A SYNOPSIS OF THE TUNA AND BILLFISH STATUS OF STOCKS REPORTS 



The current evaluation of the status of tuna stocks and tuna fisheries 

 is based on a large number of foreign and domestic data sources, and 

 analyses performed by NMFS scientists or by international or foreign 

 fishery agencies. Many of the evaluations presented here are the results 

 of international fishery workshops in which NMFS/SWFC scientists 

 participated. Expert judgement is required in choosing the analytical 

 techniques to be applied and in interpreting the results; therefore, care 

 has been taken in setting forth the results of each analysis in order to 

 indicate its reliability and to point out where weaknesses in the data or 

 techniques may exist. This is especially indicated in light of possible 

 discrepancies in the data or inconsistencies in the outcome or conclusions 

 of similar analyses. 



The papers presented herein summarize the available information and 

 conclusions to be drawn for some 25 species or stocks of the world's tuna 

 and bill fish. In several cases it is not known whether a species is 

 represented by a single breeding population or by two or more separately 

 breeding stocks. Whenever prevailing opinion or overwhelming evidence is 

 present to strongly suggest the presence of separate stocks, we have 

 separated the analyses and results accordingly and presented these in 

 separate papers, e.g., south and north Atlantic albacore. However, in some 

 cases where there is some evidence to suggest that two or more stocks of 

 the same species may be present, or where it is of interest to investigate 

 the hypotheses of separate stocks, we have performed the analyses under 

 both the single and multiple stock hypotheses (if sufficient data exist) 

 and have presented the results in a single paper, e.g.. Pacific swordfish 

 or Atlantic skipjack. 



A summary of the reasonable conclusions to be drawn from the current 

 status of stocks is given in Table 1. Each species or stock is evaluated 

 in terms of whether or not catches could be increased by (1) simply 

 increasing the effort expended, or (2) instituting certain management 

 measures. These overly simplified categories are modified somewhat by the 

 information presented in the matrix. (NOTE: The reader should be 

 cautioned that, in order to give a quick overview, most of the qualifying 

 remarks about the reliability of these conclusions have been stripped from 

 the original text as it was lifted from the detailed status of stock papers 

 and placed in the table.) 



The question arises as to why the SWFC performs tuna stock assessments 

 and fishery evaluations when the U.S. fishery seems to be relatively 

 healthy economically and opportunities for tuna fishery development are 

 fairly well identified. Often a remark about the difficulty and 

 uncertainty of success of international negotiations accompanies the 

 question. 



The answer to why this work is required lies in the analysis and 

 comparison of (1) the tuna fisheries' value to the United States, (2) the 



