Distribution and Abundance of Seagrasses in Qatar Marine Zone

2021 ◽  
pp. 327-362
Author(s):  
Ekhlas M. M. Abdelbary ◽  
Aisha A. Al Ashwal
Keyword(s):  
Marine Zone

Conservation Status of the Fish Fauna in the Danube Delta Marine Zone

2017 ◽  
pp. 443-472
Author(s):  
Carmen Georgeta Nicolae ◽  
Magda Ioana Nenciu ◽  
Valodia Maximov ◽  
Dana Popa ◽  
Monica Marin ◽  
...  
Keyword(s):  
Conservation Status ◽  
Fish Fauna ◽  
Danube Delta ◽  
Marine Zone

Differential Use of the Campbell River Estuary, British Columbia by Wild and Hatchery-Reared Juvenile Chinook Salmon (Oncorhynchus tshawytscha)

1986 ◽  
Vol 43 (7) ◽  
pp. 1386-1397 ◽  
Author(s):  
C. D. Levings ◽  
C. D. McAllister ◽  
B. D. Chang
Keyword(s):  
Transition Zone ◽  
Chinook Salmon ◽  
Oncorhynchus Tshawytscha ◽  
River Estuary ◽  
Transition Zones ◽  
Juvenile Chinook Salmon ◽  
Hatchery Fish ◽  
Mean Size ◽  
Juvenile Chinook ◽  
Marine Zone

From March 1982 to December 1983, juvenile chinook salmon (Oncorhynchus tshawytscha) were sampled by beach-seine in the Campbell River estuary and adjacent waters of Discovery Passage in order to examine estuarine use by wild and hatchery stocks. Wild juvenile chinook entered the estuary as migrant fry and were present in the estuarine zone mainly in late April to June, in the transition zone in mid-May to July, and in the marine zone in July. Hatchery fish were released from early May to early July. Maximum catches of wild stocks were similar in the estuarine and transition zones, while the maximum catches of most hatchery stocks were higher in the transition zone. For both wild and hatchery chinook, catches in the marine zone were much lower than in the estuarine and transition zones. Wild fry resided in the estuary for 40–60 d, while most hatchery fish used the estuary for about one-half this period. Wild stocks showed a relatively constant rate of increase in mean size from May to September. Higher rates of increase in the mean size of hatchery fish were shown by groups with earlier release dates and smaller mean sizes. Residency time and growth rates for wild fish were comparable with those observed in an estuary without hatchery fish. Potential for interaction between wild and hatchery stocks was greatest in the transition zone, where hatchery fish were most abundant and because hatchery releases occurred when catches of wild fish were highest in this foreshore area.

Exposure Test of FRP-Reinforced Concrete Structure in Temperate Marine Tide Zone

2012 ◽  
Vol 166-169 ◽  
pp. 538-542
Author(s):  
Ming Jin Chu ◽  
Zhi Juan Sun ◽  
Hui Chen Cui ◽  
Ke Zhang
Keyword(s):  
Reinforced Concrete ◽  
Concrete Structure ◽  
Chloride Ion ◽  
Test Results ◽  
Reinforced Concrete Structure ◽  
Freezing And Thawing ◽  
Concrete Member ◽  
Exposure Test ◽  
Reinforced Concrete Member ◽  
Marine Zone

Through exposure test of FRP-reinforced concrete member in littoral test area of temperate marine zone, the durability and constructional measures of FRP-reinforced concrete structure are investigated. The test results show that FRP shell on the surface of FRP-reinforced concrete member is effective in avoiding wave flush, freezing and thawing damage, preventing chloride ion corrosion and improving durability. On the other hand, reliable measures should be taken to protect concrete structures with no FRP shell on the surface. Based on above, the provided reference for evaluation durability of FRP-reinforced concrete structure, and proper constructional measures for FRP-reinforced concrete structure are presented.

scholarly journals Age and fine-scale marine growth of Atlantic salmon post-smolts in the Northeast Atlantic

2012 ◽  
Vol 69 (9) ◽  
pp. 1668-1677 ◽  
Author(s):  
Arne J. Jensen ◽  
Niall Ó Maoiléidigh ◽  
Katie Thomas ◽  
Sigurdur M. Einarsson ◽  
Monika Haugland ◽  
...  
Keyword(s):  
Atlantic Salmon ◽  
Growth Rates ◽  
Average Rate ◽  
Fine Scale ◽  
Large Area ◽  
Growth Indices ◽  
Northeast Atlantic ◽  
Marine Zone ◽  
Feeding Migration ◽  
Smolt Age

Abstract Jensen, A. J., Ó Maoiléidigh, N., Thomas, K., Einarsson, S. M., Haugland, M., Erkinaro, J., Fiske, P., Friedland, K. D., Gudmundsdottir, A. K., Haantie, J., Holm, M., Holst, J. C., Jacobsen, J. A., Jensås, J. G., Kuusela, J., Melle, W., Mork, K. A., Wennevik, V., and Østborg, G. M. 2012. Age and fine-scale marine growth of Atlantic salmon post-smolts in the Northeast Atlantic. – ICES Journal of Marine Science, 69: 1668–1677. Surface trawls were conducted over a large area of the Northeast Atlantic in 2002, 2003, 2008, and 2009 to collect samples of Atlantic salmon (Salmo salar) post-smolts during their marine feeding migration (n = 2242). The dominant smolt age of wild post-smolts was 2 years, followed by 1- and 3-year-old fish, and a few 4-year-old fish. The average rate of circulus formation in the marine zone of scales was estimated to be 6.3 d circulus−1. Both the age structure and the number of marine circuli in the scales suggest that the majority of the post-smolts originated in rivers in southern Europe. Applying intercirculi distances in scales as a proxy variable of growth rate suggests that putative marine growth rates varied among years, with the fastest growth rates in 2002 and the slowest growth rates in 2008. Further, the first marine intercirculi distances were narrowest in 1-year-old smolts, successively increasing with smolt age, indicating that growth rates during the first period at sea were lowest for salmon of southernmost origin. Growth indices are linked to prevailing environmental and biological conditions.

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