CHAPTER VIII 



ENTANGLEMENT IN MARINE DEBRIS 



The tendency of marine mammals and other marine species 

 to become entangled in net fragments, packing bands, and 

 other synthetic materials lost and discarded at sea has been 

 recognized for many years. More recently, problems caused by 

 the ingestion of plastic bags and plastic objects also have 

 become apparent. Plastic debris represents a worldwide 

 pollution problem affecting sea birds, turtles, fish, and 

 invertebrates, as well as marine mammals. The problem 

 appears particularly acute in the North Pacific Ocean where 

 debris-related injuries and mortality may be contributing to 

 declines in populations of North Pacific fur seals, Hawaiian 

 monk seals, Steller sea lions, harbor seals, and a number of 

 other marine species. 



Since the early 1980s, the Marine Mammal Commission has 

 played a major role in focusing domestic and international 

 efforts to assess the extent and impact of entanglement on 

 marine mammals and to identify ways to reduce or eliminate 

 the problem. The Commission's past efforts, discussed in 

 previous Annual Reports, are summarized briefly below. 

 Activities of the Commission and others in 1986 are described 

 in greater detail. 



Background 



The Nature of the Problem 



Over the past 3 years, the use of plastics and other 

 synthetic materials has developed at a rapid pace. In the 

 U.S., for example, plastic resin production increased more 

 than seven-fold between 1960 and 1985 (from 6.3 billion 

 pounds per year to 47.9 billion pounds per year). As these 

 materials have been developed, applied, and made available to 

 more people, there has been a corresponding increase in the 

 rate and quantity of plastic debris entering the marine 

 environment. Many of these products degrade very slowly. 

 Those that float remain suspended at the sea surface for 

 extended periods of time, and those that sink may remain for 

 decades on the sea floor. 



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