There is no major stock issue with sardines but the total stock and stock reproduction is affected by oceanographic conditions - sea temperatures, windflow, upswelling and distribution of plankton which sardines feed on.

The most common fishing equipment used for small pelagic schooling fish like sardines is the purse seine net which is wrapped around the school of fish and then drawn in (like a purse). These can vary in size and small by-catch of similar pelagic fish, such as anchovy or horse mackerel, can occur. Sardines can also be fished by midwater trawling gear which basically means a net stretched between a pair of boats and this method implicitly causes greater by-catch, although our research has not shown up statistics or analysis of by-catch.