A tracer investigation of nitrogen cycling in a pristine tundra river

The fate of nitrogen (N) in drainages depends in part on N storage and transformation within the river network. The addition of an [15N]NH4+ isotopic tracer to a tundra river provided information on the uptake, food web transfer, and ecosystem retention of N. The fourth-order Kuparuk River ecosystem took up 60% of the NH4+ within 1 h and 1 km of the point of tracer addition. Long-lived biota and epilithon retained measurable amounts of the added 15N for up to 2 years. These transformations and storages within rivers exert control over the timing of N export, the chemical form of exported N, and, consequently, its ecological impact on downstream aquatic ecosystems.

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A FOOD WEB BIOACCUMULATION MODEL FOR ORGANIC CHEMICALS IN AQUATIC ECOSYSTEMS

Environmental Toxicology and Chemistry ◽

10.1897/03-438 ◽

2004 ◽

Vol 23 (10) ◽

pp. 2343 ◽

Cited By ~ 289

Author(s):

Jon A. Arnot ◽

Frank A.P.C. Gobas

Keyword(s):

Food Web ◽

Aquatic Ecosystems ◽

Organic Chemicals

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In-between chemical and ecological status: a systematic approach to assess the ecological impact of chemical pollution on aquatic ecosystems

SIMI 2019, Abstract Book - International Symposium "The Environmental and The Industry" ◽

10.21698/simi.2019.ab19 ◽

2019 ◽

pp. 52-52

Author(s):

Ivana Teodorovic ◽

Andreas Focks ◽

Thomas Backhaus ◽

Werner Brack

Keyword(s):

Aquatic Ecosystems ◽

Systematic Approach ◽

Ecological Impact ◽

Ecological Status ◽

Chemical Pollution ◽

Chemical And Ecological Status

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Bacterial growth response to copepod grazing in aquatic ecosystems

Journal of the Marine Biological Association of the United Kingdom ◽

10.1017/s0025315407056275 ◽

2007 ◽

Vol 87 (3) ◽

pp. 667-674 ◽

Cited By ~ 8

Author(s):

Cristian A. Vargas ◽

L. Antonio Cuevas ◽

Humberto E. González ◽

Giovanni Daneri

Keyword(s):

Food Web ◽

Bacterial Growth ◽

Bacterial Communities ◽

Aquatic Ecosystems ◽

Field Measurements ◽

Zooplankton Biomass ◽

Aquatic Environments ◽

Coastal Embayment ◽

Copepod Grazing ◽

Bacterial Assemblages

The growth rate response of bacterial communities to the potential increase of dissolved organic matter (DOM) produced by the copepod Acartia tonsa was assessed in experiments conducted in three stations representing three contrasting aquatic environments (coastal embayment, shelf and ocean). Bacterial assemblages were inoculated in filtered seawater where A. tonsa had previously grazed. Utilization of DOM over time was evaluated after the addition of bacterial inoculums as the biomass changes in both ‘control’ and ‘copepod’ treatments. In the embayment and ocean a high bacterial growth was observed in the treatments with seawater where copepod were feeding. Additional field measurements of bacterial, primary production and zooplankton biomass support the idea that bacterial communities living in oceanic environments can be efficient to utilize the newly available substrate. Copepods play a key role not only as conveyors of carbon up through the classical food-web, but also generated significant amounts of bacterial substrate in the microbial loop food-web.

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The Role of Consumers in Food Web Dynamics and Functioning of Aquatic Ecosystems

Journal of Siberian Federal University Biology ◽

10.17516/1997-1389-0096 ◽

2013 ◽

pp. 335-353

Author(s):

Golubkov Sergey M. ◽

Keyword(s):

Food Web ◽

Aquatic Ecosystems ◽

Food Web Dynamics

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Molecular diet analysis in zebra and quagga mussels (Dreissena spp.) and an assessment of the utility of aquatic filter feeders as biological eDNA filters

10.1101/2021.03.01.432951 ◽

2021 ◽

Author(s):

Sven Weber ◽

Lukas Brink ◽

Manuel Wörner ◽

Sven Künzel ◽

Michael Veith ◽

...

