My new website

Please see my new website, ostracoda.net (http://ostracoda.net/), for latest information on my research.

NEW PAPERS

Tsujimoto, A., Nomura, R., Yasuhara, M., Yamazaki, H., Yoshikawa., S., 2006. Impact of eutrophication on shallow marine benthic foraminifers over the last 150 years in Osaka Bay, Japan. Marine Micropaleontology 60, 258–268.

Yasuhara, M., Seto, K., 2006. Holocene relative sea-level change in Hiroshima Bay, Japan: a semi-quantitative reconstruction based on ostracodes. Paleontological Research 10, 99–116.

Tsujimoto, A., Nomura, R., Yasuhara, M., Yoshikawa., S., 2006. Benthic foraminiferal assemblages in Osaka Bay, southwestern Japan: faunal changes over the last 50 years. Paleontological Research 10, 141–161.

SUMMARY OF MY PREVIOUS RESEARCH

Introduction: background and significance of research

The Japanese Islands are surrounded by the sea and coastal pollution including eutrophication has progressed rapidly with industrialization, urbanization, and population since World War II. Such marine pollution in broad sense has seriously influenced coastal marine ecosystems. In spite of legal environmental regulation after 1970s, coastal marine ecosystems have not, for the most part, recovered. Recently, increasing interest in ‘environmental’ research on coastal environments and their biology has been actively carried out and the relationship between coastal marine environment and ecosystem and anthropogenic impact has been analyzed using the various methods. These include marine ecology, marine chemistry, coastal engineering, etc. However, almost all of these studies are on modern systems (short term, several to several tens years) and the present is just a snapshot of the history. Thus, the relationship between environment and ecosystem and anthropogenic impact on ecosystem cannot be fully understood unless a longer-term perspective is gained through the application of geological and paleoecological methods.

Ostracodes are small Crustacea sensitive to various environmental factors (e.g., water depth, temperature, salinity, dissolved oxygen, grain size of substrates, anthropogenic pollution, etc). They are the only metazoan benthos continuously and abundantly preserved as fossils in sediment cores. Thus, it is very important for elucidating the temporal changes in the influences of environmental changes on metazoan ecosystem to investigate the relationship between temporal changes in ostracode faunas from core sediment and environmental changes. At present, such studies are only rarely carried out. Thus, the applicant, since his studies in graduate school, has consistently carried out ostracode faunal analysis in core sediment to address these issues. My main research contributions are briefly described below (see list of publications for other research contributions than mentioned here).

