scholarly journals Seasonal Variations In Species Composition And Community Structure In The Eastern Coast of South Korea

2021 ◽  
Author(s):  
Jeonghoon Han ◽  
Do-Hyung Kang ◽  
Heung-Sik Park ◽  
Young-ung choi
Keyword(s):  
Community Structure ◽  
Species Composition ◽  
Water Temperature ◽  
Seasonal Variations ◽  
Eastern Coast ◽  
Monthly Variation ◽  
Fish Community Structure ◽  
Average Water Temperature ◽  
Number Of Individuals

Abstract The seasonal variations in species composition of set net fisheries were investigated in the eastern coast of Korea, from 2007 to 2008. In total, 51 species were found that were classified into 15 orders and 33 families. The water temperature of the study area was 0.1–2.1 °C during the study period, which was higher than the average water temperature in the last decade. Monthly variation in the number of species peaked twice, in May (spring) and November (autumn) when the water temperature increased and decreased, respectively, and monthly variation in the number of individuals showed a remarkably high trend in winter and autumn and was mainly caused by large migratory species. Based on the cluster analysis of the 18 most dominant species with more than 0.4% of the total number of individuals, we divided the species composition and community structure into three groups: fishes with temporary appearance (Group A), fishes with long-term appearance (Group B), and dominant pelagic fishes appearing with long-term appearance (Group C). We could conclude that seasonal variation in the fish community structure was mainly caused by pelagic migration of species under high water temperature conditions during the study period.

scholarly journals Climate Change Impact on Salmon (Salmo salar) and Sea Trout (Salmo trutta) in the Salaca River, Latvia

2020 ◽  
pp. 17-26
Author(s):  
Janis Birzaks
Keyword(s):  
Atlantic Salmon ◽  
Water Temperature ◽  
Salmo Salar ◽  
Salmo Trutta ◽  
Age Groups ◽  
Average Water Temperature ◽  
Sea Trout ◽  
The One ◽  
The Baltic

Hydrometeorological conditions are important determinants of the distribution, abundance and growth of Atlantic salmon (Salmo salar) and sea trout (Salmo trutta) parr and smolt in rivers. Long-term monitoring of the temperate zone Salaca River was conducted to investigate long-term changes in water temperature and streamflow and their effects on juvenile Atlantic salmon and sea trout. The average water temperature in the Salaca River was found to increase over time, particularly in autumn, winter and spring. River discharge increased in winter and summer, which was caused by increased precipitation. Goals of our study were: 1) to examine trends in water temperature and discharge in the river, 2) to explore relations between hydrometeorological trends, on the one hand, and abundance, size at age of salmon and sea trout parr and smolt, as well as changes in smolt migration patterns, on the other. This was the first occasion that a study of this type had been carried out in the Baltic Sea basin. In summer, growth of salmon parr in all age groups in the Salaca River was reduced. However, the size of smolt was found to increase. Migration of sea trout smolt in the Salaca River took place earlier, and the end of both salmon and sea trout migration was also observed earlier. The age structure of salmon smolt changed, with the one-year- old age group dominating. Judging from the total numbers of salmon and sea trout smolt in the River Salaca, production of smolt in the river during the monitoring period increased.

scholarly journals Environmental factors predicting fish community structure in two neotropical rivers in Brazil

2007 ◽  
Vol 5 (1) ◽  
pp. 61-68 ◽  
Author(s):  
Yzel Rondon Súarez ◽  
Miguel Petrere Júnior
Keyword(s):  
Community Structure ◽  
Environmental Factors ◽  
Species Composition ◽  
Species Distribution ◽  
Fish Community ◽  
Abundant Species ◽  
Longitudinal Variation ◽  
Fish Community Structure ◽  
Gill Nets ◽  
The Difference

In order to assess the organization patterns of the fish communities in the Jogui and Iguatemi rivers, we collected fish with gill nets tri-monthly from November 1999 to August 2000. Hypostomus ancistroides and Parauchenipterus galeatus were the most abundant species in the Jogui and Iguatemi rivers, respectively. Longitudinal variation was more important than seasonal in determining the species composition in both rivers, and the difference between seasons was not statistically significant. Altitude was the most important factor determining species distribution.

scholarly journals Effect of Flood Disaster and Long Term Changes during 2011 to 2018 on Community Structure of Zooplankton in the Inner Gulf of Thailand

2020 ◽  
Vol 11 (8) ◽  
pp. 383-389
Author(s):  
Porntep Punnarak ◽  
Pramot Sojisuporn ◽  
Hattaya Jitrapat ◽  
Ajcharaporn Piumsomboon
Keyword(s):  
Community Structure ◽  
Environmental Parameters ◽  
Distribution Patterns ◽  
Flood Disaster ◽  
Eastern Coast ◽  
Gulf Of Thailand ◽  
Calanoid Copepods ◽  
Data Set ◽  
Contour Maps

This study of community structure of zooplankton in the Inner Gulf of Thailand was initiated in late 2011 in response to a major flood disaster event and continued intermittently to 2018. Six cruises with 13-20 replicate stations/cruise, provided data for contour maps of zooplankton, nutrients, water hydrography, pigments and algae; this manuscript utilized this diverse data set to focus on mesozooplankton. Immediately after the flood, November 2011, mesozooplankton communities were dominated by calanoid copepods with contributions of about 78% of the total. This changed in 2012 to 2018 which the proportion of calanoid copepods was decreased while the other zooplankton such as hydromedusae, polychaete larvae, barnacle nauplii, pelagic shrimp (Lucifer sp. and protozoea) and chaetognaths were increased. The density of mesozooplankton varied between 1.70 x 104 to 1.26 x 106 ind./100 m3 with noticeably high densities near the four river mouths that flow into Inner Gulf. Distribution patterns of mesozooplankton emerged that are likely similar to the long-term patterns of this region which effected by water circulation in the Inner Gulf of Thailand. However, high density of zooplankton in November 2012 and October 2017 appeared along the north-eastern coast and may be related to the availability of food (i.g., algae). Zooplankton abundances in the Inner Gulf of Thailand were significantly correlated with environmental parameters mainly temperature, salinity and food supplies as represented by chlorophyll a concentrations.

Influence of Deforestation on the Community Structure of Sand Flies (Diptera: Psychodidae) in Eastern Amazonia

2019 ◽  
Vol 56 (4) ◽  
pp. 1004-1012
Author(s):  
José Manuel Macário Rebêlo ◽  
Jorge Luiz Pinto Moraes ◽  
Gustavo Barbosa Vieira Cruz ◽  
Joudellys Andrade-Silva ◽  
Maria Da Conceição Abreu Bandeira ◽  
...  
Keyword(s):  
Community Structure ◽  
Species Composition ◽  
Significant Influence ◽  
Sand Fly ◽  
Forest Fragments ◽  
Sand Flies ◽  
Human Occupation ◽  
Short Term

Abstract Variation in the structure of phlebotomine (sand fly) communities in forest fragments with different degrees of preservation and human occupation (peridomicile) in eastern Amazonia was studied. We identified 43 species of sand flies in our study, of which 38 occurred in both preserved forest areas and in the peridomiciles of short-term settlements, while another 28 species occurred in altered forest fragments and long-term settlements. The composition of the community at each site changed with the type of environment (forest or peridomicile), with the species Lutzomyia evandroi, L. whitmani, L. choti, L. serrana, L. triacantha, L. migonei, L. hirsuta, L. shannoni, and L. brachyphylla accounting for more than 54% of the differences among environments. The quality of the environment exerted a significant influence on the structure of phlebotomine communities, and affected their species composition, richness, and abundance.

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