Food and initial size influence overwinter survival and condition of a juvenile marine fish (age-0 Atlantic cod)

In subarctic Newfoundland, age-0 Atlantic cod (Gadus morhua) settle into coastal habitats in several summer–autumn pulses, resulting broad length-frequency distributions before winter. Low winter temperatures and potential decreases food availability pose challenges for young-of-year fish. To examine how size variation affects overwintering success under contrasting scenarios, we conducted 114-day laboratory feeding trials at ambient overwinter sea temperatures, using demersal collected from Newman Sound, Newfoundland. We reared two classes of juvenile four daily ration levels (starvation, low, medium, high). used Fulton’s K condition factor to interpret effects fish on survival over showed that small amounts consumed (<1% BW·day ?1 ) maximized growth Newfoundland waters. With no food, dropped below 80% Day 47, whereas large juveniles remained >80% until 74. Therefore, expect higher earlier settlers increased size-selective mortality during either unproductive or protracted winters, when abundance is often low.