FIGURE 2-12 Average, annual input (1990-1999) of petroleum hydrocarbons (kilotonnes) for the Canadian Arctic.

Effort to reduce the frequency and size of such spills should continue to be undertaken.

Alaska was divided into two regions, divided by the Aleutian Islands. Inputs to these regions are presented in Table 2-9 and Figure 2-16, showing dramatically different sources and loads for coastal and offshore waters. Surprisingly, aircraft dumping is estimated to be one of the largest sources of oil into offshore areas, and inputs from spills from non-tank vessels are small but one-two orders of magnitude greater than spills from tankers. In coastal waters, seeps in south-central Alaska are responsible for over 40 percent of the calculated inputs³ during the reporting period (1990-1999; Table 2-9).