| Autor: |
Reinert, Thomas R., Will, Ted A., Jennings, Cecil A., Davin, William T. |
| Předmět: |
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| Zdroj: |
North American Journal of Fisheries Management; May2004, Vol. 24 Issue 2, p704-710, 7p, 2 Charts, 2 Graphs, 1 Map |
| Abstrakt: |
Surface push nets have been employed in the Savannah River estuary (SRE) to monitor striped bass Morone saxatilis spawning activity since the 1960s, but most intensively since the mid-1980s. These methods provide relative catch-per-unit-effort data for comparing station-to-station and year-to-year changes in egg abundance but do not provide total annual production estimates. To quantify the sampling efficiency of our gear, we investigated the use of gellan beads as striped bass egg surrogates. Gellan beads were comparable to striped bass eggs in size and specific gravity, and are appropriate surrogates for efficiency trials. In 1999 and 2000, we released known quantities of gellan beads to evaluate the efficiency of our egg sampling gear. Efficiency ranged from 1 bead per 11,300 at large (0.009%) to about 1 bead per 300,000 at large (0.0003%), depending on release and recapture locations. The use of egg surrogates was an effective and informative technique for evaluating our standardized egg sampling gear and may be similarly useful for other systems and other species with semibuoyant pelagic eggs. Additionally, the use of egg surrogates uncovered previously unsuspected biases in sampling efficiency because of differences in channel morphology and hydrology within the SRE. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Supplemental Index |
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