DISTRIBUTION OF FISH EGGS AND LARVAE, 



TEMPERATURE, AND SALINITY IN THE 

 GEORGES BANK-GULF OF MAINE AREA, 1953 



by 



Robert R. Marak' and John B. Colton, Jr. 



Fishery Research Biologists 



Bureau of Commercial Fisheries 



U. S. Fish and Wildlife Service 



Woods Hole, Massachusetts 



ABSTRACT 



Basic data on the distribution of fish eggs and larvae in the Georges Bank-Gulf of 

 Maine area were collected on surveys made by the Bureau of Commercial Fisheries 

 research vessel Albatross III during the spring of 1953. The data are presented in tabular 

 and graphic form. The methods and operational procedures pertinent to these surveys 

 are given. Plots and tables of surface temperature and salinity are also included. 



mTRODUCTION 



A program to study the early life history of 

 haddock on Georges Bank, Browns Bank, and 

 in the Gulf of Maine was started at the Bureau 

 of Commercial Fisheries Biological Laboratory, 

 Woods Hole, Massachusetts, in the spring of 

 1953. It was the purpose of this program to 

 attempt to relate the pattern of drift of eggs 

 and larvae to the success of the year class. 

 Fish egg and larvae surveys were undertaken 

 to locate centers of abundance of haddock eggs 

 and larvae and to trace their movements during 

 the early, and presumably critical, months of 

 their existence in relation to time, space, and 

 ecological conditions. The purposes of this 

 report are to describe the methods used and 

 to present basic data on the distribution of fish 

 eggs and larvae, temperature, and salinity 

 during the spring of 1953. To avoid confusion 

 all young fish (prolarvae, postlarvae, juveniles) 

 are referred to as larvae. A list of species of 

 fish eggs and larvae (with species code letters 

 used in the tables) collected during the surveys 

 of 1953 is given in table 1, 



Data for temperature and salinity observations 

 in relation to 1 -meter tows and Hardy Plankton 

 Recorder gauze sections are given in tables 2, 

 3, and 4. 



' Temporarily detailed to Bureau of Commercial Fisheries Biological 

 Laboratory, Auke Eiay, Alaska. 



COLLECTION OF DATA 



Three cruises were made during the spring of 

 1953 by the Albatross III: cruise no. 46, March 19 

 to April 2; cruise no. 48, April 24 to May 8; and 

 cruise no. 50, May 25 to June 3. The cruises 

 were planned so the area of investigation would 

 be covered twice in approximately 14 days to 

 make possible the observation of any rapid 

 changes that might affect the eggs and larvae. 



The procedure involved continuous towing of 

 Hardy Plankton Recorders (Hardy, 1936 and 

 1939), bathythermograph lowerings, surface 

 temperature and salinity observations, drift- 

 bottle releases, and surface tows with a 1 -meter 

 net. 



Cruise Plan 



With the ship stopped, the number of the gauze 

 division at the bottom of the tunnel was noted 

 and the recorders lowered to the proper marks 

 on the towing cables. A Loran fix was taken, 

 and the ship was brought promptly to 10 knots 

 (normal towing speed). Every hour a bathy- 

 thermograph lowering was made and a surface 

 temperature was taken by bucket thermometer. 

 When time permitted, a water sample was taken 

 for a salinity determination, concurrent with the 

 surface-temperature observation. Drift bottles 

 were released every 3 hours or approximately 

 30 miles apart. Twelve bottles were released 

 at each station; 6 were ballasted with sand to 

 float vertically with the necks just breaking 

 the surface, thus minimizing the wind effect. 



