东库克海峡腔吻鳕(Macruronus novaezelandiae)卵及稚鱼与水文状况的关系

Distribution of Hoki(Macruronus novaezelandiae)Eggs.and Larvae in Relation to Hydrography in Eastern Cook strait

1987年9月,我们进行了一次详细的调查,确定了东库克海峡(Cook Stait)中腔吻鳕的卵及稚鱼分布与水文状况的关系。由于地方性风的原因,当地的水文结构非常复杂。南塔拉纳基湾(Taranaki Bight)水占据了库克海峡北部和中部的大部分水域。克劳迪湾(Cloudy Bay)沿岸水被河水冲淡,并由于库克海峡峡谷上升流进入克利福德湾(Clifford Bay)和开普.坎贝尔(Cape Campbell)南部沿岸,使克劳迪湾的沿岸水向近岸呈羽状伸展。东开普流水体出现在库克海峡峡谷水深200m附近和陆架外缘。开普.帕利瑟(Cape Palliser)南部的深层混合说明,该地区有一股反气旋涡旋。叶绿素α浓度与混合层深度有关,它在垂直分层的表面水体中最高。腔吻鳕卵在库克海峡峡谷内最多,该地区是这种鱼类著名的产卵场。小的腔吻鳕稚鱼(2.0～3.9mm)数在卵高密度集区和开普。坎贝尔附近最多,而较大的稚鱼(>10mm)在近岸区最多。根据刚孵化出来的稚鱼的分布情况来看,腔吻鳕卵随着当地的上升流进入开普。坎贝尔的近岸地区。

A detailed survey in September 1987 determined the distribution of hoki eggs and larvae in relation to the hydrography of eastern Cook Strait. The hydrographic structure was complex, and appeared to be a response to local winds. South Taranaki Bight water occuppied much of northern and central Cook Strait. The coastal waters of Cloudy Bay were diluted by river outflows, and appeared to plume offshore as a consequence of water within the Cook Strait Canyon up-welling into Clifford Bay and nearshore south of Cape Campbell. East Cape Current water occurred deeper than 200 m in the Cook Strait Canyon, and beyond the shelf edge. Deep mixing south of Cape Palliser indicated the presence of an anticyclonic eddy. Chlorophyll a concentrations were related to the mixed layer depth and were highest in vertically stratified surface waters. Hoki eggs were most abundant over the Cook Strait Canyon, an area known to be a hoki spawning site. Numbers of small hoki larvae (2.0～3.9 mm) were greatest in areas of high egg abundance and near Cape Campbell, whereas larger larvae (>10 mm) were most abundant in nearshore areas. The distribution of newly hatched larvae suggested that hoki eggs were advected from the Cook Strait Canyon into the nearshore region off Cape Campbell as a result of local up-welling.