| Mode | Description |
| Vocalization | Bellowing or trumpeting noise produced by a whale and heard above and below the water. Emanates from the blowhole at the time of the expiration. |
| Bubbling | Premature or underwater release of breath in a straight line or as a single "belch" allowing the whale to avoid having a [visible] blow. Bubbles released usually 2-3 m below the water's surface. |
| Finning | Flipper slapping; the striking of the water's surface with the pectoral fins. |
| Tail Lobbing | Raising the flukes well out of the water and crashing or slapping them back flat against the water's surface producing a loud sound. |
| Tail Rake | A subset of the tail lobbing is the rake in which the flukes are raked laterally across the water's surface. |
| Half or Full Bodied Breach | A leap from the water in which a portion of the whale's body emerges from the water only to reenter with a large splash. |
| Avoidance | The temporary leaving of an area or a change in the direction of travel. |
| Abandonment | Leaving an area prematurely and not being seen again for at least one season in that area. |
TABLE 5. Juraszs' vessel/aircraft classes (after Jurasz and Jurasz, 1979)
| Class 1 | Touring Vessel Over 10k Tons |
| Class 2 | Touring Vessel 5k-10k tons |
| Class 3 | Commercial Fishing/Crabbing |
| Class 4 | Charter & Pleasure |
| Class 5 | Cabined High RPM Outdrive Units |
| Class 6 | Sailboat Using Aux. Power |
| Class 7 | Utility Craft, Outboard Engine |
| Class 8 | Kayak, Sailboat (no engines) |
| Class 9 | Aircraft, Fixed |
| Class 10 | Aircraft, Rotor |
| Class 11 | Aircraft, Jet |
| Class 12 | Hydrofoil |
| Class 13 | Another Humpback |
| Class 14 | Killer whales |
| Class 15 | Minke Whales |
| Class 16 | R/V GINJUR (Juraszs' research vessel) |
| Class 17 | Wake Only |
The increase in visitors and vessels to Glacier Bay is presented in [Tables 6-8]. (Data included in Table 6 cannot be compared to data presented in [Table 7] because of difference in methods of data collection, sample area, time, effort, etc.)
Commercial fishing vessel activity in the Bay was probably low until the 1970's. Since 1972 (it is not known whether data are available prior to 1972) commercial fishing vessel visits have fluctuated ([Figure 4]), but fishing activity has been greatest during the summer months ([Figure 5]). Sport fishing visits have increased during the same time period ([Figure 6]).
[4] This summary is based on information presented at the meeting by Mr. John Chapman and Charles and Virginia Jurasz.
POSSIBLE CAUSE-EFFECT RELATIONSHIPS BETWEEN HUMAN USE OF GLACIER BAY AND THE DISPLACEMENT OF HUMPBACK WHALES FROM THE BAY[5]
The meeting participants agreed that the observed decrease in the number of whales in Lynn Canal in 1974 and Glacier Bay in 1978 may be attributable to a number or combination of factors. Available evidence suggests human activity was at least one of the causes, or served to trigger otherwise "natural events". In Lynn Canal, humpback whales were known to feed on herring (Clupea harengus pallasi). In 1974, the year a herring fishery began, the number of humpback whales dropped to one ([Table 1]). Between 1974 and 1978 fishing continued. There was no fishing in 1979.