Trophic positions and predator–prey mass ratio of the pelagic food web in the East China Sea and Sea of Japan

2016 ◽  
Vol 67 (11) ◽  
pp. 1692 ◽  
Author(s):  
Seiji Ohshimo ◽  
Hiroshige Tanaka ◽  
Koh Nishiuchi ◽  
Tohya Yasuda
Keyword(s):  
Food Web ◽  
Food Webs ◽  
East China Sea ◽  
Sea Of Japan ◽  
Trophic Position ◽  
Mass Ratio ◽  
The East China Sea ◽  
Predator Prey ◽  
Prey Mass ◽  
Scaled Models

Size-based food webs analysis is essential for understanding food web structure and evaluating the effects of human exploitation on food webs. We estimated the predator–prey mass ratio (PPMR) of the pelagic food web in the East China Sea and Sea of Japan by using the relationships between body mass and trophic position. Trophic position was calculated by additive and scaled models based on nitrogen stable isotope ratios (δ15N). The PPMRs based on additive and scaled models were 5032 (95% confidence interval (CI) 2066–15506) and 3430 (95% CI 1463–10083) respectively. The comparatively high PPMRs could reflect low ecosystem transfer efficiency and high metabolic rate.

scholarly journals Estimation of predator-prey mass ratios using stable isotopes: sources of errors

2014 ◽  
Author(s):  
Eric Hertz ◽  
James Robinson ◽  
Marc Trudel ◽  
Asit Mazumder ◽  
Julia K Baum
Keyword(s):  
Stable Isotopes ◽  
Food Web ◽  
North Sea ◽  
Trophic Position ◽  
Trophic Levels ◽  
Environmental Stability ◽  
Food Web Structure ◽  
Predator Prey ◽  
Web Structure ◽  
Prey Mass

In aquatic systems, the ratio of predator mass to prey mass (PPMR) is an important constraint on food web structure, and has been correlated with environmental stability. One common approach of estimating PPMR uses nitrogen stable isotopes (δ15N) as an indicator of trophic position, under the assumption that the discrimination between diet and tissue is constant with increasing diet δ15N (an additive approach). However, recent studies have shown that this assumption may not be valid, and that there is a negative trend between the δ15N of the diet and the discrimination value (a scaled approach). We estimated PPMR for a simulated food web using the traditional additive approach and improved scaled approach, before testing our predictions with isotope samples from a North Sea food web. Our simulations show that the additive approach gives incorrect estimates of PPMR, and these biases are reflected in North Sea PPMR estimates. The extent of the bias is dependent on the baseline δ15N and trophic level sampled, with the greatest differences for samples with low baseline δ15N sampled at lower trophic levels. The scaled approach allows for the comparison of PPMR across varying δ15N baselines and trophic levels, and will refine estimates of PPMR.

scholarly journals Estimation of predator-prey mass ratios using stable isotopes: sources of errors

2014 ◽  
Author(s):  
Eric Hertz ◽  
James Robinson ◽  
Marc Trudel ◽  
Asit Mazumder ◽  
Julia K Baum
Keyword(s):  
Stable Isotopes ◽  
Food Web ◽  
North Sea ◽  
Trophic Position ◽  
Trophic Levels ◽  
Environmental Stability ◽  
Food Web Structure ◽  
Predator Prey ◽  
Web Structure ◽  
Prey Mass

In aquatic systems, the ratio of predator mass to prey mass (PPMR) is an important constraint on food web structure, and has been correlated with environmental stability. One common approach of estimating PPMR uses nitrogen stable isotopes (δ15N) as an indicator of trophic position, under the assumption that the discrimination between diet and tissue is constant with increasing diet δ15N (an additive approach). However, recent studies have shown that this assumption may not be valid, and that there is a negative trend between the δ15N of the diet and the discrimination value (a scaled approach). We estimated PPMR for a simulated food web using the traditional additive approach and improved scaled approach, before testing our predictions with isotope samples from a North Sea food web. Our simulations show that the additive approach gives incorrect estimates of PPMR, and these biases are reflected in North Sea PPMR estimates. The extent of the bias is dependent on the baseline δ15N and trophic level sampled, with the greatest differences for samples with low baseline δ15N sampled at lower trophic levels. The scaled approach allows for the comparison of PPMR across varying δ15N baselines and trophic levels, and will refine estimates of PPMR.

scholarly journals Predator-prey mass ratio drives microbial activity under dry conditions inSphagnumpeatlands

2018 ◽  
Vol 8 (11) ◽  
pp. 5752-5764 ◽  
Author(s):  
Monika K. Reczuga ◽  
Mariusz Lamentowicz ◽  
Matthieu Mulot ◽  
Edward A. D. Mitchell ◽  
Alexandre Buttler ◽  
...  
Keyword(s):  
Microbial Activity ◽  
Mass Ratio ◽  
Predator Prey ◽  
Dry Conditions ◽  
Prey Mass

scholarly journals Trophic structure of the pelagic food web in the East China Sea

2015 ◽  
Vol 54 (1) ◽  
Author(s):  
Mei-Ling Bai ◽  
Fan-Sian Lin ◽  
Yu-Ching Lee ◽  
Gwo-Ching Gong ◽  
Chih-hao Hsieh
Keyword(s):  
Food Web ◽  
East China Sea ◽  
Trophic Structure ◽  
East China ◽  
The East China Sea ◽  
China Sea ◽  
Pelagic Food Web

scholarly journals Finless porpoises (Neophocaena asiaeorientalis) in the East China Sea: insights into feeding habits using morphological, molecular, and stable isotopic techniques

