Distribution of bioluminescence in the Mediterranean Sea and

Distribution of bioluminescence in the Mediterranean Sea and predicted effects on a neutrino telescope Jessica Craig, Alan Jamieson, Amy Heger, Alain Zuur & Monty Priede Oceanlab, University of Aberdeen, Scotland, UK www. oceanlab. abdn. ac. uk

Talk outline n Bioluminescent sources (BL) n Measurement methods n BL Distribution in the Mediterranean Sea n BL Distribution at neutrino telescope sites n Modelling the frequency of BL n BL around the PMT optical module

Bioluminescent sources n BACTERIA - Steady baseline source of light n ANIMALS - Non steady-state flashes n Centred on 480 nm Mesoplankton – 0. 2 -20 mm (e. g. copepods) Macroplankton – 20 -200 mm (e. g. euphausiids) Megaplankton – 200 -2000 mm (e. g. medusae & large colonial organisms (e. g. pyrosomes)) (Dussart et al. 1965, Sieburth et al. 1978)

Bioluminescent sources n Mechanical, chemical and visual stimulation n Quantum emission (photons. flash-1) (Heger 2007)

Measurement method n ISIT profiler • ISIT camera – 5 x 10 -6 lux (min faceplate sens. ) • ‘Splat screen’ – 500 x 375 mm C A B D A – Ultra-low-light camera B – Power/control unit C – Lamp D – Splat-screen (Priede et al. 2006, Heger et al. 2008)

Mediterranean BL distribution n Sampling stations from 4 cruises ANTARES - Jan 2004 ANTARES - May 2004 RV Meteor 60 -1 - October 2006 NESTOR RV Aegeao - May 2007

Mediterranean BL distribution

Mediterranean BL distribution Depth range 500 -1500 -2500 Adriatic 2. 51 Strait of Sicily 1. 38 ANTARES 1. 65 0. 62 Tyrrhenian 1. 53 0. 40 NW Ionian 1. 53 0. 21 NESTOR 0. 30 0. 06 2500 -3500 >3500 0. 04 0. 02

Mediterranean Sea productivity n High surface productivity High abundance bioluminescent sources January July April October MODIS monthly composites Chlorophyll a (2006) (Ocean Colour Portal: http: // marine. jrc. cec. eu. int)

Near seafloor BL density n Near-bottom BL density decreases with increasing seafloor depth BL density (sources. m-3) Seafloor depth (m) R 2 = 0. 92 NEMO site not yet sampled At seafloor depth of 3500 m Estimate: 0. 05 sources. m-3

Modelling BL frequency n n Impacts on detector n Background Predicted number of bioluminescent flashes in vicinity of OM Impacts on detector Background Flash rate Density m-3 min-1 Flash Interval h-1 min r =1 m min r = 10 m ANTARES 1500 -2500 m 0. 622 0. 28 16. 79 3. 57 2. 29 x 105 54. 5 NESTOR 1500 -2500 m 0. 068 0. 031 1. 84 32. 69 1. 91 x 107 4565 NESTOR 2500 -3500 m 0. 043 0. 019 1. 16 52. 68 4. 78 x 107 11416 NESTOR >3500 m 0. 018 0. 008 0. 49 125. 47 2. 73 x 108 65150 NEMO 3500 m 0. 05 0. 02 1. 31 45. 5 3. 97 x 107 9498 (Priede et al. submitted; Heger 2007; Buskey & Swift 1990)

BL around the PMT module

BL around the PMT module (Latz et al. 1987; Bowlby & Case 1991)

BL around the PMT module (Latz et al. 1987; Bowlby & Case 1991; Bowlby et al. 1990)

BL around the PMT module

Summary n Low surface productivity Low BL density n Deeper site Low BL density More detailed info: Priede et al. (submitted) The potential influence of bioluminescence from marine animals on a deep sea underwater neutrino telescope array in the Mediterranean Sea. DSR I.

Thanks to: John Carr, the ANTARES collaboration and crew of the GGIX fast catamaran Andre Freiwald, (University of Erlangen) and crew of the FS Meteor (cruise M 70 leg-1) Spyros Stavrakakis (HCMR) and crew of the RV Aegaeo UK Natural Environment Research Council Luxembourgish Ministry of Culture Thank you!