Saturday, 20 August 2016

Pearl Mussel Project Success

Diane Baum and Lucy Ballantyne, who work for Lochaber Fisheries Trust, returned to West Ardnamurchan today for the fifth time in recent weeks in the hope that the local pearl mussels were finally behaving themselves and producing spat which were ready to join their host. With the warm weather, and with spat seen last Tuesday in stages three and four, it was hoped that some had finally reached the crucial stage five.

They were joined on the banks of the Sruthan Bhraigh nan Allt by the owner of the land, Helen, and her son Innes. Picture shows Lucy, sitting, sampling the mussels which Diane, Helen and Innes had collected and, at last....

....she found some spat, like the one arrowed, which looked like pakman and which were also snapping their mouths, ready to leave their parent to find a host fish.

The most promising mussels were placed in a container which was allowed to warm slightly, encouraging the production of spat - the creamy-orange mass visible in this picture.

While this was happening, Diane, right, operating the electric electric stun machine, walked upstream along the burn while Lucy netted....

....twenty-four small trout and salmon.

The mussels were then removed from their container and the water thoroughly stirred to separate the spat, after which the fish, in the black bucket, and now completely recovered from the electric shock, were carefully transferred into the spat container and left there for about thirty seconds. The time is kept short in order to ensure that the fish do not get too many spat on their gills, which might threaten their survival.

Finally, the fish were gently returned to the burn. In May, Lucy and Diane will return to catch fish along this stretch of water, by which time the mussel spat should, hopefully, be large enough to be visible on the gills.

No comments:

Post a Comment