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Intricate links between aquatic animals and their environment expose them to chemical and pathogenic hazards, which can disrupt seafood supply. Here we outline a risk schema for assessing potential impacts of chemical and microbial hazards on discrete subsectors of aquaculture—and control measures that may protect supply. As national governments develop strategies to achieve volumetric expansion in seafood production from aquaculture to meet increasing demand, we propose an urgent need for simultaneous focus on controlling those hazards that limit its production, harvesting, processing, trade and safe consumption. Policies aligning national and international water quality control measures for minimizing interaction with, and impact of, hazards on seafood supply will be critical as consumers increasingly rely on the aquaculture sector to supply safe, nutritious and healthy diets.

Anaerobic conditions develop below about 1-m depth in soil stockpiles and this can lead to an accumulation of ammonium (NI-h +) and transformations of a normally relatively inert organic-N pool within the soil. After reinstatement of the soil from the stockpile, the NH~" may rapidly be transformed to nitrate (NO3-) and lost from the soil with the labile organic-N. These losses may lead to a pollution risk in addition to the loss of a resource. The magnitude of N losses were measured from a soil that had been reinstated for agricultural use after being stored in a stockpile for 12 yr. Nitrogen movement in the soil profile and losses into the water-course were monitored for 2 yr beginning immediately after reinstatement. Relatively large movements of N were detected within the soil profile and large losses to the atmosphere and/or water-courses were estimated. Over the 2-yr monitoring period, 2449 kg ha -~ of N was lost from the soil profile; 90% of this was not accounted for either in the soil or in the runoff or drainage water as mineraI-N and was presumed to have entered either the atmosphere or aquatic environment as organic-N. To aid remedial measures, the proportion entering the atmosphere as nitrogen and nitrous oxides or the aquatic environment as organic-N, needs further investigation.

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