学会発表（国外）

84)Jun NISHIOKA, East Asia GEOTRACES Workshop: Trace Element and Isotope (TEI) study in the Northwestern Pacific and its marginal seas, 北大低温研, 16-18 Jan. 2017
A sub-polar marginal sea controls oceanic iron cycles in the North Pacific, the Arctic Ocean


83)Jun NISHIOKA, I. Yasuda, Y. N. Volkov, A. Scherbinin, The 8 th science workshop program of the East Asian Cooperative Experiments (PEACE) WS, Pacific Ocean Institute FEBRAS, Vladivostok, Russia, 3 August 2016
Biogeochemical processes in the Sea of Okhotsk and the linkages to the Pacific Ocean, the Arctic Ocean


82)Jun NISHIOKA, N. Takesue, Goldshmid conference 2015, Prague Congress Centre, Prague, 21 August 2015
A role of sea ice melt water on iron supply to surface water in the Chukchi Sea, the Arctic Ocean


81)Kanna,N., Jun NISHIOKA, T. Toyota, Goldshmid conference 2015, Prague Congress Centre, Prague, 21 August 2015
Iron Enrichment by sea ice melting in the surface water in the Okhotsk Sea


80)Takuya NAKANOWATARI, Keisuke UCHIMOTO, Tomohiro NAKAMURA, Jun NISHIOKA, Humio MITSUDERA, Masaaki WAKATSUCHI, Asia Oceania Geoscience Society 2014 Annual Meeting, Sapporo, 1 August 2014
Seasonal variability of dissolved iron in the western subarctic North Pacific: Importance of lateral advection processes

79)Jun Nishioka, Takeshi Nakatsuka, Asia Oceania Geoscience Society 2014 Annual Meeting, Sapporo, 1 August 2014
Quantitative evaluation of iron transport processes in the Sea of Okhotsk

78)Koji SUZUKI, Ai HATTORI-SAITO, Yosuke SEKIGUCHI,Jun Nishioka, Masahito SHIGEMITSU, Tomonori ISADA, Hongbin LIU, Robert Michael MCKAY, Asia Oceania Geoscience Society 2014 Annual Meeting, Sapporo, 1 August 2014
Variability in Iron Nutritional Status of Large Diatoms in the Sea of Okhotsk with Special Reference to the Amur River Discharge

77)Hajime Obata, Jun Nishioka, Taejin Kim, Kazuhiro Norisuye, Shigenobu Takeda, Youhei Wakuta, Toshitaka Gamo, Asia Oceania Geoscience Society 2014 Annual Meeting, Sapporo, 29 July 2014
Clean Seawater Sampling for Trace Metals During Japanese GEOTRACES Cruises

76)Kanna Naoya, Takenobu Toyota, Jun Nishioka, Asia Oceania Geoscience Society 2014 Annual Meeting, Sapporo, 1 August 2014
Iron and Macro-nutrient Concentrations in Sea Ice and Their Impact on the Nutritional Status of Surface Waters in the Southern Okhotsk Sea.

75)Jun Nishioka, Hajime Obata, Asia Oceania Geoscience Society 2014 Annual Meeting, Sapporo, 29 July 2014
West-to-east Dissolved Iron Distribution in the Subarctic Pacific

74)Jun Nishioka, Hajime Obata, Ocean Sciences Meeting, Honolulu Feb.24, 2014
West-to-east Dissolved Iron Distribution in the Subarctic Pacific

73)Jun Nishioka, Hajime Obata, Daisuke Tsumune, Ocean Sciences Meeting, Salt-lake city Feb.22, 2012
Evidence of an extensive spread of hydrothermal dissolved iron in the Indian Ocean

72) Kanna Naoya, Jun Nishioka, Aiko Murayama, Takenobu Toyota, Ocean Sciences Meeting, Salt-lake city Feb.22, 2012
Quantitative evaluation of iron and nutrients in sea ice in the southern Sea of Okhotsk

71)Kanna Naoya, Koji Suzuki, Aiko Murayama, Jun Nishioka, PICES annual meeting, Hiroshima Oct. 20, 2012
Bioavailavility of Sea ice-derivered iron for phytoplankton growth.

