Water resources, meat and dairy
How may the activities of the meat and dairy processing industry impact water resources?
Abstracted water used for the meat and dairy industry is frequently discharged back into a nearby river or stream. The discharged water replaces a significant proportion of the water abstracted from upstream, but may carry with it additional heat, contaminants, and nutrients, depending on the industry. The proportion of flow removed, especially in smaller streams, may make some rivers or streams more vulnerable to water abstraction than larger ones. Changes to natural flow affects many chemical and physical properties - including water temperature, channel shape, and species habitats - which can limit the abundance and diversity of species, especially native mahinga kai species and water quality levels.
Impacts of water take (abstraction) on water quality and mahinga kai
- Changes in flow - changes in water levels and flow variability alters available mahinga kai habitat and the invertebrates they feed on.
- Reduction in habitat - a decrease in water levels reduces habitat for fish and can impact feeding and spawning success.
- Reduction in specialist habitats - a decrease in water levels reduces flow to riparian wetlands, backwaters, and intermittent streams.
- Decreases in species abundance and diversity - aquatic species have developed life history strategies in direct response to natural flows; for example, diadromous fish species migrate up and down the river at various times of the year and rely on preferred velocities and depths.
- Changes in sediment accumulation - flow reduction affects movement and deposition of sediments in streams and rivers.
- Changes in water quality parameters - for example, turbidity and temperature levels can increase with reduced flows in rivers.
- Increases in algae accumulation - algae respond to changes in temperature and nutrients, which are likely to increase with reduction of flow, especially during summer months.