scholarly journals Indirect Effects of Predation in a Freshwater, Benthic Food Chain

Ecology ◽  
1992 ◽  
Vol 73 (5) ◽  
pp. 1662-1674 ◽  
Author(s):  
Christer Bronmark ◽  
Steven P. Klosiewski ◽  
Roy A. Stein
Keyword(s):  
Food Chain ◽  
Indirect Effects ◽  
Benthic Food

Competition, predation and flow rate as mediators of direct and indirect effects in a stream food chain

Oecologia ◽  
2008 ◽  
Vol 157 (1) ◽  
pp. 93-104 ◽  
Author(s):  
S. Blanchet ◽  
G. Loot ◽  
J. J. Dodson
Keyword(s):  
Flow Rate ◽  
Food Chain ◽  
Indirect Effects ◽  
Direct And Indirect Effects

scholarly journals TRANSFER OF RADIOCAESIUM FROM CONTAMINATED BOTTOM SEDIMENTS TO MARINE ORGANISMS THROUGH BENTHIC FOOD CHAIN IN POST-FUKUSHIMA AND POST-CHERNOBYL PERIODS

2016 ◽  
Author(s):  
Roman Bezhenar ◽  
Kyung Tae Jung ◽  
Vladimir Maderich ◽  
Stefan Willemsen ◽  
Govert de With ◽  
...  
Keyword(s):  
Baltic Sea ◽  
Bottom Sediments ◽  
Food Chain ◽  
Demersal Fish ◽  
Marine Organisms ◽  
Benthic Organisms ◽  
The Baltic Sea ◽  
Benthic Food ◽  
The Baltic ◽  
Deposit Feeding

Abstract. After the earthquake and tsunami on 11 March, 2011 damaged the Fukushima Dai-ichi Nuclear Power Plant (FDNPP), an accidental release of a large amount of radioactive isotopes into both the air and the ocean occurred. Measurements provided by the Japanese agencies over the past four years show that elevated concentrations of 137Cs still remain in sediments, benthic organisms and demersal fishes in the coastal zone around the FDNPP. These observations indicate that there are 137Cs transfer pathways from bottom sediments to the marine organisms. To describe the transfer quantitatively, the dynamic food chain model BURN has been extended to include benthic marine organisms. The extended model takes into account both pelagic and benthic marine organisms grouped into several classes based on their trophic level and type of species: phytoplankton, zooplankton, and fishes (two types: piscivorous and non-piscivorous) for the pelagic food chain; deposit feeding invertebrates, demersal fishes feeding by benthic invertebrates and bottom omnivorous predators for the benthic food chain; crustaceans, molluscs and coastal predators feeding on both pelagic and benthic organisms. Bottom invertebrates ingest organic parts of bottom sediments with adsorbed radionuclides which then migrate up through the food chain. All organisms take radionuclides directly from water as well as food. The model was implemented into the compartment model POSEIDON-R and applied to the Northwestern Pacific for the period of 1945–2010 and then for the period of 2011–2020 to assess the radiological consequences of releases of 137Cs due to FDNPP accident. The model simulations for activity concentrations of 137Cs in both pelagic and benthic organisms in the coastal area around the FDNPP agree well with measurements for the period of 2011–2015. The decrease constant in the fitted exponential function of simulated concentration for the deposit ingesting invertebrates (0.45 y–1) is close to the decrease constant for the sediment observations (0.44 y–1), indicating that the gradual decrease of activity in the demersal fish (decrease constant is 0.46 y–1) was caused by the transfer of activity from organic matter deposited in bottom sediment through the deposit feeding invertebrates. The estimated from model transfer coefficient from bulk sediment to demersal fish in the model for 2012–2020 (0.13) is larger than that to the deposit feeding invertebrates (0.07) due to the biomagnification effect. In addition, the transfer of 137Cs through food webs for the period of 1945–2020 has been modelled for the Baltic Sea that was essentially contaminated due to global fallout and the Chernobyl accident. The model simulation results obtained with generic parameters are also in good agreement with available measurements in the Baltic Sea. Due to weak water exchange with the North Sea of the semi-enclosed Baltic Sea the chain of water-sediments- biota slowly evolves into a quasi-equilibrium state unlike the processes off the open Pacific Ocean coast where the FDNPP is located. Obtained results demonstrate the importance of the benthic food chain in the long-term transfer of 137Cs from contaminated bottom sediments to marine organisms and the potential of a generic model for the use in different regions of the World Ocean.

scholarly journals Is there a BMAA transfer in the pelagic and benthic food webs in the Baltic Sea?

