World's Best Scientists 2026 revealed!

D-Index & Metrics

Environmental Sciences

D-Index
52
Citations
8563
World Ranking
4559
National Ranking
76

Isao Koike publication distribution in Environmental Sciences in 2026

The chart shows the distribution of publications by all Research.com ranked scientists in the field of Environmental Sciences in 2026. The highlighted bar marks where Isao Koike sits on this spectrum.

41–50 publications: 21 scientists 51–60 publications: 62 scientists 61–70 publications: 133 scientists 71–80 publications: 257 scientists 81–90 publications: 361 scientists 91–100 publications: 440 scientists 101–110 publications: 492 scientists 111–120 publications: 541 scientists 121–130 publications: 617 scientists 131–140 publications: 544 scientists 141–150 publications: 541 scientists 151–160 publications: 539 scientists 161–170 publications: 444 scientists 171–180 publications: 444 scientists 181–190 publications: 400 scientists 191–200 publications: 377 scientists 201–210 publications: 318 scientists 211–220 publications: 282 scientists 221–230 publications: 263 scientists 231–240 publications: 220 scientists 241–250 publications: 217 scientists 251–260 publications: 180 scientists 261–270 publications: 181 scientists 271–280 publications: 155 scientists 281–290 publications: 130 scientists 291–300 publications: 127 scientists 301–310 publications: 130 scientists 311–320 publications: 85 scientists 321–330 publications: 106 scientists 331–340 publications: 80 scientists 341–350 publications: 83 scientists 351–360 publications: 75 scientists 361–370 publications: 69 scientists 371–380 publications: 52 scientists 381–390 publications: 54 scientists 391–400 publications: 56 scientists 401–410 publications: 44 scientists 411–420 publications: 40 scientists 421–430 publications: 36 scientists 431–440 publications: 25 scientists 441–450 publications: 25 scientists 451–460 publications: 32 scientists 461–470 publications: 29 scientists 471–480 publications: 21 scientists 481–490 publications: 26 scientists 491–500 publications: 26 scientists 501–510 publications: 17 scientists 511–520 publications: 19 scientists 521–530 publications: 15 scientists 531–540 publications: 22 scientists 541–550 publications: 12 scientists 551–560 publications: 15 scientists 561–570 publications: 11 scientists 571–580 publications: 19 scientists 581–590 publications: 9 scientists 591–600 publications: 9 scientists 601–610 publications: 7 scientists 611–620 publications: 11 scientists 621–630 publications: 5 scientists 631–640 publications: 5 scientists 641–650 publications: 6 scientists 651–660 publications: 3 scientists 661–670 publications: 3 scientists 671–680 publications: 4 scientists 681–689 publications: 4 scientists 690+ publications: 100 scientists
41 publications 690+

This scientist: 116 publications — 22nd percentile

22% of scientists in this discipline score the same or lower.

The last bar groups every scientist with 690 publications or more.

Isao Koike D-index placement in Environmental Sciences in 2026

The chart shows the D-index (discipline H-index) distribution of Environmental Sciences scientists ranked by Research.com in 2026. The highlighted bar marks where Isao Koike sits on this spectrum.

