Biosphere conservation : for nature, wildlife, and humans
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Volume 5 , Issue 2
Showing 1-5 articles out of 5 articles from the selected issue
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Original Papers
  • Seiji Nakaya, Shoji Yamazato
    Type: Original Papers
    Volume 5 (2003) Issue 2 Pages 47-52
    Released: October 12, 2017
    JOURNALS FREE ACCESS
    Outbreaks of crown-of-thorns starfish Acanthaster planci have repeatedly occurred on Okinawan coral reefs, Japan, since the 1960s. The only countermeasure to the outbreaks has been to hand-collect individual starfish. To identify the characteristics of professional divers who are willing to participate in starfish control programs, we administered a questionnaire to 254 diving shops and marine leisure outlets as well as to 45 fishing cooperatives in Okinawa. Among the attributes of respondents, only the type of job affected the willingness, while others, including the number of years of diving experience, frequency of diving, former participation in control program, did not. Divers from the tourism sector were willing to participate in control/monitoring programs more than those from the fishery sector. Involving divers from the tourism industry may help develop an effective system to control and monitor the starfish. As the tourism and marine leisure industries grow, the existing management system exclusively influenced by the fishery sector needs to be supplemented with a multi-sectoral coral reef management regime.
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  • Vo Cong Thanh, Huynh Ky, Truong Ba Thao, Yutaka Hirata
    Type: Original Papers
    Volume 5 (2003) Issue 2 Pages 53-61
    Released: October 12, 2017
    JOURNALS FREE ACCESS
    In order to evaluate genetic variation for conservation of cultivated landraces and wild Glycineae species samples collected in the Mekong Delta, 626 soybean cultivars, one perennial soybean-related species (wild, 'Dau Han The'), and another perennial wild species ('Dau Hoang') were analyzed to search for genetic variations of Kunitz trypsin inhibitor (KTI), 7S and 11S globulins. Interestingly, all 185 local cultivars had only one TiaTia genotype and the normal type of 7S conglycinin, whereas 441 cultivars introduced from foreign countries had 15 TibTib and 1 Ti0Ti0 genotypes and several variations of 7S conglycinin. However, variation of 11S subunits was higher in soybean landraces than among introduced soybean cultivars. These data indicate that soybean landraces in Viet Nam have differentiated independently from a limited number of original soybean cultivars introduced to Viet Nam since 1975. Two wild Glycine relatives, 'Dau Han The' and 'Dau Hoang', contained subunit variations on 7S conglycinin and extremely reduced amounts of 11S glycinin. 'Dau Han The' had only oneα-type subunit corresponding with 7S α-subunit of soybean, but 'Dau Hoang' contained two α-type subunits smaller than α'-and α-subunits of soybean. In particular, this wild species had yellow flowers similar to some cultivars of Glycine wightii but its inflorescences were different, thus 'Dau Hoang' is being investigated to see if it really belongs within G. wightii or not. The 'Dau Han The' protein pattern was so different from other wild perennial species such as G. tomentella, and G. tabacina that we considered 'Dau Han The' to belong within G. mekongensis Thanh and Hirata. Moreover, 'Dau Han The' has many interesting characteristics such as the presence of creeping stolons, helping dry tolerant conditions, and an apparent resistance to pod borers (Etiella zinckenella), being a main serious insect to soybean seed production in tropical regions. The information will be necessary to improve essential amino acid composition and protein content in soybean cultivars.
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  • Kazuki Suda, Ryota Araki, Naoki Maruyama
    Type: Original Papers
    Volume 5 (2003) Issue 2 Pages 63-70
    Released: October 12, 2017
    JOURNALS FREE ACCESS
    The effects of sika deer Cervus nippon on two forest mice species, Apodemus speciosus and A. argenteus, were studied in evergreen broad-leaved forest on the Tsushima Islands, western Japan, in 1997. Four study areas with different deer densities were established: 1) deer-free, 2) 3.6 deer/(km)2, 3) 22.8 deer/(km)2, and 4) 74.9 deer/(km)2. Mice were caught in snap traps; 100 traps per area (45 m × 45 m), on three consecutive nights (300 trapnights/area). The weight of leaf litter, which can be regarded as a habitat index for Apodemus species, was less in areas with higher deer densities. The density of A. speciosus tended to be inversely proportional to deer density; this trend was more obvious in the breeding season. The relationship between A. argenteus and deer density was vague or proportional. The total standing stock of both Apodemus species was lower in higher deer density areas; nevertheless, density changes of both species were inconsistent. The decrease in the standing stock of A. speciosus was not accounted for by an increase in A. argenteus. The effects of sika deer on both Apodemus species possibly operate by affecting their predators on Tsushima.
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  • Mikio Inoue, Tomoya Iwata, Shigeru Nakano, Atsushi Doi, Hitoshi Miyasa ...
    Type: Original Papers
    Volume 5 (2003) Issue 2 Pages 71-86
    Released: October 12, 2017
    JOURNALS FREE ACCESS
    Habitat use, abundance-habitat relationships and assemblage composition of tropical freshwater fishes were surveyed in streams running through primary and secondary (deforested 9-20 years prior to the survey by slash-and-burn agriculture) forests in the Rayu River watershed, Sarawak, Borneo. Five species (Puntius kuchingensis, P. binotatus, Rasbora sarawakensis, R. caudimaculata, and Hemirhamphodon kuekenthali), of which habitat use was investigated, exhibited distinct diel habitat shifts between midstream and channel margin. Their abundances were related to habitat variables with the exception of P. binotatus. Puntius kuchingensis decreased with the increase of eroded banks. The abundance of R. caudimaculata increased downstream, while R. sarawakensis was less abundant in streams without riffle habitats. Hemirhamphodon kuekenthali was absent from high-gradient streams. Both habitat characteristics and fish assemblage composition differed distinctly between the primary-and secondary-forest streams. The secondary-forest streams were characterized by sandy substrates and eroded banks, suggesting a long persistence of sedimentation caused by the past deforestation. Macrognathus maculatus, Betta akarensis and P. kuchingensis appeared to be susceptible to sedimentation effects. Our data provide circumstantial evidence of the impact of past deforestation on fish assemblages in the Rayu River watershed.
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