Groundtruthing in Donegal and Sligo Bays

From the 6th to 8th of July 2009, a ground truthing or seabed sampling survey was undertaken in the region of Donegal and Sligo Bay.

A local vessel, the K-Mar-K from Killybegs, was chartered for this purpose. The vessels top speed of greater than 20 knots, high maneuverability and experienced crew proved highly successful for sample acquisition.

Local vessel, the K-Mar-K from Killybegs, provided the platform for the ground truthing leg.

90 proposed sample sites were identified in the area, based on bathymetric data previously collected by INFOMAR surveys and also on seabed classification map products by INFOMAR. Of these proposed locations, 80 were successfully sampled, despite adverse weather conditions.

Map of the sample locations in Donegal and Sligo Bays .

In all instances, the 'Day Grab' was used to ensure consistency in results and due to ease of handling of this grab design. The samples recovered were described and photographed once brought on deck but will also undergo further detailed particle size analysis and will be used to refine INFOMAR seabed classification and geology products for the region.

The Day Grab (to left) on the back deck of the K-Mar-K which was used at all sampling sites.


Example of a sediment sample collected during the ground truthing leg.

The use of a suitable, locally sourced vessel capable of high-speed transits between sample locations, maximised the cost effectiveness of this sampling campaign in Donegal and Sligo Bays.

All INFOMAR data is available for free download here.

CV09_23 Ground Truthing in Bantry and Dunmanus Bays

From 22nd to 28th April, INFOMAR staff were amongst a crew of scientists that were busy collecting a large number of ground truthing samples from the seabed in Bantry and Dunmanus Bays in Cork on the Celtic Voyager as part of research by Dublin City University (DCU) on pockmark features in the bays. Also included were scientists from University of Limerick (UL) and Aquafact Environmental Survey Specialists. Before the transit to west Cork, mobilisation, testing and training was done in Cork Harbour.

Day Grab recovery from Cork Harbour of coarse grained sediment and large shells.



The 290 metre long Grand Princess cruise liner in Cobh.

Gravity cores, box cores and day grabs were recovered from the seabed with video footage from selected sites. In all over 5 days of 24 hour operations, 132 sampling stations and 12 gravity core stations were covered. The physical, chemical and biological content of these samples will be analysed to gain an insight into the nature of the seabed in the bays and also close to the pockmarks features. The leg ended in demobilisation in Castletown Bere and was deemed very successful for all parties.

Plan view of day grab recovery. Note the muddy nature of the seabed and the brittle starfish recovered in the grab.

Elevation view of box core recovery. Note the change in colour of the sediment from green/brown to grey around 5 cm from the surface. Sediments recovered were generally composed of mud and clay.

Recovery of the gravity corer with 2 metre barrel from the A-frame of the Celtic Voyager. Average recovery from the corer was around 1.20 metres of mud and clay.

View of the west Cork coastline on the Sheep's Head peninsula from inner Dunmanus Bay.

All INFOMAR data is available for free download here.