A Statistical Method for Analyzing Data Collected by a Creel/Angler Survey (Part 2)

Abstract

This article describes a unique analytical method employed to characterize angler activities on the lower 6-mile stretch of the Passaic River in New Jersey. The method used data collected by a creel/angler survey that was designed to capture the information necessary to calculate the exposure factors needed to characterize the fish consumption pathway for recreational anglers in a human health risk assessment for the river. The survey used two methods to address the challenges of conducting a creel/angler survey in an urban and industrial setting with limited river access. While unique, the analytical method described in this article is based upon accepted methods of interpreting survey data and basic laws of probability. This article was written as a companion to two other articles, also in this issue and cited here, of which one describes in detail the survey methodology designed for the lower Passaic River creel/angler survey to meet various challenges unique to conducting such a survey in urban and industrialized rivers, and the other presents, validates, and interprets the results of the lower Passaic River work relating to human exposure factors using the methodology described in this article.

Risk of Gastrointestinal Disease Associated with Exposure to Pathogens in the Water of the Lower Passaic River

“…The visitor scenario is intended to represent individuals who may engage in activities with minimal water contact, such as anglers, boaters, individuals wading in the surface water, and individuals engaging in other activities that may not be limited to the summer months. It is known that angling occurs at several points along the Lower Passaic River throughout the year (14,23,24), and USEPA considered this a complete pathway in their risk assessment of the Lower Passaic River (2). In this scenario, the potential route of exposure is indirect ingestion as a result of hand-to-mouth activities.…”

“…Angling and other recreational activities are relatively infrequent, due in part to the highly industrial and developed shoreline along the lower 6 miles of the river. However, recreational activities are known to occur as there are access points where individuals catch fish (which they may consume) and otherwise come in contact with surface water (14,23,24). In addition, homeless populations have been observed living along the shores of this section of the river (21).…”

Risk of Gastrointestinal Disease Associated with Exposure to Pathogens in the Sediments of the Lower Passaic River

“…The visitor exposure scenario is intended to quantify potential risks among individuals who may engage in activities with minimal sediment contact, such as anglers, picnickers, or people collecting trash from the shoreline. It is known that angling occurs at several points along the Lower Passaic River on a regular basis (29,41,42), and USEPA considered this to be a complete pathway in their draft risk assessment of the Lower Passaic River (7). Again, a triangular distribution was assumed for incidental ingestion (mg/day) for adults and adolescents (minimum ϭ 25, mode ϭ 50, maximum ϭ 95).…”

Utilization Survey of a Rural Creek Fishery in Central Alabama

“…This study used the weighting approach developed for the Passaic River Creel and Angling Survey, ( 3,6,7 ) which has been peer reviewed and accepted as an appropriate technique. ( 8 ) This approach was designed for an infrequently visited system and improves upon earlier attempts to correct for avidity bias, such as that developed by Price et al .…”

“…Ray et al . ( 6 ) show that the probability of not being interviewed within a stratum is represented by the hypergeometric distribution parameterized using the number of interviews for that angler (in this case, 0), the angler's trips within that stratum ( t ij ), the number of times that stratum was sampled ( n j ), and the total number of opportunities to sample within that stratum ( N j ): …”