Answer:
increased runoff from rivers
Step-by-step explanation:
Salinity of the ocean is the degree of concentration of salts in the ocean. It is the extent to which ocean water contains dissolved salt materials in it. It describes the saltiness of the ocean.
When runoff from rivers increases into an ocean, the salinity will reduce drastically. More fresh water implies a reduction in salt water content of the ocean. Runoff reduces or we can say dilutes the degree to which ocean water is salty.