Dáil Éireann díospóireacht -
Thursday, 2 Dec 1993

Vol. 436 No. 6

Written Answers. - Clarinbridge Oyster Bed Disease.

Proinsias De Rossa

Ceist:

51 Proinsias De Rossa asked the Minister for the Marine the investigation that has been held into the circumstances of the outbreak of bonamia in the Clarinbridge oyster beds; the information available on the source of the outbreak; the damage caused; the steps, if any, that are being considered to prevent further outbreaks; and if he will make a statement on the matter.

Minister for the Marine (Mr. Andrews)

The outbreak of bonamia disease in the Clarinbridge oyster bed, was first detected in September 1989 by the Department's Fisheries Research Centre.

An investigation undertaken by the Department's senior fish pathologist in 1989 concluded that the disease was in all likelihood introduced into the Clarinbridge Fishery by unauthorised transfers into the area of native oysters.

While bonamia does not affect the taste or edibility of the oyster in any way and poses no health risk whatsoever to oyster consumers, it does result in heavy mortalities in the affected stocks. Once established it is notoriously difficult to control and eliminate.

The quality of oysters taken by oyster fishermen in the Clarinbridge fishery has steadily declined since 1989. This has been confirmed by ongoing sampling during the past four years. Recent fishing effort disclosed that very few adult oysters remain on the beds at Clarinbridge and catch returns were extremely poor.

Even prior to the outbreak of bonamia at Clarinbridge in 1989 movements of molluscan shellfish within the State other than for direct human consumption were subject to strict controls under licensing procedures. These controls have been maintained and rigorously enforced. Restrictions on the importation of oysters from outside the State have been in place since 1959 and have enabled Ireland to keep out shellfish diseases which are endemic in other countries. Oysters brought in from abroad are subject to strict health certification requirements as prescribed by Council Directive 91/67 EEC. This Directive lays down health rules for the placing on the market, including intra community trade, of aquaculture animals and products such as oysters in the context of the completion of the internal market and the need to open up trade while avoiding the spread of infectious or contagious diseases.

Following the 1989 bonamia outbreak at Clarinbridge the Galway Bay area was subject to intensive sampling by the Department to track and contain the outbreak. Initially all movements of oysters to, from and within the area were suspended other than for direct human consumption. Once identified, the affected site at Clarinbridge was totally destocked under the Department's direction and subsequent oyster movements continued to be strictly controlled.

These control and monitoring measures have assisted in preventing the disease spreading to unaffected oyster fisheries around the country which are regularly tested to ensure their continued general health status.

The Department is currently reviewing the existing restriction on movement arrangements in consultation with the Fisheries Board, BIM and the shellfish industry to ensure that the maximum protection possible is in place for unaffected fisheries and to strengthen and enhance controls if possible.

In addition, and also in conjunction with the Western Regional Fisheries Board, BIM and the industry, the Department is working to identify further management measures which could be introduced to minimise the disease impact in the Clarinbridge oyster fishery and rebuild stocks.

I would stress that full co-operation of the industry and compliance with national and Community movement controls absolutely vital to ensure the containment of the disease. Unauthorised and reckless movements of oysters can only accelerate the problem and are not in the interests of the Irish shellfish industry.