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Application of Stock Density Indices as a Tool for Broad‐Scale Population Assessment for Four Cyprinid Species in Central Italy
Author(s) -
Pedicillo Giovanni,
Lorenzoni Massimo,
Carosi Antonella,
Ghetti Lucia
Publication year - 2013
Publication title -
north american journal of fisheries management
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.587
H-Index - 72
eISSN - 1548-8675
pISSN - 0275-5947
DOI - 10.1080/02755947.2012.747453
Subject(s) - stock (firearms) , fishery , sampling (signal processing) , statistics , population , stock assessment , recreation , geography , ecology , biology , mathematics , fishing , demography , computer science , archaeology , filter (signal processing) , sociology , computer vision
Stock‐density indices are standardized methods for analyzing length‐frequency data that quantify the length structure of a fish population into length categories that are of interest to recreational anglers. We adapted North American relative stock density (RSD) and proportional stock density (PSD) indices to four Italian endemic or native cyprinid species by means of two methods. In accordance with the traditional approach, the benchmarks of length categories were established according to Gabelhouse's percentage classification and calculated on the basis of the largest individual in the data set for each species. In the second method, asymptotic length and size at maturity were used to define the length categories for index calculation. Both methods were tested on length‐frequency data from fish collected from sampling sites in the Tiber River basin. The results showed that the traditional approach displayed better applicability, required less sampling effort, and provided a better insight into the length structure of the fish populations studied. Received January 17, 2012; accepted November 4, 2012