Sea surface temperatures recorded by the Government Laboratory show that 2014 was the warmest year on record.
The sea surface temperature has been measured daily since 1904 in Port Erin bay and 2014 was an exceptional year, said Dr Kev Kennington, Marine Monitoring Scientist at the Laboratory, part of the Department of Environment, Food and Agriculture.
Monthly average records were broken for six of the 12 months of 2014, with temperatures during May, June, July, October, November and December exceeding previous records for those months.
The highest sea surface temperature of the year was on the 6th August, when 16.7° Celsius was recorded. Temperatures exceeded 16°C on nine days during August, something that had happened on only five days over the whole of the past 110 years and all in the recent past – twice in 2003, once in 2006 and twice in 2011.
2014 was also an unusual year for marine wildlife, with record concentrations of chlorophyll, a measure of the quantity of phytoplankton (plant plankton) being recorded during the spring months. The high concentrations of phytoplankton were not matched by the same concentrations of zooplankton (animal plankton), which is the preferred diet of certain fish, including basking sharks. Recordings of basking sharks in Manx waters were low in 2014.
Decaying vegetable matter from the high levels of phytoplankton resulted in a reduction of oxygen concentrations towards the sea floor to the south and west of the Island during spring and summer. Warm and calm sea conditions during the summer contributed to this effect. The reduced oxygen caused stress to bottom-dwelling organisms such as starfish and clams, which resulted in reports of mortalities of these organisms being made by local divers during the summer.
A prolonged bloom of one particular species of phytoplankton occurred during early summer off the west coast of the Isle of Man. This species (Pseudo-nitzschia seriata) produces chemicals that can accumulate in shellfish such as queen and king scallops. Although entirely natural, at high levels these chemicals can cause health problems in humans.
With key functions to protect health and support the fishing industry, DEFA closely monitors both the phytoplankton in the water and shellfish toxins in order to ensure that there is no risk to humans, and this led to the temporary closure of some of the king scallop beds off the west coast of the Island towards the end of 2014. They have now fully reopened.
'This past winter has also been mild, with average sea temperatures recorded from the beginning of December 2014 and end of February 2015 being the 10th warmest over the 110-year database,' noted Dr Kennington.
Richard Ronan MHK, Minister for Environment, Food and Agriculture, said: 'The long-term monitoring conducted by the Government Laboratory provides data that feeds into international studies on climate. The data shows that, whatever the cause, the temperature of the sea has recently started to rise faster than previously. This is of concern to the Isle of Man because changes like this, if it continues, can have a profound effect on sea life and on our fishing industry, which is one of the reasons behind the papers on climate challenges that I will be presenting to May Tynwald.'
