@article{article_298981, title={Accounting for Zero Inflation of Mussel Parasite Counts Using Discrete Regression Models}, journal={Sakarya University Journal of Science}, volume={21}, pages={378–384}, year={2017}, DOI={10.16984/saufenbilder.298981}, author={Çankaya, Emel and Alpay, Olcay and Özer, Ahmet}, keywords={Parasite counts,Poisson regression,Negative binomial regression,Zero-inflated regression model,Hurdle model,Mediterranean mussels}, abstract={<p class="zet"> <span class="fontstyle0">In many ecological applications, the absences of species are inevitable due to either detection faults in samples or <br />uninhabitable conditions for their existence, resulting in high number of zero counts or abundance. Usual practice for <br />modelling such data is regression modelling of log(abundance+1) and it is well know that resulting model is <br />inadequate for prediction purposes. New discrete models accounting for zero abundances, namely zero-inflated <br />regression (ZIP and ZINB), Hurdle-Poisson (HP) and Hurdle-Negative Binomial (HNB) amongst others are widely <br />preferred to the classical regression models. Due to the fact that mussels are one of the economically most important <br />aquatic products of Turkey, the purpose of this study is therefore to examine the performances of these four models <br />in determination of the significant biotic and abiotic factors on the occurrences of Nematopsis legeri parasite <br />harming the existence of Mediterranean mussels (Mytilus galloprovincialis L.). The data collected from the three <br />coastal regions of Sinop city in Turkey showed more than 50% of parasite counts on the average are zero-valued and <br />model comparisons were based on information criterion. The results showed that the probability of the occurrence of <br />this parasite is here best formulated by ZINB or HNB models and influential factors of models were found to be <br />correspondent with ecological differences of the regions. </span>   <br style="line-height:normal;" /> </p> <p> </p>}, number={3}, publisher={Sakarya University}