Answer:
Farms
laundry detergents 
pet wastes
Water treatment plants
Explanation:
Because its not construction materials or mining wastes.
 
        
                    
             
        
        
        
One constant kept in this experiment is the amount of food available to the larvae.
        
             
        
        
        
Temp causes water to rise or sink through convection, and salinity affects the density of the water, so higher salinity water will contribute to deep water currents