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result sql = Mercury cycling in stream ecosystems. 2. Benthic methylmercury production and bed sediment-pore water partitioning.
Mercury cycling in stream ecosystems. 2. Benthic methylmercury production and bed sediment-pore water partitioning.
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char = r;code = 114
char = ;code = 32
char = m;code = 109
char = i;code = 105
char = c;code = 99
char = r;code = 114
char = o;code = 111
char = b;code = 98
char = i;code = 105
char = a;code = 97
char = l;code = 108
char = ;code = 32
char = m;code = 109
char = e;code = 101
char = t;code = 116
char = h;code = 104
char = y;code = 121
char = l;code = 108
char = a;code = 97
char = t;code = 116
char = i;code = 105
char = o;code = 111
char = n;code = 110
char = .;code = 46
char = ;code = 32
char = I;code = 73
char = n;code = 110
char = ;code = 32
char = c;code = 99
char = o;code = 111
char = n;code = 110
char = j;code = 106
char = u;code = 117
char = n;code = 110
char = c;code = 99
char = t;code = 116
char = i;code = 105
char = o;code = 111
char = n;code = 110
char = ;code = 32
char = w;code = 119
char = i;code = 105
char = t;code = 116
char = h;code = 104
char = ;code = 32
char = r;code = 114
char = a;code = 97
char = d;code = 100
char = i;code = 105
char = o;code = 111
char = t;code = 116
char = r;code = 114
char = a;code = 97
char = c;code = 99
char = e;code = 101
char = r;code = 114
char = -;code = 45
char = d;code = 100
char = e;code = 101
char = r;code = 114
char = i;code = 105
char = v;code = 118
char = e;code = 101
char = d;code = 100
char = ;code = 32
char = r;code = 114
char = a;code = 97
char = t;code = 116
char = e;code = 101
char = ;code = 32
char = c;code = 99
char = o;code = 111
char = n;code = 110
char = s;code = 115
char = t;code = 116
char = a;code = 97
char = n;code = 110
char = t;code = 116
char = s;code = 115
char = ;code = 32
char = o;code = 111
char = f;code = 102
char = ;code = 32
char = 2;code = 50
char = 0;code = 48
char = 3;code = 51
char = H;code = 72
char = g;code = 103
char = (;code = 40
char = I;code = 73
char = I;code = 73
char = );code = 41
char = ;code = 32
char = m;code = 109
char = e;code = 101
char = t;code = 116
char = h;code = 104
char = y;code = 121
char = l;code = 108
char = a;code = 97
char = t;code = 116
char = i;code = 105
char = o;code = 111
char = n;code = 110
char = ,;code = 44
char = ;code = 32
char = H;code = 72
char = g;code = 103
char = (;code = 40
char = I;code = 73
char = I;code = 73
char = );code = 41
char = R;code = 82
char = ;code = 32
char = w;code = 119
char = a;code = 97
char = s;code = 115
char = ;code = 32
char = u;code = 117
char = s;code = 115
char = e;code = 101
char = d;code = 100
char = ;code = 32
char = t;code = 116
char = o;code = 111
char = ;code = 32
char = c;code = 99
char = a;code = 97
char = l;code = 108
char = c;code = 99
char = u;code = 117
char = l;code = 108
char = a;code = 97
char = t;code = 116
char = e;code = 101
char = ;code = 32
char = M;code = 77
char = e;code = 101
char = H;code = 72
char = g;code = 103
char = ;code = 32
char = p;code = 112
char = r;code = 114
char = o;code = 111
char = d;code = 100
char = u;code = 117
char = c;code = 99
char = t;code = 116
char = i;code = 105
char = o;code = 111
char = n;code = 110
char = ;code = 32
char = p;code = 112
char = o;code = 111
char = t;code = 116
char = e;code = 101
char = n;code = 110
char = t;code = 116
char = i;code = 105
char = a;code = 97
char = l;code = 108
char = ;code = 32
char = r;code = 114
char = a;code = 97
char = t;code = 116
char = e;code = 101
char = s;code = 115
char = ;code = 32
char = a;code = 97
char = n;code = 110
char = d;code = 100
char = ;code = 32
char = t;code = 116
char = o;code = 111
char = ;code = 32
char = e;code = 101
char = x;code = 120
char = p;code = 112
