CE12006 Biodiscovery and deep-ocean ecosystems

This 16 day bio-discovery and deep ocean ecosystems survey, led by National University of Ireland, Galway (NUIG), took place in April 2012 on board the Marine Institute's R.V. Celtic Explorer in the North East Atlantic Ocean. This was a multidisciplinary deep-sea research cruise, combining two components: bio-discovery, and ecosystem functioning and nutrient recycling. Both components are inter-institutional and interdisciplinary. The survey used the remotely operated vehicle ROV Holland 1 to survey the area and collect marine specimens. CTD (conductivity-temperature-depth) sampling was also conducted at ROV dive sites where possible. This is a multidisciplinary deep-sea research cruise, combining two components: biodiscovery, and ecosystem functioning and nutrient recycling. Both components are inter-institutional and interdisciplinary. The scientific objectives of the two components are as follows: [1] Biodiscovery Working on the lower slope and at bathyal/abyssal depths in canyon regions we aim to: (i) Identify and map benthic macrofauna using conventional cores and ROV surveys (ii) Improve systematic knowledge of Porifera and Mollusca (iii) Collect specimens for the MI Marine Biodiscovery Laboratory (iv) Collect specimens likely to have novel photoactive molecules (vi) Characterise bacterial and archaeal diversity in water and sediment (vii) Collect marine invertebrates (particularly sponges), seawater, and sediment to study and compare the microbiota associated with each of the samples, culture microorganisms and construct metagenomic libraries. [2] Ecosystem function and nutrient cycling We aim to: (i) Examine the mechanisms whereby biogenic material, essentially derived for the spring diatom bloom and deposited on the continental shelf, is advected into layers within the open ocean water column from whence it sinks to the sea bed; (ii) Delineate the advective extent of these nepheloid layers of biogenic material derived from the continental shelf; (iii) Detect and determine the diversity and abundance of deep-sea nitrogen cycling microorganisms; (iv) Characterise and determine the origins, lability and recycling rates of dissolved and particulate organic matter supporting the currently accepted net heterotrophic nature of deep-sea cold-water coral reef communities; (v) Collect calcifying detritivores, Lophelia branches, coral rubble and sediment to study the transfer of C and N through the detritivore foodweb; and (vi) Determine mixing and resuspension rates at the sediment water interface using natural radiotracers.