نتایج جستجو برای: benthic health

تعداد نتایج: 990175  

2016
Jenny Ask Owen Rowe Sonia Brugel Mårten Strömgren Pär Byström Agneta Andersson

In this study, we measured depth-dependent benthic microalgal primary production in a Bothnian Bay estuary to estimate the benthic contribution to total primary production. In addition, we compiled data on benthic microalgal primary production in the entire Baltic Sea. In the estuary, the benthic habitat contributed 17 % to the total annual primary production, and when upscaling our data to the...

Journal: :Science 1996
R W Buddemeier

ated with transitions to benthic communities dominated by noncalcareous benthos (4, 8). The results of Kayanne et al. (1) reveal metabolic measures to be sensitive indicators of reef health (9), but the findings more likely reflect the condition of the local sampling site than the normal behavior of healthy reef communities. Robert W. Buddemeier Kansas Geological Survey, 1930 Constant Avenue, L...

2015
Patrick T. Schwing Isabel C. Romero Gregg R. Brooks David W. Hastings Rebekka A. Larson David J. Hollander

Sediment cores were collected from three sites (1000-1200 m water depth) in the northeastern Gulf of Mexico from December 2010 to June 2011 to assess changes in benthic foraminiferal density related to the Deepwater Horizon (DWH) event (April-July 2010, 1500 m water depth). Short-lived radioisotope geochronologies (²¹⁰Pb, ²³⁴Th), organic geochemical assessments, and redox metal concentrations w...

2013
Andreas F. Haas Craig E. Nelson Forest Rohwer Linda Wegley-Kelly Steven D. Quistad Craig A. Carlson James J. Leichter Mark Hatay Jennifer E. Smith

Benthic primary producers in tropical reef ecosystems can alter biogeochemical cycling and microbial processes in the surrounding seawater. In order to quantify these influences, we measured rates of photosynthesis, respiration, and dissolved organic carbon (DOC) exudate release by the dominant benthic primary producers (calcifying and non-calcifying macroalgae, turf-algae and corals) on reefs ...

2010
Larry E. Brand Carol Stephens Charles Mazel

Our overall goal is to understand how photosynthetic and photoprotective pigments in benthic plants (primarily benthic microalgae) affect the optical properties (primarily spectral reflectance and fluorescence) of shallow benthic environments. The information gained will be used for the development and testing of rapid scanning optical techniques for detecting and assessing changes and specific...

پایان نامه :دانشگاه تربیت معلم - تهران - دانشکده علوم زمین 1393

در این پژوهش سازندهای جهرم و رازک از نظر ویژگی های سنگ شناسی، فسیل شناسی، محیط رسوبی و الکتروفاسیس در تاقدیس سرخون، در ناحیه هینترلند بندرعباس مورد ارزیابی قرار گرفته اند. ضخامت نهشته های مورد مطالعه در این چاه به طورکلی 215 متر می باشد که از عمق 3035 متری شروع و تا عمق 2820 متری ادامه می یابد. سازند جهرم 169 متر از این ضخامت را شامل می شود و سازند رازک نیز دارای 46 متر ضخامت است. درستون لیتو ا...

Journal: :international journal of environmental research 2014
f. abdolahpur monikh m. hosseini j. kazemzadeh khoei a.f. ghasemi

in this study, three stations of the north persian gulf were analyzed in order to determinethe effect of trophic levels on the concentration of harmful pahs in fish and sediment. in all cases,similar distributions were observed in which benzo(a)pyrene largely predominated andbenzo(b)fluoranthene and pyrene were the second major compounds in fish tissues. the predominantcomponents of pahs in sed...

Journal: :شیلات 0
لیما طیبی1 1. دانش آموخته دکترای تخصصی شیلات، گروه شیلات، دانشکده منابع طبیعی، دانشگاه تهران، کرج، ایران هادی پورباقر2 2. دانشیار، گروه شیلات، دانشکده منابع طبیعی، دانشگاه تهران، کرج، ایران حمید فرحمند3 3. استاد، گروه شیلات، دانشکده منابع طبیعی، دانشگاه تهران، کرج، ایران غلامرضا رفیعی3 3. استاد، گروه شیلات، دانشکده منابع طبیعی، دانشگاه تهران، کرج، ایران علیرضا میرواقفی3 3. استاد، گروه شیلات، دانشکده منابع طبیعی، دانشگاه تهران، کرج، ایران

the gamasiab river has one of the highest discharge in the western iran receiving wastewater of trout frames. the present study investigated effects of wastewater using bioassessment of benthic organisms. the benthos were sampled over four seasons using a surber sampler on four stations, upstream, on the farm outlet, 500 and 1000 m down the farm outlet. 5454 benthic fauna were identified that w...

Journal: :Environmental monitoring and assessment 2011
Andrew K Leight Ward H Slacum Ed F Wirth Mike H Fulton

We examined benthic condition in three small watersheds in the Chesapeake Bay. Characterization of benthic condition was based on the combined measurements of benthic fauna, sediment toxicity, and sediment contaminant loads. Significant differences between watersheds were detected for sediment contaminant concentrations and water quality. The intensity of benthic impairment was greatest in the ...

A. M. Gozler, B. Verep, Ç. Eruz, C. Şahin, E. Agirbas, L. Tolun, M. Mantikci, N.S. Bascinar, S. Serdar,

The present study was conducted to examine the impact of cage aquaculture on benthic communities in coastal areas (depth 25 to 50 m) from fish farming operations located along the southeastern Black Sea (Ordu-Perşembe, Trabzon-Yomra and Rize central). Sampling was conducted seasonally from April 2007 to 2009. Sediment samples were taken using Ekman Grab (box core- 0.04 m2). Temperature, salinit...

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