Supplementary Information

Table 1. Physicochemical characteristics of control and test sediments

Sediment / TOC / PCB total congeners / % particle sizea / density
mg/g / ng/g dw / ng/g TOC / sand / silt / clay / g dw/ml
Control A / 18 / 21 (<T) / - / 11 / 73 / 16 / 0.88
Control B / 110 / 21 (<T) / - / 24 / 70 / 6 / 0.41
Site 1 / 120 / 1300 / 11000 / 18 / 71 / 11 / 0.19
Site 2 / 11 / 340 / 31000 / 67 / 13 / 4 / 1.63
a sand 62-1000μm, silt 2.63-62μm, clay <2.63μm
<T a measurable trace amount

Table 2. Resulting volumes of sediment (ml)and ratios of TOC to organism dry weight for three loading densities (50:1 and 27:1 TOC:organism dry weight, and standard volume(140 ml sediment/g wet weight of tissue)) based on sediment- and organism-specific characteristics.

Standard volume / 27:1 / 50:1 / Dry/wet
weight
Ratio
Lumbriculus variegatus / 0.13
Control B / 700 / 47:1 / 400 / 750
Site 1 / 700 / 24:1 / 800 / 1500
Site 2 / 700 / 19:1 / 1000 / 1900
Hexagenia spp. / 0.15
Control A / 700 / 14:1 / 1300 / 2400
Site 1 / 700 / 21:1 / 900 / 1700
Site 2 / 700 / 16:1 / 1200 / 2200
Pimephales promelas / 0.18
Control A / 700 / 12:1 / 1600 / 2300
Site 1 / 700 / 17:1 / 1100 / 2000
Site 2 / 700 / 14:1 / 1400 / 2600

Table 3. Water quality characteristics of overlying water from tests examining the effect of organism density on survival, growth, and bioaccumulation in three species. Data are rangeof values for all sediment-density treatments.

pH / Conductivity
(μS/cm) / DO
(mg/L) / Total / Unionized / Total PCBs (ng/L) a
Ammonia (mg/L) / Site 1 / Site 2
Day 0 all species and tests
8.0-8.2 / 350-450 / 7.9-8.8 / 0.2-1.8 / ≤0.1-0.2 / Not measuredb
Day 28
Lumbriculus variegatus
Test 1 / 7.2-8.1 / 500-750 / 7.3-8.1 / ≤0.1 / <0.1 / 20 (<=W) / 20 (<=W)
Test 2 / 7.0-8.2 / 500-700 / 6.3-8.1 / ≤0.1 / <0.1 / 20 (<=W) / 20,20,30 (<T)
Test 3 / 7.4-8.2 / 500-700 / 7.3-8.2 / ≤0.1 / <0.1 / 20 (<=W) / 20 (<=W)
Hexagenia spp.
Test 1 / 7.6-8.0 / 450-650 / 6.7-7.8 / ≤0.1 / <0.1 / 31,40,47 (<T) / 56,52,97 (<T)
Test 2 / 7.7-8.1 / 450-650 / 6.7-8.0 / <0.1 / <0.1 / 30,25,29 (<T) / 40,47,75 (<T)
Test 3 / 7.6-8.2 / 450-700 / 6.2-8.4 / <0.1-0.2 / <0.1 / 20 (<=W) / 20 (<=W)
Pimephales promelas
Test 1 / 7.6-8.2 / 500-600 / 5.7-7.6 / ≤0.1 / <0.1 / 20,25,27 (<T) / 20 (<=W)
Test 2 / 7.8-8.4 / 450-600 / 5.9-8.3 / <0.1 / <0.1 / 20 (<=W) / 20 (<=W)
Test 3 / 7.7-8.3 / 400-600 / 6.8-8.2 / <0.1 / <0.1 / 20 (<=W) / 20 (<=W)
a multiple values indicate treatments (50:1, 27:1, 140ml/g)
b routine measurement in laboratory water = 20 (<=W)
<=W no measurable response (zero): <reported value
<T a measurable trace amount