Comprehensive study in Osaka Bay

For comprehensive and detailed study of the relationship between ostracode faunas and environmental changes in Osaka Bay, I studied the three time-scales, i.e., past 10,000 years, past 100 years, and present, using many core sediments and coretops covering broad areas of the Bay. In particular, the modern ostracode distribution was first studied, and it is shown that the distribution is mainly controlled by water depth and summer hypoxia (Yasuhara et al., 1999; Yasuhara and Irizuki, 2001) . I concluded that modern ostracodes in the inner bay adjacent to metropolitan areas are seriously influenced by anthropogenic pollution (i.e., summer hypoxia). Secondly, ostracode faunal changes during the past 10,000 years were elucidated using three sediment cores from　which changes in depositional environments and sea level were reconstructed (Yasuhara et al., 2002a, b). I then assembled published and new data, and reconstructed detailed paleobiogeographic changes in Osaka Bay during the Holocene (Yasuhara et al., 2004). Based on detailed age-model and high-resolution analysis, this study showed evidence for the significant impact of the opening of straits and the increase of bay area as sea-level rose on ostracode fauna, following the last glacial period. Third, I analyzed five sediment cores to spatiotemporally investigate the impact of marine pollution on ostracode fauna during the last 100 years. Above-mentioned baseline information about natural environmental variability largely contributed its interpretation. Part of this study was already published (Yasuhara and Yamazaki, 2005) and a more comprehensive paper has been submitted to Limnology & Oceanography and is now under review (Yasuhara et al., submitted). This study showed that anthropogenic marine pollution has influenced on marine benthos after the Meiji Period, especially during high economic growth period after World War II. In particular, I showed based on detailed time-series data of many sediment cores that eutrophication and summer hypoxia are the major factors controlling ostracode fauna causing sharp decrease of ostracode populations and species composition among sites (beta diversity) due to bay-wide eutrophication.
Currently, I am collaborating with foraminiferal, diatom, and geochemical (heavy metal and organic) specialists for comprehensive analysis of the relationship between marine pollution and benthic fauna in Osaka Bay (Tsujimoto et al., 2005, 2006a, b). Osaka Bay has rich observational data on properties of water, and long time-series fixed-point observation is continued. Furthermore, Osaka Bay is adjacent to Osaka City and is one of the most polluted bay in Japan. Thus, if detailed study is carried out in Osaka Bay, it make detailed and comprehensive understanding of the influences of anthropogenic pollution on benthic fauna possible and could be typical case example in Japan.
The above-mentioned studies are internationally important as case studies because integrated and comprehensive study of a single bay is rarely done. Because geological and paleoecological approaches to analyze impacts of pollution and sea-level change is useful for future prospects and prevention of impact of pollution and global warming on organisms, my work is an example of how geology contributes to the field of environmental science and biology.
In addition to work in Osaka Bay, I also studied the sediment cores in Hiroshima Bay to examine the influences of anthropogenic pollution on ostracodes in conjunction with geochemical analysis (Yasuhara et al., 2003). The results indicate that ostracodes are useful bio-indicators of inner-bay pollution and ostracode faunas have been significantly modified by the pollution during the last 100 years. This was one of the first studies showing detailed temporal changes of impact of anthropogenic pollution on ostracodes.
Furthermore, I wrote a review paper with leading European researchers to summarize international present state of ostracode research related to anthropogenic pollution (Ruiz et al., 2005). In this comprehensive review, the importance of ostracodes in of the study of pollution was discussed, and problems to be solved were outlined.

Deep-sea diversity study

I am currently studying deep-sea species diversity to analyze relationship between environment and ecosystem in global scale while visiting the US Geological Survey as JSPS Postdoctoral Fellow for Research Abroad. With Dr. Thomas M. Cronin, we are writing a review paper on the influence of climatic changes on deep-sea species diversity. The major part of my post-doc research involves analysis of original data from many deep-sea cores and is not at publishing stage yet.

WHAT IS OSTRACODA?

Ostracoda is small bivalved Crustacea, and is sensitive to various environmental factors.
It is useful metazoan group abundantly fossilized in sediments that allow quantitative faunal analysis in sediment cores.
Its common name is ostracode or ostracod.

Further information is found in:

International Research Group on Ostracoda (IRGO)
http://www.uh.edu/~rmaddock/IRGO/irgohome.html

CYPRIS: International Ostracoda Newsletter
http://biology.usgs.gov/cro/Ostracode/cypris.htm

University of Greenwich
School of Earth and Environmental Sciences
Ostracoda Group
http://www.gre.ac.uk/schools/nri/earth/ostracod/index.htm

CURRENT RESEARCH INTERESTS

1. Paleoclimatic impact on deep-sea species diversity （深海底種多様性への気候変動の影響）
2. Paleo-perspective on macroecological theories（地質学的・古生物学的視点を重視したマクロ生態学）
3. Anthropogenic impacts on coastal marine ecosystem（沿岸海洋生態系への人為的影響）
4. Paleontology of Ostracoda（貝形虫の古生物学）

WORK ADDRESS

PhD. Moriaki Yasuhara (安原盛明)

U.S. Geological Survey National Center
Mail Stop 926A, 12201 Sunrise Valley Drive
Reston, Virginia 20192, USA
E-mail address:myasuharaATusgs.gov
*AT=@

PROFESSIONAL EXPERIENCE

JSPS (the Japan Society for the Promotion of Science) Postdoctoral Fellow for Research Abroad (October 2005–Present)
(日本学術振興会海外特別研究員：2005年10月〜現在)

