Fish firm off hook over nitrogen

HUON Aquaculture says an Institute for Marine and Antarctic Studies report about a 2015 incident — in which the company breached its nitrogen cap for the Huon Estuary — shows no cause for concern.

The report was completed last October, but released by the Department of Primary Industries, Parks, Water and the Environment yesterday.

The report was commissioned by the State Government after Huon reported in July 2015 that it had exceeded its nitrogen limit in the Port Huon/Esperance area.

The report concluded that although there had been an increase in bottom ammonia concentration in the southern D’Entrecasteaux Channel and lower Huon Estuary, there was little indication the nitrogen level had a large impact.

The report found Huon Aquaculture exceeded its nitrogen limit in the Huon Estuary by 44 per cent between December 2014 and November 2015. It said by the time the study had started Huon’s nitrogen impacts had fallen to comparatively low levels.

The overall nitrogen cap for the area was not exceeded because Tassal was farming below its nitrogen limit.

Huon Aquaculture chief executive Peter Bender said the report found the nitrogen exceedance had a temporary, small and localised impact. He said it happened after the company moved its southern fish population to the Huon while changing moorings on other leases.