A new drifting underwater camera system for observing spawning Japanese eels in the epipelagic zone along the West Mariana Ridge

Spawning-condition Japanese eels Anguilla japonica, fertilized eggs, and newly-hatched preleptocephali have been captured, and studies for observing spawning eels with underwater camera systems have begun. This study describes a new, less invasive, free-drifting underwater camera observation system that was deployed from the research vessel (R/V) Natsushima in June 2013. Three drifting buoy camera systems (Una-Cam) with lights-on/lights-off programmed sequencing during daytime and nighttime hours were deployed over a period of seven days at 20 locations south of a salinity front along the southern West Mariana Ridge. Live artificially matured A. japonica eels held in transparent chambers were used as an attractant source through the release of reproductive pheromones and other odors. Each system was suspended from a buoy array at a depth of 174–200 m, with four cameras and three lights pointed downward at different angles towards the eel chamber. The Una-Cam systems were stable and were effective at recording images of fish, crustaceans, and gelatinous zooplankton. Olfactory cues may have attracted male and female Derichthys serpentinus eels, which showed what seemed to be reproductive behavior and attraction to the Japanese eels in the chamber. Una-Cam systems are capable of recording images of anguillid eels, if they approach, and may be useful for observing spawning eels in their offshore spawning areas.

[1]  Paul G. Fernandes,et al.  Autonomous underwater vehicles: future platforms for fisheries acoustics , 2003 .

[2]  K. Tsukamoto.  Oceanic biology: Spawning of eels near a seamount , 2006, Nature.

[3]  K. Tsukamoto.  Discovery of the spawning area for Japanese eel , 1992, Nature.

[4]  M. Miller,et al.  An introduction to leptocephali : biology and identification , 2007 .

[5]  L. Riemann,et al.  Oceanic fronts in the Sargasso Sea control the early life and drift of Atlantic eels , 2010, Proceedings of the Royal Society B: Biological Sciences.

[6]  Euan S. Harvey,et al.  Development and validation of a mid-water baited stereo-video technique for investigating pelagic fish assemblages , 2014 .

[7]  K. Tsukamoto,et al.  Swimming depths of offshore migrating longfin eels Anguilla dieffenbachii , 2005 .

[8]  Michael J. Miller,et al.  First observations of the oceanic migration of Japanese eel, from pop-up archival transmitting tags , 2011 .

[9]  K. Tsukamoto,et al.  First capture of post-spawning female of the Japanese eel Anguilla japonica at the southern West Mariana Ridge , 2011, Fisheries Science.

[10]  E. Edinger,et al.  Geological features supporting deep-sea coral habitat in Atlantic Canada , 2011 .

[11]  Michael J. Miller,et al.  Oceanic spawning ecology of freshwater eels in the western North Pacific , 2011, Nature communications.

[12]  Michael J. Miller,et al.  Spawning Sites of the Japanese Eel in Relation to Oceanographic Structure and the West Mariana Ridge , 2014, PloS one.

[13]  P. I. Miller,et al.  Oceanic migration behaviour of tropical Pacific eels from Vanuatu , 2013 .

[14]  C. Baldwin.  FAO SPECIES IDENTIFICATION GUIDE FOR FISHERY PURPOSES. THE LIVING MARINE RESOURCES OF THE WESTERN CENTRAL PACIFIC , 2003, Copeia.

[15]  H. M. Dye,et al.  Induced ovulation in coho salmon (Oncorhynchus kisutch). I. Further studies on the use of salmon pituitary preparations , 1981 .

[16]  K. Tsukamoto,et al.  Sympatric spawning of Anguilla marmorata and Anguilla japonica in the western North Pacific Ocean. , 2009, Journal of fish biology.

[17]  B. Robison,et al.  Direct observations of the association between a deep-sea fish and a giant scyphomedusa , 2004 .

[18]  Michael J. Miller,et al.  Now you see me, now you don’t: observation of a squid hiding in its ink trail , 2014, Marine Biodiversity.

[19]  K. Mori,et al.  Observations of wild hunting behaviour and bioluminescence of a large deep-sea, eight-armed squid, Taningia danae , 2007, Proceedings of the Royal Society B: Biological Sciences.

[20]  K. Mori,et al.  First-ever observations of a live giant squid in the wild , 2005, Proceedings of the Royal Society B: Biological Sciences.

[21]  T. Inagaki,et al.  Evaluation of the larval distribution and migration of the Japanese eel in the western North Pacific , 2011, Reviews in Fish Biology and Fisheries.

[22]  Dhugal J. Lindsay,et al.  Biodiversity in midwater cnidarians and ctenophores: submersible-based results from deep-water bays in the Japan Sea and north-western Pacific , 2005, Journal of the Marine Biological Association of the United Kingdom.

[23]  B. Erisman,et al.  Observations of spawning in the Leather Bass, Dermatolepis dermatolepis (Teleostei: Epinephelidae), at Cocos Island, Costa Rica , 2009, Environmental Biology of Fishes.

[24]  中坊 徹次,et al.  Fishes of Japan : with pictorial keys to the species , 2002 .

[25]  Michael B. Lowry,et al.  Comparison of baited remote underwater video (BRUV) and underwater visual census (UVC) for assessment of artificial reefs in estuaries , 2012 .

[26]  Michael J. Miller,et al.  Vertical body orientation by a snipe eel (Nemichthyidae, Anguilliformes) in the deep mesopelagic zone along the West Mariana Ridge , 2014 .

