Carbon-based balanced trophic structure and flows in the offshore Lake Ontario food web before (1987–1991) and after (2001–2005) invasion-induced ecosystem change

2011 ◽  
Vol 222 (3) ◽  
pp. 692-708 ◽  
Author(s):  
Thomas. J. Stewart ◽  
W. Gary Sprules
Keyword(s):  
Food Web ◽  
Trophic Structure ◽  
Lake Ontario ◽  
Ecosystem Change ◽  
Carbon Based

Biomagnification of α- and γ-Hexabromocyclododecane Isomers in a Lake Ontario Food Web

2004 ◽  
Vol 38 (8) ◽  
pp. 2298-2303 ◽  
Author(s):  
Gregg T. Tomy ◽  
Wes Budakowski ◽  
Thor Halldorson ◽  
D. Michael Whittle ◽  
Micahel J. Keir ◽  
...  
Keyword(s):  
Food Web ◽  
Lake Ontario

scholarly journals Trophic structure of a nektobenthic community exploited by a multispecific bottom trawling fishery in Northeastern Brazil

PLoS ONE ◽  
2021 ◽  
Vol 16 (2) ◽  
pp. e0246491
Author(s):  
Alex Souza Lira ◽  
Flávia Lucena-Frédou ◽  
Frédéric Ménard ◽  
Thierry Frédou ◽  
Júlio Guazzelli Gonzalez ◽  
...  
Keyword(s):  
Stable Isotope ◽  
Food Web ◽  
Benthic Invertebrates ◽  
Trophic Structure ◽  
Fish Fauna ◽  
Cumulative Effects ◽  
Northeastern Brazil ◽  
Population Parameters ◽  
Bottom Trawling ◽  
Trophic Pathways

We used complementary stable isotope (SIA) and stomach content (SCA) analyses to investigate feeding relationships among species of the nektobenthic communities and the potential ecological effects of the bottom trawling of a coastal ecosystem in northeastern Brazil. Carbon (δ13C) and nitrogen (δ15N) compositions were determined for five basal sources and 28 consumers, from zooplankton to shrimp and fish species. Fishes and basal sources showed a broad range of δ15N (fishes: 6.49–14.94‰; sources: 2.58–6.79‰) and δ13C values (fishes: -23.86 to -13.71‰; sources: -24.32 to -13.53‰), while shrimps and crabs exhibited similar nitrogen and carbon ratios. Six trophic consumer groups were determined among zooplankton, crustaceans and fishes by SIA, with trophic pathways associated mostly with benthic sources. SCA results indicated a preference for benthic invertebrates, mainly worms, crabs and shrimps, as prey for the fish fauna, highlighting their importance in the food web. In overall, differences between SCA and the SIA approaches were observed, except for groups composed mainly for shrimps and some species of high δ15N values, mostly piscivorous and zoobenthivores. Given the absence of regulation for bottom trawling activities in the area, the cumulative effects of trawling on population parameters, species composition, potentially decreasing the abundance of benthic preys (e.g., shrimps, worms and crabs) may lead to changes in the trophic structure potentially affect the food web and the sustainability of the fishery.

Dechlorane plus monoadducts in a lake ontario (Canada) food web and biotransformation by lake trout (Salvelinus namaycush)liver microsomes

2013 ◽  
Vol 32 (6) ◽  
pp. 1376-1381 ◽  
Author(s):  
Gregg T. Tomy ◽  
Ed Sverko ◽  
Vince Palace ◽  
Bruno Rosenberg ◽  
Robert McCrindle ◽  
...  
Keyword(s):  
Food Web ◽  
Lake Trout ◽  
Liver Microsomes ◽  
Lake Ontario ◽  
Salvelinus Namaycush ◽  
Dechlorane Plus

From Catastrophe to Recovery: Stories of Fishery Management Success

2019 ◽  
Keyword(s):  
Food Web ◽  
Fishery Management ◽  
Conservation Status ◽  
Lake Ontario ◽  
Water Clarity ◽  
Lessons Learned ◽  
Alosa Pseudoharengus ◽  
Nutrient Inputs ◽  
Rainbow Smelt ◽  
Trawl Surveys

