Bottom trawling on soft bottoms also stirs up bottom sediments and loading suspended solids into the water column. One bottom trawler can put more than ten times the amount of suspended solids pollution per hour into the water column than all the suspended solids pollution from all the sewerage, industrial, river and dredge disposal operations in Southern California combined. These turbidity plumes can be seen on Google Earth in areas where they have high resolution offshore photos (see bottom trawling). When the turbidity plumes from bottom trawlers are below a thermocline, the surface may not be impacted, but less visible impacts can still occur, such as persistent organic pollutant transfer into the pelagic food chain.