RESOURCE DEVELOPMENT ALONG COASTS 



189 



dinal and seasonal factors in their effects 

 upon the birds. We consider herein only 

 coastal and ocean floor developments and 

 their anticipated generalized impacts on 

 populations. 



Although this is a discussion of "northern" 

 marine birds, it is important to remember 

 that we are considering a diverse avifauna 

 existing in an environmental gradient from 

 temperate to polar regions. In general, the 

 more southerly portions of this marine envi- 

 ronment are characterized by a greater diver- 

 sity of species, more complex food chains, and 

 a resultant greater stability (Dunbar 1968). 

 Arctic marine ecosystems, on the other hand, 

 are characterized by numerical dominance by 

 a few species, relatively simple food chains, 

 and an inherent instability or fragility (Dun- 

 bar 1968). According to Dunbar, arctic sys- 

 tems are regulated primarily by temporal os- 

 cillations in the physical environment, where- 

 as biological interactions (e.g., competition, 

 predation) are considered more significant in 

 the maintenance of temperate and tropical 

 ecosystems. 



Because of their relative instability, arctic 

 ecosystems are more susceptible to alteration 

 by extreme environmental perturbation, 

 either natural or man-imposed (Burns and 

 Morrow 1973). Slow growth and maturation 

 rates of the avian constituents of these eco- 

 systems and resultant long recovery periods 

 (Ashmole 1971) further aggravate this 

 situation. 



Regardless of their seasonal availability, 

 these arctic waters constitute some of the 

 most productive areas for seabirds in the 

 western hemisphere (Bartonek et al. 1974). 

 Upwelling, nutrient-rich waters, combined 

 with intense and prolonged incident radiation, 

 result in lush phytoplankton "blooms" that 

 form the foundation of relatively simple but 

 numerically strong plant and animal com- 

 munities (Ashmole 1971). A relatively small 

 number of avian species have evolved to take 

 advantage of this seasonally available food 

 supply, and the ability to migrate to lower 

 latitudes in winter is a characteristic of most 

 arctic-nesting species. Because summers are 

 short in arctic regions, early arrival and a syn- 

 chronous breeding schedule are necessary to 

 enable the young to leave the breeding 

 grounds before severe weather conditions pre- 



vail (Ashmole 1971). Arrival of these birds 

 generally coincides closely with the earliest 

 availability of nesting habitat and food (Wil- 

 liamson et al. 1966). Migration, molting, and 

 reproduction place tremendous stresses on 

 these birds, and as a result, arctic-nesting 

 species tend to reproduce less often and at 

 older ages than do those of more temperate re- 

 gions (Ashmole 1971). 



In spite of these adaptations, arctic bird 

 species tread a thin line between extinction 

 and survival, and natural disasters take a 

 heavy toll. Bailey and Davenport (1972) re- 

 ported a massive mortality in a pelagic popu- 

 lation of common murres in Bristol Bay, 

 Alaska, during April 1970. They felt that this 

 disaster, resulting in the death of probably 

 100,000 or more birds, most likely resulted 

 from starvation precipitated by severe 

 weather. Barry (1968) reported a similar loss 

 to starvation of about 100,000 eiders along 

 the Beaufort Sea coast during the extremely 

 cold spring of 1964. Observers along Alaska's 

 Beaufort Sea reported finding eiders and old- 

 squaws dead and dying from the effects of 

 cold weather in 1970 (Bartonek et al. 1971). It 

 is readily apparent that the tenuous existence 

 into which these birds have evolved leaves 

 them particularly vulnerable to the man-in- 

 duced stress of developments during the arc- 

 tic summer. 



Direct Effects of Oil Pollution 



The most obvious, and perhaps the most 

 disastrous consequence of petrochemical de- 

 velopment on northern marine bird popula- 

 tions is that of a major oil spill or a well blow- 

 out into marine waters. Although temperate 

 and tropical waters are apparently able to as- 

 similate oil spills and chronic pollution from 

 petroleum and its products (Nelson-Smith 

 1972), this has not been demonstrated to be 

 true for arctic waters. In fact, studies in the 

 Beaufort Sea have shown that the bacteria 

 that degrade oil do not use hydrocarbons at 

 the ambient temperatures of the Arctic 

 (Glaeser and Vance 1971). Therefore, a large 

 oil spill in the Arctic could persist for many 

 years. As demonstrated by Campbell and 

 Martin (1973), the diffusion and transport 

 mechanisms generated by the pack-ice dy- 

 namics of the Beaufort Sea and the slow rate 