70)Jun Nishioka, SOLAS-Open Science meeting, Cle Elum, USA May 6, 2012
Pivotal roles of sea ice on iron transport in the Sea of Okhtosk

69)Jun Nishioka, NIOZ colocium Nov. 18, 2011, invited
The annual cycle of surface iron and the source or iron supporting the spring diatom bloom in the Oyashio region, Western subarctic Pacific

68)Jun Nishioka, Japanese- German Frontiers of Science Symposium 2011, invited
The biogeochemical cycle of iron and the role of iron on phytoplankton growth in the ocean

67)Jun Nishioka, Tsuneo Ono, Hiroaki Saito, Keiichiro Sakaoka, Takeshi Yoshimura, post-ＩＣＡＳ symposium, 2011, May Kyoto
The annual cycle of surface iron and the source or iron supporting the spring diatom bloom in the Oyashio region, Western subarctic Pacific

66)Jun Nishioka, Tsuneo Ono, Hiroaki Saito, Keiichiro Sakaoka, Takeshi Yoshimura, and Sumito Matoba, AGU fall meeting, 2010,Dec. San Francisco USA
Oceanic iron supply mechanisms supporting the spring diatom bloom in the Oyashio region, western subarctic Pacific

65)Jun Nishioka, Tsuneo Ono, Hiroaki Saito, Keiichiro Sakaoka, and Takeshi Yoshimura, PICES annual meeting, 2010, Oct. Portland USA
Oceanic iron supply mechanisms supporting the spring diatom bloom in the Oyashio region, western subarctic Pacific

64) Ｊｕｎ　Ｎｉｓｈｉｏｋａ，Takeshi Nakatsuka, Kenshi Kuma Yutaka W. Watanabe, Tsuneo Ono, Kay I. Ohshima, N. Ebuch, 2009 ASLO aquatic science meeting
The importance of sea-ice formation in the Sea of Okhotsk for supplying iron to the western subarctic pacific

63)Ｊｕｎ　Ｎｉｓｈｉｏｋａ，Takeshi Nakatsuka, Hiroaki Saito, Tsuneo Ono, Takayuki Shiraiwa, 2008 IMBER/IMBIZO workshop
The importance of sea-ice formation in the Sea of Okhotsk for supplying iron to the western subarctic pacific

62） Ｊｕｎ　Ｎｉｓｈｉｏｋａ，Takeshi Nakatsuka, Kenshi Kuma Yutaka W. Watanabe, Tsuneo Ono, Kay I. Ohshima, 2008 PICES annual meeting
The importance of sea-ice formation in the Sea of Okhotsk for supplying iron to the western subarctic pacific

61) Jun NISHIOKA, Kenshi KUMA, Yutaka W. WATANABE, Tsuneo ONO, Takeshi NAKATSUKA, 2008 AOGS meeting, Busan
Importance of  lateral iron transportation from the Sea of Okhotsk to western subarctic Pacific

60) Keisuke UCHIMOTO, Tomohiro NAKAMURA, Jun NISHIOKA, Junji MATSUDA, Humio MITSUDERA, 2008 AOGS meeting, Busan
Modeling the Intermediate Layer Circulation in the Sea of Okhotsk

59)Takeshi YOSHIMURA, Jun NISHIOKA, Takeshi NAKATSUKA, 2008 AOGS meeting, Busan
Iron Nutrition of Phytoplankton Assemblage in the Okhotsk Sea

58) Takeshi NAKATSUKA, Jun NISHIOKA, Takayuki SHIRAIWA and All members of " Amur-Okhotsk Project", 2008 AOGS meeting, Busan
Linkage between Inland and OpenOceanEcosystems through River and Intermediate Water Flows: Huge but Vulnerable System in the Amur River Watershed and the Sea of Okhotsk

57) Koji SUZUKI, Tomonori ISADA, Honbin LIU, Jun NISHIOKA, Takeshi NAKATSUKA, 2008 AOGS meeting, Busan
Characteristics of phytoplankton productivity in the Sea of Okhotsk

56) Yutaka W. WATANABE1, Jun NISHIOKA, Masahito SHIGEMITSU1, Aki MIMURA1 and Takeshi NAKATSUKA, 2008 AOGS meeting, Busan
Remarkable increases of alkalinity and pH in the Okhotsk Sea during the 1990s and 2000s

