1078 U. S. BUREAU OF FISHERIES 



An important new .series of observations was initiated in 11>29 when 

 blank books were furnished the captains of mackerel vessels in which 

 to record their daily fishing activities and observations on the mack- 

 erel at sea. Of the G<S distributed we have already received 18 com- 

 plete daily records and 22 extending over part of the season. The 

 sj)lendid cooperation of the ves.sel captains in keeping these detailed 

 records under the rigorous conditions at sea has the bureau's fullest 

 appreciation. These logs have been and will continue to be exceed- 

 ingly useful in sujiplementing our data on the occurrence of schools 

 of mackerel observed but not caught, the presence of young mackerel 

 beloA\' commercial sizes, and the shifting of schools from one ground 

 to another. In addition they will be of particular value in estimat- 

 ing fishing intensity, for from them we may secure much needed 

 information on periods of enforced idleness due to stormy weather 

 and other modifications of the activities of the fleet. 



The investigation also included the collection and analysis of sta- 

 tistics with regard to the total nuickerel catch and tlie size of the 

 nuu'kerel fleet, together with other data pertinent to an estimate of 

 the intensity of fishing. These are to be treated more fully in the 

 ivport of the division of fishery industries. 



One of the most obvious i)roblems arising from the phenomenon 

 of age dominance which has been observed in the mackerel fishery 

 is to determine the probable causes for success in some years and 

 failure in many others. To provide information on this })hase of the 

 problem, ocean()grai)hic cruises to the mackerel sj)awning grounds 

 were made during the 1929 season. Four tri])s were nuide from 

 April to July in the waters of the continental shelf between Cape 

 Cod and North Carolina, and additional stations weie occupied at a 

 limited number of locations in the offing of Ca])e Cod and Massa- 

 chusetts Bay. Altogether, 288 stations were occupied during the 

 season. 



The primary' object was to determine the abundance of mackerel 

 eggs spawned in various areas and the relative success of the hatch- 

 ing and survival of larvae. In addition to the townet collections made 

 for this purpose, the usual series of temperatures and salinities at 

 various levels were taken at most of the stations on the April and 

 July cruises. 



Judging from the examination of only part of the material col- 

 lected on these cruises, mackerel eggs were approximately as abund- 

 ant in 1929 as in the two previous years — the only years of which we 

 have any record. An abundance of newly hatched larvse in the hauls 

 of the early June trip indicates a fairly successful hatch; but the 

 scai-city of larger larvae in July would make it ap])ear that the 1929 

 brood was rather less successful in surviving through its early 

 stages than was the 1928 brood, of which some very good catches of 

 large larvae Avere taken at certain .stations ofl' southern New England 

 in July of 1928. 



NEW EX(JLANl) SMELT ^ 



I 



One section of the second report concerning the smelt, by Dr. 

 AVilliam C. Kendall, was completed early in the year. This section 

 comprises a synopsis of the classification of the smelts as ]>resented 

 in the literature and a di.scussion of the relationship of the nominal 

 species so far as indicated by available data. A second section of 



