scholarly journals A food chain ecoepidemic model: Infection at the bottom trophic level

2015 ◽  
Vol 21 ◽  
pp. 233-245 ◽  
Author(s):  
Alessandra De Rossi ◽  
Francesco Lisa ◽  
Luca Rubini ◽  
Alberto Zappavigna ◽  
Ezio Venturino
Keyword(s):  
Trophic Level ◽  
Food Chain

TOXICITY AND BIOACCUMULATION OF SELENIUM TO A THREE–TROPHIC LEVEL FOOD CHAIN

1996 ◽  
Vol 15 (3) ◽  
pp. 340 ◽  
Author(s):  
Michael G. Dobbs ◽  
Donald S. Cherry ◽  
John Cairns Jr.
Keyword(s):  
Trophic Level ◽  
Food Chain

Stable carbon isotopic analysis of amino acids in a simplified food chain consisting of the green alga Chlorella spp., the calanoid copepod Calanus sinicus, and the Japanese anchovy (Engraulis japonicus)

2018 ◽  
Vol 96 (1) ◽  
pp. 23-30 ◽  
Author(s):  
Hai-zhen Liu ◽  
Lin Luo ◽  
De-ling Cai
Keyword(s):  
Amino Acids ◽  
Green Alga ◽  
Trophic Level ◽  
Food Chain ◽  
Calanoid Copepod ◽  
Trophic Levels ◽  
Japanese Anchovy ◽  
Calanus Sinicus ◽  
Engraulis Japonicus ◽  
Green Alga Chlorella

Japanese anchovy (Engraulis japonicus Temminck and Schlegel, 1846) is a keystone species in the food web of the Yellow Sea and East China Sea ecosystem. To study nutrient flow at intermediate and lower trophic levels, a controlled feeding experiment was carried out on a simplified food chain of the green alga Chlorella Beijerinck, 1890 – the calanoid copepod Calanus sinicus Brodsky, 1962 – E. japonicus. For the whole organism, bulk δ13C was found to be enriched with escalating trophic level, although the intertrophic gap in δ13C was slightly lower than the commonly reported 1.5‰ per increase in level. Furthermore, 15 amino acids (AAs) were detected in the studied organisms. Among them, the δ13C values of 12 AAs were determined and were found to exhibit diverse patterns of variation. The δ13C levels of essential AAs changed very little and were highly correlated across trophic levels, indicating that they underwent little trophic fractionation and were mainly ingested by the consumers from the proteins in their food. In contrast, the δ13C values of nonessential AAs differed greatly across trophic levels, indicating that the nonessential AAs in consumers were synthesized de novo from food proteins. The fractionation pattern of nonessential AAs may depend on the carbon pool and the AA composition of the organism at the lower trophic level.

Food Chain Structure in Ontario Lakes Determines PCB Levels in Lake Trout (Salvelinus namaycush) and Other Pelagic Fish

1990 ◽  
Vol 47 (10) ◽  
pp. 2030-2038 ◽  
Author(s):  
J. B. Rasmussen ◽  
D. J. Rowan ◽  
D. R. S. Lean ◽  
J. H. Carey
Keyword(s):  
Trophic Level ◽  
Lipid Content ◽  
Food Chain ◽  
Organic Contaminants ◽  
Lake Trout ◽  
Chain Structure ◽  
Food Chains ◽  
Species Introductions ◽  
Top Predators ◽  
Glacial Relict

The trophic structure of pelagic communities in lakes of glaciated regions is highly variable due to restricted dispersal of glacial relict taxa and recent species introductions. Much of the enormous between-lake variability in PCB levels in lake trout flesh (15–10 000 ng/g) from the St. Lawrence system results from differences in the length of pelagic food chains. Ontario Ministry of the Environment data (1978–81) on PCB concentrations in lake trout flesh indicate that PCB concentrations increased with the length of the food chain and tissue lipid content, and decreased with distance north of urban-industrial centres. Each trophic level contributed about a 3.5-fold biomagnification factor to the PCB concentrations in the trout, and the lipid content of the trout flesh increased by a factor of 1.5 for each additional trophic level. An empirical model capable of predicting PCB levels in pelagic salmonids and forage fish (smelt and coregonids) indicated that biomagnification of small atmospheric inputs of persistent lipophilic contaminants can explain the frequent occurrence of high levels of contaminants in some biota from remote areas, and that species introductions that lengthen food chains will lead to significant increases in levels of atmospherically dispersed persistent organic contaminants in top predators.

Predation, Yield, and Ecological Efficiency in Aquatic Food Chains

1976 ◽  
Vol 33 (2) ◽  
pp. 313-316 ◽  
Author(s):  
L. M. Dickie
Keyword(s):  
Primary Production ◽  
Trophic Level ◽  
Food Chain ◽  
Food Chains ◽  
Ecological Efficiency ◽  
Aquatic Food ◽  
Predation Rates

Given constancy of biomasses and sizes of predators and prey, the basic ecological equations are used to show that relative predation rates must increase rapidly as trophic level in aquatic food-chains drops towards primary production. The implications of this conclusion for exploitation at different food-chain levels is discussed.

