Oil Vulnerability Index for Marine Oriented Birds 



by 



James G. King 



U.S. Fish and Wildlife Service 



P. O. Box 1287 

 Juneau, Alaska 99802 



and 

 Gerald A. Sanger 



U.S. Fish and Wildlife Service 

 Anchorage, Alaska 



Abstract 



The 176 species of birds using marine habitats of the Northeast Pacific are 

 graded on the basis of 20 factors that affect their survival. A score of 0, 1, 3, or 5, 

 respectively, representing no, low, medium, or high significance is assigned for 

 each factor. The total score is the Oil Vulnerability Index (OVI). The OVI's range 

 from 1 to 100, an index of 100 indicating the greatest vulnerability. Using this 

 system, one can rank the avifauna of different areas according to their vulner- 

 ability to environmental hazards as an aid in making management decisions. 



Today's decision makers require an ever-in- 

 creasing array of information and planning 

 documents. The Federal Government's re- 

 quirement for environmental impact state- 

 ments under the National Environmental Pro- 

 tection Act of 1969 is but one example of this 

 trend. These documents generally consider 

 the effects of proposed actions on waterfowl 

 and a few other species of birds, but the bulk 

 of the avifauna is usually only listed, or some- 

 times ignored completely. A simple system 

 for evaluating and presenting avian data is 

 badly needed so that those interested in birds, 

 whether technically trained or not, can easily 

 grasp the implications of proposed actions. It 

 is incumbent on biologists to devise new ways 

 of presenting their knowledge so that it can be 

 easily and effectively used by decision 

 makers, who are often less informed. In short, 

 biologists must do for the environmental im- 

 pact statement assessors what Roger Tory 

 Peterson did for the bird watchers by giving 

 them a simple and comprehensible system. 



The need for a system to evaluate relative 

 vulnerabilities of bird populations is particu- 

 larly great for birds that are being increas- 

 ingly affected by marine oil pollution. The sys- 

 tem needs to allow comparisons of potential 

 impacts to birds resulting from various oil de- 

 velopment projects in different locations and 

 served by various modes of transport. The Oil 

 Vulnerability Index (OVI) is our attempt to 

 fulfill this informational need on the avifauna 

 of the Northeast Pacific. Insofar as we know, 

 this approach to assessing a wildlife manage- 

 ment problem has been attempted only for 

 ranking endangered species in a numeric rank- 

 ing system that identified where restoration 

 efforts could best be directed (Sparrowe and 

 Wight 1975). 



We are indebted to Gene Ruhr and Keith 

 Schreiner for ideas generated in their work 

 with endangered species. Frank Pitelka, 

 James Bartonek, Kent Wohl, and Mary Lou 

 King reviewed portions of the manuscript and 

 offered helpful suggestions. Jack Hodges 

 helped prepare the OVI tables. 



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