The Porcupine Abyssal Plain Observatory is a sustained, multidisciplinary observatory in the North Atlantic coordinated by the National Oceanography Centre, Southampton. For over 20 years the observatory has provided key time-series datasets for analysing the effect of climate change on the open ocean and deep-sea ecosystems. As is normally the case during cruises which are needed to refurbish the observatory, a wide range of other activities were carried out during the cruise.
The main mooring of the observatory broke in December 2013 during the horrendous winter storms which destroyed a number of Met Office moorings around the UK. However we were fortunate that the break occurred just below the main sensor frame and as a result we were able to recover it along with the massive Ocean Data Acquisition System (ODAS) buoy after it had drifted towards Ireland. We were therefore able to recover all of the sensors and, most importantly, the data stored in them. Prior to Meteor cruise 108 they were all refurbished and were deployed during M108 along with some additional sensors. In addition we recovered a set of sediment traps which had been collecting sinking material in the lower part of the water column for the previous 12 months and a new set was deployed.
Furthermore some entirely novel research was carried out on the distribution and characteristics of marine snow particles in the top few hundred meters of the water column. These are inanimate particles which are the principle vehicles by which material sinks out of the upper sunlit zone down to the abyss, taking carbon down with them and out of contact with the atmosphere for centuries. We used optical methods to characterise their distribution and collected samples using the Marine Snow catcher thereby providing material for a variety of experiments with colleagues from Bremen.
The Bathysnap time-lapse camera system which had been taking photos of the seabed at 4800m was recovered to give an assessment of the behaviour of the benthic animals and how the seabed appearance changes in response to deposition of material. A new module was deployed.
Temporal variability of the water column and seabed fauna - a task which is difficult or impossible to do autonomously was assessed using nets and cores
