Michio Fukushima

• National Institute for Environmental Studies

Describing and explaining patterns of individual animal behaviors in situ, and their repeatability over the annual cycle, is an emerging field in ecology owing largely to advances in tagging technology. We describe individual movements of adult Sakhalin taimen Parahucho perryi, an endangered salmonid fish, in the headwaters of a river in northern J...

Four combinations of fish and prawn species were stocked in organic rice–fish systems to examine their growth performance, feeding habits, competitive interactions, and food-web structure. The species combinations were: (I) three fish species commonly stocked in rice–fish systems in the Lower Mekong countries, namely Barbonymus gonionotus, Cyprinus...

The frequency of reproduction and homing success are crucial in determining the lifetime reproductive fitness of iteroparous salmonids. We examined consecutive spawning and homing by Sakhalin taimen (Parahucho perryi), one of the least-studied iteroparous salmonids. The average consecutive return rate was 69.5%, the highest ever reported for an ite...

Understanding the proximate factors and mechanisms driving primary production in manmade reservoirs is crucial because such production can translate into added fish yields that provide people with food and livelihoods. Furthermore, reservoir fish production could potentially compensate for the loss of fish yields due to habitat fragmentation and al...

The conservation of land-locked populations of migratory fishes is increasingly important in the era of dam removal and habitat reconnection. We used an otolith strontium (Sr) tracer (⁸⁷Sr/⁸⁶Sr) to test the hypothesis that a land-locked population of an endangered salmonine species, Sakhalin taimen (Parahucho perryi), retains the capacity for anadr...

The assemblage patterns of larval fishes from three neighboring tributaries viz., Songkram, Gam and Mun of the Mekong River in Thailand were investigated between August 2009 and June 2010. These rivers interact with their floodplains, which are important spawning and nursery grounds for the Mekong fishes. There is no dam along the Songkram River; m...

In the face of plans for increased construction of dams and reservoirs in the Mekong River Basin, it is critically important to better understand the primary-producer community of phytoplankton, especially the warm-water cyanobacteria. This is because these algae can serve as the primary source of carbon for higher trophic levels, including fishes,...

Solar irradiance data measured during the study period at 4 locations throughout the study area of the Mekong basin. (Courtesy of Solar Energy Research Laboratory, Silapakorn University). (TIF)

For field ecologists, detecting a target species in the wild is a severe bottleneck to understanding its distribution and population status. Recently, environmental DNA (eDNA) techniques have been developed as a noninvasive monitoring tool for aquatic organisms. While applications of eDNA techniques for biomass estimation have been proposed, little...

Sakhalin taimen Parahucho perryi, an east Asian fish noted to be one of the largest salmonids in the world, is threatened throughout its range in northern Japan and neighboring Russian Federation. We report here on the first effort to enumerate and characterize the spawning run of a river population. We apply sonar and video methods in a tributary...

Diversity and community structure of fishes were studied in three neighbouring tributaries of the Mekong River in Thailand, namely the Mun, Songkhram and Gam Rivers. The rivers are located in the same ecoregion but have contrasting levels of both hydrological regulations and mitigation measures; the Mun River has a hydropower dam with a fish ladder...

The migration of Siamese mud carp (Henicorhynchus siamensis and H. lobatus), two of the most economically important fish species in the Mekong River, was studied using an otolith microchemistry technique. Fish and river water samples were collected in seven regions throughout the whole basin in Thailand, Laos and Cambodia over a 4 year study period...

The Mekong River is one of the great rivers of the world and is characterized by high fish biodiversity (Valbo-Jorgensen et al. 2009). The Mekong region is in fact a fish biodiversity hotspot whose richness is only now being revealed. During the last decade more than 279 new species of fish have been discovered in this basin alone (WWF 2009). An an...

In conservation biology, spatially explicit models, sometimes known as predictive habitat distribution models (Guisan and Zimmermann 2000), have been widely used to predict distributions of plants (Leathwick 1998), insects (Lobo and Martin-Piera 2002; Gutiérrez et al. 2005), amphibians (Ray et al. 2002), reptiles (Fisher et al. 2002), fishes (Joy a...

