Environmental and food web determinants of Lake Trout mercury concentrations in Ontario Lakes

Prey composition and availability are considered a primary predictor of Lake Trout (Salvelinus namaycush) mercury (Hg) concentrations. Evidence from other freshwater fishes suggests that environmental and landscape factors likely also contribute to fish Hg dynamics, yet comprehensive, contemporary assessments for Lake Trout from boreal and north-temperate lakes are lacking. Here, we reassess the importance of prey characteristics using both previously published and contemporary data, incorporating additional variables and model complexity to better understand factors influencing Hg dynamics of Ontario Lake Trout. Our analyses indicate that 1) Lake Trout Hg concentrations are primarily associated with individual body size, 2) high dissolved organic carbon (DOC) concentrations elevate Hg for fish of a given size, and 3) a coarse categorization of food chain length, specifically the presence of Mysis diluviana, informs Hg biomagnification slopes. The inclusion of DOC was vital for assessin..., , , # Environmental and food web determinants of Lake Trout mercury concentrations in Ontario lakes

[https://doi.org/10.5061/dryad.0gb5mkm96](https://doi.org/10.5061/dryad.0gb5mkm96)

Raw data associated with two Lake Trout Hg datasets.

### Cabana.et.al(1994)\_cjfasMercuryData.csv

1\) Cabana et al. (1994) summary data. These data were transposed from the tables published within the main publication [Cabana.et.al(1994)_cjfasMercuryData.csv]

*ColumnID; Column Info; Unit; Notes*

* SPC; Species name; n/a; lt = Lake Trout, Sm = Smallmouth Bass
* Lk_Nm; Lake name; n/a; n/a
* LATD; Latitude; degrees; n/a
* LATM; Latitude; minutes; n/a
* LONGD; Longitude; degrees; n/a
* LONGM; Longitude; minutes; n/a
* Region; Region; units; All cells intentionally left blank though initial manuscript has northern and southern region distinction
* Lat_DD; Latitude, decimal degrees; n/a
* Long_DD; Longitude, decimal degrees; n/a
* AREA_ha; Lake surface area; hectares; n/a
* ZMax_m; Max lake depth; m; n/a
* pH; ...,