Transport Process of the Alaska Pollack Eggs in Funka Bay and the Adjacent Waters, Hokkaido

Abstract

In March 1977, the Alaska pollack Theragra chalcogramma (Pallas) eggs of the early stages (stages 1–2) were found mainly near the entrance of Funka Bay, while the eggs of stages 3–5 were found in the inner area of the bay. On the other hand, the surface water of the Oyashio current flowed from the northeastern part of the bay and then occupied almost all the area of the bay. These facts suggest that the Alaska pollack in this study area spawned near the entrance of the bay and that the surface water of the Oyashio current drifted the eggs to the inner area of the bay. In the same period, water temperature in the inner area of the bay was 2.0–2.5°C, whereas that in the area outside the bay was 0.2–0.4°C. This shows that the eggs spawned near the entrance were transported to a suitable nursery ground. © 1981, The Japanese Society of Fisheries Science. All rights reserved.