Sakhalin taimen (Parahucho perryi) range from the Russian Far East mainland along the Sea of Japan coast, and Sakhalin, Kuril, and Hokkaido Islands and are considered to primarily be an anadromous species. We used otolith strontium-to-calcium ratios (Sr/Ca) to determine the chronology of migration between freshwater and saltwater and identify migra...

We have made substantial progress on filling key research gaps and providing guidance on conservation activities related to Sakhalin taimen Parahucho perryi through their limited range in the Russian Far East and northern Japan. The species is recognized as threatened by various authorities, including the governments of Russia and Japan, and the IU...

We have made substantial progress on filling key research gaps and providing guidance on conservation activities related to Sakhalin taimen Parahucho perryi through their limited range in the Russian Far East and Northern Japan. The species, one of the largest salmonids in the world, is recognized as threatened by various authorities, including the...

Although scientists agree that a significant portion of fishes in the Mekong River is migratory throughout their lives, little quantitative investigations have been conducted to study migration ecology of the species. It is, however, imperative that the major migration routes of at least commercially and biologically important fish species and thei...

Variation in stream life, spawning efficiency, and spawning habitat among adult pink salmon (Oncorhynchus gorbuscha) in the Auke Lake system, southeastern Alaska, was best explained by stream discharge, stream temperature, and a combination of stream temperature and discharge. We estimated these attributes of female pink salmon spawners in samples...

The Sakhalin taimen Parahucho perryi is an endangered salmonid with a natural range limited to the Russian Far East and Japan. We constructed a classification tree to determine the environmental factors shaping the historical global distribution of this species and then predicted its potential geographic range. The distribution was most strongly in...

Identifying and quantifying relationships among landscape patterns, anthropogenic disturbances, and aquatic ecosystems is a new and rapidly developing approach to riverine ecology. In this review, we begin by describing the policy and management drivers for landscape-scale riverine research and we synthesize the technological advances that have ena...

Identifying and quantifying relationships among landscape patterns, anthropogenic disturbances, and aquatic ecosystems is a new and rapidly developing approach to riverine ecology. In this review, we begin by describing the policy and management drivers for landscape-scale riverine research and we synthesize the technological advances that have ena...

Rainbow trout introduced into Hokkaido in 1920 have become widely distributed due to extensive release into many reservoirs and lakes for sport-fishing; their presence often results in reductions of native fish populations. We analyzed and predicted the relationship between the probability of occurrence of rainbow trout and the proximity of dams (o...

We analyzed the patterns of total, endangered and exotic fish species richness in 80 reservoirs throughout Japan using Generalized Linear Models (GLMs) with variables of dam characteristics (e.g. reservoir size, isolated period, altitude, DO, pH, rainfall, and air temperature) and watershed characteristics (e.g. watershed area, human population, an...

In the Mekong River watershed, traditional social and industrial systems have long existed in harmony with water and biological resources. Since the 1950s, many dam-construction projects have been started to develop power and water resources to meet increasing demand for energy and food production. Since the 1970s, there have been temporary interru...

Abstract – The native and non-native freshwater fish species richness as well as the proportion of native fish species to overall fish species were examined to test a hypothesis of a spatial linkage between the distributions of dams and non-native fishes based on survey data collected in rivers and streams in Hokkaido, Japan. Non-native fish specie...

In recent years, biodiversity conservation and ecosystem restoration have been key issues of watershed management in many countries. To maintain or restore the environmental quality of watersheds, we need to assess the impact of anthropogenic changes on stream ecosystems with accuracy. In addition, watershed conservation planners have to make strat...

We examined the effects of dams on freshwater fish species based on data collected during 1990–2004 from 200 drainage systems in Japan. Of the 76 fish species examined, the occurrence of 20 species within Petromyzontidae, Cyprinidae, Cobitididae, Salmonidae, Cottidae, and Gobiidae was negatively affected by the presence of dams located in the downs...

