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Supplemental Information:

An investigation of enhanced mercury bioaccumulation in fish from offshore feeding

John Chételat1, Louise Cloutier and Marc Amyot

Groupe de recherche interuniversitaire en limnologie, Département de sciences biologiques, Université de Montréal, Montréal, Québec H3C 3J7, Canada

Present address:

1 Environment Canada, National Wildlife Research Centre, CarletonUniversity, Ottawa, OntarioK1A 0H3, Canada

The following three tables and one figure are provided as supplementary information:

Table S1Diet composition by percent occurrence (% Occ.) and mean percent abundance (% Abun.) of items in guts of white sucker, brown bullhead, pumpkinseed and smallmouth bass from Morency Lake.

Table S2Presence of invertebrate taxa, identified to the lowest feasible level, in the guts of four fish species in Morency Lake.

Table S3 Presence of invertebrate taxa, identified to the lowest feasible level, in sediment from littoral (3 m) and profundal sites (616 m) in Morency Lake.

Figure S1 PCA ordination of benthic invertebrate taxa found in sediment collected at sites in the littoral zone (open circles, 0−3 m depth) and profundal zone (closed circles, 6−16 m depth) of Morency Lake.

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Table S1 Diet composition by percent occurrence (% Occ.) and mean percent abundance (% Abun.) of items in guts of white sucker, brown bullhead, pumpkinseed and smallmouth bass from Morency Lake.Abundant items (> 5% abundance) are highlighted in bold and rare items (< 1% abundance for all fish species) were excluded.

Common name of diet item
(taxonomic group) / White sucker
(n = 8) / Brown bullhead
(n = 11) / Pumpkinseed
(n = 20) / Smallmouth bass
(n = 9)
% Occ. / % Abun. / % Occ. / % Abun. / % Occ. / % Abun. / % Occ. / % Abun.
Benthic primary consumers
Amphipods (Amphipoda) / 50 / < 1 / 64 / 45 / 35 / 6 / 0 / 0
Caddisflies (Trichoptera) / 75 / < 1 / 45 / 2 / 55 / 2 / 33 / < 1
Chironomids (Chironomidae) / 100 / 48 / 100 / 40 / 85 / 17 / 67 / 21
Isopods (Isopoda) / 88 / 41 / 55 / 6 / 50 / 16 / 11 / 1
Mayflies (Ephemeroptera) / 63 / 3 / 64 / 2 / 60 / 2 / 33 / 1
Sandflies (Ceratopogonidae) / 100 / 6 / 9 / 1 / 20 / 2 / 11 / 1
Snails (Gastropoda) / 75 / 1 / 9 / 1 / 55 / 35 / 11 / 1
Predatory benthic invertebrates
Crayfish (Decapoda) / 0 / 0 / 18 / 1 / 0 / 0 / 11 / 2
Dragonflies (Anisoptera) / 100 / 1 / 55 / 2 / 40 / 1 / 22 / 1
Planktonic primary consumers
Cladocerans (Cladocera) / 13 / 1 / 0 / 0 / 15 / 8 / 22 / 14
Bivalves (Sphaeriidae) / 88 / < 1 / 45 / 2 / 65 / 7 / 22 / < 1
Predatory planktonic invertebrates
Opossum shrimp (Mysis diluviana) / 0 / 0 / 9 / < 1 / 5 / < 1 / 56 / 54
Water bugs (Hemiptera) / 13 / < 1 / 0 / 0 / 15 / < 1 / 22 / 2
Terrestrial insects
Hymenoptera / 0 / 0 / 0 / 0 / 10 / < 1 / 11 / 1
Fish
Unidentified remains / 0 / 0 / 9 / 1 / 10 / 1 / 11 / 1

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Table S2 Presence of invertebrate taxa, identified to the lowest feasible level, in the guts of four fish species in Morency Lake.

