776 



Abstract.-The bluefish, Pomatomus 

 saltatrix, has long been considered a 

 key predator on U.S. east coast fish 

 species. Many of its prey species are 

 also landed by humans, but no compari- 

 son of prey biomass harvested by blue- 

 fish versus fishermen has been at- 

 tempted previously. We used data on 

 growth, mortality, gross growth effi- 

 ciency, and abundance to model the to- 

 tal prey consumption rate by bluefish 

 at-the population level. This estimate 

 and previously published information 

 on diet were used to calculate the bio- 

 mass of individual resource species 

 "harvested" by bluefish. The prey bio- 

 mass consumed by bluefish annually 

 along the U.S. Atlantic coast is equal 

 to eight times the biomass of the blue- 

 fish population. Bluefish consume a 

 much higher biomass of squid and but- 

 terfish than is currently harvested by 

 commercial fisheries for these species. 

 Bluefish consumption of Atlantic men- 

 haden, however, was below the current 

 fisheries landings for this species. For 

 resource species that are shared with 

 bluefish, our findings highlight the 

 need for multi-species assessment and 

 management. 



Mutual prey of fish and humans: 

 a comparison of biomass consumed by 

 bluefish, Pomatomus saltatrix, with 

 that harvested by fisheries* 



Jeffrey A. Buckel 



Marine Sciences Research Center 



State University of New York 



Stony Brook, New York 11794-5000 



Present address: James J. Howard Marine Sciences Laboratory 



National Marine Fisheries Service, NOAA 



74 Magruder Road 



Highlands, New Jersey 07732 

 E-mail address jbuckelgsh nmfsgov 



Michael J. Fogarty 



Northeast Fisheries Science Center 

 National Marine Fishenes Service. NOAA 

 Woods Hole, Massachusetts 02543 



David O. Conover 



Marine Sciences Research Center 

 State University of New York 

 Stony Brook, New York 11794-5000 



Manuscript accepted 11 January 1999. 

 Fish. Bull. 97:776-785 (1999). 



The bluefish, Pomatomus saltatrix, 

 has long been regarded as one of the 

 most voracious piscivores of the 

 western North Atlantic. In 1873 the 

 U.S. Commissioner of Fisheries, S. 

 F. Baird, stated in a report to con- 

 gress that: "... I am quite inclined 

 to assign to the bluefish the very 

 first position among the most inju- 

 rious influences that have affected 

 the supply of fishes ... a daily loss 

 of 25 hundred million pounds . . . 

 their trail is marked by fragments 

 of fish and the stain of blood . . ." 

 (Baird, 1873). Baird was concerned 

 with the possibility that the high 

 abundance of bluefish during that 

 period was the cause of concomitant 

 declines in fish landings. 



Bluefish abundance along the 

 U.S. Atlantic coast has been known 

 to fluctuate dramatically over the 

 past two centuries (Bigelow and 

 Schroeder, 1953). The impact of 

 variations in bluefish abundance on 



their principal prey as well as on the 

 community structure of the conti- 

 nental shelf as a whole may be sub- 

 stantial (Clepper, 1979; Kerfoot and 

 Sih, 1987). If the major prey of blue- 

 fish are also harvested by humans, 

 then the potential fishery landings 

 of such species may be influenced 

 strongly by bluefish abundance. 

 Moreover, species management 

 through adjustment of the fishing 

 effort will likely be ineffective if the 

 amount of prey consumed by a key 

 natural predator is substantially 

 larger than the landings and ig- 

 nored as a variable component of 

 natural mortality. 



In this study, we estimate the to- 

 tal prey biomass consumed annu- 

 ally by a given biomass of bluefish 

 using a model developed by Pauly 



' Contribution 1136 of the Marine Sciences 

 Research Center, State University of New- 

 York, Stony Brook, New York 11794. 