char = l;code = 108
char = a;code = 97
char = i;code = 105
char = n;code = 110
char = ;code = 32
char = t;code = 116
char = h;code = 104
char = e;code = 101
char = ;code = 32
char = s;code = 115
char = p;code = 112
char = a;code = 97
char = t;code = 116
char = i;code = 105
char = a;code = 97
char = l;code = 108
char = ;code = 32
char = v;code = 118
char = a;code = 97
char = r;code = 114
char = i;code = 105
char = a;code = 97
char = b;code = 98
char = i;code = 105
char = l;code = 108
char = i;code = 105
char = t;code = 116
char = y;code = 121
char = ;code = 32
char = i;code = 105
char = n;code = 110
char = ;code = 32
char = M;code = 77
char = e;code = 101
char = H;code = 72
char = g;code = 103
char = ;code = 32
char = c;code = 99
char = o;code = 111
char = n;code = 110
char = c;code = 99
char = e;code = 101
char = n;code = 110
char = t;code = 116
char = r;code = 114
char = a;code = 97
char = t;code = 116
char = i;code = 105
char = o;code = 111
char = n;code = 110
char = .;code = 46
char = ;code = 32
char = T;code = 84
char = h;code = 104
char = e;code = 101
char = ;code = 32
char = %;code = 37
char = H;code = 72
char = g;code = 103
char = (;code = 40
char = I;code = 73
char = I;code = 73
char = );code = 41
char = R;code = 82
char = ;code = 32
char = (;code = 40
char = o;code = 111
char = f;code = 102
char = ;code = 32
char = T;code = 84
char = H;code = 72
char = g;code = 103
char = );code = 41
char = ;code = 32
char = w;code = 119
char = a;code = 97
char = s;code = 115
char = ;code = 32
char = l;code = 108
char = o;code = 111
char = w;code = 119
char = ;code = 32
char = (;code = 40
char = 2;code = 50
char = .;code = 46
char = 1;code = 49
char = ;code = 32
char = +;code = 43
char = /;code = 47
char = -;code = 45
char = ;code = 32
char = 5;code = 53
char = .;code = 46
char = 7;code = 55
char = %;code = 37
char = );code = 41
char = ;code = 32
char = a;code = 97
char = n;code = 110
char = d;code = 100
char = ;code = 32
char = w;code = 119
char = a;code = 97
char = s;code = 115
char = ;code = 32
char = i;code = 105
char = n;code = 110
char = v;code = 118
char = e;code = 101
char = r;code = 114
char = s;code = 115
char = e;code = 101
char = l;code = 108
char = y;code = 121
char = ;code = 32
char = r;code = 114
char = e;code = 101
char = l;code = 108
char = a;code = 97
char = t;code = 116
char = e;code = 101
char = d;code = 100
char = ;code = 32
char = t;code = 116
char = o;code = 111
char = ;code = 32
char = b;code = 98
char = o;code = 111
char = t;code = 116
char = h;code = 104
char = ;code = 32
char = m;code = 109
char = i;code = 105
char = c;code = 99
char = r;code = 114
char = o;code = 111
char = b;code = 98
char = i;code = 105
char = a;code = 97
char = l;code = 108
char = ;code = 32
char = s;code = 115
char = u;code = 117
char = l;code = 108
char = f;code = 102
char = a;code = 97
char = t;code = 116
char = e;code = 101
char = ;code = 32
char = r;code = 114
char = e;code = 101
char = d;code = 100
char = u;code = 117
char = c;code = 99
char = t;code = 116
char = i;code = 105
char = o;code = 111
char = n;code = 110
char = ;code = 32
char = r;code = 114
char = a;code = 97
char = t;code = 116
char = e;code = 101
char = s;code = 115
char = ;code = 32
char = a;code = 97
char = n;code = 110
char = d;code = 100
char = ;code = 32
char = s;code = 115
char = e;code = 101
char = d;code = 100
char = i;code = 105
char = m;code = 109
char = e;code = 101
char = n;code = 110
char = t;code = 116
char = ;code = 32
char = t;code = 116
char = o;code = 111
char = t;code = 116
char = a;code = 97
char = l;code = 108
char = ;code = 32
char = r;code = 114
char = e;code = 101
char = d;code = 100
char = u;code = 117
char = c;code = 99
char = e;code = 101
char = d;code = 100
char = ;code = 32
char = s;code = 115
char = u;code = 117
char = l;code = 108
char = f;code = 102