Brown bullhead / Pumpkinseed / Smallmouth bass / White sucker
Prey taxon* / n = 11 / n = 20 / n = 9 / n = 8
Anisoptera / 1 / 1 / 1 / 1
Zygoptera / 0 / 1 / 0 / 0
Ephemeroptera (unidentified) / 1 / 1 / 1 / 1
Caenidae / 1 / 1 / 0 / 1
Ephemerellidae / 1 / 0 / 0 / 1
Heptageniidae / 1 / 1 / 1 / 0
Leptophlebiidae / 0 / 1 / 0 / 0
Gerridae / 0 / 1 / 1 / 0
Corixidae / 0 / 0 / 1 / 1
Trichoptera (unidentified) / 1 / 1 / 1 / 1
Oxyethira / 0 / 1 / 0 / 1
Leptoceridae / 0 / 0 / 0 / 1
Phryganeidae / 0 / 1 / 1 / 0
Phryganea / 1 / 1 / 0 / 1
Polycentropus / 0 / 0 / 0 / 1
Coleoptera / 0 / 1 / 1 / 0
Hymenoptera / 0 / 1 / 1 / 0
Chironomidae (unidentified) / 1 / 1 / 1 / 1
Tanytarsini / 1 / 1 / 0 / 1
Micropsectra / 0 / 1 / 0 / 1
Chironomus / 1 / 0 / 0 / 1
Cryptochironomus / 1 / 1 / 0 / 1
Dicrotendipes / 0 / 1 / 0 / 1
Glyptotendipes / 0 / 1 / 0 / 0
Microtendipes / 1 / 1 / 1 / 1
Omisus / 0 / 1 / 1 / 1
Phaenopsectra-Sergentia / 1 / 1 / 1 / 1
Polypedilum / 1 / 1 / 1 / 1
Pseudochironomus / 1 / 1 / 1 / 1
Ablabesmyia / 0 / 1 / 0 / 1
Procladius / 1 / 1 / 1 / 1
Heterotrissocladius / 1 / 1 / 0 / 0
Protanypus / 1 / 1 / 1 / 0
Ceratopogonidae / 1 / 1 / 1 / 1
Psychodidae / 1 / 1 / 0 / 0
Arachnida / 0 / 1 / 0 / 0
Hydracarina / 0 / 0 / 0 / 1
Cladocera / 0 / 1 / 1 / 1
Ephippium / 0 / 1 / 1 / 0
Ostracoda / 1 / 1 / 0 / 1
Mysis diluviana / 1 / 1 / 1 / 0
Isopoda / 1 / 1 / 1 / 1
Amphipoda / 1 / 1 / 0 / 1
Decapoda / 1 / 0 / 1 / 0
Sphaeriidae / 1 / 1 / 1 / 1
Gastropoda (unidentified) / 1 / 0 / 0 / 1
Hydrobiidae / 0 / 1 / 0 / 0
Planorbiidae / 0 / 1 / 0 / 1
Viviparidae / 0 / 1 / 1 / 1

* present = 1, absent = 0

Table S3 Presence of invertebrate taxa, identified to the lowest feasible level, in sediment from littoral (3 m) and profundal sites (616 m) in Morency Lake.

Taxon / Profundal sites
(n = 13) / Littoral sites
(n = 5)
Oligochaete / 1 / 1
Hyalella azteca / 0 / 1
Pontoporeia / 1 / 1
Isopoda / 1 / 1
Mysis diluviana / 1 / 0
Ostracoda / 1 / 0
Hydracarina / 1 / 0
Sphaeriidae / 0 / 1
Gastropoda / 1 / 1
Anisoptera / 0 / 1
Zygoptera / 0 / 1
Baetidae / 0 / 1
Hexagenia / 0 / 1
Leptophlebiidae / 0 / 1
Danella / 0 / 1
Caenis / 0 / 1
Megaloptera / 0 / 1
Oxyethira / 0 / 1
Oecetis / 0 / 1
Trianodes / 0 / 1
Phryganeidae / 0 / 1
Fabria / 1 / 1
Ceratopogonidae / 0 / 1
Tabanidae / 0 / 1
Chironomidae (unidentified) / 1 / 1
Procladius / 1 / 1
Chironomus / 1 / 1
Cryptochironomus / 0 / 1
Dicrotendipes / 0 / 1
Endochironomus / 0 / 1
Microtendipes / 0 / 1
Parachironomus / 0 / 1
Paralauterborniella / 0 / 1
Polypedilum / 0 / 1
Pseudochironomus / 0 / 1
Cladotanytarsus / 0 / 1
Tanytarsus / 0 / 1
Cricotopus / 1 / 0
Synorthocladius / 0 / 1

* present = 1, absent = 0

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