We found a match
Your institution may have access to this item. Find your institution then sign in to continue.
- Title
A Bayesian approach to estimating target strength.
- Authors
Fässler, Sascha M. M.; Brierley, Andrew S.; Fernandes, Paul G.
- Abstract
Fässler, S. M. M., Brierley, A. S., and Fernandes, P. G. 2009. A Bayesian approach to estimating target strength. – ICES Journal of Marine Science, 66: 1197–1204.Currently, conventional models of target strength (TS) vs. fish length, based on empirical measurements, are used to estimate fish density from integrated acoustic data. These models estimate a mean TS, averaged over variables that modulate fish TS (tilt angle, physiology, and morphology); they do not include information about the uncertainty of the mean TS, which could be propagated through to estimates of fish abundance. We use Bayesian methods, together with theoretical TS models and in situ TS data, to determine the uncertainty in TS estimates of Atlantic herring (Clupea harengus). Priors for model parameters (surface swimbladder volume, tilt angle, and s.d. of the mean TS) were used to estimate posterior parameter distributions and subsequently build a probabilistic TS model. The sensitivity of herring abundance estimates to variation in the Bayesian TS model was also evaluated. The abundance of North Sea herring from the area covered by the Scottish acoustic survey component was estimated using both the conventional TS–length formula (5.34×109 fish) and the Bayesian TS model (mean = 3.17×109 fish): this difference was probably because of the particular scattering model employed and the data used in the Bayesian model. The study demonstrates the relative importance of potential bias and precision of TS estimation and how the latter can be so much less important than the former.
- Subjects
PACIFIC herring fisheries; FISH sounds; ANIMAL morphology; BAYESIAN analysis; AIR bladders in fishes; VERTICAL distribution of fish
- Publication
ICES Journal of Marine Science / Journal du Conseil, 2009, Vol 66, Issue 6, p1197
- ISSN
1054-3139
- Publication type
Article
- DOI
10.1093/icesjms/fsp008