<i>Abstract</i>.—Fish population recoveries can result from ecosystem change in the absence of targeted restoration actions. In Lake Ontario, native Deepwater Sculpin <i>Myoxocephalus thompsonii</i> were common in the late 1800s, but by the mid-1900s the species was possibly extirpated. During this period, mineral nutrient inputs increased and piscivore abundance declined, which increased the abundance of the nonnative planktivores Alewife <i>Alosa pseudoharengus</i> and Rainbow Smelt <i>Osmerus mordax</i>. Deepwater Sculpin larvae are pelagic and vulnerable to predation by planktivores. Annual bottom trawl surveys did not capture Deepwater Sculpin from 1978 to 1995 (<i>n</i> = 6,666 tows) despite sampling appropriate habitat (trawl depths: 7–170 m). The absence of observations during this time resulted in an elevated conservation status for the species, but no restoration actions were initiated. In 1996, three individuals were caught in bottom trawls, the first observed since 1972. Since then, their abundance has increased, and in 2017, they were the second most abundant Lake Ontario prey fish. The food-web changes that occurred from 1970 through the 1990s contributed to this recovery. Alewife and Rainbow Smelt abundance declined during this period due to predation by stocked salmonids and legislation that reduced nutrient inputs and food web productivity. In the 1990s, proliferation of nonnative, filter-feeding dreissenid mussels dramatically increased water clarity. As light penetration increased, the early-spring depth distribution of Alewife and Rainbow Smelt shifted deeper, away from larval Deepwater Sculpin habitat. The intentional and unintentional changes that occurred in Lake Ontario were not targeted at Deepwater Sculpin restoration but resulted in conditions that favored the species’ recovery. While standard surveys documented the recovery, more diverse information (e.g., observations in deep habitats and early-life stages) would have improved our understanding of why the species recovered when it did. Annual Lake Ontario trawl surveys have collaboratively expanded their spatial extent and diversified habitat sampled, based on lessons learned from the Deepwater Sculpin recovery.

Trophic Structure and Biomagnification of Total Mercury in Ray Species Within a Benthic Food Web

2019 ◽  
Vol 77 (3) ◽  
pp. 321-329 ◽  
Author(s):  
Daniela A. Murillo-Cisneros ◽  
Todd M. O’Hara ◽  
Fernando R. Elorriaga-Verplancken ◽  
Alberto Sánchez-González ◽  
Emigdio Marín-Enríquez ◽  
...  
Keyword(s):  
Food Web ◽  
Trophic Structure ◽  
Total Mercury ◽  
Benthic Food Web ◽  
Benthic Food

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

The threat of exotic species to the food web in Lake Ontario

2006 ◽  
Vol 29 (3) ◽  
pp. 1194-1198 ◽  
Author(s):  
M. Munawar ◽  
I.F. Munawar ◽  
R. Dermott ◽  
M. Fitzpatrick ◽  
H. Niblock
Keyword(s):  
Food Web ◽  
Exotic Species ◽  
Lake Ontario

Temporal trends of polychlorinated biphenyls (PCBs) in Lake Ontario fish and invertebrates

1999 ◽  
Vol 7 (4) ◽  
pp. 203-223 ◽  
Author(s):  
E Bentzen ◽  
D Mackay ◽  
B E Hickie ◽  
D RS Lean
Keyword(s):  
Food Web ◽  
Lake Trout ◽  
Temporal Trends ◽  
Lake Ontario ◽  
Fish Food ◽  
International Joint Commission ◽  
Analytical Protocol ◽  
Fish Lipid ◽  
Key Species ◽  
Aquatic Food

A comprehensive review is presented of changes of PCB concentrations in aquatic biota collected from Lake Ontario between 1977 and 1993, with emphasis on data for lake trout. Results of three major lake trout surveys from Canadian and United States agencies indicate lake trout PCBs have declined from the early 1980s, but changes in recent years are masked by interannual variability. These results also apply to other biota in the aquatic food web. PCB concentrations were consistent among the surveys after consideration of fish lipid content, age or size and analytical protocol. Variability of 20 to 30% in annual average estimates is attributed to both analytical and in situ sources. Current levels of PCBs in many salmonids exceed PCB consumption and wildlife protection advisories. The average half-life for PCBs in Lake Ontario biota is about 12 years and it will take three to four times that to reach the International Joint Commission target of 100 ng/g (ww) for protection of wildlife. It is essential that the design of monitoring programs ensures consistent, coordinated sampling and analysis. A monitoring strategy of annual sampling of key species supplemented with periodic intensive sampling of the entire food web (e.g., every 5 years) is suggested as more effective than current practices. There is a frequently neglected need for fuller interpretation of contaminant dynamics based on complementary research on the nature of the changing biotic and abiotic environments in a complex aquatic ecosystem like Lake Ontario. Key words: Lake Ontario, PCBs, fish, food webs, monitoring data, bioaccumulation.

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