Impacts of the Nakhodka heavy-oil spill on an intertidal ecosystem: an approach to impact evaluation using geographical information system

A major heavy-oil spill from the Russian tanker Nakhodka occurred in the Sea of Japan on 2 January 1997. We investigated the impacts of this spill on a rocky intertidal ecosystem along the southern coast of the Sea of Japan. We selected Imago-Ura Cove as our study site to observe temporal changes along the oiled shore, because minimal cleaning effort was made in this area. Field surveys were conducted every autumn and spring from 1997 to 2000. We measured coverage by macroalgae in 1 x 1-m(2) quadrats and counted the animals in 5 x 5-m(2) quadrats along the intertidal zone. Changes in the ecosystem caused by the oil spill were analyzed by applying a geographical information system (GIS) to the Sea of Japan for the first time. The GIS showed that following the accident there were heavily oiled areas in sheltered regions, but these decreased over the three years. It also showed that coverage by macroalgae and the number of animals increased, although some species of algae with microscopic sporophyte generations, and some populations of perennial shellfish, remained stable or decreased during the study period. GIS was able to trace temporal changes in intertidal communities resulting from the impacts of heavy oil on flora and fauna at a spatial scale of 10-100 m. GIS is thus a practical tool for visualizing, analyzing, and monitoring changes in an ecosystem polluted by oil, taking into account topographic differences along the coastline.     

Morphological Comparison between Chinese Ayu and Japanese Ayu and Establishment of Plecoglossus altivelis chinensis Wu&Shan subsp.nov.

Ayu(Plecoglossus altivelis)belongs to Osmeri-formes,Qsmeridae,Plecoglossus.It is small-sized,one-year living species with high economic value.It can befound in China,Japan,the Peninsula of Korea,andthe north of Vietnam.Nishida(1988)classifiedJapanese native Ayu into two subspecies:nominatesubspecies(Plecoglossus altivelis altivelis)mainlydistributed in the mainland of Japan,the peninsula ofKorea,Taiwan and China mainland;Ryukyus sub-species(Plecoglossus altivelis ryukyuensis)only dis-tr…     

Regional Summer Temperature Decrease against Global Warming in China, Landform Effect？

The data of 160 national meteorological observatory(NMO)stations with long-term monthly temperature data for China were analyzed in this study to show the basin-centered summer temperature decrease against global warming in the past half century. The summer and winter isotherm structures of 1950s and 1990s worked out by interpolation show the isotherm structure variations: the isotherm structure generally moves northward in winter, but in summer it is characterized with separate high-temperature and low-temperature centers and the isotherm structure moves inward the centers with global warming, indicating that the temperature in the highland areas increases but that in the lowland areas decreases in the summer of the duration. The possible mechanism of the basin-centered temperature decrease in summer is discussed in this paper.