FISHERIES patrol boat FPV Barrule has been used to launch an underwater glider 20 miles south of the island to investigate a seasonal plankton bloom phenomenon.
The western Irish Sea ‘gyre’ is a seasonal anomaly that occurs west and southwest of the Isle of Man.
Currents in the gyre retain plankton – minute plants and animals – which bloom during the spring and summer, providing a rich source of food at both the sea surface and the sea floor.
Juveniles of commercially important species such as Dublin Bay prawns are also found in great numbers within the gyre and it is thought that it plays an important role in the ecology of the extensive prawn grounds found in the region.
The bright yellow glider is packed with scientific instruments and its unique design powers it through the water using very little energy and enabling it to stay at sea for long periods of time.
Zigzagging through the water at a speed of about 1 knot and reaching depths of 90m, it will collect and send back data including temperature, salinity, dissolved oxygen, dissolved organic matter, plant photosynthesis and depth.
This will enable a greater understanding of how the gyre develops and its influence on the ecology of the area.
The glider’s survey work has been organised via the United Kingdom’s Integrated Monitoring Network (IMON) and co-ordinated by the National Oceanographic Centre in Liverpool and the Agri-Food and Biosciences Institute of Northern Ireland.
Additional scientific support for the deployment was given by the Government Analysts Laboratory of the Department of Environment Food and Agriculture.
The FPV Barrule was chosen to launch the glider because it carries a large RIB (Rigid Inflatable Boat) and can lower a working platform into the water.
It was therefore able to safely lower the glider into position and also check that it was moving properly.
Progress of the glider is continuously monitored by scientists at the National Oceanography Centre in Liverpool and within the first day of operation, it had crossed the western part of the Irish Sea, made its initial turn and was returning to the east.
DEFA Minister Phil Gawne MHK said: ‘Having taken the decision to allow the Barrule to be chartered to others for projects, I am very pleased that it has been selected to be used in this fascinating project.
‘It’s amazing to hear that a similar glider completed a transatlantic crossing, taking 221 days to travel from New Jersey to the Spanish coast.
‘The Barrule will retrieve the glider in about a month’s time but, in the meantime, it will continue its vital work in enforcing fisheries legislation and taking environmental samples at sea to ensure the fish caught and processed in the Isle of Man are from a well managed stock and of the highest standard.’