1. We examined the effects of habitat fragmentation caused by dams on freshwater fish species using a database of 7848 fish presence/absence surveys, conducted between 1953–2003 in Hokkaido, Japan. 2. A series of generalised linear models showed that for 11 of 41 taxa examined, the probability of occurrence had been influenced either negatively (ei...

Based on a predictive habitat modelling approach, we investigated 1) the effects of damming on the distribution of salmonids and 2) whether the existing conservation areas for the salmonids are appropriate and effective in protecting their habitats in Hokkaido. A habitat model for masu salmon, one of the most commercially important species, predict...

Spatial and temporal patterns of redd construction by Sakhalin taimen, Hucho perryi, were studied in small streams on northern Hokkaido, Japan. Spawning took place in late April with close relation to discharge patterns. Observed redd size (mean ± 95% C.I.) was 145 ± 11·8 cm in length and 84 ± 5·8 cm in width. The number of egg pockets per redd was...

Enclosure experiments were performed in a eutrophic lake in order to evaluate the effects of filter-feeding fish (silver carp) on production of planktonic protozoa and the carbon flux from protozoa to zooplankton. The densities of heterotrophic nanoflagellates (HNF) and ciliates (<60 mum) increased when fish were introduced to enclosures, and then...

Quasi-continuous DO and pH measurements (total 47 days) were conducted during enclosure experiments (6 enclosures; 5 5 2.5m), in which a biomass gradient of silver carp was created. After subtracting the air–water exchanges of O2 and CO2, the chemical and biochemical changes in DO (dissolved oxygen) and DIC (dissolved inorganic carbon) were estimat...

We investigated aquatic macrophytes, water quality, and phytoplankton biomass and species composition in three shallow lakes with different levels of vegetation cover and nutrient concentration in Kushiro Moor, during August 2000. Trapa japonica can live in a wide range of nutrient levels. This species forms an environment with a steeper extinction...

A close spatial association was detected between riffle crests and the spawning redds of masu and pink salmon in three streams with contrasting channel types. This association was most significant when a distance equivalent to one channel width around the redds was examined. Conversely, the redds were mostly constructed within 3 m (Sarufutsu Creek)...

1. We conducted enclosure experiments in a shallow eutrophic lake, in which a biomass gradient of the filter-feeding planktivore, silver carp, Hypophthalmichthys molitrix Valenciennes, was created, and subsequent community changes in both zooplankton and phytoplankton were examined. 2. During a summer experiment, a bloom of Anabaena flos-aquae deve...

A link between stream geomorphology and lotic ecosystems was demonstrated by quantitatively examining the precise locations of salmonid redds with respect to the planform geometry of streams using a differential global positioning system. A total stream distance of 59 km was surveyed in 17 streams, in which a total of 309 redds of Sakhalin taimen (...

This study investigated whether repeated use of limited spawning grounds (i.e., redd superimposition) by pink salmon (Oncorhynchus gorbuscha) can cause density-dependent mortality. Loss of eggs from part of Auke Creek, Alaska, was estimated from a series of mark-recapture experiments and maximum likelihood models. The number of eggs lost per day du...

Spatiotemporal distributions and microhabitat use of pink salmon Oncorhynchus gorbuscha and sockeye salmon O. nerka were studied in Lake Creek, southeast Alaska, during three spawning seasons. Sockeye salmon migrated approximately 1 week earlier than pink salmon and spawned 250–350 m upstream from pink salmon. Habitat overlap measured with proporti...

Historical fry and smolt productions of pink and sockeye salmon in the Auke Lake system, southeast Alaska, were well expressed by the Ricker spawner-recruit model over 14 years. Average fry and smolt production per spawner was twelve fry for pink salmon and nine smolts for sockeye salmon. Time series of recruit-per-spawner were positively oorrelate...

Variation in stream life, spawning efficiency, and spawning habitat among adult pink salmon (Oncorhynchus gorbuscha) in the Auke Lake system, southeastern Alaska, was best explained by stream discharge, stream temperature, and a combination of stream temperature and discharge. We estimated these attributes of female pink salmon spawners in samples...