55)Hiroaki Saito, Atsushi Tsuda, Takashi Ota, Yukihiro Nojiri, Takafumi Aramaki, Keiri Imai, Hiroshi Kiyosawa, Jun Nishioka, Hiroshi Ogawa, Koji Suzuki, Shigenobu Takeda, Takeshi Yoshimura, 2008 Ocean Sciences Meeting, Orlando,
THE ROLE OF ECOSYSTEM COMPONENTS FOR BIOGEOCHEMICAL CYCLING IN THE HNLC SUBARCTIC PACIFIC: IMPORTANCE OF TOP-DOWN CONTROL

54) Yoshie, N., K. Suzuki, A. Kuwata, J. Nishioka and H. Saito, 2008 Ocean Sciences Meeting, Orlando
Temporal and spatial variations of phytoplankton photosynthetic physiology in the western subarctic Pacific in spring

53)Jun Nishioka, Tsuneo Ono, Hiroaki Saito, Takeshi Nakatsuka, Shigenobu Takeda, Takeshi Yoshimura, Koji Suzuki, Kenshi Kuma, Shigeto Nakabayashi, Daisuke Tsumune, Humio Mitsudera, W. Keith Johnson, Atsushi Tsuda, 2008 Ocean Sciences Meeting, Orlando,
Iron supply to the western subarctic Pacific: Importance of iron export from the Sea of Okhotsk

52） Yoshimura, J. Nishioka, K. Suzuki, H. Hattori, H. Kiyosawa, D. Tsumune, K. Misumi, T. Nakatsuka,2007 PICES annual meeting, Victoria,
Responses of phytoplankton assemblage and organic carbon dynamics to CO2 increase

51） Yasuda, I., S. Ito, M. Yagi, S. Osafune, H. Kaneko, H. Nagae, T,. Nakatsuka, J. Nishioka, 2007 PICES annual meeting, Victoria,
Turbulence observation around the Kuril Straits

50） J. Nishioka, T. Ono, H. Saito,2007 PICES annual meeting, Victoria,
Seasonal variability of iron concentration in the Oyashio region

49） Nakatsuka, T., J. Nishioka, 2007 ,
An alternative way to transport iron from inland area to open ocean and its implications for past changes in ocean productivity-Intermediate water iron hypothesis

48）Nakatsuka, S., M. Kinugasa, Y. Sohrin, J. Nishioka, S. Takeda, A. Tsuda 2006 PICES annual meeting, Yokohama,
Dynamics of bioactive trace metals during the mesoscale iron enrichment in the Subarctic Western North Pacific

47）Kondo, Y, S, Takeda, J. Nishioka, H. Obata, K. Furuya, W.K. Johnson, N. Sutherland, C.S. Wong2006 PICES annual meeting, Yokohama,
Behavior of organic iron (III) complexing ligands during SEEDS-II experiment

46）Kudo, I, Y, Noiri, J. Nishioka, 2006 PICES annual meeting, Yokohama,
Phytoplankton community response to Fe and temperature gradients in the NE(SERIES) and NW(SEEDS) subarctic Pacific Ocean

45）Yoshimura, T., H. Ogawa, K. Imai, J. Nishioka, Y. Taira, H. Kiyosawa, A. Tsuda2006 PICES annual meeting, Yokohama,
The dynamics of dissolved organic matter during in situ iron enrichment experiments in the subarctic North Pacific

44）Takeda, S., J. Nishioka, C.S. Wong・W.K. Johnson・S.・M. Kinugasa・Y. Kondo・K.Kuma・S. Nakatsuka・H. Obata・E. Roy・M. Saito・N. Sutherland・Y. Sohrin・H. Takata・H. Tani・A.Tsuda・M.L. Wells2006 PICES annual meeting, Yokohama,
Iron geochemistry of SEEDS-I, II and SERIES

43）Tsumune, D, Jun Nishioka, A. Akifumi, Y. W. Watanabe, S.　Takeda, A.Tsuda2006 PICES annual meeting, Yokohama,
The physical behavior of the iron patches detected by SF6 tracer during SEEDS-I and SEEDS-II

42）Tsuda, A, S. Takeda, H. Saito, J. Nishioka, Y. Nojiri and I. Kudo 2006 PICES annual meeting, Yokohama,
SEEDS I summary

41）Yoshie, N., K. Sato, Y. Yamanaka and J. Nishioka 2006 PICES IFEP/MODEL WS, Yokohama,
Incorporating iron cycle into a lower trophic level marine ecosystem model, Nemuro

