on the GMS of tilapia (p>0.05). Pearson correlation test showed a weak relationship between OWL with condition factors (r = 0,204) and tilapia GMS (r =-0,001). Therefore, tilapia uses less energy in osmotic work to produce good growth performance because it has more energy for growth, as indicated by the high condition factor (K>1) and domination by fish with GMS IV level of mature gonads.

Pulau Karimunjawa dan Pulau Kemujan merupakan Kawasan dalam Taman Nasional Karimunjawa (TNKJ) yan... more Pulau Karimunjawa dan Pulau Kemujan merupakan Kawasan dalam Taman Nasional Karimunjawa (TNKJ) yang memiliki ekosistem terumbu karang berupa reef flat dan reef slope. Kedua pulau ini seringkali dikunjungi wisatawan, sehingga aktivitas tersebut diperkirakan mempengaruhi kualitas perairannya. Penurunan kualitas perairan menyebabkan perubahan struktur komunitas biota, dalam studi ini ikan karang dan terumbu karang. Berdasarkan alur pemikiran tersebut, maka dilakukan penelitian dengan tujuan mengetahui keanekaragaman, kelimpahan serta hubungan ikan karang dan terumbu karang pada daerah reef flat dan reed slope. Pengambilan data dilaksanakan pada bulan Agustus tahun 2020 di perairan Pulau Karimunjawa (Tanjung Gelam dan Legon Lele) dan Pulau Kemujan (Pulau Sintok dan Batulawang), Kabupaten Jepara, Jawa Tengah. Pengamatan terumbu karang dilakukan dengan menggunakan metode UPT (Underwater Photo Transect) kemudian data diolah menggunakan aplikasi CPCe (Coral Point Count with Excel). Pengamatan ikan karang dilakukan menggunakan metode UVC (Underwater Visual Census). Hasil menunjukkan bahwa kelimpahan karang hidup di lokasi penelitian termasuk kategori sedang hingga sangat baik (24%-77,89%). Indeks keanekaragaman tertinggi terumbu karang ditemukan di Pulau Sintok (2,322) dan terendah di Legon Lele (1,815). Indeks keanekaagaman dan kelimpahan ikan karang tertinggi ditemukan di Pulau Sintok (H' = 3,254 dan 500 ind/150m 2) dengan dominasi famili Pomacentridae, sedangkan terendah ditemukan di Tanjung Gelam (H' = 2,372 dan 123 ind/150m 2). Kelimpahan ikan karang dipengaruhi oleh kondisi terumbu karang sebesar 95,83% (R 2 = 0,9583). Semakin baik kondisi terumbu karang, maka semakin tinggi kelimpahan ikannya. Hasil uji anova menunjukkan nilai F hitung = 54,498 dengan tingkat signifikasi sebesar 0,0034 (α<0,05). Hal ini menunjukkan bahwa data signifikan dan hipotesis diterima.