Keyword(s):

Food Web ◽

Water Samples ◽

Large Scale ◽

Ecological Impact ◽

Diet Analysis ◽

Alternative Source ◽

Dietary Analysis ◽

Alpha And Beta Diversity ◽

Invasive Bivalves ◽

Primer Sets

AbstractMolecular gut content analysis is a popular tool to study food web interactions and was recently also suggested as an alternative source for DNA based biomonitoring. However, the overabundant consumer’s DNA often outcompetes that of its diet during PCR. Blocking approaches are an efficient means to reduce consumer amplification while retaining broad specificity for dietary taxa. We here designed an assay to monitor the eukaryotic diet of mussels and test their utility as biological eDNA filters to monitor planktonic communities. We designed several rDNA primer sets with a broad taxonomic suitability for eukaryotes, which suppress the amplification of mussels. The primers were tested using mussel DNA extracts and the results were compared to eDNA water samples collected next to the mussel colonies. Taxonomic recovery, as well as patterns of alpha and beta diversity, were compared between mussels and water samples. In addition, we analyzed time series samples of mussel samples from different German rivers. Our primer sets efficiently block the amplification of various mussel genera. The recovered DNA reflects a broad dietary preference across the eukaryotic tree of life and considerable taxonomic overlap with filtered water samples. We also recover various taxa of possible commensals and parasites, associated with the mussels. Our protocol will enable large scale dietary analysis in mussels, facilitate aquatic food web analysis, elucidate the ecological impact of invasive bivalves and the rapid survey of mussel aquacultures for pathogens. Moreover, we show that mussels could serve as an interesting complementary DNA source for biomonitoring.

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Pengaruh Perbedaan Intensitas Cahaya Terhadap Kelimpahan Arthropoda di Perairan Desa Tambakpolo, Demak

Journal of Marine Research ◽

10.14710/jmr.v9i1.25776 ◽

2020 ◽

Vol 9 (1) ◽

pp. 9-12

Author(s):

Arrico Fathur Yudha Bramasta ◽

Wilis Ari Setyati ◽

Ria Azizah Tri Nuraini

Keyword(s):

Light Intensity ◽

Food Web ◽

Trophic Level ◽

Aquatic Ecosystems ◽

Sampling Method ◽

Purposive Sampling ◽

Composition And Structure

ABSTRAK: Zooplankton merupakan organisme laut yang memiliki peran dalam rantai makanan di laut. Zooplankton berperan pada tingkat energi kedua yang menghubungkan produsen (fitoplankton) dengan konsumen tingkat tinggi. Penelitian ini bertujuan untuk mengetahui komposisi dan struktur komunitas Arthropoda dengan dua perbedaan intensitas cahaya (300 lux dan 2000 lux). Penelitian ini dilakukan menggunakan metode purposive sampling yang terdiri dari tiga stasiun. Pengambilan sample zooplankton dilakukan dengan bantuan plankton net yang ditarik kapal tiga kali pengulangan. Berdasarkan penelitian ditemukan 5 genus yaitu Calanus, Paracalanus, Sergia, Eucalanus dan Candacia. Genus yang paling banyak ditemukan adalah Calanus dan Sergia. Kelimpahan Arthropoda tertinggi terdapat pada Stasiun 1 dengan intensitas 2000 lux sebesar 8.492 ind/L dan terendah pada Stasiun 3 dengan intensitas 300 lux sebesar 2.286 Ind/L, hal ini diduga karena pengaruh gaya fototastik positif dari fitoplankton terhadap sumber cahaya yang direspon baik oleh zooplankton khususnya Arthropoda sebagai sumber makanan. Tingkat keanekaragaman (H’) Arthropoda di perairan tersebut termasuk dalam kategori rendah, indeks keseragaman (E) dalam kategori rendah, dan terdapat dominansi (C). ABSTRACT: Zooplankton are those organisms which have a role in food-web in aquatic ecosystems. Zooplankton as second trophic level organism whose connects producers (phytoplankton) with consumers at a higher trophic level. This research aims to know the composition and structure of the Arthropode community with two differences in light intensity (300 lux and 2000 lux). This research was done by using purposive sampling method which consists of three stations, by using a plankton net that was pulled by the boat. The results of the study found five genera namely Calanus, Paracalanus, Sergia, Eucalanus, Candacia. The most common genera are Calanus and Sergia. The highest abundance of Arthropode at Station 1 with an intensity 2000 lux is 8.492 ind/L and the lowest at Station 3 with an intensity 300 lux is 2.286 Ind/L. The level of diversity (H') of Arthropode categorized as low, the index of uniformity (E) is categorized medium, the level of dominance (C) is classified as high.

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