摘要:

Commercial landings of alfonsino(Beryx splendensLowe, 1834) from the Palliser Bank, Tuaheni High, and Paoanui Ridge were sampled to describe growth and determine the age composition of catches. The study indicated that one opaque and one hyaline zone were formed annually in sagittal otoliths, the hyaline zone being deposited in late autumn. Fish were probably about 10 months old when the otolith nucleus was fully formed. The length‐weight equations for males and females differed and both changed throughout the year in parallel with the spawning cycle. Size‐selective mortality did not occur on the Palliser Bank. Females were significantly larger at any given age than males on all grounds examined, but growth of males and females appeared consistent between grounds. Growth was slower than in Japanese waters and the Atlantic. Age structure varied between grounds, but was reasonably constant over time on the Palliser Bank. Full recruitment to the commercial fishery occurred at age 5 on the Palliser Bank. Fish recruited onto the ground from February to July.

ISSN:0028-8330    

DOI:10.1080/00288330.1990.9516407

出版商:Taylor & Francis Group    

年代:1990

数据来源: Taylor

摘要:

A technique is described for obtaining rapid high‐quality silhouette photographs of plankton samples at sea. This technique was designed to facilitate identification and enumeration of pelagic marine fish eggs in near real‐time. It uses readily available photographic materials and unlike previously described techniques, the silhouettes are recorded directly on to photographic paper rather than film. The resolution is adequate for microscopic measurements. Examples are presented from a cruise off Westland, New Zealand, which investigated the distribution of hoki eggs.

ISSN:0028-8330    

DOI:10.1080/00288330.1990.9516408

出版商:Taylor & Francis Group    

年代:1990

数据来源: Taylor

摘要:

Results from five current meters moored in Hauraki Gulf are analysed. Tidal flows and the tidal constituents M2, S2, and N2are deduced. Time series techniques are used to examine the effects of wind stress and the spatial coherence in the flow. It is found that currents of oceanic water, set up under south‐west to southerly directed winds, flow into the Gulf through Jellicoe and Cradock Channels, with those through Cradock Channel probably passing more or less directly out through Colville Channel. A net anti‐clockwise circulation is suggested to occur in the inner Gulf, south of the latitude of Kawau Island. A lack of any particular spectral features and limited spatial coherence suggests that in the Hauraki Gulf, variations in circulation in the 2‐ to 15‐day time band considered are not well defined but that the Gulf responds to external forcing events with transient currents which last typically from 2 to 5 days.

ISSN:0028-8330    

DOI:10.1080/00288330.1990.9516409

出版商:Taylor & Francis Group    

年代:1990

数据来源: Taylor