ILMU KELAUTAN: Indonesian Journal of Marine Sciences, 2004

Aktifitas manusia yang terus meningkat di wilayah pesisir, telah menyebabkan terjadinya peningkat... more Aktifitas manusia yang terus meningkat di wilayah pesisir, telah menyebabkan terjadinya peningkatan tekanan lingkungan yang berasal dari berbagai macam sumber pencemaran, antara lain limbah industri, pertanian, transportasi, dan limbah domestik. Salah satu sumber pencemar yang cukup dominan di lingkungan perairan pantai adalah pencemaran akibat limbah domestik. Selama ini yang dipakai untuk mengetahui pencemaran lingkungan oleh limbah domestik adalah menggunakan indikator biologi yaitu bakteri coliform. Namun penggunaan bakteri coliform sebagai indikator pencemaran limbah domestik mempunyai permasalahan antara lain tidak terdeteksinya bakteri coliform tersebut pada perairan pantai, sementara diduga kuat bahwa perairan tersebut tercemar oleh limbah domestik termasuk feces. Oleh karena itu indikator alternatif sangat diperlukan. Salah satu indikator alternatif pencemaran limbah domestik adalah koprostanol, yang mempunyai sifat cukup konservatif, dapat dikuntitatifkan dan dapat dihubungkan dengan sumber pencemar yang spesifik. Namun perlu diingat bahwa di alam, koprostanol mengalami proses degradasi oleh bakteri, sehingga perlu dilakukan penelitian mengenai isolasi dan identifikasi bakteri pendegradasi koprostanol pada lingkungan sungai, muara, dan perairan pantai Banjir Kanal Timur Semarang pada monsun timur. Penelitian dilakukan pada bulan Juli s/d Agustus 2003 pada lingkungan sungai, muara, dan perairan pantai Banjir Kanal Timur Semarang. Isolasi bakteri dari sampel air dan sedimen dilakukan di Laboratorium Mikrobiogenetika, FMIPA Jurusan Biologi UNDIP Semarang dan identifikasi bakteri pendegradasi koprostanol terseleksi dilakukan di Laboratorium Hama dan Penyakit Balai Besar Pengembangan Budidaya Air Payau (BBPBAP) Jepara. Hasil penelitian diperoleh bahwa bakteri pendegradasi koprostanol yang berasal dari lokasi Banjir Kanal Timur Semarang pada berbagai variasi lingkungan dan habitat diperoleh 69 isolat (83,13%) dari 83 isolat yang diuji. Sedangkan hasil identifikasi terhadap 6 isolat terbaik diperoleh 3 (tiga) genus bakteri mampu mendegradasi koprostanol, yaitu Achromobacter, Bacillus, dan Branhamella. Dari 3 genus bakteri pendegradasi koprostanol yang didapatkan, ada 2 (dua) genus yang selama ini belum dilaporkan, yaitu genus Achromobacter, dan Branhamella.

IOP conference series, Jun 1, 2022

Mangrove areas in the northern coast of Jepara Regency have been threatened by coastal erosion an... more Mangrove areas in the northern coast of Jepara Regency have been threatened by coastal erosion and changes in land use since 1980. These areas represent coastal ecosystems with significant ecological, biological, and economic importance. The status of these ecosystems needs to be monitored; the latest condition is important to local authorities. Rate of change in mangrove conditions can be used to forecast the future condition of these coastal areas. This study aims to determine the temporal changes in the area and density of mangrove vegetation in Jepara Regency in 2017 and 2020. This study applied analysis of Sentinel 2-A multitemporal satellite imagery and classification using random forest on the Google Earth Engine platform. It was found that the mangrove area shrank from 103 ha in 2017 to 95 ha in 2020. The vegetations showed that changes in mangrove area in Jepara Regency have decreased in the rare and dense mangrove density types. The density of rare and dense mangroves experienced a decrease in area of 6 and 5 hectares, respectively. No mangroves with dense cover were found in 2020. Meanwhile, mangroves with moderate cover experienced an increase in area of 3 hectares in 2020 compared to last year 2017.

Groundwater discharge is known to transport nutrients into estuaries at several locations around ... more Groundwater discharge is known to transport nutrients into estuaries at several locations around the world. However, few studies report groundwater-associated nutrient fluxes from tropical developing regions such as Southeast Asia, even though this area shows the strongest human modifications in the coastal zone worldwide. We investigated groundwater nutrient flux into two streams and estuaries (Awur and Sekumbu Bay) in the urban area of Jepara, Indonesia, and its relation with the land usage surrounding the estuaries.We found that average concentrations of NO3, NH4, and PO4 in Jepara's aquifer reached 145 µM, 68 µM, and 14 µM, respectively, and our results indicate that these were mainly originated from untreated sewage, agriculture, and manure input. Approximately 2200 ton N per year and 380 ton P per year were removed in the soil and aquifer before the nutrients were discharged into the river. The total groundwater discharge into the river and estuary was estimated to 461 × 103 m**3/day, or up to 42% of the river discharge. Discharge of groundwater-associated NO3 (72 × 103 mol/day), NH4 (34 × 103 mol/day), PO4 (5 × 103 mol/day), and additional surface runoff may contribute to eutrophication and a decrease of nearshore surface water quality. Nutrient concentrations in groundwater, river, and coastal seawater in the Jepara region are similar to those found in major urban areas in Southeast Asia, e.g. Manila and Bangkok, even though Jepara has smaller size and population. Thus, our results indicate that medium populated cities with highly modified regional land use can contribute a significant amount of nutrient discharge in the coastal area and should be included in global assessments of nutrient budget calculation.

