Evidence for inshore spawning of northern Atlantic cod (Gadus morhua) in Trinity Bay, Newfoundland, 1991-1993

Abstract

Northern Atlantic cod (Gadus morhua) were found to spawn in Trinity Bay, Newfoundland, during the early summer each year from 1991 to 1993. Prior to this study, only indirect evidence of inshore spawning by cod along the northeast coast o f Newfoundland existed. We observed (1) the progressive maturation of Trinity Bay cod from ripening to spawning and spent condition, (2) a spawning aggregation of cod in Trinity Bay, and (3) the presence of recently spawned cod eggs ( #10 d old) in the bay. We estimate that peak spawning occurred in the bay from mid-June to mid-July for the years 1991-1993. This spawning was delayed relative to estimated times of offshore spawning by northern cod. A simple model is proposed to explain this delay based upon the subzero temperatures that bay cod experience during the winter. Model predictions of oocyte development times for female bay cod were in phase with observed spawning times.