30 D-Index: 12 scientists 31 D-Index: 26 scientists 32 D-Index: 51 scientists 33 D-Index: 88 scientists 34 D-Index: 123 scientists 35 D-Index: 163 scientists 36 D-Index: 206 scientists 37 D-Index: 267 scientists 38 D-Index: 265 scientists 39 D-Index: 275 scientists 40 D-Index: 321 scientists 41 D-Index: 343 scientists 42 D-Index: 305 scientists 43 D-Index: 336 scientists 44 D-Index: 330 scientists 45 D-Index: 348 scientists 46 D-Index: 291 scientists 47 D-Index: 275 scientists 48 D-Index: 272 scientists 49 D-Index: 273 scientists 50 D-Index: 263 scientists 51 D-Index: 232 scientists 52 D-Index: 266 scientists 53 D-Index: 217 scientists 54 D-Index: 198 scientists 55 D-Index: 177 scientists 56 D-Index: 202 scientists 57 D-Index: 204 scientists 58 D-Index: 166 scientists 59 D-Index: 177 scientists 60 D-Index: 166 scientists 61 D-Index: 152 scientists 62 D-Index: 143 scientists 63 D-Index: 150 scientists 64 D-Index: 124 scientists 65 D-Index: 119 scientists 66 D-Index: 120 scientists 67 D-Index: 118 scientists 68 D-Index: 82 scientists 69 D-Index: 98 scientists 70 D-Index: 94 scientists 71 D-Index: 105 scientists 72 D-Index: 74 scientists 73 D-Index: 84 scientists 74 D-Index: 70 scientists 75 D-Index: 67 scientists 76 D-Index: 78 scientists 77 D-Index: 60 scientists 78 D-Index: 59 scientists 79 D-Index: 52 scientists 80 D-Index: 47 scientists 81 D-Index: 38 scientists 82 D-Index: 48 scientists 83 D-Index: 42 scientists 84 D-Index: 42 scientists 85 D-Index: 43 scientists 86 D-Index: 29 scientists 87 D-Index: 37 scientists 88 D-Index: 29 scientists 89 D-Index: 30 scientists 90 D-Index: 34 scientists 91 D-Index: 20 scientists 92 D-Index: 22 scientists 93 D-Index: 17 scientists 94 D-Index: 19 scientists 95 D-Index: 24 scientists 96 D-Index: 21 scientists 97 D-Index: 20 scientists 98 D-Index: 24 scientists 99 D-Index: 17 scientists 100 D-Index: 17 scientists 101 D-Index: 21 scientists 102 D-Index: 25 scientists 103 D-Index: 18 scientists 104 D-Index: 26 scientists 105 D-Index: 20 scientists 106 D-Index: 15 scientists 107 D-Index: 10 scientists 108 D-Index: 13 scientists 109 D-Index: 15 scientists 110 D-Index: 12 scientists 111 D-Index: 8 scientists 112 D-Index: 7 scientists 113 D-Index: 9 scientists 114 D-Index: 6 scientists 115 D-Index: 12 scientists 116 D-Index: 7 scientists 117 D-Index: 8 scientists 118 D-Index: 3 scientists 119 D-Index: 5 scientists 120 D-Index: 7 scientists 121 D-Index: 2 scientists 122 D-Index: 4 scientists 123 D-Index: 8 scientists 124 D-Index: 7 scientists 125 D-Index: 9 scientists 126+ D-Index: 92 scientists
30 D-Index 126+

This scientist: 52 D-Index — 55th percentile

55% of scientists in this discipline score the same or lower.

The last bar groups every scientist with 126 D-Index or more.

Overview

Isao Koike is affiliated with the University of Tokyo in Japan and specializes in environmental science with a focus on oceanography, pollution, and environmental chemistry. Their research primarily addresses topics related to marine and coastal ecosystems, microplastics and plastic pollution, and per- and polyfluoroalkyl substances (PFAS) research.

The scientist's recent scholarly contributions include the paper titled "Heterogeneity of Transparent Exopolymer Particles in a Coastal Marine Environment (Sagami Bay, Japan): Seasonal Variation and Its Possible Bacterial Causes", published in 2021 in Frontiers in Marine Science.

  • Heterogeneity of Transparent Exopolymer Particles in a Coastal Marine Environment (Sagami Bay, Japan): Seasonal Variation and Its Possible Bacterial Causes (2021, Frontiers in Marine Science)

Isao Koike has collaborated frequently with several co-authors in their research work:

  • Kugako Sugimoto
  • Hideki Fukuda
  • Toshi Nagata

Publications by Isao Koike have appeared in the journal Frontiers in Marine Science, which is also a notable venue for their recent work.

In terms of research domains, Isao Koike works extensively within the fields of:

  • Environmental Science
  • Earth and Planetary Sciences

Their specific subfields of study include:

  • Oceanography
  • Pollution
  • Environmental Chemistry

The main topics covered throughout Isao Koike's research are:

  • Marine and coastal ecosystems
  • Microplastics and Plastic Pollution
  • Per- and polyfluoroalkyl substances research

Best Publications

  • Direct Determination of Carbon and Nitrogen Contents of Natural Bacterial Assemblages in Marine Environments

    Rumi Fukuda;Hiroshi Ogawa;Toshi Nagata;Isao Koike

  • Production of Refractory Dissolved Organic Matter by Bacteria

    Hiroshi Ogawa;Yukio Amagai;Isao Koike;Karl Kaiser

  • The Importance of marine sediment biodiversity in ecosystem processes

    P Snelgrove;T Blackburn;Hutchings P.A;Alongi Dm

  • Denitrification and ammonia formation in anaerobic coastal sediments.

    Isao Koike;Akihiko Hattori

  • Abundance of viruses in marine waters: assessment by epifluorescence and transmission electron microscopy.