IOP Conference Series: Earth and Environmental Science, 2021

Mining in the world consists of modern and traditional mining. Various studies have discussed how... more Mining in the world consists of modern and traditional mining. Various studies have discussed how field workers were precarious at being exposed to Covid-19 in modern mining. Many studies discuss ways of modern mines overcoming Covid-19, but discussion of research related to the impacts of Covid-19 on traditional mining has not been carried out. This study addressed the effect of the Covid-19 pandemic on traditional oil mining in Wonocolo, Bojonegoro Regency. This work is a descriptive study using observation and in-depth interviews and reviewing secondary data related to conventional mining activities. The results showed that the Covid-19 pandemic has an indirect effect on traditional oil mining activities in Wonocolo. The pandemic caused a decrease in demand, a drop in selling prices, lower production, and temporary closure of wells in Wonocolo traditional mining. In contrast, Covid-19 did not directly affect miners’ activities since the miners believed that Covid-19 could not inf...

Management of Aquatic Resources Journal, Dec 19, 2018

Perairan Morosari merupakan kawasan pesisir yang memiliki dinamika tinggi akibat dari adanya obje... more Perairan Morosari merupakan kawasan pesisir yang memiliki dinamika tinggi akibat dari adanya objek wisata bahari, dimana akan berpengaruh pada struktur komunitas sumberdaya perikanan, salah satu diantaranya adalah larva ikan yang ada diperairan tersebut. Larva ikan merupakan fase massa kritis dimulai bagi ikan, dimana pembentukan organ tubuh belum terbentuk secara sempurna. Penelitian ini bertujuan untuk mengetahui jenis dan kelimpahan larva ikan berdasarkan pasang surut yang terdapat di perairan sekitar lokasi wisata bahari Dukuh Morosari Desa Bedono, Kabupaten Demak. Penelitian dilaksanakan pada bulan Juli 2017. Metode penelitian yang digunakan adalah survei dengan penentuan titik sampling secara purposive yang dilakukan di 6 stasiun baik pada saat pasang dan surut. Hasil yang diperoleh menunjukkan bahwa jumlah larva ikan yang tertangkap sebanyak 1156 ind/600m 3 terdiri dari 8 famili yakni: Ambassidae (551 ind/600m 3), Belonidae (33 ind/600m 3), Engraulidae (118 ind/600m 3), Gobiidae (8 ind/600m 3), Lutjanidae (7 ind/600m 3), Mugilidae (130 ind/600m 3), Nemipteridae (206 ind/600m 3), Oryziatidae (103 ind/600m 3). Larva famili Ambassidae merupakan larva yang paling banyak tertangkap, sedangkan larva yang tertangkap dengan jumlah paling sedikit ialah famili Lutjanidae. Hasil uji Independent-Sample T test ialah tidak terdapat perbedaan yang signifikan antara kelimpahan larva ikan saat pasang dan surut pada setiap stasiun maupun setiap pengulangan. Jumlah larva ikan pada saat pasang 613 ind/600m 3 dan pada saat surut 543 ind/600m 3 .

