scholarly journals Effect of Microhabitat Structure on the Distribution of an Endangered Fish, Coreoperca kawamebari (Temminck & Schlegel, 1843) in the Geum River, South Korea

Water ◽  
2020 ◽  
Vol 12 (6) ◽  
pp. 1690
Author(s):  
Jong-Yun Choi ◽  
Seong-Ki Kim ◽  
Jeong-Cheol Kim ◽  
Jong-Hak Yun

Macrophytes play a major role in the structuring of aquatic environments and may influence the distribution and feeding habits of fish species. We explored the microhabitat characteristics influencing the spatial distribution of newly discovered Coreoperca kawamebari (Temminck & Schlegel, 1843) in the upstream reaches of the Geum River. Out of 21 study sites, C. kawamebari was found in 10 sites, and its abundance was strongly positively correlated with “vegetated” microhabitats, especially those covered by elodeids (e.g., Ceratophyllum demersum). The utilization of elodeids by the piscivores fish, C. kawamebari, may limit the abundance of other native fishes, and stable isotope analysis also showed that C. kawamebari is likely to consume other fish species. However, the influence of other fish species on C. kawamebari is assumed to be small, considering that C. kawamebari is a latent predator. Although the abundance of other fish was low within the preferred microhabitat of C. kawamebari, other species were abundant in each site where C. kawamebari was dominant. From this finding, we conclude that the successful settlement of C. kawamebari in the upper section of the Geum River can be attributed to their habitat preferences. Although the elodeids favored by C. kawamebari generally have difficulty developing in the upstream section, the habitat creation by humans has contributed to the stable settlement of new fish species.

Polar Record ◽  
2021 ◽  
Vol 57 ◽  
Author(s):  
Frigga Kruse ◽  
Gary R. Nobles ◽  
Martha de Jong ◽  
Rosanne M. K. van Bodegom ◽  
G. J. M. (Gert) van Oortmerssen ◽  
...  

Abstract Arctic mining has a bad reputation because the extractive industry is often responsible for a suite of environmental problems. Yet, few studies explore the gap between untouched tundra and messy megaproject from a historical perspective. Our paper focuses on Advent City as a case study of the emergence of coal mining in Svalbard (Norway) coupled with the onset of mining-related environmental change. After short but intensive human activity (1904–1908), the ecosystem had a century to respond, and we observe a lasting impact on the flora in particular. With interdisciplinary contributions from historical archaeology, archaeozoology, archaeobotany and botany, supplemented by stable isotope analysis, we examine 1) which human activities initially asserted pressure on the Arctic environment, 2) whether the miners at Advent City were “eco-conscious,” for example whether they showed concern for the environment and 3) how the local ecosystem reacted after mine closure and site abandonment. Among the remains of typical mining infrastructure, we prioritised localities that revealed the subtleties of long-term anthropogenic impact. Significant pressure resulted from landscape modifications, the import of non-native animals and plants, hunting and fowling, and the indiscriminate disposal of waste material. Where it was possible to identify individual inhabitants, these shared an economic attitude of waste not, want not, but they did not hold the environment in high regard. Ground clearances, animal dung and waste dumps continue to have an effect after a hundred years. The anthropogenic interference with the fell field led to habitat creation, especially for vascular plants. The vegetation cover and biodiversity were high, but we recorded no exotic or threatened plant species. Impacted localities generally showed a reduction of the natural patchiness of plant communities, and highly eutrophic conditions were unsuitable for liverworts and lichens. Supplementary isotopic analysis of animal bones added data to the marine reservoir offset in Svalbard underlining the far-reaching potential of our multi-proxy approach. We conclude that although damaging human–environment interactions formerly took place at Advent City, these were limited and primarily left the visual impact of the ruins. The fell field is such a dynamic area that the subtle anthropogenic effects on the local tundra may soon be lost. The fauna and flora may not recover to what they were before the miners arrived, but they will continue to respond to new post-industrial circumstances.


2006 ◽  
Vol 86 (6) ◽  
pp. 1443-1447 ◽  
Author(s):  
D. Fourgon ◽  
G. Lepoint ◽  
I. Eeckhaut

Analyses of the natural abundance of carbon and nitrogen stable isotopes were performed to investigate the feeding habits of two ophiuroids, Ophiomastix venosa and Ophiocoma scolopendrina, and to assess the potential benefit obtained by the symbiotic Ophiomastix venosa juveniles. A tracer experiment was also carried out to clarify the contribution of algae to the nitrogen uptake amongst the tested ophiuroids. Our results suggest that Ophiocoma scolopendrina adults occupy a higher position in the food web than Ophiomastix venosa and mainly feed on neuston. In contrast, O. venosa adults feed on the alga Sargassum densifolium and on organic matter associated with sediment. Free juveniles and symbiotic juveniles of O. venosa have intermediate δ13C values between both adult species. The high proportion of 13C in the symbiotic juveniles compared to the one in their conspecific adults indicates that their diet slightly differs from the latter and is closer to that of Ophiocoma scolopendrina. This raises the hypothesis that symbiotic juveniles steal neuston from their associated host, O. scolopendrina.


