| Autor: |
Hartman, KyleJ., Margraf, F.Joseph |
| Zdroj: |
Lake and Reservoir Management; September 2007, Vol. 23 Issue: 3 p211-218, 8p |
| Abstrakt: |
AbstractHigh latitudes of North America and Asia have many unstudied small lakes. The remoteness of these lakes presents a challenge to biologists who manage these systems. At Togiak National Wildlife Refuge in Alaska we evaluated the use of mobile hydroacoustic surveys as a tool for assessing unstudied lakes and setting priorities for further study. We sampled 50-ha Hole Lake in July 2002 with a 120-kHz split-beam hydroacoustic system, completing four surveys at different times throughout daylight and darkness. Despite day-night changes in distribution of fishes in the lake we found no significant differences in relative biomass, density, or in the detection of larger fish targets that may be of importance from a fisheries management perspective. However, between-transect variability in acoustic measures was high and may have masked the ability to detect these changes. Nonetheless, a simple design bisecting the study lake that was completed in 25 min was capable of detecting fish populations of potential interest to fisheries managers. We suggest a simple design (bisecting the lake) for scanning such lakes for the presence of fish populations of interest in these remote areas. |
| Databáze: |
Supplemental Index |
| Externí odkaz: |
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