Management of Aquatic Resources Journal, Dec 19, 2018

Permasalahan sediaan air di kawasan pesisir sangat kompleks sesuai dengan ragam peruntukan sepert... more Permasalahan sediaan air di kawasan pesisir sangat kompleks sesuai dengan ragam peruntukan seperti halnya di Desa Pesantren dan Desa Mojo. Penelusuran tentang kualitas air untuk ragam peruntukan sangat penting dalam meningkatkan kualitas sosial dan ekonomi masyarakat. Tujuan penelitian adalah untuk mengkaji kelayakan sumber daya air untuk beberapa peruntukan dan menganalisis variabel penurun kualitas air di kawasan pesisir. Penelitian didasarkan kepada metode survei dan dilaksanakan pada bulan Mei 2017 di Desa Pesantren dan Desa Mojo, Ulujami, Pemalang. Pengambilan sampel mengacu pada metode purposive sampling di 3 lokasi sungai, 2 lokasi sumur, 1 lokasi sawah, serta 2 lokasi tambak. Variabel yang diukur adalah bau, warna, rasa, suhu, TDS, kekeruhan air, debit sungai, kesadahan, pH, amonia, nitrit, nitrat, Cd, dan Pb. Mutu air dievaluasi berdasarkan Indeks Pencemaran (IP) sesuai KEPMEN LH No.115 Tahun 2003 dan PP No.82 Tahun 2001. Hasil penelitian menunjukkan bahwa tambak, sawah, dan sungai dinyatakan tidak memenuhi kelayakan air, dengan status tambak 1 yang terletak cukup jauh dari laut telah tercemar berat (IP= 21,17), tambak 2 yang terletak dekat dengan laut memiliki status tercemar sedang (IP= 8,18), sawah yang terletak cukup jauh dari laut dinyatakan tercemar ringan (IP= 3,88), sungai 1 yang letaknya kearah kawasan hulu tergolong tercemar ringan (IP= 3,14), sungai 2 yang terletak di tengah dan dekat dengan cabang Sungai Comal telah tercemar sedang (IP= 5,12), sungai 3 yang letaknya dekat dengan laut yaitu tercemar ringan (IP= 4,99), sedangkan mutu air sumur 1 dan 2 yang terletak di kawasan pemukiman cukup jauh dari laut dinyatakan layak karena masih memenuhi baku mutu (IP= 0,91 dan 0,85). Warna, kekeruhan air, amonia, TDS, logam Pb dan Cd merupakan variabel penurun kualitas air di tambak, sawah, sungai dan sumur. Warna, kekeruhan air, amonia, dan TDS kemungkinan besar berasal dari sisa pakan ikan di tambak dan pupuk di sawah yang tidak terserap oleh padi, sedangkan logam Pb dan Cd dalam penelitian ini kemungkinan berasal dari limbah domestik di kawasan hulu yang terbawa oleh Sungai Comal.

Science of The Total Environment, Jun 1, 2018

Groundwater discharges 106,000 mol d −1 of DIN and 5000 mol d −1 of DIP to the river. • Land use ... more Groundwater discharges 106,000 mol d −1 of DIN and 5000 mol d −1 of DIP to the river. • Land use and environmental infrastructure correlates with nutrient dynamics. • Medium populated cities can contribute to nutrient flux comparable with megacities.

SAINTEK PERIKANAN : Indonesian Journal of Fisheries Science and Technology, Feb 14, 2019

Populasi alamiah penyu di Indonesia terus menurun 20-30% per tahun terutama lebih disebabkan oleh... more Populasi alamiah penyu di Indonesia terus menurun 20-30% per tahun terutama lebih disebabkan oleh faktor manusia dibandingkan dengan faktor alam dan predator. Beberapa di antara teknik penyelamatan untuk pelestarian penyu antara lain melalui penetasan di sarang semi-alami, perlindungan translokasi habitat (konservasi in-situ), penegakan hukum, penyuluhan dan pemberdayaan masyarakat sekitar. Di sarang semi-alami jenis pakan yang tepat pada saat pemeliharaan awal tukik sebelum dilepas ke laut akan mempengaruhi kelulus-hidupan mereka. Padahal, sampai saat ini jenis pakan yang tepat untuk tukik belum banyak diketahui. Penelitian ini menggunakan tiga 3 perlakuan pakan (Sardinella lemuru 100%; Sargassum filipendula 100%; campuran S. lemuru dan S. filipendula 50:50%), analisis data enggunakan Rancangan Acak Lengkap (RAL) dengan 3 pengulangan. Secara statistik, diketahui bahwa tiap perlakuan pakan menghasilkan perbedaan pada variabel panjang, lebar karapas dan bobot tukik. Berdasarkan analisis alometri tukik E.imbricata selama penelitian, dihasilkan konstanta b <  antar perlakuan yang menunjukkan bahwa pertumbuhan bersifat alometri negatif pada variabel panjang karapas dan bobot tubuh serta panjang dan lebar karapas; kecuali pada hubungan panjang dan lebar karapas tukik dengan pakan S. lemuru.