Synchrony in Metapopulations with Sporadic Dispersal

2015 ◽  
Vol 25 (07) ◽  
pp. 1540002 ◽  
Author(s):  
Russell Jeter ◽  
Igor Belykh
Keyword(s):  
Trophic Level ◽  
Food Chain ◽  
Meteorological Conditions ◽  
Ecological Networks ◽  
Chain Model ◽  
Spatial Synchrony ◽  
Short Term ◽  
Realistic Assumption ◽  
Metapopulation Persistence ◽  
Food Chain Model

We study synchronization in ecological networks under the realistic assumption that the coupling among the patches is sporadic/stochastic and due to rare and short-term meteorological conditions. Each patch is described by a tritrophic food chain model, representing the producer, consumer, and predator. If all three species can migrate, we rigorously prove that the network can synchronize as long as the migration occurs frequently, i.e. fast compared to the period of the ecological cycle, even though the network is disconnected most of the time. In the case where only the top trophic level (i.e. the predator) can migrate, we reveal an unexpected range of intermediate switching frequencies where synchronization becomes stable in a network which switches between two nonsynchronous dynamics. As spatial synchrony increases the danger of extinction, this counterintuitive effect of synchrony emerging from slower switching dispersal can be destructive for overall metapopulation persistence, presumably expected from switching between two dynamics which are unfavorable to extinction.

scholarly journals Plastic Litter as Pollutant in the Aquatic Environment: A mini-review

2020 ◽  
Vol 12 (1) ◽  
pp. 167
Author(s):  
Rifka Rimbi Anggraini ◽  
Yenny Risjani ◽  
Uun Yanuhar
Keyword(s):  
Environmental Health ◽  
Trophic Level ◽  
Food Chain ◽  
Aquatic Environment ◽  
Negative Impact ◽  
Trophic Levels ◽  
Aquatic Biota ◽  
Chain Process ◽  
Special Concern ◽  
Entire World

HighlightThe issue of plastic litter and microplastics which is currently of special concern in global particularly IndonesiaThe review of size, colour and shape of microplastics that becomes part of the plastic litterThe observed review highlight of plastic litter and microplastics impact on environmental health particularly aquatic biotaAbstractThe negative impact that comes from plastic litter in the aquatic environment is a scourge for the entire world including Indonesia.Plastic litter has a huge influence on the most biota who lives in symbiosis with along the aquatic environment as it is able to sustainability. Moreover, there are other factors that cause the death of aquatic biota. Nowadays, the negative impact of plastic litter occurs on an ongoing basis through the food chain process which until now has not been well studied. Therefore, it is necessary to do further studies on the influence of the food chain as a vector of plastic litter distribution, particularly microplastic on aquatic biota from the first trophic level to high trophic levels. 

Toxicity and bioaccumulation of selenium to a three-trophic level food chain

1996 ◽  
Vol 15 (3) ◽  
pp. 340-347 ◽  
Author(s):  
Michael G. Dobbs ◽  
Donald S. Cherry ◽  
John Cairns
Keyword(s):  
Trophic Level ◽  
Food Chain

scholarly journals Does moving up a food chain increase aggregation in parasites?

2016 ◽  
Vol 13 (118) ◽  
pp. 20160102 ◽  
Author(s):  
R. J. G. Lester ◽  
R. McVinish
Keyword(s):  
Stochastic Model ◽  
Trophic Level ◽  
Food Chain ◽  
Feeding Behaviour ◽  
Parasite Species ◽  
Fish Parasites ◽  
Data Points ◽  
Parasite Aggregation ◽  
High Parasite ◽  
Chain Increase

General laws in ecological parasitology are scarce. Here, we evaluate data on numbers of fish parasites published by over 200 authors to determine whether acquiring parasites via prey is associated with an increase in parasite aggregation. Parasite species were grouped taxonomically to produce 20 or more data points per group as far as possible. Most parasites that remained at one trophic level were less aggregated than those that had passed up a food chain. We use a stochastic model to show that high parasite aggregation in predators can be solely the result of the accumulation of parasites in their prey. The model is further developed to show that a change in the predators feeding behaviour with age may further increase parasite aggregation.

scholarly journals Komposisi Jenis dan Tingkat Trofik (Trophic Level) Hasil Tangkapan Bagan di Perairan Desa Ohoililir, Kabupaten Maluku Tenggara

2018 ◽  
pp. 43
Author(s):  
Erna Almohdar ◽  
Fabian N. J Souisa
Keyword(s):  
Trophic Level ◽  
Food Chain

Upaya untuk mempertahankan keanekaragaman jenis di dalam suatu ekosistem dan ikan yang dimanfaatkan oleh manusia merupakan bagian yang tidak dapat dipisahkan dari ekosistem secara keseluruhan. Tingkatan trofik menggambarkan tahapan transfer material atau energi dari setiap tingkat atau kelompok ke tingkat berikutnya, yang dimulai dengan produsen primer, konsumen primer (herbivora), sekunder, tersier, dan predator puncak. Pada dasarnya tingkat trofik (trophic level) merupakan urutan tingkat pemanfaatan pakan atau material dan energi seperti yang tergambarkan oleh rantai makanan (food chain). Tujuan penelitian adalah untuk menganalisis komposisi jenis dan tingkat trofik hasil tangkapan bagan di perairan Desa Ohoililir, Kabupaten Maluku Tenggara. Variabel yang diamati meliputi komposisi jenis, panjang dan berat ikan serta tingkat trofik hasil tangkapan. Alat tangkap yang digunakan saat pengamatan adalah bagan. Metode yang digunakan dalam penelitian ini adalah metode experimental fishing, yaitu berupa operasi penangkapan ikan menggunakan alat tangkap bagan. Hasil penelitian menunjukan tingkat trofik ikan pada alat tangkap bagan berada pada pengelompokan tingkat trofik (TL3) yakni didominasi oleh jenis Omnivora yang cenderung pemakan hewan, yang akan menyebabkan struktur komunitas ikan menjadi berubah dan piramida menjadi tidak stabil. Untuk mengatasi hal tersebut dibutuhkan pengelolaan sumberdaya ikan berdasarkan pendekatan interaksi trofik dengan mempertimbangkan komponen ekosistem seperti sumberdaya ikan dan berbagai pola hubungan makan memakan atau rantai dan jaring makanan.

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