40）Tsumune, DK, Lindsay, G, Danabasoglu, S, Doney, Jun Nishioka T. Yoshimura, F, Brian and N, Nakashiki,, 2006 PICES IFEP/MODEL WS, Yokohama,
Phosphate and iron concentrations in an ocean carbon cycle model

39）Ooki, Atsushi., Jun Nishioka and Tsuneo Ono, 2006 PICES IFEP/MODEL WS, Yokohama,
Determination of iron solubility of Asian dust in the surface seawater

38）Wm. Keith Johnson, C.S. Wong, Nes Sutherland, Jun Nishioka and Shigenobo Takeda, 2006 A symposium to mark the 50th anniversary of Line-P, Victoria,
Iron distributions, enhancement, and transport in the Gulf of Alaska

37) Nishioka, J, Tsuneo Ono, Hiroaki Saito, Takeshi Nakatsuka, Shigenobu Takeda, Takeshi Yoshimura, Koji Suzuki, Kenshi Kuma, Shigeto Nakabayashi, Atsushi Tsuda, 2006 WPGM,
Iron supply to the western subarctic Pacific: importance of lateral iron transport from the Sea of Okhotsk and winter mixing

36) Isao Kudo, Yoshifumi Noiri, Jun Nishioka, Yousuke Taira, Hiroshi Kiyosawa and Atsushi Tsuda, 2006, PICES 15th Annual Meeting,
Phytoplankton community response to Fe and temperature gradients in the NE (SERIES) and NW (SEEDS) subarctic Pacific Ocean

35) S. Takeda, J. Nishioka, C.S. Wong, W.K. Johnson, M. Kinugasa, Y. Kondo, K. Kuma, S. Nakatsuka, H. Obata, E. Roy, M. Sato, N. Sutherland, Y. Sohrin, H. Takata, H. Tani, A. Tsuda and M.L. Wells, 2006, PICES 15th Annual Meeting,
Iron geochemistry of SEEDS-I, -II and SERIES

34) Seiji Nakatsuka, Masatoshi Kinugasa, Yoshiki Sohrin, Jun Nishioka, Shigenobu Takeda, Atsushi Tsuda, 2006, PICES 15th Annual Meeting,
Dynamics of Bioactive Trace Metals During the Mesoscale iron Enrichment in the Subarctic Western North Pacific Gyre (SEEDS I and II)

33) Takeshi Yoshimura, Hiroshi Ogawa, Keiri Imai and Jun Nishioka, 2006, PICES 15th Annual Meeting,
Dissolved organic matter dynamics during in situ iron enrichment experiments in the subarctic North Pacific

32) Naoki Yoshie, Katsunari Sato, Yasuhiro Yamanaka, and Jun Nishioka, 2006 PICES 15th Annual Meeting,
Introduction of iron cycles into a lower trophic level marine ecosystem model, NEMURO

31) Yoshiko Kondo, Shigenobu Takeda, Jun Nishioka, Hajime Obata, Ken Furuya, William Keith Johnson, Agnes Sutherland and C.S. Wong, 2006 PICES 15th Annual Meeting,
Behavior of organic iron (III) complexing ligands during SEEDS-II experiment

30) Nishioka, J, Tsuneo Ono, Hiroaki Saito, Takeshi Nakatsuka, Shigenobu Takeda, Takeshi Yoshimura, Koji Suzuki, Kenshi Kuma, Shigeto Nakabayashi, Humio Mitsudera, Atsushi Tsuda, 2006 PICES 15th Annual Meeting,
Iron supply to the western subarctic Pacific: importance of lateral iron transport from the Sea of Okhotsk and winter mixing,

29) Atsushi Tsuda, Shigenobu Takeda, Hiroaki Saito, Jun Nishioka, Yukihiro Nojiri, Isao Kudo, 2006 PICES 15th Annual Meeting,
SEEDS I summary

28) Suzuki, K., H. Saito, Y. Nojiri, J. Nishioka, S. Takeda, A. Tsuda, 2005 ASLO,
COMPARISONS OF PHYTOPLANKTON COMMUNITY STRUCTURE AND NUTRIENTS IN TWO MESOSCALE IRON ENRICHMENT EXPERIMENTS IN THE NW SUBARUCTIC PACIFIC

