The horizontal and vertical dynamics of swordfish in the South Pacific Ocean

Abstract The movement patterns of broadbill swordfish ( Xiphias gladius ) in the South Pacific Ocean are largely unknown. Understanding the connectivity of the species across the Pacific and any variability in diving behaviour as it relates to fisheries availability/catchability are of particular relevance. Here, we present an electronic tagging dataset spanning the western and eastern South Pacific Ocean regions. Movements observed suggest a lack of connectivity between the southern and northern regions of the western and central Pacific Ocean (WCPO) and limited connectivity between the eastern and western parts of the Tasman and Coral Seas in the south-western Pacific Ocean. At least some swordfish appear to undertake movements between tropical waters extending from around Vanuatu to French Polynesia to waters around New Zealand, indicating greater connectivity than previously thought. Observations indicate no movement between the WCPO and the eastern Pacific Ocean (EPO), although data from boundary areas are lacking. Swordfish demonstrated a mixture of diel vertical distributions and daytime surface behaviour, spending time mostly in waters  400 m during the day. Diel vertical movements resulted in movement through water temperatures that varied on the order of 15–20° C with temperatures at depth as low as 2.4° C and those at the surface as high as 31.4° C. Vertical distributions of swordfish varied both spatially and temporally with swordfish in the Tasman/Coral Seas demonstrating the least variability. Spatio-temporal variability in vertical distributions is likely driven by variability in environmental conditions and associated prey distributions. Swordfish tagged in the Tasman/Coral Seas and in the EPO interrupted deeper daytime distributions with two distinct types of surfacing behaviour: temporally associated and temporally isolated. Temporally isolated surface behaviour occurred throughout the year and in association with on average lower sea surface temperatures. Temporally associated surface behaviour was restricted to austral summer months only and in association with on average higher sea surface temperatures. Our results represent a major step towards reducing uncertainty about the spatial dynamics of swordfish in the South Pacific Ocean. At the same time, questions as to the extent of connectivity of swordfish throughout the south Pacific and the linkages between spawning ground and foraging ground locations are raised. Further investigation of the movements of swordfish from the central southern Pacific Ocean is required to determine what linkages there may be between the WCPO and the EPO and whether connectivity suggested by genetic studies is supported.

[1]  C. Wilcox,et al.  Resolving estimation of movement in a vertically migrating pelagic fish: Does GPS provide a solution? , 2011 .

[2]  J. Hoolihan Horizontal and vertical movements of sailfish (Istiophorus platypterus) in the Arabian Gulf, determined by ultrasonic and pop-up satellite tagging , 2005 .

[3]  P. Kasapidis,et al.  Stock structure of swordfish ( Xiphias gladius ) in the Pacific Ocean using microsatellite DNA markers , 2008 .

[4]  Toby A Patterson,et al.  Classifying movement behaviour in relation to environmental conditions using hidden Markov models. , 2009, The Journal of animal ecology.

[5]  J. Stevens,et al.  Satellite tagging of blue sharks (Prionace glauca) and other pelagic sharks off eastern Australia: depth behaviour, temperature experience and movements , 2010 .

[6]  H. Okamura,et al.  Swimming behaviour and migration of a swordfish recorded by an archival tag , 2003 .

[7]  Steven X. Cadrin,et al.  Accounting for Spatial Population Structure in Stock Assessment: Past, Present, and Future , 2009 .

[8]  Karen Evans,et al.  Reproductive Schedules in Southern Bluefin Tuna: Are Current Assumptions Appropriate? , 2012, PloS one.

[9]  Tim Sippel,et al.  Investigating Behaviour and Population Dynamics of Striped Marlin (Kajikia audax) from the Southwest Pacific Ocean with Satellite Tags , 2011, PloS one.

[10]  David A. Fournier,et al.  MULTIFAN-CL: a length-based, age-structured model for fisheries stock assessment, with application to South Pacific albacore, Thunnus alalunga , 1998 .

[11]  Anders Nielsen,et al.  State–space model for light-based tracking of marine animals , 2007 .

[12]  E. Josse,et al.  Movement patterns of large bigeye tuna (Thunnus obesus) in the open ocean, determined using ultrasonic telemetry , 2000 .

[13]  Richard W. Brill,et al.  Harpoon method for attaching ultrasonic and Popup satellite tags to giant bluefin tuna and large pelagic fishes , 1998 .

[14]  Mark N. Maunder,et al.  Interpreting catch per unit effort data to assess the status of individual stocks and communities , 2006 .

[15]  A. Punt,et al.  Standardizing catch and effort data: a review of recent approaches , 2004 .

[16]  J. O'Brien,et al.  Ocean color variability in the Tasman Sea , 2002 .

[17]  B. Block,et al.  Migration of an upper trophic level predator, the salmon shark Lamna ditropis, between distant ecoregions , 2008 .

