Characteristics of sea floor sediments around trawl fishing grounds in the East China Sea

sea floor sediments around trawl fishing grounds

Abstract

In this study, we aimed to clarify the characteristics of sea floor sediments around trawl fishing grounds in the East China Sea, marine sediments were collected by using a Smith-McIntyre grab sampler total 29 times trawl operations. The sample were analyzed for particle size using a laser diffraction particle size analyzer. The amount of calcium carbonate in the dried 1g sediments was calculated by titration with hydrochloric acid at a concentration of 2 mol/L. Also, the amount of organic matter was determined by the ignition loss method, where 2 g of the dried sample was ignited at 550 °C for 4 hours, and the content ratio relative to the dried sample was calculated from the weight difference before and after ignition. Each sample was measured three times and the average value was calculated. As the result, the grain size distribution was such that the proportion of sand was higher at the eastern and western ends of the fishing ground, and the proportion of particle size under 62.5μm mud was higher near the center. A slightly positive correlation was found between the amount of organic matter and the proportion of mud.