Fish and Hydrographic Collections Made by the 

 Research Vessels Dolphin and Delaware II 

 During 1968-72 From New York to Florida 



S. J. WILK and M. J. SILVERMAN' 



ABSTRACT 



InformatioD is given in tabular form for fish and hydrographic observations collected during 18 

 cruises made by the research vessels Do^kin and Delatuare II from New York to Florida during 1968-72. 

 Tables include station locations with related hydrographic observations and number, weight, and size range 

 of fish species caught. 



INTRODUCTION 



The Sandy Hook Marine Laboratory began a series of 18 

 trawl cruises in 1968 to study the Life histories of five species 

 of the family Sciaenidae occurring along the Atlantic coast: 

 weakfish, Cynoscion regalis; spot, Leiostomus xanthurus; 

 southern kingfish, Menticirrhus americanus; northern 

 kingfish, Menticirrhus saxatilis; and Atlantic croaker, 

 Micropogon undulatus. These studies included age and 

 growth, distribution, migration, reproduction, and popula- 

 tion structure. This paper reports the fishes collected and 

 hydrographic observations made during these trawl cruises. 



SURVEY DESIGN 



Sampling areas and time of each cruise depended on the 

 particular aspect of sciaenid biology under study and the 

 availability of vessels. All cruises, with the exception of 

 those specifically desig^ned for tagging or gear experiments, 

 were conducted along predetermined transects. These were 

 normal to the shore and extended seaward as far as 167 km 

 (90 nautical mUes). Sampling stations were spaced at 

 intervals of 1 to 22 km (0.5 to 12.0 nautical miles), the 

 spacing depending on the fishing intensity required to fulfill 

 particular collection requirements. In addition, when time 

 and weather permitted, special trawl stations were made at 

 the mouths of inlets. 



In all tables, the Dolphin cruises are encoded by the 

 letter D and the Delaware II cruises by the abbreviation 

 Del. These are followed by year digits and a series of 

 numbers assigned consecutively during the year. For 

 example, Del-72-15 was the 15th cruise of the Delaware II in 

 1972. Each station is designated by a number, indicating the 

 consecutive station order for the particular cruise. 



Table 1 gives the cruise designations, dates, geographical 

 boundaries, number of stations completed, and primary 

 purpose of each cruise. Appendix Table 1 g^ves station 

 dates, coordinates to the nearest 0.2 km (0.1 nautical milej, 



'Middle Atlantic Coastal Fisheries Center Sandy Hook Laboratory. 

 National Marine Fisheries Service, NOAA, Highlands, NJ 07732. 



time of day, trawling time, total catch, and hydrographic 

 observations. 



INSTRUMENTS AND COLLECTING GEAR 



A strip-chart recorder provided a continuous record of 

 surface water temperature. On station, surface water 

 temperatures were measured with stem thermometers 

 accurate to ±0.1°C. Vertical temperature profiles were 

 obtained with a mechanical bathj^thermograph. Salinity was 

 measured with a portable salinometer, which also provided 

 supplementary temperature data. 



All finfish collections were made with a % -scale version 

 of a Yankee No. 36 otter trawl having a 16.5-m (54-foot) 

 footrope and an 11.9-m (39-foot) headrope. The wings, 

 square, and bellies of the trawl were constructed of 127-mm 

 (5-inch) stretched measure No. 54 braided flat nylon and the 

 cod end of 51-mm (2-inch) stretched measure No. 30 braided 

 flat nylon. A sweep line consisting of about 1,000 rubber 

 discs 114 mm (4.5 inches) in diameter strung on 10-mm 

 (0.38-inch) chain was attached to the footrope at intervals of 

 about 356 mm (14 inches). Twelve 203-mm (8-inch) diameter 

 aluminum trawl floats were equally spaced along the 

 headrope. The trawl was fished with 11.6-m (38-foot) legs 

 and 16.5-m (54-foot) ground cables. The bottom legs and 

 ground cables were both constructed of 19-mm (0.75-inch) 6 

 X 19 steel cable and the top legs of 13-mm (0.50-inch) 6 x 19 

 steel cable. New England otter trawl doors constructed of 

 wood and steel weighing 226.8 kg (500 pounds) were used 

 with this trawl during cruises aboard the Dolphin. Doors of 

 the same basic design weighing 226.8 to 340.2 kg (500-700 

 pounds) were used aboard the Delaware II. 



THE SURVEY 



Loran A navigation was the principal method used for 

 positioning the Dolphin and Delaware II on collecting 

 stations. Because of inherent limitations of Loran A 

 navigation, accuracy of positioning on offshore stations 

 cannot be considered better than ±1.8 km (1.0 nautical 

 mile). Increased accuracy was obtained on inshore stations 

 by use of radar, land ranges, and by visual sightings of 

 buoys, lightships, and light towers. 



