Use of the Canal by Class 5 vessels (cabin cruisers with high RPM outdrive units) increased by 15-20 percent each year after 1970 (Jurasz and Jurasz, 1979, p. 85). Three humpback whales were seen in Lynn Canal during the 1975-1977 seasons, the number increasing to five in 1978-1979. The relationship between vessel activity, fishing effort, fish take, fish abundance, and the presence and activity of whales in Lynn Canal does not appear to be documented.
In Glacier Bay, increased vessel traffic may be one of the factors responsible for the movement of humpback whales from the Bay in 1978 and 1979. The Juraszs' data, while not evaluated fully, suggest that there has been a general increase in avoidance by humpback whales of Class 1 through 5 vessels over the three year period, 1976-1978.
TABLE 6. Number of visitors and vessels to Glacier Bay National Monument.[a]
| Year | Visitation | Increase | Private Vessels Juraszs' Classes 1-2 | Cruise Ships (incomplete count) Juraszs' Classes 4-8 | |
| 1965 | 1,800 | ||||
| 1969 | 16,000 | 789% over 1965 | 450 | ||
| 1970 | 29,700 | 86% over 1969 | |||
| 1972 | 33 | ||||
| 1978 | 109,500 | 269% over 1970 584% over 1969 | 123 | 1800 | |
| 1979 | 123 | ||||
[a] Based on a table and information provided at the meeting by Mr. John Chapman, National Park Service. (Modified by adding Juraszs' classes of vessels.)
TABLE 7. Number of vessel sightings per month in each class as seen from the Juraszs' R/V GINJUR. (from Jurasz and Jurasz, 1979)
| 1977 | 1978 | ||||||||
| Vessel Class | June | July | August | TOTAL | June | July | August | TOTAL | |
| 1 | 20 | 22 | 11 | 53 | 17 | 25 | 8 | 50 | |
| 3 | 67 | 18 | 6 | 91 | 62 | 31 | 64 | 157 | |
| 4 | 37 | 42 | 30 | 109 | 29 | 125 | 64 | 218 | |
| 5 | 38 | 45 | 17 | 100 | 27 | 61 | 24 | 112 | |
| 6 | 3 | 14 | 0 | 17 | 0 | 29 | 19 | 48 | |
| 7 | 6 | 4 | 6 | 16 | 8 | 4 | 5 | 17 | |
| 8 | 7 | 2 | 7 | 16 | 2 | 12 | 3 | 17 | |
| 12 | 4 | 3 | 7 | ||||||