Measurement of salt-wedge excursion distance in the Duwamish River Estuary, Seattle, Washington, by means of the dissolved-oxygen gradient

1972 ◽  
Keyword(s):  
Dissolved Oxygen ◽  
River Estuary ◽  
Salt Wedge ◽  
Oxygen Gradient

scholarly journals ANALISIS KELIMPAHAN TOTAL BAKTERI COLIFORM DI PERAIRAN MUARA SUNGAI SAYUNG, MOROSARI, DEMAK (Analysis of Total Abundance of Coliform Bacteria at the Sayung River Estuary, Morosari, Demak)

2018 ◽  
Vol 14 (1) ◽  
pp. 30
Author(s):  
Lani Febriana Safitri ◽  
Niniek Widyorini ◽  
Oktavianto Eko Jati
Keyword(s):  
Water Quality ◽  
Organic Matter ◽  
Dissolved Oxygen ◽  
Random Sampling ◽  
River Estuary ◽  
Total Coliform ◽  
Coliform Bacteria ◽  
Total Abundance ◽  
Average Abundance ◽  
Total Coliform Bacteria

Perairan Muara Sungai Sayung terletak di wilayah Kabupaten Demak sebelah barat. Perairan ini telah dipengaruhi oleh berbagai aktivitas manusia yang menyebabkan terjadinya penurunan kualitas perairan. Bakteri Coliform merupakan bakteri gram negatif yang berbentuk batang dan tidak membentuk spora. Bakteri ini merupakan bakteri indikator terjadinya pencemaran perairan maupun indikator keberadaan bakteri patogen lainnya. Perhitungan total bakteri Coliform perlu dilakukan untuk mengetahui adanya pencemaran limbah organik yang terjadi di Perairan Muara Sungai Sayung, Morosari, Demak. Tujuan dari penelitian ini adalah untuk mengetahui kelimpahan total bakteri Coliform, dan status perairan di Perairan Muara Sungai Sayung, Morosari, Demak. Penelitian ini juga bertujuan untuk mengetahui hubungan dari jumlah total bakteri Coliform dengan bahan organik terlarut dan oksigen terlarut (DO). Pelaksanaan penelitian ini dilakukan pada bulan Mei 2018. Metode yang digunakan dalam penelitian ini adalah metode survei dan teknik pengambilan sampel menggunakan metode random sampling yang dilakukan pada lima stasiun. Hasil penelitian menunjukkan bahwa kelimpahan rata-rata total bakteri Coliform yang diperoleh berkisar antara 4 x 103 – 550 x 10 3/100ml. Kelimpahan rata-rata total bakteri Coliform yang diperoleh pada setiap stasiun menunjukkan bahwa kandungan total bakteri Coliform telah melebihi baku mutu air menurut Keputusan Menteri Lingkungan Hidup Nomor 51 Tahun 2004. Keberadaan total bakteri Coliform memiliki hubungan yang lemah dengan kandungan bahan organik terlarut, sedangkan keberadaan total bakteri Coliform memiliki hubungan yang cukup dengan oksigen terlarut (DO) di perairan Muara Sungai Sayung Morosari, Demak. Sayung River Estuary is located in the western part of Demak Regency. This estuary has been affected by various human activities which have led to a decline in water quality. Coliform bacteria are a gram-negative bacteria that are rod-shaped and do not form spores. This bacterium is an indicator bacteria of water pollution and an indicator of the presence of other pathogenic bacteria. Total Coliform bacteria calculation needs to be carrid out to find out if there any contamination of organic waste in Sayung River Estuary, Morosari, Demak.. The purpose of this research was to determine total abundance of Coliform bacteria, water quality in Sayung River Estuary, Morosari, Demak and relationship between the total abundance of Coliform bacteria with dissolved organic matter and dissolved oxygen (DO). This research was carried out in May 2018. The method that used in this research were survey method and the sampling technique was random sampling method in five stations. The results showed that the average abundance of total Coliform bacteria obtained ranged between 4 x 103 - 550 x 103 / 100ml. Average abundance of total Coliform bacteria obtained at each station shows that the total content of Coliform bacteria has exceeded the water quality standard according to Minister of Environment Decree number 51 of 2004. The total presence of Coliform bacteria has a weak relationship with the content of dissolved organic matter, while the total number of Coliform bacteria have sufficient relationship with dissolved oxygen (DO) in the Sayung River Estuary,Morosari, Demak.

scholarly journals Artificially oxygenating the Swan River estuary increases dissolved oxygen concentrations in the water and at the sediment interface

2019 ◽  
Vol 128 ◽  
pp. 112-121 ◽  
Author(s):  
Sarah J. Larsen ◽  
Kieryn L. Kilminster ◽  
Alessandra Mantovanelli ◽  
Zoë J. Goss ◽  
Georgina C. Evans ◽  
...  
Keyword(s):  
Dissolved Oxygen ◽  
River Estuary ◽  
Swan River ◽  
Sediment Interface ◽  
Oxygen Concentrations

Stratification and salt-wedge in the Seomjin river estuary under the idealized tidal influence

2017 ◽  
Vol 52 (4) ◽  
pp. 469-487 ◽  
Author(s):  
Jin Hwan Hwang ◽  
Dongmin Jang ◽  
Yong Hoon Kim
Keyword(s):  
River Estuary ◽  
Salt Wedge ◽  
Tidal Influence ◽  
Seomjin River

Salt-Wedge Response to Variable River Flow and Sea-Level Rise in the Microtidal Rječina River Estuary, Croatia

2017 ◽  
Vol 33 (4) ◽  
pp. 802-814 ◽  
Author(s):  
Nino Krvavica ◽  
Vanja Travaš ◽  
Nevenka Ožanić
Keyword(s):  
Sea Level Rise ◽  
Sea Level ◽  
River Flow ◽  
River Estuary ◽  
Salt Wedge ◽  
And Sea Level

Hypoxia-based habitat compression in the Neuse River Estuary: context-dependent shifts in behavioral avoidance thresholds

2002 ◽  
Vol 59 (6) ◽  
pp. 952-965 ◽  
Author(s):  
Lisa A Eby ◽  
Larry B Crowder
Keyword(s):  
Dissolved Oxygen ◽  
Nutrient Loading ◽  
Sublethal Effects ◽  
River Estuary ◽  
Classification And Regression Tree ◽  
Neuse River Estuary ◽  
Estuarine Fish ◽  
Behavioral Avoidance ◽  
Context Dependent ◽  
Oxygen Concentrations

Anthropogenic activities in estuarine watersheds alter physical and chemical characteristics of these ecosystems. Increased nutrient loading and changes in hydrology affect oxygen budgets and subsequently alter the spatial and temporal extent of hypoxia. We used classification and regression tree analyses to examine behavioral avoidance thresholds over a range of dissolved oxygen concentrations. In an examination of 10 fish species, all avoided areas with dissolved oxygen concentrations of <2.0 mg·L–1. Our data suggest that the dissolved oxygen avoidance threshold expressed by fish may be context-dependent. Specifically, the spatial extent of hypoxia significantly affected avoidance thresholds. Fish may occupy poorer quality habitat (areas with lower dissolved oxygen levels) as conditions worsen and the size of the oxygenated refuge shrinks. When the entire estuary is oxygenated, fish utilize all depths. During hypoxic episodes, fish are restricted to oxygenated, shallow, warmer areas. This habitat compression may result in higher densities and greater overlap with potential competitors and predators. Hypoxic zones alter habitat use and may increase bioenergetic costs, potentially resulting in sublethal effects, i.e., decreased growth and condition, on the estuarine fish community.

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