TROPHIC RELATIONS OF SEABIRDS 



119 



Recommendations for 

 Further Research 



Many people realize intuitively that sea- 

 birds are important members of marine eco- 

 systems. Although the supporting evidence is 

 not now available, it will be needed if seabirds 

 are to be protected. Emotion alone will not 

 justify the protection of seabirds in an age 

 when the human race moves steadily toward 

 global famine. The job at hand is, in part, to 

 sell seabirds, not just to the public, govern- 

 ment officials, executives of oil companies, or 

 fish-packing concerns, but also to marine 

 biologists and oceanographers, for the scien- 

 tists have the best means to study organisms 

 at sea. We must move away from the concept 

 that seabirds are merely yo-yos of various 

 sizes, shapes, and colors on strings of various 

 lengths that venture forth to sea from the 

 land, grab a quick lunch, and then return to 

 the safety of terra firma. Seabirds are marine 

 organisms and deserve at least as much re- 

 search attention as that currently given 

 marine mammals. 



The information now available on seabird 

 diets is largely presented in terms of the num- 

 ber and volume of various prey species taken. 

 Whereas these data provide the relative im- 

 portance of prey, fishery data on prey stocks 

 are usually measured in terms of biomass. 

 Thus, it is difficult to relate seabird data to 

 the immense wealth of information on biologi- 

 cal oceanography. If we are to recognize the 

 importance of seabirds in the nutrient and 

 energy cycling of marine ecosystems, rather 

 than considering them merely as "yo-yo 

 predators," we must relate them to the total 

 marine community. 



The goal of marine ornithologists should be 

 to refine and broaden considerably in detail 

 such studies as those by Sanger (1972), Shun- 

 tov (1974), and Laws (1977), who attempted to 

 assess the relations between seabird popula- 

 tions and stocks of other marine organisms 

 for the northern North Pacific, the world 

 oceans, and the Antarctic, respectively. The 

 trophic roles played by seabirds must be 

 studied in detail at the community level year- 

 round before those analyses can be properly 

 refined. Another exemplary work is that done 

 by Brownell (1974), who studied trophic rela- 



tions of higher vertebrates off Uruguay, in- 

 cluding dolphins, pinnipeds, seabirds, and 

 some large fish. In a review study, Sanger 

 (1974) considered the food-chain relations of 

 similar vertebrates in the Bering Sea. These 

 sorts of studies will serve to bring the role of 

 seabirds into perspective with other upper 

 trophic level feeders. 



Acknowledgments 



We much appreciate the opportunity to par- 

 ticipate in the symposium at which this paper 

 was presented. The encouragement and help 

 given by J. C. Bartonek was indispensable. 

 D. G. Ainley's participation in the sym- 

 posium was supported by the Point Reyes 

 Bird Observatory. This is contribution No. 

 124 of the Point Reyes Bird Observatory. 



References 



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