Research Student of Osaka City University (April 2005–September 2005)
(大阪市立大学研究生：2005年4月〜2005年9月)

Research Fellow of the Japan Society for the Promotion of Science (April 2003–March 2005)
(日本学術振興会特別研究員：2003年4月〜2005年3月)

EDUCATION

PhD. Geosciences, Osaka City University, March 2003

MS. Geosciences, Osaka City University, March 2001

BS. Geosciences, Osaka City University, March 1999

TEACHING EXPERIENCE

Japan Science and Technology Agency, SPP (Science Partnership Project), lecture and practical work, at Takamatsu High School, 15 and 16th November 2004.
(科学技術振興機構・サイエンス・パートナーシップ・プロジェクト（SPP）講義・実習: 香川県立高松高等学校, 2004年11月15日・16日)

Japan Science and Technology Agency, SPP (Science Partnership Project), practical work, at Takamatsu High School, 13 and 14th December 2004.
(SPP実習: 香川県立高松高等学校, 2004年12月13日・14日)

Lecture at Takamatsu High School, Geologic Mapping, 16th November and 14th December 2004.
(高松高等学校講義, 地質図学，2004年11月16日, 12月14日)

ACQUIRED RESEARCH FUNDS

Grant for the Graduate Student, Osaka City University (April 2002–March 2003). Principal Investigator: Moriaki Yasuhara
[大阪市立大学大学院学生特別経費（2002年4月〜2003年3月）代表者：安原盛明]

A Grant-in-Aid for Scientific Research from the Ministry of Education, Culture, Sports, Science, and Technology of Japan (No. 05950) (April 2003–March 2005). Principal Investigator: Moriaki Yasuhara
[平成15・16年度科学研究費補助金（特別研究員奨励費）（2003年4月〜2005年3月）代表者：安原盛明]

PEER REVIEWED PUBLICATIONS

Please contact me for PDFs or reprints (some of them can be found below).

Tsujimoto, A., Nomura, R., Yasuhara, M., Yamazaki, H., Yoshikawa., S., 2006. Impact of eutrophication on shallow marine benthic foraminifers over the last 150 years in Osaka Bay, Japan. Marine Micropaleontology 60, 258–268.

Yasuhara, M., Seto, K., 2006. Holocene relative sea-level change in Hiroshima Bay, Japan: a semi-quantitative reconstruction based on ostracodes. Paleontological Research 10, 99–116.

Tsujimoto, A., Nomura, R., Yasuhara, M., Yoshikawa., S., 2006. Benthic foraminiferal assemblages in Osaka Bay, southwestern Japan: faunal changes over the last 50 years. Paleontological Research 10, 141–161.

Yasuhara, M., Yamazaki, H., 2005. The impact of 150 years of anthropogenic pollution on the shallow marine ostracode fauna, Osaka Bay, Japan. Marine Micropaleontology 55, 63–74.

Yasuhara, M., Yoshikawa, S., Nanayama, F., 2005. Reconstruction of the Holocene seismic history of aseabed fault using relative sea-level curves reconstructed by ostracode assemblages: Case study on the Median Tectonic Line in Iyo-nada Bay, western Japan. Palaeogeography, Palaeoclimatology, Palaeoecology 222, 285–312.

Kawamura, K., Yasuhara, M., Hirose, K., Murakami, A., 2005. Development of Teaching Materials to Study Paleoenvironmental Reconstruction, Using Holocene Microfossils and Molluscan Megafossils from The Shin-Yodogawa Drilling Core, Osaka Plain, Japan. Education of Earth Science 58, 215–224 (in Japanese).
(川村教一・安原盛明・広瀬孝太郎・村上晶子，2005．古環境復元の教材化：大阪平野新淀川コア中の完新世微化石および貝類化石を用いて．地学教育 58，215–224)

Okahashi, H., Yasuhara, M., Mitamura., M., Hirose., K., Yoshikawa, S., 2005. Event deposits associated with tsunamis and their sedimentary structure in Holocene marsh deposits on the east coast of the Shima Peninsula, central Japan. Journal of Geosciences, Osaka City University 48, 143–158.

