Atlantic cod stocks had once been so plentiful that early explorers joked about walking on the
backs of the teeming fish. Today, cod stocks are at historically low levels and show no signs of
imminent recovery, even after drastic conservation measures and severely limited fishing. Fishermen
often blame the diminishing stocks on seals, which prey on cod and other species, but scientists
believe that decades of overfishing are to blame. Studies on fish populations have shown that cod
disappeared from Newfoundland at the same time that stocks started rebuilding in Norway, raising the
possibility that the cod had migrated. Still no one can predict whether and when the cod will return to
the Grand Banks.