27) Hyakawa, M., K. Suzuki, A. Kuwata, H. Saito, J. Nishioka, A Tsuda, 2005 ASLO,
CEELL VIABILITY OF PHYTOPLANKTON COMMUNITY IN THE NORTHWESTERN SUBARCTIC PACIFIC DURING SUMMER

26) de Baar, H.J.W., P. Boyd, K. Buesseler, D. Bakker, Y. Bozec, M. Boye, K. Coale, P.L. Croot, P. Laan, C. Lancelot, M. Levasseur, J. Nishioka, Y.Nojiri, T. van Oijen, S. Takeda, K. R. Timmermans, A. Tsuda, M. Veldhuis, 2004, The Ocean in the High CO2 World, An international Science symposium, UNESCO,
Synthesis of in-situ Iron Enrichment Experiments

25) Ono, T. and J. Nishioka, IOC Westpac Meeting 2004,
Response of net primary production in western subarctic Pacific against future climate change: importance of iron source.

24) Yoshimura,T., H. Ogawa, J. Nishioka, K. Imai, Y. Nojiri, I. Koike, A. Tsuda, 2004 Ocean Research Conference, ASLO
DISSOLVED ORGANIC CARBON DYNAMICS DURING IN-SITU IRON ENRICHMENT EXPERIMENT IN THE WESTERN AND EASTERN SUBARCTIC PACIFIC

23) Nishioka, J., S. Takeda, I. Kudo, D. Tsumune, T. Yoshimura, K. Kuma, T. Ono, H. Saito, A. Tsuda, 2004 Ocean Research Conference, ASLO,
IRON LIMITATION PROCESSES IN THE NW SUBARCTIC PACIFIC

22) Kudo, I., Y. Noiri, J. Nishioka, H. Kiyosawa, A. Tsuda, 2004 Ocean Research Conference, ASLO,
PHYTOPLANKTON COMMUNITY RESPONSE TO FE AND TEMPERATURE GRADIENT IN THE NW AND NE SUBARCTIC PACIFIC OCEAN

21) Tsuda, A., S. Takeda, H. Saito, J. Nishioka, Y. Nojiri, I. Kudo, 2004 Ocean Research Conference, ASLO
AN IN-SITU IRON ENRICHMENT EXPERIMENT IN THE WESTERN SUBARCTIC PACIFIC (SEEDS): INTRODUCTION AND SUMMARY

20) Iwade, S., K. Kuma, M. Yoshida, Y. Isoda, I, Kudo, J. Nishioka, 2004 Ocean Research Conference, ASLO,
IMPACT OF SUPERSATURATED IRON ON IRON UPTAKE AND GROWTH OF A COASTAL MARINE DIATOM

19) Kondo, Y., S. Takeda, J. Nishioka, H. Saito, K. Suzuki, K. Furuya, 2004 Ocean Research Conference, ASLO,
IRON LIMITATION STATUS OF PHYTOPLANKTON COMMUNITY IN THE OYASHIO REGION DURING SPRING

18) Sohrin, Y., M. Kinugasa, K. Okamura, S. Takeda, J. Nishioka, A. Tsuda, 2004 Ocean Research Conference, ASLO,
DYNAMICS OF BIOACTIVE TRACE METALS DURING THE SUBARCTIC PACIFIC IRON EXPERIMENT FOR ECOSYSTEM DYNAMICS STUDY (SEEDS2001)

17) Kinugasa, M., Y. Sohrin, T. Ishita, S. Takeda, J. Nishioka, A. Tsuda. IUGG2003 JSM02, 2003,
Sapporo Dynamics of dissolved and dissolvable trace metals during the subarctic Pacific iron experiment for ecosystem dynamics study (SEEDS 2001)

16) Tsuda, A., T. Ono, H. Saito, K. Suzuki, J. Nishioka, Y. Nojiri, I. Kudo, S. Takeda, IUGG2003 JSM02, 2003, Sapporo,
IRON FERTILIZATION EXPERIMENT IN THE WESTERN SUBARCTIC PACIFIC (SEEDS)

15) Takeda, S., N. Ramaiah, K. Furuya, T. Yoshimura, J. Nishioka, H. Ogawa , T. Aono, Y. Nojiri, H. Saito, A. Tsuda, IUGG2003 JSM02, 2003, Sapporo,
FORMATION OF Transparent exopolymer particles during in-SITU IRON ENRICHMENT EXPERIMENT IN the WESTERN Subarctic PACIFIC (SEEDS)