2017 ◽  
Vol 74 (10) ◽  
pp. 1628-1645 ◽  
Author(s):  
Bingyao Chen ◽  
Lin Wang ◽  
Hui Wang ◽  
Shanshan Li ◽  
Thomas A. Jefferson ◽  
...  
Keyword(s):  
East China Sea ◽  
Prey Species ◽  
Trophic Position ◽  
Feeding Habits ◽  
Stomach Contents ◽  
East China ◽  
The East China Sea ◽  
Stable Isotopic ◽  
Short And Long Term

Describing feeding habits of cetaceans is crucial to understanding their feeding strategies and conservation status. Here, both morphological and molecular techniques were employed to identify the stomach contents of 122 finless porpoises (Neophocaena spp.) in the East China Sea for insight into their short-term feeding habits, and stable isotopes of δ13C and δ15N were used to analyze prey resource use and trophic position as a manifestation of their long-term feeding habits. In total, 33 prey species consisting of 19 teleosts, seven crustaceans, five cephalopods, and two gastropods were identified. In both short- and long-term analyses, teleosts represented primary prey, cephalopods and crustaceans were secondary prey, and gastropods were occasional prey; but the primary prey species composition differs between the short- and long-term diets. The composition of stomach contents showed sexual and age-related variation. This finding is supported by stable isotopic analyses, which indicated the separation of trophic position of adult males, adult females, and young males. In general, finless porpoises prey on species that are primarily caught by fisheries.

Predator–prey mass ratio revisited: does preference of relative prey body size depend on individual predator size?

2016 ◽  
Vol 30 (12) ◽  
pp. 1979-1987 ◽  
Author(s):  
Cheng‐Han Tsai ◽  
Chih‐hao Hsieh ◽  
Takefumi Nakazawa
Keyword(s):  
Body Size ◽  
Mass Ratio ◽  
Predator Prey ◽  
Predator Size ◽  
Prey Mass

scholarly journals Loss of functionally unique species may gradually undermine ecosystems

2010 ◽  
Vol 278 (1713) ◽  
pp. 1886-1893 ◽  
Author(s):  
Eoin J. O'Gorman ◽  
Jon M. Yearsley ◽  
Tasman P. Crowe ◽  
Mark C. Emmerson ◽  
Ute Jacob ◽  
...  
Keyword(s):  
Food Web ◽  
Food Webs ◽  
Ecosystem Functioning ◽  
Trophic Position ◽  
Interaction Strength ◽  
Natural Systems ◽  
Interacting Species ◽  
Weakly Interacting ◽  
Taxonomic Groups ◽  
Unique Species

Functionally unique species contribute to the functional diversity of natural systems, often enhancing ecosystem functioning. An abundance of weakly interacting species increases stability in natural systems, suggesting that loss of weakly linked species may reduce stability. Any link between the functional uniqueness of a species and the strength of its interactions in a food web could therefore have simultaneous effects on ecosystem functioning and stability. Here, we analyse patterns in 213 real food webs and show that highly unique species consistently tend to have the weakest mean interaction strength per unit biomass in the system. This relationship is not a simple consequence of the interdependence of both measures on body size and appears to be driven by the empirical pattern of size structuring in aquatic systems and the trophic position of each species in the web. Food web resolution also has an important effect, with aggregation of species into higher taxonomic groups producing a much weaker relationship. Food webs with fewer unique and less weakly interacting species also show significantly greater variability in their levels of primary production. Thus, the loss of highly unique, weakly interacting species may eventually lead to dramatic state changes and unpredictable levels of ecosystem functioning.

Depth-specific patterns in benthic–planktonic food web relationships in Lake Superior

2006 ◽  
Vol 63 (7) ◽  
pp. 1496-1503 ◽  
Author(s):  
Michael E Sierszen ◽  
Gregory S Peterson ◽  
Jill V Scharold
Keyword(s):  
Great Lakes ◽  
Food Web ◽  
Food Webs ◽  
Water Column ◽  
Trophic Position ◽  
Lake Superior ◽  
Benthic Algae ◽  
Isotope Ratios ◽  
Food Sources ◽  
Large Lakes

In an investigation of the spatial characteristics of Laurentian Great Lakes food webs, we examined the trophic relationship between benthic amphipods (Diporeia) and plankton in Lake Superior. We analyzed the carbon and nitrogen stable isotope ratios of Diporeia and plankton at stations in water column depths of 4–300 m. Neither δ15N nor δ13C of plankton from the upper 50 m of the water column varied significantly with station depth. Diporeia isotope ratios exhibited depth-specific patterns reflecting changes in food sources and food web relationships with plankton. Diporeia was 13C enriched at station depths of <40 m, reflecting increased dietary importance of benthic algae. There was a systematic increase in Diporeia δ15N with depth, which appeared to result from a combination of dietary shifts in the nearshore and decompositional changes in Diporeia's principal food, sedimented plankton, in deep habitats. Diporeia δ13C and δ15N together described changes in food web isotope baseline with depth. They also discriminated three depth strata representing photic, mid-depth, and profundal zones. These findings have implications for our understanding of Great Lakes food webs and analyses of trophic position within them, the ecology of zoobenthos and plankton communities, and sampling designs for large lakes.

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