Effect of Sediment on the Population of Macrobrachium nipponense (De Haan, 1849) in Anzali Lagoon.

<b>Background and Objective:</b> The role of sediment in water bodies is significant because sediment can affect water quality and benthic organisms. This study investigated sediment's effect on the <i>Macrobrachium nipponense</i> population in the Anzali Lagoon. <b>Materials and Methods:</b> The samples were taken at three different sites of Anzali Lagoon in 2015. All the prawns cached by traps and sediment samples were taken exactly next to the traps. All samples were transported to the laboratory for analysis. Canonical correspondence analysis (CCA) was used to analyze the total catch for prawns across the sediment gradients measured. <b>Results:</b> It showed clear separation in all sites. Site 2 is more affected by clay; in Site 2, the number and the weight of <i>M. nipponense</i> were lower than in the other sites. In Sites 1 and 3, fine sand and medium sand were more affected, respectively. The results showed a relationship between the prawn population and sediment in the Anzali Lagoon. <b>Conclusion:</b> In some parts of the Anzali Lagoon, the quality and quantity of sediments were different, which directly affected the population of <i>M. nipponense</i>. Furthermore, because some parts of the lagoon are in good condition according to sediments and water quality, the Anzali Lagoon has a good potential for growing and living <i>M. nipponense</i>.