[27]  Tim P. Lynch,et al.  Pelagic fish assemblages assessed using mid-water baited video: standardising fish counts using bait plume size , 2007 .

[28]  H. Fricke,et al.  Seamounts and the Mystery of Eel Spawning , 1998, Naturwissenschaften.

[29]  M. Okazaki,et al.  Vertical distribution of transparent exopolymer particle (TEP) concentration in the oligotrophic western tropical North Pacific , 2014 .

[30]  S. Ross,et al.  Persistent near-bottom aggregations of mesopelagic animals along the North Carolina and Virginia continental slopes , 2008 .

[31]  K. Tsukamoto.  Oceanic migration and spawning of anguillid eels. , 2009, Journal of fish biology.

[32]  R. Cowen,et al.  In situ ichthyoplankton imaging system (ISIIS): system design and preliminary results , 2008 .

[33]  Johs. Schmidt,et al.  The Breeding Places of the Eel , 1923 .

[34]  Matthew D. Taylor,et al.  Tidal currents, sampling effort and baited remote underwater video (BRUV) surveys: Are we drawing the right conclusions? , 2013 .

[35]  F. Tesch,et al.  Spatial distribution of 0-group eel larvae (Anguilla sp.) in the Sargasso Sea , 1982, Helgoländer Meeresuntersuchungen.

[36]  K. Tsukamoto,et al.  A model for the larval migration of the Japanese eel: roles of the trade winds and salinity front , 1994 .

[37]  K. Tsukamoto,et al.  Vertical migrations may control maturation in migrating female Anguilla dieffenbachii , 2010 .

[38]  B. Robison.  Shape change behavior by mesopelagic animals , 1999 .

[39]  C. Ryer,et al.  Evaluating the role of fish behavior in surveys conducted with underwater vehicles , 2008 .

[40]  K. Tsukamoto,et al.  The salinity front in the North Equatorial Current: A landmark for the spawning migration of the Japanese eel (Anguilla japonica) related to the stock recruitment , 2006 .

[41]  L. Prieur,et al.  Vertical distribution of aggregates (>110 µm) and mesoscale activity in the northeastern Atlantic: Effects on the deep vertical export of surface carbon , 2007 .

[42]  M. Benfield,et al.  In Situ Video Observations of Two Manefishes (Perciformes: Caristiidae) in the Mesopelagic Zone of the Northern Gulf of Mexico , 2009, Copeia.

[43]  G. Gorsky,et al.  Vertical distribution (0–1000 m) of macrozooplankton, estimated using the Underwater Video Profiler, in different hydrographic regimes along the northern portion of the Mid-Atlantic Ridge , 2008 .

[44]  T. Pietsch,et al.  In-Situ Observations of a Deep-sea Ceratioid Anglerfish of the Genus Oneirodes (Lophiiformes: Oneirodidae) , 2008, Copeia.

[45]  K. Tsukamoto,et al.  Effects of water temperature on early development of Japanese eel Anguilla japonica , 2007, Fisheries Science.

[46]  K. Tsukamoto,et al.  Discovery of mature freshwater eels in the open ocean , 2009, Fisheries Science.

[47]  R. Kleckner,et al.  The northern limit of spawning by Atlantic eels ( Anguilla spp.) in the Sargasso Sea in relation to thermal fronts and surface water masses , 1988 .

[48]  S. Kimura,et al.  Numerical simulation to resolve the issue of downstream migration of the Japanese eel , 1999 .

[49]  V. Trenkel,et al.  Variability in natural behaviour, and observed reactions to an ROV, by mid-slope fish species , 2006 .

[50]  P. Castle.  Distribution, Larval Growth, and Metamorphosis of the Eel Derichthys serpentinus Gill, 1884 (Pisces: Derichthyidae) , 1970 .

[51]  H. Fricke,et al.  Spawning time and place of the Japanese eel Anguilla japonica in the North Equatorial current of the western North Pacific Ocean , 2001 .

[52]  S. Simpson,et al.  Boat noise disrupts orientation behaviour in a coral reef fish , 2013 .

[53]  T. Lynch,et al.  Bait type affec ts fi sh assemblages and feeding guilds observed at baited remote underwater video , 2013 .

[54]  Kim Aarestrup,et al.  Oceanic Spawning Migration of the European Eel (Anguilla anguilla) , 2009, Science.

[55]  H. Fricke,et al.  Seamounts, New Moon and eel Spawning: The Search for the Spawning Site of the Japanese eel , 2003, Environmental Biology of Fishes.

[56]  K. Tsukamoto,et al.  Influence of artificial fertilization methods of the hormone-treated Japanese eel Anguilla japonica upon the quality of eggs and larvae (Comparison between stripping-insemination and spontaneous spawning methods) , 2008 .

[57]  Katsumi Tsukamoto,et al.  Observations on the spawning behavior of artificially matured Japanese eels Anguilla japonica in captivity , 2007 .

[58]  T. Lynch,et al.  Bait type affects fish assemblages and feeding guilds observed at baited remote underwater video stations , 2013 .

[59]  Steven H. D. Haddock,et al.  Using red light for in situ observations of deep-sea fishes , 2005 .

[60]  P. Bagley,et al.  Behavioural responses to structures on the seafloor by the deep-sea fish Coryphaenoides armatus: Implications for the use of baited landers , 2006 .

[61]  S. Kimura,et al.  Fluctuation in the distribution of low-salinity water in the North Equatorial Current and its effect on the larval transport of the Japanese eel , 2001 .