Danielle Crocker and Michael Perkins, N.C. Wildlife Resources Commission, snorkeling : 無料・フリー素材/写真
Danielle Crocker and Michael Perkins, N.C. Wildlife Resources Commission, snorkeling / USFWS/Southeast
| ライセンス | クリエイティブ・コモンズ 表示 2.1 |
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| 説明 | Service biologists recently joined biologists from the N.C. Wildlife Resources Commission, and Conservation Fisheries, Inc. to monitor the spotfin chub on the Little Tennessee River between the town of Franklin and Fontana Reservoir. The spotfin chub is a small, slender fish, growing up to four inches long and was placed on the federal endangered species list as threatened in 1977. It’s found in four states, and in North Carolina is known from the Little Tennessee and Cheoah rivers.This year’s monitoring is year nine of a ten-year effort which should provide a clearer idea of the viability of the Little Tennessee River population. Biologists use two different methods to count the fish. The first is laying down chains to mark 50m lines, or transects, up and down the river. Biologists snorkel upstream along the chain, then downstream, counting spotfin chubs as they go. In the second technique, biologists snorkel spotfin chub habitat, counting the chubs they see – this results in what’s called a catch per unit effort, or how many spotfin chubs did one biologists find searching suitable habitat for one hour. The numbers from the two techniques can then be compared, year to year, providing biologists with a picture of how well the population is doing.Photo credit: Gary Peeples/USFWS |
| 撮影日 | 2015-08-06 11:24:20 |
| 撮影者 | USFWS/Southeast |
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| カメラ | Canon PowerShot G10 , Canon |
| 露出 | 0.013 sec (1/80) |
| 開放F値 | f/4.0 |
| 焦点距離 | 15123.28767 dpi |