Jurnal pengelolaan sumberdaya alam dan lingkungan, Aug 12, 2021

Global nitrogen pollution in the aquatic environment has been increased mostly due to the disposa... more Global nitrogen pollution in the aquatic environment has been increased mostly due to the disposal of organic wastewater from human activities. Chronic disposal of nitrogen compounds into the waters caused eutrophication and death of aquatic organisms. The process of reducing nitrogen in wastewater can be carried out economically and efficiently using nitrifying-denitrifying bacteria. Besides that, another environmentally friendly technology that can also be used is bioremediation using microalgae such as Chlorella sp. The synergistic relationship between bacteria and microalgae has a better performance in reducing nitrogen compounds in organic wastewater. This study aims to determine the rate of nitrification, changes in nitrate concentrations, and the effect of differences in treatments and time on changes in nitrate levels in organic wastewater. This study was conducted from July to August 2020 was an experimental laboratory using a randomized block design. Organic wastewater samples were taken from Lake Rawa Pening Central Java. The results showed the highest nitrification rate was performed by treatment C (a combination of probiotics and Chlorella sp.) of 0.2 mg NH4-N l-1.hour-1, followed by treatment B (Chlorella sp.), D (control), and A (probiotics) of 0.169, 0.009 and 0.008 mg NH4-N l-1.hour-1, respectively. The highest percentage change in nitrate levels during the study was treatment C (1 874%), B (1 664%), D (200%), and A (175%), respectively. The analysis of variance and the DMRT test showed that there were differences between treatments and times of changes in nitrate levels (pvalue <0.05), with the highest average change in nitrate levels found in treatment C.

Management of Aquatic Resources Journal, Mar 9, 2018

is one of the largest river owned by the city of Semarang. The river has a main function as drain... more is one of the largest river owned by the city of Semarang. The river has a main function as drainage system and flood control of the city. Several streams flowing into the East Banjir Kanal River and end at the estuary. As estuary accommodates all loads from the river, therefore, the trophic status of waters in particular for East Banjir Kanal River needs to be evaluated in the context of environmental management and utilization of natural resources.

Berkala perikanan terubuk, Jul 25, 2021

Aacl Bioflux, 2020

Potential stock of fish larvae is an indicator of the sustainability of fisheries resources in co... more Potential stock of fish larvae is an indicator of the sustainability of fisheries resources in coastal waters. Various types of human activities cause waste either in the form of domestic or industrial waste, that have a role in reducing the number of species and number of fish larvae stock in natural environments. The west coast region of Demak Regency has the potential of mangroves and estuaries as a function of the ecosystem for the protection and the growth of several species of fish larvae. The purpose of the study was to determine the composition, abundance, and distribution of fish larvae in the waters of the west coast of Demak. Sampling locations were situated on the west coast of Demak, namely in Sri Wulan, Bedono, and Timbulsloko seawater. The study was conducted in May 2018 and sampling was conducted three times. Each sampling period took place 14 days apart and was carried out in estuarine habitats, around mangrove forests and abraded coastline. Salinity, seawater temperature, current, pH, dissolved oxygen, nitrates, nitrites, H2S and seawater transparency were analyzed. The study had found 13 genera of fish larvae, namely Ambasis,

