UNASSIGNED: Total @entity349 levels in aquatic birds and fish communities have been monitored across the Canadian Great Lakes by Environment and Climate Change Canada (ECCC) for the past 42 years (1974-2015). These data (22 sites) were used to examine spatio-temporal variability of @entity349 levels in herring gull (Larus argentatus) eggs, @entity17360 trout (Salvelinus namaycush), @entity68913 ( @entity68913 ), and @entity41817 ( @entity41817 ). Trends were quantified with dynamic linear models, which provided time-variant rates of change of @entity349 concentrations. Lipid content (in both fish and eggs) and length in fish were used as covariates in all models. For the first three decades, @entity349 levels in gull eggs and fish declined at all stations. In the 2000s, trends for herring gull eggs reversed at two sites in @entity17360 Erie and two sites in @entity17360 Ontario. Similar trend reversals in the 2000s were observed for @entity17360 trout in @entity17360 Superior and at a single station in @entity17360 Ontario. @entity349 levels in @entity17360 trout continued to slowly decline at all of the remaining stations, except for @entity17360 Huron, where the levels remained stable. A post-hoc Bayesian regression analysis suggests strong trophic interactions between herring gulls and @entity41817 in @entity17360 Superior and @entity17360 Ontario, but also pinpoints the likelihood of a trophic decoupling in @entity17360 Huron and @entity17360 Erie. Continued monitoring of @entity349 levels in herring gulls and fish is required to consolidate these trophic shifts and further evaluate their broader implications.

XXXX levels in herring gulls and fish: 42 years of spatio-temporal trends in the Great Lakes.

@entity349 :: ('MESH:D008628', 'Chemical') :: ['Mercury', 'mercury'] @entity41817 :: ('8014', 'Species') :: ['rainbow smelt', 'Osmerus mordax'] @entity68913 :: ('283036', 'Species') :: ['Sander vitreus', 'walleye'] @entity17360 :: ('83971', 'Species') :: ['Lake', 'lake']
@entity349 :: (MESH:D008628,Chemical) :: ['Mercury']
