The Diversity and Distribution of Cephalopods in the Charlie-Gibbs Fracture Zone Richards JC1*, Vecchione M1,2 1Department of Invertebrate Zoology, National Museum of Natural History, Smithsonian Institution 2National Marine Fisheries Service, National Museum of Natural History, Washington DC, 20560, USA

Introduction Submarine Dive Video Site Diversity The majority of the oceans still remain unexplored. For this reason, the MARECO project of the Gonatus steenstrupi ROV sightings Squid Species Census of Marine Life explored biodiversity along the Charlie-Gibbs Fracture Zone (CGFZ): 0 Showcase: the region of the Mid-Atlantic Ridge running from Iceland to the Azores. Number of Mean North Species Diversity: 2.4 present: Cephalopods play an integral part in marine environments, where they take on both predator Mean South and prey roles. Cephalopods are also important within the fishing industry. The distribution Diversity: 4.75

and diversity of cephalopods was quantified in order to learn more about the ecosystems surrounding the CGFZ. 1000 Charlie Gibbs Fracture Zone Mid Water Site Diversity rs) te (me h

Squid Dept Sighting Mean North 2000 Diversity: 3.5 Day Night Mean South Diversity: 3.25 Muusoctopus johnsonianus Gonatus steenstrupi Mastigoteuthis agassizii Photograph courtesy of David Shale, MARECO Photograph courtesy of David Shale, MARECO Photograph courtesy of David Shale, MARECO Charlie Gibbs Fracture Zone Bottom Site Diversity Sampling Sites 12:00 AM 6:00 AM 12:00 PM 6:00 PM 12:00 AM Maps depicting the number of species present at each site. Each site is divided into Graph depicting 11 separate dives and their distinct paths; red points signify the sighting of a two zones: mid water and bottom. Blue signifies a northern site and red signifies a Charlie Gibbs Fracture Zone Gonatus steenstrupi. Blue represents day and purple represents night. Atlantic Ocean southern site. 11 13 15 Conclusion: Conclusion: Gonatus steenstrupi are most common closer to the ocean surface; the majority live Mid waters in southern sites have the highest diversity and mid 12 North above depths of 1000 meters. waters in northern sites have the lowest diversity. America 16

18 Africa 20 Squid Abundances Site Similarity 17 19 21 Gonatus steenstrupi Diel Abundances Mid Water Site Similarity Octopod Eleven sites along the CGFZ were 14% 20 11% Legend: Species sampled. Each site consisted of two 30% North Showcase: major trawling zones: Mid water and 0 m 40 (%) 43% South bottom. The mid water zone is further 200 m rity 60 62% 63% broken up into four discrete depth 700 m 200 la ranges: 0 – 200 meters, 200 – 700 mi 80% 89% Si 80 79% meters, 700 - 1900 meters, and 1900 1900 m Mid Water 96% 1 100

– 2900 meters. Roughly 20 species of rs)

cephalopod were collected across all te 2900 m 00 20 21 15 17 16 19 13 18 11 12 sites. (me

Bottom h Tree depicting similarity (%) amongst the mid water trawl zones of sites. Ocean Floor

Dept 0% Bottom Site Similarity 900 Night Day 20 22% Legend: Methods 32% North (%) 40 40% Juvenile G. Steenstrupi 46% South Submarine Dive Video Site Diversity collected during trawls rity la 60 56% 2900 mi 50 hours of video across 11 dives were viewed. The total number of species recorded at each Si 71% 80 Sightings of the most common species, Gonatus site via trawling was mapped using 12 4 3 steenstrupi, were recorded alongside the time of GeoMapApp. Each site was divided between Abundance (Squids/10 m water) 100 day and depth. Dive data is separate from trawl mid water and bottom trawling zones. Day vs. Night (i.e. Diel) graph depicting G. steenstrupi abundances at various depths. data. 19 11 13 15 20 9 21 17 Conclusion: Tree depicting similarity (%) amongst the bottom trawl zones of sites. Squid Abundances Site Similarity Gonatus steenstrupi display the highest abundances during the day and at Conclusion: The total number of Gonatus steenstrupi caught The species composition (number of individuals of shallower depths. Mid water sites are more similar than bottom sites. at all sites via discrete depth trawling was each species) at each site was compared to other standardized by the total water filtered at each sites with Bray-Curtis Similarity.6 These similarity Acknowledgements References depth. Trawls were divided temporally (e.g. Day values were used to produce tree diagrams.5 Each We thank April Cook for providing the discrete-depth zones and their volume calculations. We thank Abby Reft 1. Cook A.B, Sutton T.T, Galbraith J.K, Vecchione M, 2012, ”Deep-pelagic (0–3000m) fish 4. Clarke, KR (1993). Non-parametric multivariate analyses of changes in community structure. and Night). Only mid water depth ranges were site was categorized as north or south and divided for assisting with specimens. We thank NOAA for providing ship time and support for the 2009 Bigelow Cruise assemblage structure over the Mid-Atlantic Ridge in the area of the Charlie-Gibbs Fracture Australian Journal of Ecology 18: 117-143 and the 2004 SARS Cruise. We Thank Elizabeth Cottrell for mapping with GeoMapApp. A special thanks to the Zone”, Deep Sea Research Part II, 98: 279-291 5. Vecchione M, Young R.E, and Piatkowski U, 2010, “Cephalopods of the northern MidAtlantic used for these calculations. 2. GeoMapApp: http://www.geomapapp.org Ridge”, Marine Biology Research, 6: 1, 25 – 52 between mid water and bottom. Smithsonian Institution. All data are associated with the MARECO program of the Census of Marine Life. Funding 3. Ryan et al., 2009 6. v7: Clarke, KR, Gorley, RN, 2015. PRIMER v7: User Manual/Tutorial. PRIMER-E, Plymouth, was provided by NSF. 296pp.