    Shigemitsu Hara;Kazuki Terauchi;Isao Koike

  • Bacterioplankton distribution and production in deep Pacific waters: Large-scale geographic variations and possible coupling with sinking particle fluxes

    Toshi Nagata;Hideki Fukuda;Rumi Fukuda;Isao Koike

  • Estimates of Denitrification and Nitrification in Coastal and Estuarine Sediments

    Takashi Nishio;Isao Koike;Akihiko Hattori

  • Fine-scale mapping of land-derived nitrogen in coral reefs by δ15N in macroalgae

    Yu Umezawa;Toshihiro Miyajima;Masumi Yamamuro;Hajime Kayanne

  • Importance of foraminifera for the formation and maintenance of a coral sand cay: Green Island, Australia

    H. Yamano;T. Miyajima;I. Koike

  • Nitrification rates and 15 N abundances of N 2 O and NO 3 − in the western North Pacific

    Naohiro Yoshida;Hajime Morimoto;Mitsuhiro Hirano;Isao Koike

  • Inorganic nitrogen metabolism by Antarctic phytoplankton with special reference to ammonium cycling

    I Koike;O Holm-Hansen;DC Biggs

  • Vertical distributions of dissolved organic carbon and nitrogen in the Southern Ocean

    Hiroshi Ogawa;Rumi Fukuda;Isao Koike

  • Energy yield of denitrification: an estimate from growth yield in continuous cultures of Pseudomonas denitrificans under nitrate-, nitrite- and oxide-limited conditions.

    Unknown

  • Denitrification, nitrate reduction, and oxygen consumption in coastal and estuarine sediments.

    Takashi Nishio;Isao Koike;Akihiko Hattori

  • N2O production, nitrification and denitrification in an estuarine sediment

    T. Usui;I. Koike;N. Ogura

  • Simultaneous determinations of nitrification and nitrate reduction in coastal sediments by a 15N dilution technique

    Unknown

  • Significance of groundwater nitrogen discharge into coral reefs at Ishigaki Island, southwest of Japan

    Y. Umezawa;T. Miyajima;H. Kayanne;I. Koike

  • Growth yield of a denitrifying bacterium, Pseudomonas denitrificans, under aerobic and denitrifying conditions.

    Unknown

  • Translocation and conservation of organic nitrogen within the coral-zooxanthella symbiotic system of Acropora pulchra, as demonstrated by dual isotope-labeling techniques

    Yasuaki Tanaka;Toshihiro Miyajima;Isao Koike;Takeshi Hayashibara

  • Evidence of ontogenetic migration from mangroves to coral reefs by black-tail snapper Lutjanus fulvus: stable isotope approach

    Yohei Nakamura;Masahiro Horinouchi;Takuro Shibuno;Yoshiyuki Tanaka

  • Nitrogen metabolism of the filter-feeding bivalve Corbicula japonica and its significance in primary production of a brackish lake in Japan

    Masumi Yamamuro;Isao Koike

  • Amino acid and ammonium utilization by heterotrophic marine bacteria grown in enriched seawater

    Luis Tupas;Isao Koike

  • Hydrographic features of the deep water of the Bering Sea—the sea of Silica

    Shizuo Tsunogai;Masashi Kusakabe;Hitoshi Iizumi;Isao Koike

Frequent Co-Authors

Toshi Nagata
Toshi Nagata University of Tokyo
Hajime Kayanne
Hajime Kayanne University of Tokyo
Paul V. R. Snelgrove
Paul V. R. Snelgrove Memorial University of Newfoundland
Gary M. King
Gary M. King Louisiana State University
Melanie C. Austen
Melanie C. Austen Plymouth University
Ken Furuya
Ken Furuya Soka University
Craig R. Smith
Craig R. Smith University of Hawaii at Manoa
Hiroya Yamano
Hiroya Yamano National Institute for Environmental Studies
Yoshiki Sohrin
Yoshiki Sohrin Kyoto University
Osmund Holm-Hansen
Osmund Holm-Hansen University of California, San Diego

If you think any of the details on this page are incorrect, let us know.

Report an issue

We appreciate your kind effort to assist us to improve this page, it would be helpful providing us with as much detail as possible in the text box below:

Related Online Degrees & Career Pathways

For those interested in advancing their education in Environmental Sciences, exploring related online degrees can open various career pathways. Many students seek flexible options such as doctoral programs online no dissertation, which allow them to earn advanced credentials without the demands of a dissertation, ideal for professionals balancing work and studies.

Educators aiming to elevate their qualifications may consider an eds to edd bridge program. These programs provide a seamless pathway from a Master’s in Education to a Doctorate in Education, enhancing leadership opportunities, including those focused on environmental policy and education.

Additionally, for those passionate about social impact and environmental justice, pursuing a doctorate in social work can be highly relevant. Programs like the fully funded dsw programs eliminate financial barriers, making advanced education more accessible to a wider audience.

Finally, individuals seeking broad foundational knowledge can explore the most affordable online general studies degree programs. These programs allow flexibility to tailor coursework toward environmental topics and interdisciplinary studies, supporting diverse career goals in the environmental sector.

Best Scientists Citing Isao Koike

Trending Scientists

Recently Published Articles