Ruiz, F., Abad, M., Bodergat, A.M., Carbonel, P., Rodríguez-Lázaro, J., Yasuhara, M., 2005. Marine and brackish-water ostracods as sentinels of anthropogenic impacts. Earth-Science Reviews 72, 89–111.

Yasuhara, M., Irizuki, T., Yoshikawa, S., Nanayama, F., Mitamura, M., 2004. Holocene ostracode paleobiogeography in Osaka Bay, southwestern Japan. Marine Micropaleontology 53, 11–36.

Yasuhara, M., Yamazaki, H., Irizuki, T., Yoshikawa, S., 2003. Temporal changes of ostracode assemblages and anthropogenic pollution during the last 100 years, in sediment cores from Hiroshima Bay, Japan. The Holocene 13, 527–536.

Yasuhara, M., Irizuki, T., Yoshikawa, S., Nanayama, F., 2002a. Holocene sea-level changes in Osaka Bay, western Japan: ostracode evidence in a drilling core from the southern Osaka Plain. The Journal of the Geological Society of Japan 108, 633–643.

Yasuhara, M., Irizuki, T., Yoshikawa, S., Nanayama, F., 2002b. Changes in Holocene ostracode faunas and depositional environments in the Kitan Strait, southwestern Japan. Paleontological Research 6, 85–99.

Miura, K., Nanayama, F., Uchiumi, M., Sugiyama, Y., Yasuhara, M., Yokoyama, Y., Kitada, N., Takemura, K., 2002. Holocene activity of the Uemachi fault in the Osaka Plain evaluated by high-resolution analysis of the Shin-Yodo-gawa array boring cores. Annual Report on Active Fault and Paleoearthquake Researches 2, 109–123 (in Japanese with English abstract).
(三浦健一郎・七山太・内海実・杉山雄一・安原盛明・横山芳春・北田奈津子・竹村恵二．2002：新淀川群列ボーリングコアの高解像度解析に基づく上町断層の完新世活動性評価．活断層・古地震研究報告，第２号，109–123．)

Otsuka, K., Nanayama, F., Miura, K., Ikeda, M., Kanayama, S., Kobayashi, S., Tokuma, S., Anma, K., Yokoyama, Y., Yasuhara, M., Sugiyama, Y., Tsukuda, E., 2002. Holocene faulting history of the Shimonada-oki-minami fault at the western tip of the MTL’s Iyo segment. Annual Report on Active Fault and Paleoearthquake Researches 2, 125–140 (in Japanese with English abstract).
（大塚一広・七山太・三浦健一郎・池田倫治・金山清一・小林修二・徳間伸介・安間恵・横山芳春・安原盛明・杉山雄一・佃栄吉．2002：中央構造線活断層系伊予セグメント西端部，下灘沖南断層の完新世活動履歴．活断層・古地震研究報告，第２号，125–140．）

Yasuhara, M., Irizuki, T., 2001. Recent Ostracoda from northeastern part of Osaka Bay, southwestern Japan. Journal of Geosciences, Osaka City University 44, 57–95.

ERRATUM:

Yasuhara, M., Yoshikawa, S., Nanayama, F., 2006. Erratum to “Reconstruction of the Holocene seismic history of a seabed fault using relative sea-level curves reconstructed by ostracode assemblages: Case study on the Median Tectonic Line in Iyo-nada Bay, western Japan” [Palaeogeogr. Palaeoclimatol. Palaeoecol. 222/3–4 (2005) 285–312]. Palaeogeography, Palaeoclimatology, Palaeoecology 235, 431–433.

OTHER PUBLICATIONS

Please contact me for PDFs or reprints.

