PROGRESS IN BIOLOGICAL INQUIRIES, 1934 347 



up ro tlu> tMid of I!);?!.', 1.1 iKM-ciMi( ill ID.Ti, and 0.3 percent in 1!t:'>4. Of the total 

 lecaptuifs (24.S pc'rc«>nt). !)() lu'ictnt were taken locail.v and 10 ipcrcent from 

 distant Idcalilii's. Of 1.4S1 cod nmrkt'd (Inrinj; in:J2 with cclhiloid stri)is in- 

 .i;ertcd into the body cavity and relt>asc>d in tlie above mentioned locality, IS.G 

 percent were returned up to the end of ]!t.'j;i and 2.8 percent in 1934. Of the 

 total returns of 21.4 percent. 1)1 pi'rcent were recaptured locally and 9 percent 

 jit distant jxiints. 



Th(>se experiments were undertaken in order to determine whether the young 

 cod tliat predominate in the population along the sliore migrate away from 

 the shore as tliey grow ohler, thus serving to replenish tlie important fishing 

 hanks ofTshore. While these experiments have produced a liigher proportion 

 of distant recaptnres than resulted from earlier experiments with less iterma- 

 nent tags, there does not appear tt> be any decided trend toward offsliore riH-ap- 

 fures as the lish grow older. To he sure, the fish involved in the experiment 

 have not yet reached the age that is most common on the offshore grounds, and 

 the exiK'riment needs to run until they do reach such age before negative 

 results l)ecome significant. However, the sharp reduction in returns threatens 

 to reduce the numbers to the point of unreliability liefore this stage in the ex- 

 periment is reached. It is believed that the sharp decline in returns from the 

 1931 releases is due to loss of the celluloid disks, and from tiie 1932 releases, to 

 the belly tags becoming covered with mesenteric tissue so that they escajie detec- 

 tion, especially on the offshore groimds where the fish are cleaned very hur- 

 rietlly. Thus, it may be necessary to have further improvement in marking 

 methods or to approach this question by another method, perhaps scale studies, 

 in order to solve the problem. 



At present the trawlino; fleet fishes mainly for haddock. Studies 

 of the haddock resource (see above) make it apjDear certain that in- 

 creased fishin<r Avill cause no considerable or sustained increase in the 

 yield. This bein": the case, we can anticipate a more intense fishery 

 for cod. In fact, there appears to be a trend in this direction already, 

 and it is urgent, therefore, that studies of the condition of the cod 

 resource be resumed. The most effective corrective measures are those 

 that are applied before irreparable damage is done. Since the major 

 portion of the fishery is carried on by a fleet of vessels which land their 

 catches mainly at Boston, only a moderate outlay would be necessary 

 to make the pertinent observations on the condition of this fishery 

 along with those now made on haddock. 



FLOUNDERS 



The flounder fishery has assumed major importance during the last 

 two decades. The various species of flounders are caught mainly by the 

 smaller vessels of the otter trawl fleet commonly called " draggers." 

 This type of boat has been increasing in numbers and concern is felt 

 as to the capability of the resource to w^ithstand the present intensity 

 of fishing — so much so that several of the flounder-producing States 

 have passed laws restricting the flounder fishery in various ways. 

 Further restrictions are contemplated in at least one of these States. 

 Although such restrictions are based on good intentions, they have not 

 l)een preceded by any examination into the question of whether they 

 will produce the desired results. No one knows whether the pre.sent 

 sacrifices tliey impose will be compeitsated by future gains. In fact, 

 little is known of the life history of the six species that make uj) the 

 catch. Nothing is known of their rate of growth, the amomit of 

 migration from one region to another, or most important, to wdiat de- 

 gree the annual replacement compensates for removals by the com- 

 mercial fishery and by natural mortality. 



