Table 3. Dissolved concentrations (μg · L⁻¹ ) of trace metals from sediment elutriates.

	Arsenic (μg · L−1)	Cadmium (μg · L−1)	Copper (μg · L−1)	Lead (μg · L−1)	Zinc (μg · L−1)
ANZECC Guidelines 99%a	ID	0.7	0.3	2.2	7
ANZECC Guidelines 95%a	ID	5.5	1.3	4.4	15
Humber Drain	<4	<0.2	<1	4.1*	75*
Humber Estuary	ND	0.2	1	1.6	33*
Old Tutaekuri Riverbed	<4	<0.2	<1	5.3*	59*
Old Tutaekuri Estuary	ND	0.2	2.2*	2.2	44*
Waitangi Estuary	<4	0.5	8.3*	4	33*

Notes:

Analyses obtained from the four study sites at the Ahuriri Estuary, and from the reference site, the Waitangi Estuary. Analyses above the ANZECC guidelines thresholds values are indicated with * for a level of protection of 95% and above.

ID, Insufficient data; ND, Not detected.

^aANZECC (2000) water quality guidelines trigger values for 99 and 95% of protection levels for species in marine waters.