FN Archimer Export Format PT J TI Sampling design optimization for EROD measurements in fish BT AF BELIAEFF, Benoit BURGEOT, Thierry AS 1:1;2:1; FF 1:;2:; C1 IFREMER, F-44311 NANTES 3, FRANCE. C2 IFREMER, FRANCE IN WOS Ifremer jusqu'en 2018 IF 1.928 TC 6 UR https://archimer.ifremer.fr/doc/00337/44787/44483.pdf LA English DT Article DE ;biomonitoring;estimation;EROD activity;statistical power;sample size;sampling design AB Activity of 7-ethoxyresorufin-O-deethylase (EROD) in fish is certainly the best-studied biomarker of exposure applied in the field to evaluate biological effects of contamination in the marine environment. Since 1991, a feasibility study for a monitoring network using this biomarker of exposure has been conducted along French coasts. Using data obtained during several cruises, this study aims to determine the number of fish required to detect a given difference between 2 mean EROD activities, i.e. to achieve an a priori fixed statistical power (l-beta) given significance level (alpha), variance estimations and projected ratio of unequal sample sizes (k). Mean EROD activity and standard error were estimated at each of 82 sampling stations. The inter-individual variance component was dominant in estimating the variance of mean EROD activity. Influences of alpha, beta, k and variability on sample sizes are illustrated and discussed in terms of costs. In particular, sample sizes do not have to be equal, especially if such a requirement would lead to a significant cost in sampling extra material. Finally, the feasibility of longterm monitoring is discussed. PY 1997 SO Marine Ecology Progress Series SN 0171-8630 PU Inter-research VL 153 UT A1997XR97400022 BP 239 EP 246 DI 10.3354/meps153239 ID 44787 ER EF