Tidal front and the convergence of anchovy (Engraulis japonicus) eggs in the Yellow Sea
Anchovy recruitment determines fish production and thus the sustainable exploitation of anchovy in the Yellow Sea. Haizhou Bay is a traditional spawning and nursery ground for anchovy. The retention of anchovy in its early life stages appears to be related to observed fronts. Cruises have confirmed that anchovy eggs are distributed in high density patches, particularly in the tidal frontal zone. Front and egg patches shift to the shallow area in the warm season. A diagnostic Hamburg Shelf Ocean Model was applied in the East China Sea and Yellow Sea to simulate the frontal circulation and particle movement, forced by monthly wind speed and measured temperatures. It was observed that the jet along the front and upwelling in the mixed side of the front play an important role in the transport of eggs. Convergence and divergence areas are frequently induced by frontal shear instability and topography potential vorticity balance. Numerical experiments show that tidal mixing and front play an important role to converge particles like eggs. When eggs are caught in the convergence zone they are aggregated into a patch. The convergence zone has good feeding condition for eggs to hatch and larvae to grow.
Document Type: Research Article
Affiliations: 1: Institute of Physical Oceanography, Ocean University of China, Qingdao 266003, China 2: Institute of Yellow Sea Fishery Research, Qingdao 266071, China 3: Second Institute of Oceanography, SOA, Hangzhou 310012, China
Publication date: September 1, 2003