char = u;code = 117
char = r;code = 114
char = ;code = 32
char = c;code = 99
char = o;code = 111
char = n;code = 110
char = c;code = 99
char = e;code = 101
char = n;code = 110
char = t;code = 116
char = r;code = 114
char = a;code = 97
char = t;code = 116
char = i;code = 105
char = o;code = 111
char = n;code = 110
char = .;code = 46
char = ;code = 32
char = W;code = 87
char = h;code = 104
char = i;code = 105
char = l;code = 108
char = e;code = 101
char = ;code = 32
char = s;code = 115
char = e;code = 101
char = d;code = 100
char = i;code = 105
char = m;code = 109
char = e;code = 101
char = n;code = 110
char = t;code = 116
char = ;code = 32
char = T;code = 84
char = H;code = 72
char = g;code = 103
char = ;code = 32
char = c;code = 99
char = o;code = 111
char = n;code = 110
char = c;code = 99
char = e;code = 101
char = n;code = 110
char = t;code = 116
char = r;code = 114
char = a;code = 97
char = t;code = 116
char = i;code = 105
char = o;code = 111
char = n;code = 110
char = s;code = 115
char = ;code = 32
char = w;code = 119
char = e;code = 101
char = r;code = 114
char = e;code = 101
char = ;code = 32
char = h;code = 104
char = i;code = 105
char = g;code = 103
char = h;code = 104
char = e;code = 101
char = r;code = 114
char = ;code = 32
char = i;code = 105
char = n;code = 110
char = ;code = 32
char = u;code = 117
char = r;code = 114
char = b;code = 98
char = a;code = 97
char = n;code = 110
char = ;code = 32
char = s;code = 115
char = t;code = 116
char = r;code = 114
char = e;code = 101
char = a;code = 97
char = m;code = 109
char = s;code = 115
char = ,;code = 44
char = ;code = 32
char = %;code = 37
char = M;code = 77
char = e;code = 101
char = H;code = 72
char = g;code = 103
char = ;code = 32
char = a;code = 97
char = n;code = 110
char = d;code = 100
char = ;code = 32
char = %;code = 37
char = H;code = 72
char = g;code = 103
char = (;code = 40
char = I;code = 73
char = I;code = 73
char = );code = 41
char = R;code = 82
char = ;code = 32
char = w;code = 119
char = e;code = 101
char = r;code = 114
char = e;code = 101
char = ;code = 32
char = h;code = 104
char = i;code = 105
char = g;code = 103
char = h;code = 104
char = e;code = 101
char = r;code = 114
char = ;code = 32
char = i;code = 105
char = n;code = 110
char = ;code = 32
char = n;code = 110
char = o;code = 111
char = n;code = 110
char = u;code = 117
char = r;code = 114
char = b;code = 98
char = a;code = 97
char = n;code = 110
char = ;code = 32
char = s;code = 115
char = t;code = 116
char = r;code = 114
char = e;code = 101
char = a;code = 97
char = m;code = 109
char = s;code = 115
char = .;code = 46
char = ;code = 32
char = S;code = 83
char = e;code = 101
char = d;code = 100
char = i;code = 105
char = m;code = 109
char = e;code = 101
char = n;code = 110
char = t;code = 116
char = ;code = 32
char = p;code = 112
char = o;code = 111
char = r;code = 114
char = e;code = 101
char = ;code = 32
char = w;code = 119
char = a;code = 97
char = t;code = 116
char = e;code = 101
char = r;code = 114
char = ;code = 32
char = d;code = 100
char = i;code = 105
char = s;code = 115
char = t;code = 116
char = r;code = 114
char = i;code = 105
char = b;code = 98
char = u;code = 117
char = t;code = 116
char = i;code = 105
char = o;code = 111
char = n;code = 110
char = ;code = 32
char = c;code = 99
char = o;code = 111
char = e;code = 101
char = f;code = 102
char = f;code = 102
char = i;code = 105
char = c;code = 99
char = i;code = 105
char = e;code = 101
char = n;code = 110
char = t;code = 116
char = s;code = 115
char = ;code = 32
char = (;code = 40
char = l;code = 108
char = o;code = 111
char = g;code = 103
char = ;code = 32
char = K;code = 75
char = d;code = 100
char = ';code = 39
char = s;code = 115
char = );code = 41
char = ;code = 32
char = f;code = 102
char = o;code = 111
char = r;code = 114
char = ;code = 32
