Northern Ireland is on its last chance - and could face millions in fines from Europe if it fails to protect the unique wildlife of Strangford Lough.
That's the stark warning from a Northern Ireland Audit Office report which is scathing over the failures of the Department of Environment and Department of Agriculture to stem the deterioration in the lough's horse mussel communities.
The lough is one of only a handful of places in the world where horse mussels settle to form living reefs which are capable of supporting up to 100 other species.
Comptroller and Auditor General Kieran Donnelly said the two departments had been slow to react to the deteriorating conditions of Strangford Lough's horse mussel reefs.
"Complaints to the European Commission represent a significant risk to the public finances," he said. "There is no scope for failure in implementing the Revised Restoration Plan with the agreed timeframe if the Northern Ireland Executive is to avoid significant financial penalties." NIAO's Protecting Strangford Lough report details an ongoing saga during which the horse mussel - or Modiolus - reefs deteriorated due to fishing and other activities.
DoE and DARD had agreed a series of measures as part of a restoration plan but by the close of the plan in 2011, few of these measures had been put into place.
It culminated in a series of complaints to the European Commission by the Ulster Wildlife Trust, which, if upheld, would have seen the Northern Ireland Executive hit with a retrospective fine of up to e9m (£6.5m) plus ongoing daily fines of up to e650,000 (£475,000).
The Commission has now agreed to close the case, with the support of the Ulster Wildlife Trust, for a revised restoration plan which was drawn up in 2013.
The report was scathing about the lengthy delays which had allowed damage to the horse mussel reefs to continue. The reefs were found throughout the lough in the 1970s and 1980s but by 1990 had been extensively damaged.
A Management Plan in 2000-2003 did nothing to stem the decline and DARD eventually banned trawling and dredging.
However, it delayed introducing non-disturbance zones, as recommended in the 2005 restoration plan, until 2011 and even then the two small non-fishing zones were judged by experts to be inadequate. It was only in 2013 that a larger non-fishing zone was introduced.
The report said: "We can only conclude that there was an unacceptable delay, of at least seven years, in completing an adequate habitats regulation assessment of the impact of commercial fishing on the Modiolus reefs."
The report says DARD did not give sufficient weight to its obligation under the habitats directive to take preventative measures against an activity which was potentially damaging to the reefs.
"The department was rightly conscious of the desire to protect the relatively small pot fishing industry on the lough: however, the significant risk of incurring multi-million pound infraction fines was well known.
"In our view, DARD should have taken more urgent action to deliver a solution that met its legal obligation and satisfied the Commission's requirements in the face of this risk."
Jennifer Fulton, chief executive at Ulster Wildlife, said: "This report recognises the value of one of our most prized natural assets and we hope the recommendations led to a renewed commitment by government to protect and restore the unique underwater habitat of the lough, which is vital to biodiversity and sustainable fisheries.
"We are encouraged to see that DARD and DoE are now taking their responsibilities seriously, making progress on implementing the revised restoration plan and hope this will still happen in light of huge budget cutbacks."
A DARD spokesman said nearly all of the fisheries-related obligations within the revised restoration plan have now been introduced.
"DoE and DARD have already made significant progress on implementing the four key recommendations in the NIAO report, through more effective and regular departmental meetings and participation in the restoration working group and through the development of a Strangford Lough Pot Fisheries Management Programme with the lough's pot fishermen," he said.
The horse mussel is one of Europe's largest mussels, ranging from 35mm to 200mm. They are a long-living species, with many in Strangford Lough living to well over 20 years of age. It is likely that they can live as long as 50 years. Strangford Lough is one of only a handful of places in the world where the species forms biogenic (living) reefs, which can support up to 100 other species. The horse mussel is a priority species in Northern Ireland's waters which requires conservation action because of its rapid decline, scarcity and importance.