Tsujimoto, A., Nomura, R., Yasuhara, M., Yamazaki, H., Yoshikawa, S. 2005. The Relationship between benthic foraminifera and anthropogenic pollution in case of Osaka Bay, Japan: environmental evaluation of enclosed coastal seas using foraminifers. The Proceedings of the 15th Symposium on Geo-Environments and Geo-Technics, 161–164 (in Japanese with English abstract).
(辻本彰・野村律夫・安原盛明・山崎秀夫・吉川周作．2005：大阪湾における人為汚染と底生有孔虫群集変化：有孔虫に基づく人間活動が及ぼした閉鎖性海域の環境評価．第15回環境地質学シンポジウム講演論文集，161–164．)

Yasuhara, M., Kumai, H., 2003. Fossil ostracodes from the Tako-Shell bed, Shimosa Group and the Somei horizontal hollow tomb floor deposits formed in its outcrop in Somei, Tako-machi, Chiba Prefecture, Japan. Monograph of the Association for the Geological Collaboration 50, 73–78 (in Japanese with English abstract).
(安原盛明・熊井久雄．2003：下総層群”多古貝層”とその露頭に形成された染井横穴墓堆積物から産出した貝形虫化石．地団研専報　50，73-78．)

Okahashi, H., Akimoto, K., Mitamura, M., Hirose, K., Yasuhara, M., Yoshikawa, S., 2002. Event deposits in marsh deposits from Osatsu, Toba City, Mie Prefecture, Central Japan: Foraminifera-based tsunami-deposits identification. Monthly Earth (Gekkan-Chikyu) 24, 698–703 (in Japanese).
(岡橋久世・秋元和實・三田村宗樹・廣瀬孝太郎・安原盛明・吉川周作．2002：三重県鳥羽市相差の湿地堆積物に見い出されるイベント堆積物ー有孔虫化石を用いた津波堆積物の認定ー．月刊地球　24, 698-703．)

Yasuhara, M., Okahashi, H., Hirose, K., Mitamura, M., Yoshikawa, S., Uchiyama, M., Haraguchi, T., 2002. Preliminary report on ostracode assemblages from event deposits in Holocene coastal marsh deposits from Osatsu, Toba City, Mie Prefecture, Central Japan. Daishiki 34, 27–31 (in Japanese).
(安原盛明・岡橋久世・廣瀬孝太郎・三田村宗樹・吉川周作・内山美恵子・原口強．2002：三重県鳥羽市相差における完新世沿岸湿地堆積物中のイベント堆積物から見い出された貝形虫化石群集．第四紀 34，27-31．)

Yasuhara, M., 2000. Result of fossil ostracode analysis. Report of Osaka Center for Cultural Heritage 48, 187–189 (in Japanese).
(安原盛明．2000：貝形虫化石分析結果．（財）大阪府文化財調査研究センタ−調査報告書第48集，東大阪市・八尾市所在，池島・福万寺遺跡1（98-3・99-1調査区）−寝屋川流域下水道八尾枚岡幹線（第3工区）下水管渠築造工事に伴う発掘調査報告書−, 187-189，財団法人大阪府文化財調査研究センタ−．)

Yasuhara, M., Yoshikawa, S., Irizuki, T., 1999. Recent Ostracoda from Osaka Bay, southwestern Japan. The Proceedings of the 9th Symposium on Geo-Environments and Geo-Technics, 167-172 (in Japanese with English abstract).
(安原盛明・吉川周作・入月俊明．1999：大阪湾における現世貝形虫群集．第9回環境地質学シンポジウム講演論文集，167-172.)

BOOKS

Yasuhara, M., in press. Holocene inner-bay ostracodes and environmental changes: especially on influences of anthropogenic pollution in broad sense. In. Kumai, H. (ed.), The Natural History of Anthropogene. Kyoritsu Shuppan, Tokyo, Japan (in Japanese).
(安原盛明，印刷中．完新世の内湾貝形虫と環境変動—特に広義の人為汚染の影響についてー．熊井久雄（編），人類紀自然学．共立出版)

PROFESSIONAL AFFILIATIONS, REVIEWER EXPERIENCE

PROFESSIONAL AFFILIATIONS:
American Geophysical Union
Geological Society of America
Palaeontological Society of Japan
Geological Society of Japan

REVIEWER EXPERIENCE:
Marine Micropaleontology
Global and Planetary Change