char = b;code = 98
char = o;code = 111
char = t;code = 116
char = h;code = 104
char = ;code = 32
char = T;code = 84
char = H;code = 72
char = g;code = 103
char = ;code = 32
char = a;code = 97
char = n;code = 110
char = d;code = 100
char = ;code = 32
char = M;code = 77
char = e;code = 101
char = H;code = 72
char = g;code = 103
char = ;code = 32
char = w;code = 119
char = e;code = 101
char = r;code = 114
char = e;code = 101
char = ;code = 32
char = i;code = 105
char = n;code = 110
char = v;code = 118
char = e;code = 101
char = r;code = 114
char = s;code = 115
char = e;code = 101
char = l;code = 108
char = y;code = 121
char = ;code = 32
char = r;code = 114
char = e;code = 101
char = l;code = 108
char = a;code = 97
char = t;code = 116
char = e;code = 101
char = d;code = 100
char = ;code = 32
char = t;code = 116
char = o;code = 111
char = ;code = 32
char = t;code = 116
char = h;code = 104
char = e;code = 101
char = ;code = 32
char = l;code = 108
char = o;code = 111
char = g;code = 103
char = -;code = 45
char = t;code = 116
char = r;code = 114
char = a;code = 97
char = n;code = 110
char = s;code = 115
char = f;code = 102
char = o;code = 111
char = r;code = 114
char = m;code = 109
char = e;code = 101
char = d;code = 100
char = ;code = 32
char = r;code = 114
char = a;code = 97
char = t;code = 116
char = i;code = 105
char = o;code = 111
char = ;code = 32
char = o;code = 111
char = f;code = 102
char = ;code = 32
char = p;code = 112
char = o;code = 111
char = r;code = 114
char = e;code = 101
char = ;code = 32
char = w;code = 119
char = a;code = 97
char = t;code = 116
char = e;code = 101
char = r;code = 114
char = ;code = 32
char = d;code = 100
char = i;code = 105
char = s;code = 115
char = s;code = 115
char = o;code = 111
char = l;code = 108
char = v;code = 118
char = e;code = 101
char = d;code = 100
char = ;code = 32
char = o;code = 111
char = r;code = 114
char = g;code = 103
char = a;code = 97
char = n;code = 110
char = i;code = 105
char = c;code = 99
char = ;code = 32
char = c;code = 99
char = a;code = 97
char = r;code = 114
char = b;code = 98
char = o;code = 111
char = n;code = 110
char = ;code = 32
char = (;code = 40
char = D;code = 68
char = O;code = 79
char = C;code = 67
char = );code = 41
char = ;code = 32
char = t;code = 116
char = o;code = 111
char = ;code = 32
char = b;code = 98
char = e;code = 101
char = d;code = 100
char = ;code = 32
char = s;code = 115
char = e;code = 101
char = d;code = 100
char = i;code = 105
char = m;code = 109
char = e;code = 101
char = n;code = 110
char = t;code = 116
char = ;code = 32
char = %;code = 37
char = f;code = 102
char = i;code = 105
char = n;code = 110
char = e;code = 101
char = s;code = 115
char = .;code = 46
char = ;code = 32
char = T;code = 84
char = h;code = 104
char = e;code = 101
char = ;code = 32
char = s;code = 115
char = t;code = 116
char = r;code = 114
char = e;code = 101
char = a;code = 97
char = m;code = 109
char = ;code = 32
char = w;code = 119
char = i;code = 105
char = t;code = 116
char = h;code = 104
char = ;code = 32
char = t;code = 116
char = h;code = 104
char = e;code = 101
char = ;code = 32
char = h;code = 104
char = i;code = 105
char = g;code = 103
char = h;code = 104
char = e;code = 101
char = s;code = 115
char = t;code = 116
char = ;code = 32
char = d;code = 100
char = r;code = 114
char = a;code = 97
char = i;code = 105
char = n;code = 110
char = a;code = 97
char = g;code = 103
char = e;code = 101
char = ;code = 32
char = b;code = 98
char = a;code = 97
char = s;code = 115
char = i;code = 105
char = n;code = 110
char = ;code = 32
char = w;code = 119
char = e;code = 101
char = t;code = 116
char = l;code = 108
char = a;code = 97
char = n;code = 110
char = d;code = 100
char = ;code = 32
char = d;code = 100
char = e;code = 101
char = n;code = 110
char = s;code = 115
char = i;code = 105