[18]  J. Holdsworth,et al.  New Zealand Billfish and Gamefish Tagging, 2010-11 , 2011 .

[19]  Timothy P. Boyer,et al.  World Ocean Atlas 2005, Volume 3: Dissolved Oxygen, Apparent Oxygen Utilization, and Oxygen Saturation [+DVD] , 2006 .

[20]  John D. Neilson,et al.  Investigations of Horizontal Movements of Atlantic Swordfish Using Pop-up Satellite Archival Tags , 2009 .

[21]  S. Åkesson,et al.  Long-distance migration: evolution and determinants , 2003 .

[22]  J. Rodriguez,et al.  Hierarchical analyses of genetic variation of samples from breeding and feeding grounds confirm the genetic partitioning of northwest Atlantic and South Atlantic populations of swordfish (Xiphias gladius L.) , 2005 .

[23]  Per K Andersen,et al.  A Finite‐State Continuous‐Time Approach for Inferring Regional Migration and Mortality Rates from Archival Tagging and Conventional Tag‐Recovery Experiments , 2008, Biometrics.

[24]  Karen Evans,et al.  Movement and behaviour of large southern bluefin tuna (Thunnus maccoyii) in the Australian region determined using pop‐up satellite archival tags , 2008 .

[25]  T. Romeo,et al.  Swordfish ( Xiphias gladius , Teleostea: Xiphiidae) surface behaviour during reproductive period in the central Mediterranean Sea (southern Tyrrhenian Sea) , 2009 .

[26]  D. Kolody,et al.  Spatial Dynamics of Swordfish in the South Pacific Ocean Inferred from Tagging Data , 2012 .

[27]  C. Bost,et al.  Diel dive depth in penguins in relation to diel vertical migration of prey: whose dinner by candlelight? , 1993 .

[28]  R. Stephenson Stock complexity in fisheries management: a perspective of emerging issues related to population sub-units , 1999 .

[29]  R. A. Heath,et al.  The effect of warm-core eddies on oceanic productivity off northeastern New Zealand , 1982 .

[30]  C. Fauvel,et al.  Reproductive dynamics of swordfish (Xiphias gladius) in the southwestern Indian Ocean (Reunion Island). Part 1: oocyte development, sexual maturity and spawning , 2009 .

[31]  F. G. Hochberg,et al.  Cephalopods in the Diet of Swordfish (Xiphias gladius) Caught off the West Coast of Baja California, Mexico1 , 2005 .

[32]  M. Domeier,et al.  Fine-scale movements of the swordfish Xiphias gladius in the Southern California Bight , 2010 .

[33]  Rudy J. Kloser,et al.  The biological oceanography of the East Australian Current and surrounding waters in relation to tuna and billfish catches off eastern Australia , 2011 .

[34]  I. Yasuda,et al.  Empirical biomass model for the Japanese sardine, Sardinops melanostictus, with sea surface temperature in the Kuroshio Extension , 2003 .

[35]  Karen Evans,et al.  Summary Report of aWorkshop on Geolocation Methods for Marine Animals , 2009 .

[36]  B. Block,et al.  Mitochondrial control region variability and global population structure in the swordfish, Xiphias gladius , 1996 .

[37]  G. Hays A review of the adaptive significance and ecosystem consequences of zooplankton diel vertical migrations , 2003, Hydrobiologia.

[38]  Steven F. Railsback,et al.  ANALYSIS OF HABITAT‐SELECTION RULES USING ANINDIVIDUAL‐BASED MODEL , 2002 .

[39]  E. Widder,et al.  Effects of a decrease in downwelling irradiance on the daytime vertical distribution patterns of zooplankton and micronekton , 2002 .

[40]  P. Ward,et al.  Broadbill swordfish: status of established fisheries and lessons for developing fisheries , 2000 .

[41]  G. Hays,et al.  When surfacers do not dive: multiple significance of extended surface times in marine turtles , 2010, Journal of Experimental Biology.

[42]  B. Block,et al.  Structure and migration corridors in Pacific populations of the Swordfish Xiphius gladius, as inferred through analyses of mitochondrial DNA , 2000 .

[43]  Murdoch K. McAllister,et al.  A sequential Bayesian methodology to estimate movement and exploitation rates using electronic and conventional tag data: application to Atlantic bluefin tuna (Thunnus thynnus) , 2009 .

[44]  J. Childers,et al.  U.S. swordfish fisheries in the North Pacific Ocean , 2014 .

[45]  B. Seibel Critical oxygen levels and metabolic suppression in oceanic oxygen minimum zones , 2011, Journal of Experimental Biology.

[46]  E. Houde,et al.  Distribution, Relative Abundance, and Seasonality of Swordfish Larvae , 1983 .

[47]  F. G. Carey,et al.  Daily patterns in the activities of swordfish, Xiphias gladius, observed by acoustic telemetry , 1981 .