2018 ◽  
Author(s):  
Nadezda Zguna ◽  
Agnes Karlson ◽  
Leopold L. Ilag ◽  
Andrius Garbaras ◽  
Elena Gorokhova
Keyword(s):  
Baltic Sea ◽  
Food Webs ◽  
Food Chain ◽  
Benthic Invertebrates ◽  
The Baltic Sea ◽  
Phytoplankton Communities ◽  
Benthic Food ◽  
Benthic Food Webs ◽  
The Baltic ◽  
Analytical Approaches

AbstractThe evidence regarding BMAA occurrence in the Baltic Sea is contradictory, with benthic sources appearing to be more important than pelagic ones. The latter is counterintuitive considering that pelagic primary producers, such as diatoms, dinoflagellates, and cyanobacteria, are the only plausible source of this compound in the food webs. To elucidate BMAA distribution in trophic pathways, we analyzed BMAA in the pelagic and benthic food webs sampled in summer 2010 in the Northern Baltic Proper. As potential BMAA sources, phytoplankton communities in early and late summer were used. As pelagic consumers, zooplankton, mysids and zooplanktivorous fish (herring) were used, whereas benthic invertebrates (amphipods, priapulids, polychaetes, and clams) and benthivorous fish (perch and flounder) represented the benthic food chain. To establish the trophic structure of the system, the stable isotope (δ13C and δ15N) composition of its components was determined. Contrary to the reported ubiquitous occurrence of BMAA in the Baltic food webs, only phytoplankton and lower consumers (zooplankton and mysids) of the pelagic food chain tested positive. Given that our analytical approaches were adequate, we conclude that no measurable levels of this compound occurred in the benthic invertebrates and any of the tested fish species in the study area. These findings indicate that widely assumed presence and transfer of BMAA to the top consumers in the food webs of the Baltic Sea and, possibly, other systems remain an open question. More controlled experiments and field observations are needed to understand the transfer and possible transformation of BMAA in the food web under various environmental settings.

Bioavailability of sediment-associated mercury toHexageniamayflies in a contaminated floodplain river

2000 ◽  
Vol 57 (5) ◽  
pp. 1092-1102 ◽  
Author(s):  
Teresa J Naimo ◽  
James G Wiener ◽  
W Gregory Cope ◽  
Nicolas S Bloom
Keyword(s):  
Food Chain ◽  
Methyl Mercury ◽  
Total Mercury ◽  
Dry Weight ◽  
Contaminated Sediments ◽  
Floodplain River ◽  
Test Water ◽  
Benthic Food

We examined the bioavailability of mercury in sediments from the contaminated Sudbury River (Massachusetts, U.S.A.). Mayfly nymphs (Hexagenia) were exposed in four 21-day bioaccumulation tests to contaminated and reference sediments (treatments) from reservoirs, flowing reaches, palustrine wetlands, and a riverine lake. Mean total mercury (ΣHg) ranged from 880 to 22 059 ng·g dry weight-1in contaminated sediments and from 90 to 272 ng·g-1in reference sediments. Mean final concentrations of methyl mercury (MeHg) in test water were greatest (8-47 ng Hg·L-1) in treatments with contaminated wetland sediments, which had mean ΣHg ranging from 1200 to 2562 ng·g-1. In mayflies, final mean concentrations of MeHg were highest in treatments with contaminated wetland sediments (122-183 ng Hg·g-1), intermediate in treatments with contaminated sediments from reservoirs, flowing reaches, and a riverine lake (75-127 ng Hg·g-1), and lowest in treatments with reference sediments (32-41 ng Hg·g-1). We conclude that the potential entry of MeHg into the benthic food chain was greater in contaminated palustrine wetlands than in the contaminated reservoirs, which had the most contaminated sediments.

Does sediment resuspension by storms affect the fate of polychlorobiphenyls (PCBs) in the benthic food chain? Interactions between changes in POM characteristics, adsorption and absorption by the mussel Mytilus galloprovincialis

2005 ◽  
Vol 25 (19-20) ◽  
pp. 2533-2553 ◽  
Author(s):  
François Charles ◽  
Susanna Lopez-Legentil ◽  
Antoine Grémare ◽  
Jean Michel Amouroux ◽  
Martin Desmalades ◽  
...  
Keyword(s):  
Food Chain ◽  
Mytilus Galloprovincialis ◽  
Sediment Resuspension ◽  
Benthic Food

Effects of Tench and Perch on Interactions in a Freshwater, Benthic Food Chain

Ecology ◽  
1994 ◽  
Vol 75 (6) ◽  
pp. 1818-1828 ◽  
Author(s):  
Christer Bronmark
Keyword(s):  
Food Chain ◽  
Benthic Food

scholarly journals The legacy of predators: persistence of trait-mediated indirect effects in an intertidal food chain

2020 ◽  
Vol 530-531 ◽  
pp. 151416
Author(s):  
Gabriel Ng ◽  
Brian Gaylord
Keyword(s):  
Food Chain ◽  
Indirect Effects

scholarly journals Supplementary material to "TRANSFER OF RADIOCAESIUM FROM CONTAMINATED BOTTOM SEDIMENTS TO MARINE ORGANISMS THROUGH BENTHIC FOOD CHAIN IN POST-FUKUSHIMA AND POST-CHERNOBYL PERIODS"

2016 ◽  
Author(s):  
Roman Bezhenar ◽  
Kyung Tae Jung ◽  
Vladimir Maderich ◽  
Stefan Willemsen ◽  
Govert de With ◽  
...  
Keyword(s):  
Bottom Sediments ◽  
Food Chain ◽  
Marine Organisms ◽  
Supplementary Material ◽  
Benthic Food

An experimental three-step benthic food chain

1978 ◽  
Vol 20 (2) ◽  
pp. 1293-1297
Author(s):  
Bruno Streit
Keyword(s):  
Food Chain ◽  
Benthic Food
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