char = t;code = 116
char = y;code = 121
char = ;code = 32
char = a;code = 97
char = l;code = 108
char = s;code = 115
char = o;code = 111
char = ;code = 32
char = h;code = 104
char = a;code = 97
char = d;code = 100
char = ;code = 32
char = t;code = 116
char = h;code = 104
char = e;code = 101
char = ;code = 32
char = h;code = 104
char = i;code = 105
char = g;code = 103
char = h;code = 104
char = e;code = 101
char = s;code = 115
char = t;code = 116
char = ;code = 32
char = p;code = 112
char = o;code = 111
char = r;code = 114
char = e;code = 101
char = ;code = 32
char = w;code = 119
char = a;code = 97
char = t;code = 116
char = e;code = 101
char = r;code = 114
char = ;code = 32
char = D;code = 68
char = O;code = 79
char = C;code = 67
char = ;code = 32
char = c;code = 99
char = o;code = 111
char = n;code = 110
char = c;code = 99
char = e;code = 101
char = n;code = 110
char = t;code = 116
char = r;code = 114
char = a;code = 97
char = t;code = 116
char = i;code = 105
char = o;code = 111
char = n;code = 110
char = ;code = 32
char = a;code = 97
char = n;code = 110
char = d;code = 100
char = ;code = 32
char = t;code = 116
char = h;code = 104
char = e;code = 101
char = ;code = 32
char = l;code = 108
char = o;code = 111
char = w;code = 119
char = e;code = 101
char = s;code = 115
char = t;code = 116
char = ;code = 32
char = l;code = 108
char = o;code = 111
char = g;code = 103
char = ;code = 32
char = K;code = 75
char = d;code = 100
char = ';code = 39
char = s;code = 115
char = ;code = 32
char = f;code = 102
char = o;code = 111
char = r;code = 114
char = ;code = 32
char = b;code = 98
char = o;code = 111
char = t;code = 116
char = h;code = 104
char = ;code = 32
char = T;code = 84
char = H;code = 72
char = g;code = 103
char = ;code = 32
char = a;code = 97
char = n;code = 110
char = d;code = 100
char = ;code = 32
char = M;code = 77
char = e;code = 101
char = H;code = 72
char = g;code = 103
char = .;code = 46
char = ;code = 32
char = N;code = 78
char = o;code = 111
char = ;code = 32
char = s;code = 115
char = i;code = 105
char = g;code = 103
char = n;code = 110
char = i;code = 105
char = f;code = 102
char = i;code = 105
char = c;code = 99
char = a;code = 97
char = n;code = 110
char = t;code = 116
char = ;code = 32
char = r;code = 114
char = e;code = 101
char = l;code = 108
char = a;code = 97
char = t;code = 116
char = i;code = 105
char = o;code = 111
char = n;code = 110
char = s;code = 115
char = h;code = 104
char = i;code = 105
char = p;code = 112
char = ;code = 32
char = e;code = 101
char = x;code = 120
char = i;code = 105
char = s;code = 115
char = t;code = 116
char = e;code = 101
char = d;code = 100
char = ;code = 32
char = b;code = 98
char = e;code = 101
char = t;code = 116
char = w;code = 119
char = e;code = 101
char = e;code = 101
char = n;code = 110
char = ;code = 32
char = o;code = 111
char = v;code = 118
char = e;code = 101
char = r;code = 114
char = l;code = 108
char = y;code = 121
char = i;code = 105
char = n;code = 110
char = g;code = 103
char = ;code = 32
char = w;code = 119
char = a;code = 97
char = t;code = 116
char = e;code = 101
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result sql = Mercury speciation, controls on methylmercury (MeHg) production, and bed sediment-pore water partitioning of total Hg (THg) and MeHg were examined in bed sediment from eight geochemically diverse streams where atmospheric deposition was the predominant Hg input. Across all streams, sediment THg concentrations were best described as a combined function of sediment percent fines (%fines; particles < 63 microm) and organic content. MeHg concentrations were best described as a combined function of organic content and the activity of the Hg(II)-methylating microbial community and were comparable to MeHg concentrations in streams with Hg inputs from industrial