2014 ◽  
Vol 74 (4) ◽  
pp. 821-827 ◽  
Author(s):  
U Wischhoff ◽  
F Marques-Santos ◽  
M Rodrigues

The Cinereous Warbling-finch Poospiza cinerea is a globally vulnerable Emberizidae passerine, patchily distributed and rare in the open savannah of central South America. Attributes of rare species include niche specificity such as feeding habits. To verify possible niche specialization in this species we aimed to describe its foraging habits related to substrate use, foraging and substrate height, attack maneuvers, and consumed food items. We monitored two groups at two study sites and sampled foraging events with intervals of 15 minutes. The substrates used in greater frequency were foliage and reproductive organs. Foraging and substrate height varied widely with study area. The attack maneuver adopted in greater frequency was glean. Most food items attacked were small invertebrates. Big invertebrates included Lepidoptera, Hemiptera, Coleoptera, Hymenoptera and Orthoptera. Poospiza cinerea was also recorded foraging in mixed bird flocks with seven other species. The generalist foraging behavior of the species cannot be associate to its rarity.


2019 ◽  
Vol 12 ◽  
pp. 194008291983414 ◽  
Author(s):  
Natalia Carrillo ◽  
Eduardo J. Naranjo ◽  
Sergio Cortina-Villar ◽  
Rafael Reyna-Hurtado ◽  
Eduardo Mendoza

Extensive, unprotected tracts of tropical forests remain in community territories of the Calakmul region, in the Yucatan Peninsula of Mexico. These forest tracts face deforestation mainly due to agricultural development. Based on the graphic theory and using the CONEFOR SENSINODE 2.2 program, we analyzed the landscape connectivity between the forests of two communities and Calakmul Biosphere Reserve. Derived from vegetation cover and land use classification, the landscape was characterized considering Baird’s tapir habitat preferences. The indices used showed a loss of connectivity between community territories and Calakmul Biosphere Reserve, making it difficult for tapirs to move outside the continuous forests. We detected a few important nodes for landscape connectivity and a reduced number of connections allowing potential tapir dispersal in each study site. Despite the evident trends of forest fragmentation across the Calakmul region, our results suggest that the landscapes of our study sites are not optimal, but still usable for tapirs, which are able to move throughout habitat mosaics of forests and agricultural areas. We recommend that farming practices should be encouraged over mechanized agriculture to mitigate deforestation and tapir habitat loss in the study area.


Author(s):  
Víctor M. Muro-Torres ◽  
Felipe Amezcua ◽  
Raul E. Lara-Mendoza ◽  
John T. Buszkiewicz ◽  
Felipe Amezcua-Linares

The trophic ecology of the chihuil sea catfish Bagre panamensis was studied through high-resolution variations in its feeding habits and trophic position (TP) in the SE Gulf of California, relevant to sex, size and season. The combined use of stomach content (SCA) and stable isotope analysis (SIA) allowed us to perform these analyses and also estimate the TP of its preys. Results of this study show that the chihuil sea catfish is a generalist and opportunistic omnivore predator that consumes primarily demersal fish and peneid shrimps. Its diet did not vary with climatic season (rainy or dry), size or sex. Results from the SIA indicated high plasticity in habitat use and prey species. The estimated TP value was 4.19, which indicates a tertiary consumer from the soft bottom demersal community in the SE Gulf of California, preying on lower trophic levels, which aids in understanding the species' trophic role in the food web. Because this species and its prey are important to artisanal and industrial fisheries in the Gulf of California, diet assimilation information is useful for the potential establishment of an ecosystem-based fisheries management in the area.


Our Nature ◽  
2013 ◽  
Vol 10 (1) ◽  
pp. 8-16
Author(s):  
P.P. Ramollo ◽  
M. Schumann ◽  
W.A.J. Pretorius

The freshwater fish of Oorlogskloof River were sampled in March 2010. The study aimed to determine the distribution and relative abundance of freshwater fish in the Oorlogskloof River. A total of 4643individuals represented by five fish species belonging to two families were sampled. The Barbus anoplus was only sampled in the upper reaches of the Oorlogskloof River gorge while endangered Labeobarbus capensis appeared downstream in the Oorlogskloof River. Barbus serra dominated the fish species in the system. The invasion of Tilapia sparmanni in this system was confirmed during the survey andthe species appeared to be widespread throughout the system. At this stage it does not appear to be posing a serious threat to the endangered fish species. The Oorlogskloof River can be considered as a potential refuge site for the conservation of some endemic and threatened freshwater fishes of South Africa.DOI: http://dx.doi.org/10.3126/on.v10i1.7746


2018 ◽  
Vol 163 ◽  
pp. 492-501 ◽  
Author(s):  
Paola L. Garnero ◽  
Magdalena V. Monferran ◽  
Germán A. González ◽  
Julieta Griboff ◽  
Bistoni María de los Ángeles

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