Design Considerations for Beach Seine Surveys of Striped Bass

Abstract

Considerable resources are expended annually on beach seine surveys to assess year-class strength of east coast populations of striped bass Morone saxatilis, yet little research has been devoted to optimizing the design of these programs. We analyzed data from ongoing beach seine monitoring programs for striped bass in the Chesapeake Bay, the Hudson River, and the Delaware River, to assess the effects of three design considerations: gear size, replicate hauls, and the relative merits of temporal versus spatial allocation of sampling effort. We found that a 60-m seine provided a more precise measure of abundance than a 30-m seine, although the gain in precision was small and may be offset by logistical difficulties associated with use of the larger net. Multiple hauls at the same site were found to be inadvisable for two reasons: (1) repeated samples within a short time period are not true replicates – the first haul consistently catches more than the second, and (2) when the Chesapeake Bay index was recalculated using data from only the first haul, there was a higher level of agreement of the index with a commercial fishery data set than when both hauls were included. We also found that variation in catch was much greater among beaches than among weeks, indicating that sampling many beaches is a better strategy for increasing the precision of a striped bass beach seine index than repeated sampling of a small set of beaches.