and mining sources. Whole sediment tin-reducible inorganic reactive Hg (Hg(II)R) was used as a proxy measure for the Hg(II) pool available for microbial methylation. In conjunction with radiotracer-derived rate constants of 203Hg(II) methylation, Hg(II)R was used to calculate MeHg production potential rates and to explain the spatial variability in MeHg concentration. The %Hg(II)R (of THg) was low (2.1 +/- 5.7%) and was inversely related to both microbial sulfate reduction rates and sediment total reduced sulfur concentration. While sediment THg concentrations were higher in urban streams, %MeHg and %Hg(II)R were higher in nonurban streams. Sediment pore water distribution coefficients (log Kd's) for both THg and MeHg were inversely related to the log-transformed ratio of pore water dissolved organic carbon (DOC) to bed sediment %fines. The stream with the highest drainage basin wetland density also had the highest pore water DOC concentration and the lowest log Kd's for both THg and MeHg. No significant relationship existed between overlying water MeHg concentrations and those in bed sediment or pore water, suggesting upstream sources of MeHg production may be more important than local streambed production as a driver of water column MeHg concentration in drainage basins that receive Hg inputs primarily from atmospheric sources.

Publication: Environ. Sci. Technol. 2009 Apr 15 ;43(8)::2726-32.
Publication Date: 2009 Apr 15
Study Author(s): Marvin-Dipasquale, Mark;Lutz, Michelle A;Brigham, Mark E;Krabbenhoft, David P;Aiken, George R;Orem, William H;Hall, Britt D;
Institution: U.S. Geological Survey, 345 Middlefield Road, Menlo Park, California 94025, USA. [email protected]
Shortcut link to this study:
Mercury speciation, controls on methylmercury (MeHg) production, and bed sediment-pore water partitioning of total Hg (THg) and MeHg were examined in bed sediment from eight geochemically diverse streams where atmospheric deposition was the predominant Hg input. Across all streams, sediment THg concentrations were best described as a combined function of sediment percent fines (%fines; particles < 63 microm) and organic content. MeHg concentrations were best described as a combined function of organic content and the activity of the Hg(II)-methylating microbial community and were comparable to MeHg concentrations in streams with Hg inputs from industrial and mining sources. Whole sediment tin-reducible inorganic reactive Hg (Hg(II)R) was used as a proxy measure for the Hg(II) pool available for microbial methylation. In conjunction with radiotracer-derived rate constants of 203Hg(II) methylation, Hg(II)R was used to calculate MeHg production potential rates and to explain the spatial variability in MeHg concentration. The %Hg(II)R (of THg) was low (2.1 +/- 5.7%) and was inversely related to both microbial sulfate reduction rates and sediment total reduced sulfur concentration. While sediment THg concentrations were higher in urban streams, %MeHg and %Hg(II)R were higher in nonurban streams. Sediment pore water distribution coefficients (log Kd's) for both THg and MeHg were inversely related to the log-transformed ratio of pore water dissolved organic carbon (DOC) to bed sediment %fines. The stream with the highest drainage basin wetland density also had the highest pore water DOC concentration and the lowest log Kd's for both THg and MeHg. No significant relationship existed between overlying water MeHg concentrations and those in bed sediment or pore water, suggesting upstream sources of MeHg production may be more important than local streambed production as a driver of water column MeHg concentration in drainage basins that receive Hg inputs primarily from atmospheric sources.
PMID: 19475941

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