著者

風呂田 利夫

出版者

公益社団法人 日本水環境学会

雑誌

水質汚濁研究 (ISSN:03872025)

巻号頁・発行日

vol.10, no.8, pp.470-474, 1987-08-10 (Released:2009-09-10)

参考文献数

19

被引用文献数

8 10

著者

岩崎 敬二 木村 妙子 木下 今日子 山口 寿之 西川 輝昭 西 栄二郎 山西 良平 林 育夫 大越 健嗣 小菅 丈治 鈴木 孝男 逸見 泰久 風呂田 利夫 向井 宏

出版者

JAPANESE ASSOCIATION OF BENTHOLOGY

雑誌

日本ベントス学会誌 = Japanese journal of benthology (ISSN:1345112X)

巻号頁・発行日

vol.59, pp.22-44, 2004-07-28

被引用文献数

24 26

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To investigate the invasion history and recent geographic distribution of marine organisms introduced to Japan or transferred domestically to non-native regions, a questionnaire survey on their occurrence in the field, including both published and unpublished records, was conducted in 2002-2003. A total of 105 taxa was reported by 94 respondents. According to three criteria, viz. known or unknown geographic origin, established invasion history, and presumed dispersal mechanisms associated with human activities, 42 taxa were designated as non-indigenous species introduced to Japan through human activities, 26 taxa as indigenous species that are distributed both in Japan and other countries but are introduced from abroad to Japan for fisheries or as fish bait, 20 taxa as cryptogenic species which are not demonstrably native or introduced, two taxa as non-indigenous species that have extended their range to Japan through natural dispersion, and one taxon as an indigenous species. The remaining 14 taxa were considered to have been transferred domestically to new areas. Analysis of the years of first record of 42 non-indigenous species suggests that the rate of invasion has increased over the past century, with seven or eight species being introduced per decade after 1960. Data on temporal change in geographic distribution revealed that many non-indigenous species have become widespread recently, from the Pacific coasts of central Japan to the coasts of the Sea of Japan or northward. However, the species listed in the present study are not exhaustive, and more extensive investigations covering all taxa and all presumed dispersal mechanisms are urgently needed before consideration of legislative management of introduced marine organisms.

著者

風呂田 利夫 木下 今日子

出版者

JAPANESE ASSOCIATION OF BENTHOLOGY

雑誌

日本ベントス学会誌 = Japanese journal of benthology (ISSN:1345112X)

巻号頁・発行日

vol.59, pp.96-104, 2004-07-28

参考文献数

27

被引用文献数

3 2

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Two introduced crab species, Pyromaia tuberculata and Carcinus aestuarii, occur abundantly in organically polluted waters in Japan. Population studies of these crabs have been conducted in Tokyo Bay, in which summer hypoxia causes destruction of the benthic animal populations on the bottom of the innerhalf of the bay. In fall, a population of P. tuberculata quickly recolonizes that bottom, which has recovered from the hypoxia, by settlement of larvae. Settled crabs reach maturity by the next spring, then release larvae until the subsequent summer hypoxia. Released larvae disperse to the outerhalf of the bay, resulting in recruitment of juveniles into the local population. These recruits reach maturity before the fall under the normoxic conditions prevailing there, then release larvae for recolonization of the innerhalf of the bay. Carcinus aestuarii grows along the shores of river-mouths and in a lagoon of the inner bay, but migrates out onto the bay bottom during fall to spring, when it releases larvae. Released larvae settle along the shores during the spring. Settled crabs grow on the shores with adult crabs that had returned from the bay bottom. Thus the crabs on the shores avoid encountering the bottom hypoxia. These results suggest that the main factor that has allowed the establishment of the new introduced populations in Tokyo Bay is complementarity between the life cycle of these crabs, including adult migration or larval dispersal, and the seasonal availability of a habitat that is recovering from hypoxia.

著者

風呂田 利夫 須之部 友基 有田 茂生

出版者

日本貝類学会

雑誌

Venus : journal of the Malacological Society of Japan (ISSN:13482955)

巻号頁・発行日

vol.61, no.1, pp.15-23, 2002-06-30

被引用文献数

2

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東京湾ならびにその近隣の干潟において, ウミニナ科ならびにキバウミニナ科に属する腹足類の地域個体群がホソウミニナを除いて消滅しつつある。埋め立てにより閉鎖状態で孤立化して存在する東京湾奥部の谷津干潟には, ウミニナ科のウミニナBatillaria multiformisとホソウミニナB. cumingiが生息する。この干潟でのウミニナ類の個体群調査結果から, ホソウミニナは新規加入による個体群の急激な増加傾向が認められたが, ウミニナは長年にわたり老齢個体がわずかに残るのみで, 絶滅が危惧される。ウミニナを水槽飼育したところ卵鞘を生産し, その中からプランクトン幼生が孵化した。谷津干潟は干潮時にはほぼ前面が干出するため, 干潟で孵化したウミニナのプランクトン幼生は東京湾水中に移送されると考えられる。東京湾ではウミニナの生息地である干潟は埋立により孤立的にしか残っておらず, また幼生が放出される夏期は底層の貧酸素化が著しい。したがって, 東京湾水に移送された幼生が干潟に回帰し着底できる可能性は低く, このことがウミニナの新規加入を抑制していると推察される。これに対して, 直達発生により親の生息場に直接加入できるホソウミニナ(Adachi & Wada, 1997)では, 親個体群が形成された後は同所的再生産により個体群は比較的容易に継続もしくは拡大されると推察される。これらのことは, 孤立化した干潟におけるウミニナ類の個体群維持において, プランクトン発生は不利に, 直達発生は有利に機能する可能性が高いことを示唆している。