Journal of Coastal Zone Management, 2007

The reproductive cycles of male and female Anadara granosa and Anadara antiquata which have been ... more The reproductive cycles of male and female Anadara granosa and Anadara antiquata which have been studied and compared by histological techniques showed great anatomical similarity. Gametogenesis is associated with a system of follicle cells which break down as the gametes approach maturity. The arrangement of follicle cells is characteristics of the sex. In the female, gametogonia are peripheral to the follicle cells, whilst in the male they are interstitial. The process of spermatogenesis parallel the classical vertebrate pattern, i.e. successive layers of spermatogenic cells (spermatogonia, primary and secondary spermatocytes, spermatids, and spermatozoa) occurring more or less regularly in succession toward the centre of the follicle. The diameter of the maximum size oocytes is 75µm for A. granosa and 65µm for A. antiquata. Spawning in both A. granosa and A. antiquata is progressing gradually throughout the year as indicated by the availability of various stages of oogonia and spermatogonia; for which the highest number of oogonia were those of 25-40µm diameter. The histological study indicated that both species are iteroparous with planktotrophic type of development, yet performing a short period of pelagic life (ca 1 month).

Biodiversitas, Apr 10, 2022

Amorphophallus variabilis Blume is a member of the genus Amorphophallus which is known as a wild ... more Amorphophallus variabilis Blume is a member of the genus Amorphophallus which is known as a wild plant that lives in forests, including Central Java, Indonesia. This plant has a high diversity but its existence is neglected and is rarely used by the community. This study aims to introduce A. variabilis through the inherent biological characteristics of the species, local the community's knowledge, ecological functions and the threat of extinction. Data on biological characteristics covering morphological characters were obtained from field observations, while data on anatomy were obtained by making semi-permanent preparations using a modified Ruzin method. Data on community's knowledge were obtained by conducting semi-structural interviews. The results showed that its morphological and ecological characters were very similar to other members of Amorphophallus, but with a very wide variety of patterns on the petiole. The anatomical structure of the leaf blade has a dorsiventral type consisting of several layers, namely a thin cuticle layer, flat upper epidermis, palisade mesophyll, spongy mesophyll, vascular tissue and lower epidermis. The tissue that composes the petiole consists of the epidermis, hypodermis, collenchyma supporting tissue, vascular bundles and secretory cells, while the tuber consists of periderm, cortex, vascular bundles, and pith tissue. This species has almost the same potential as Amorphophallus mueleri Blume which was previously known to have economic and medicinal values. However, the community's knowledge about the A. variabialis is still poor, resulting in neglect of this species that possibly causes its extinction and may have an impact on the ecological balance.

Jurnal Kelautan Tropis, Feb 12, 2021

Octopus laqueus was first discovered not long ago in 2005 in the Ryuku Islands, Japan. Its geogra... more Octopus laqueus was first discovered not long ago in 2005 in the Ryuku Islands, Japan. Its geographical distribution and molecular identification are therefore still rarely. Nucleotide sequences based on mt-DNA COI for O. laqueus that have been uploaded in the GenBank until before this study was carried out were only six sequences. Since DNA barcoding of mt-DNA COI has some advantageous characteristics, this study aimed to analyse the genetic difference of Indonesian O. laqueus to the data available in the GenBank. Samples were collected in 2019-2020 from Karimunjawa (n=16) and Bangka-Belitung (n=2). The mt-DNA COI was extracted using 10% chelex methods, PCR amplified using Folmer's primer and sequenced in Sanger methods. Pairwise alignment and genetic distance were carried out in MEGA-X, whereas the phylogenetic tree was reconstructed using Bayesian methods. BLAST identification resulted in 685 bp with a range of 92,07-99,24 percentages of identity. The genetic mean pair-wise distances within-clade were 0,002 and 0,006, whilst the distance between the clade was 0.0883. Combining the suggestion with the ITF current, it is concluded that O. laqueus taken from Karimunjawa raised from the same species as those in Malaysia (MN711655) and Japan (AB302176). Specimens from Bangka-Belitung were suggested came from different species, as they were separated into the second clade by 8.83%. One single sample from Japan (AB430543) which laid outside the two clades by 11.63%-11.38% was also suggested to represent a different species. Overall, this study opens to various further studies on O. laqueus using other loci of genetic markers.