The effects of the Huanghe River Delta on the circulation and transportation of larvae

The Huanghe River has run the current path since its last change of path in 1976.The river delta intrudes into the Laizhou Bay significantly.The effects of the Huanghe River Delta on the circulation and transportation of the eggs and larvae were investigated with a fine resolution 3-D shelf ocean model(HAMSOM).The effects are local but very significant.Before the intrusion of delta,the anti-cyclonic circulation dominates in the Laizhou Bay. At present,the circulation is totally different from that before the intrusion.Apair of headland eddies at the Huanghe River mouth is very significant.The change of the circulation is mainly due to the inter action between tides and bathymetry.Wind and baroclinic forcings also play an important role on the circulation,but the basic pattern remains.The eggs and larvae are transported tow ards the west part of bay before the intrusion of delta,which coincides with the historical nursery ground.At present,the eggs and larvae are trapped in the headland eddies, which has disadvantage on the later stage of larvae.The results may explain to some extent for the lost of the nursery ground of Peneous Chinensis.