[48]  D. Costa,et al.  Migratory shearwaters integrate oceanic resources across the Pacific Ocean in an endless summer , 2006, Proceedings of the National Academy of Sciences.

[49]  Glen Gawarkiewicz,et al.  Population connectivity in marine systems : an overview , 2007 .

[50]  Mark P. Johnson,et al.  Cheetahs of the deep sea: deep foraging sprints in short-finned pilot whales off Tenerife (Canary Islands). , 2008, The Journal of animal ecology.

[51]  J. Blanco,et al.  Seasonal climatology of hydrographic conditions in the upwelling region off northern Chile , 2001 .

[52]  Anthony J. Booth,et al.  Incorporating the spatial component of fisheries data into stock assessment models , 2000 .

[53]  A. E. Caton,et al.  Review of aspects of Southern bluefin tuna biology, population, and fisheries , 1994 .

[54]  E. Warrant The eyes of deep-sea fishes and the changing nature of visual scenes with depth. , 2000, Philosophical transactions of the Royal Society of London. Series B, Biological sciences.

[55]  EvesonJ. Paige,et al.  Using electronic tag data to improve mortality and movement estimates in a tag-based spatial fisheries assessment model , 2012 .

[56]  J. Giske,et al.  Vertical distribution and trophic interactions of zooplankton and fish in Masfjorden, Norway , 1990 .

[57]  Richard W. Brill,et al.  A review of temperature and oxygen tolerance studies of tunas pertinent to fisheries oceanography, movement models and stock assessments , 1994 .

[58]  Richard W. Brill,et al.  Vertical movements of bigeye tuna (Thunnus obesus) associated with islands, buoys, and seamounts near the main Hawaiian Islands from archival tagging data , 2003 .

[59]  K. Ridgway,et al.  Mesoscale structure of the mean East Australian Current System and its relationship with topography , 2003 .

[60]  J. Gunn,et al.  Behaviour and habitat preferences of bigeye tuna (Thunnus obesus) and their influence on longline fishery catches in the western Coral Sea , 2008 .

[61]  W. J. Richards,et al.  Synopsis of the biology of the swordfish, Xiphias gladius Linnaeus , 1981 .

[62]  R. Cowen,et al.  Larval dispersal and marine population connectivity. , 2009, Annual review of marine science.

[63]  K. Tsuchiya,et al.  Composition of piscine prey in the diet of large pelagic fish in the eastern tropical Pacific Ocean , 2001 .

[64]  Bruce R. Mate,et al.  The evolution of satellite-monitored radio tags for large whales: One laboratory's experience , 2007 .

[65]  Anthony D. M. Smith,et al.  Implementing effective fisheries-management systems – management strategy evaluation and the Australian partnership approach , 1999 .

[66]  Angela H. Arthington,et al.  Importance of the riparian zone to the conservation and management of freshwater fish: a review , 2003 .

[67]  S. Cass-Calay,et al.  The Recovery of Atlantic Swordfish: The Comparative Roles of the Regional Fisheries Management Organization and Species Biology , 2013 .

[68]  Ransom A. Myers,et al.  Identification of high‐use habitat and threats to leatherback sea turtles in northern waters: new directions for conservation , 2005 .

[69]  R. Meléndez,et al.  Feeding and trophic relationships of the swordfish (Xiphias gladius Linnaeus, 1758), off central and northern Chile during 2005 , 2009 .

[70]  S. Campana,et al.  Otolith elemental fingerprints of juvenile Pacific swordfish Xiphias gladius , 2005 .

[71]  Heidi Dewar,et al.  Evaluating post-release behaviour modification in large pelagic fish deployed with pop-up satellite archival tags , 2011 .

[72]  J. Farley,et al.  Reproductive dynamics of broadbill swordfish, Xiphias gladius, in the domestic longline fishery off eastern Australia , 2003 .

[73]  M. Musyl,et al.  Movements and behaviors of swordfish in the Atlantic and Pacific Oceans examined using pop‐up satellite archival tags , 2011 .

[74]  J. Hemmer-Hansen,et al.  Genomic signatures of local directional selection in a high gene flow marine organism; the Atlantic cod (Gadus morhua) , 2009, BMC Evolutionary Biology.

[75]  J. Polovina,et al.  Modeling swordfish daytime vertical habitat in the North Pacific Ocean from pop-up archival tags , 2012 .

[76]  J. Hare,et al.  The early life history of swordfish (Xiphias gladius) in the western North Atlantic , 2003 .

[77]  F. Abascal,et al.  Horizontal and vertical movements of swordfish in the Southeast Pacific , 2010 .

[78]  S. Canese,et al.  SWORDFISH TAGGING WITH POP - UP SATELLITE TAGS IN THE MEDITERRANEAN SEA , 2008 .