14) Tsuda, A., H.Saito, J. Nishioka and T. Ono, 2002 North Pacific Marine Science Organization (PICES) 11th Annual Meeting,
Mesozooplankton responses during the Subarctic Ocean enrichment and ecosystem dynamics study (SEEDS 2001)

13) Nishioka, J., S. Takeda, D. Tsumune, T. Yoshimura, I. Kudo, K. Kuma and A. Tsuda　2002 North Pacific Marine Science Organization (PICES) 11th Annual Meeting,
Processes of iron limitation in the subarctic NW Pacific- Higher particulate iron concentration than that in the subarctic NE Pacific‐

12) Kinugasa, M., Y. Sohrin, T. Ishita, S. Takeda, J. Nishioka and A. Tsuda, 2002 Ocean Science Meeting, ASLO,
Dynamics of Dissolved Trace Metals During the Subarctic Pacific Iron Experiment for Ecosystem Dynamics Study (SEEDS)

11) Kudo, I, Noiri, Y., Imai, K., Kiyosawa, H. J. Nishioka and Tsuda, A., 2002 Ocean Science Meeting, ASLO,
Primary production and N assimilation during the Subarctic Pacific iron Experiment for Ecosystem Dynamics Study (SEEDS 2001)

10) Boye, M., J. Nishioka, P.L. Croot, P. Laan, K. R. Timmermans, S. Takeda and H. J.W. de Baar, 2002 Ocean Science Meeting, ASLO
Colloidal Fe account for a significant part of dissolved organic Fe-complexes in the Southern Ocean

9) Takeda, S., A. Tsuda, H. Saito, Y. Nojiri, J. Nishioka, I. Kudo, D. Tsumune, 2002 Ocean Science Meeting, ASLO,
Biogeochemical Processes During the Subarctic Pacific Iron Experiment for Ecosystem Dynamics Study (SEEDS)

8) Nishioka, J., S. Takeda, D. Tsumune, T. Yoshimura, I. Kudo, H. Tani, and A. Tsuda, 2002 Ocean Science Meeting, ASLO,
Dynamics of Iron during the Subarctic Pacific Iron Experiment for Ecosystem Dynamics Study (SEEDS)

7) Takeda, S., J. Nishioka, C.S. Wong, F.A. Whitney, W.K. Johnson and T.J. Soutar, 2000 Ocean Sciences Meeting, ASLO,
Effects of Iron Supply on Phytoplankton Processes in the NE Subarctic Pacific-Deckboard and Mesocosm Experiments-

6) Nishioka, J., Shigenobu Takeda, C.S. Wong, F.A. Whitney, W.K. Johnson, 2000 Ocean Sciences Meeting, ASLO,
The Spatial and Temporal Distribution of Soluble and Small Colloidal Iron in the Northeast Pacific Ocean

5) Takeda, S., J. Nishioka, C.S. Wong, W.K., Johnson and F.A. Whitney, 1999 Aquatic Science Meeting; ASLO
The Limitation of iron, light and temperature to phytoplankton growth in the northeast subarctic Pacific in water

4) Nishioka, J., S. Takeda, C.S. Wong, F.A. Whitney, W.K. Johnson, 1999 Aquatic Science Meeting, ASLO,
Change in the Concentrations of Iron in Different Size Fractions During a Phytoplankton Bloom in Control Ecosystem Enclosures

3) Takeda, S., J. Nishioka and C.S. Wong, 1998 SCOR meeting,
Iron in the ocean, Size-fractionated iron concentrations in the northeast subarctic Pacific and the role of colloidal iron in phytoplankton growth

2) Nishioka, J., Shigenobu Takeda, C.S. Wong, F.A. Whitney, W.K. Johnson, 1998 North Pacific Marine Science Organization (PICES) Seventh Annual Meeting,
Change in the Concentrations of Iron in Different Size Fractions During a Phytoplankton Bloom in Control Ecosystem Enclosures

1) Nishioka, J. and S. Takeda, 1998 Ocean Sciences Meeting, ASLO,
Small Colloidal Iron: As a Source of Biologically Available Iron to the Oceanic Diatom Chaetoceros sp.