BACKGROUND
Distribution and Abundance of Humpback Whales in the North Pacific[1]
Humpback whales are seasonal migrants found in all of the world's oceans. In the North Pacific, humpback whales winter in tropical regions over the shallow coastal shelfs associated with the Hawaiian Islands, Baja California, central Mexico, the Ryukyu Islands, Bonin Islands, and Mariana Islands. They summer in cold temperate regions, also over shallow coastal shelfs, from Point Conception, California, north through Alaska, west through the Aleutians, and south to Honshu Island, Japan. Calving and probably breeding occur on the wintering grounds. Feeding is believed to occur primarily in the summering grounds.
In Alaska, humpback whales are known to inhabit Prince William Sound, the waters of the Alexander Archipelago, and the waters adjacent to Kodiak Island and the Aleutians. Some whales may also overwinter in the northern summering areas.
The distribution, movements, abundance, and habitat requirements of humpback whales are not well known. Based upon Japanese catch statistics, the pre-exploitation population of humpback whales in the North Pacific is estimated to have been approximately 15,000. Much of the exploitation of humpback whales occurred in the twentieth century, especially during the early 1960's. A small number of whaling stations established in southeast Alaska took humpbacks between 1907 and 1922. In 1966, the International Whaling Commission imposed a worldwide ban on the taking of humpback whales.
The present population of humpback whales in the North Pacific is estimated to be about 1,000 animals. The number occurring in tropical waters during the winter is thought to be about 600-700 in Hawaii, 200-300 in Mexican waters, and a "few whales" in the western North Pacific. More than 100 individual whales have been identified in the inland waters of southeast Alaska during the summer. Tagging experiments with Discovery Marks indicate movement between the Aleutian Islands and the Western North Pacific; recent photo-identification studies have shown movement from Southeast Alaska to both the Hawaiian Islands and Baja (and southern coastal) Mexico. There is no substantive evidence to indicate whether the number of humpback whales, on either summer or winter grounds, in the North Pacific is increasing or decreasing.
[1] This summary is based on information provided at the meeting by Drs. Michael Tillman and Louis Herman.
FIGURE 1. Map showing location of Glacier Bay, Lynn Canal and Fredrick Hole in Southeast Alaska Alexander Archipelago (from Jurasz and Jurasz, 1979)
FIGURE 2. Soundings in Fathoms (NOS Chart 17300)
FIGURE 3. GLACIER BAY, ALASKA SHOWING FORMER POSITIONS OF TERMINI 1760-1966
(from Hale and Wright, 1979)
Glacier Bay[2]
Glacier Bay is located near the north end of the Alexander Archipelago ([Figures 1 and 2]). The Bay opens into Cross Sound and Icy Strait of the Inside Passage of southeast Alaska. When Vancouver discovered the area in 1780, glacial ice filled the Bay to its mouth ([Figure 3]). In 1891, when the Bay was first mapped, Muir Inlet was still filled with ice. Today the ice has retreated up the right (Muir Inlet) arm of the "Y" shaped Bay to tide-water levels. Recently, glacial ice has started to readvance in the upper reaches of the west inlets of the Bay.
The Bay is defined by shallow sills at its entrance and the entrance to Muir Inlet. Constricted channels in which tidal currents are locally strong occur between sediment covered shores in the lower end of the Bay and the east (Muir) inlet. Deep, unconstricted bedrock channels and basins with weak currents occur in mid-Bay and the west inlet. These features and the configuration of the bay produce a tidal range of 8 meters. There is reduced mixing of waters within the Bay and between the Bay and Cross Sound/Icy Strait. Annual precipitation up to 4 meters, coupled with glacial melt water, create a surface layer and flow of cold fresh water out of the Bay. Strong flood tides push sea water into the Bay over the sills. The dynamics of the flow may effect the behavior and timing of the movement of whales into (on flood tides) and out of (on ebb tides) the Bay (see below).
During the winter, an increase in sea water flow and mixing occur. Increased nutrient levels and sunlight in spring/summer provide sufficient nutrients and energy for phytoplankton "blooms" to occur. In turn, zooplankters appear, especially in the open areas of mid and lower Bay (e.g., euphausiids) and along glacial ice faces (e.g., mysids and amphipods). By autumn, plankton concentrations diminish as light and nutrient levels decrease. Small schooling fish, (e.g., capelin, Mallotus villosus and Pacific sand lance, Ammodytes hexapterus), feed on the plankton when it becomes available. Both fish and plankton are consumed by humpback whales as well as by other predators. Other marine mammal species reported in the Bay are harbor seals (Phoca vitulina), harbor porpoise (Phocoena phocoena), killer whales (Orcinus orca), and minke whales (Balaenoptera acutorostrata).
[2] This summary is based on information provided at the meeting by Mr. Gregory Streveler.
Humpback Whales in Glacier Bay[3]
The distribution in and use of Glacier Bay by humpback whales was not well known until Charles and Virginia Jurasz began observations in 1973. Prior to this, only personal recollections of Park Service employees of the occurrence of humpback whales in the 1950's and the 1960's exist. In 1967, 60 identifiable humpback whales were observed in three southeast Alaskan areas, i.e., Lynn Canal, Frederick Sound, and Glacier Bay. The number of identifiable whales remained relatively constant until 1974 in Lynn Canal, and 1978 (July 17) in Glacier Bay ([Tables 1-3]). In the respective areas, the number of identified whales decreased from 15 and 19 to 1 and 3, respectively. Concurrently, the number of identified whales sighted in Frederick Sound increased.
TABLE 1. Relative abundance and distribution of identified humpback whales in southeast Alaskan waters 1967-79[a]
| Year | 67 | 68 | 69 | 70 | 71 | 72 | 73 | 74 | 75 | 76 | 77 | 78 | 79 |
| Glacier Bay | 20 | 20 | 20 | 20 | 20 | 20 | 25 | 25 | 25 | 25 | 25 | 19/3[] | 3 |
| Lynn Canal | 15 | 15 | 15 | 15 | 15 | 15 | 15 | 1 | 3 | 3 | 3 | 1/5 | 5 |
| Frederick Sound | 25 | 25 | 25 | 25 | 25 | 25 | 25 | 35 | 40 | 40 | 40 | 40/50 | 80 |
| Total | 60 | 60 | 60 | 60 | 60 | 60 | 65 | 61 | 68 | 68 | 68 | 60/58 | 88 |
[a] Specific dates of censuses, sighting techniques and sighting effort not given. Based on a table presented by the Juraszs at the meeting.
[] First number signifies number originally counted at beginning of season/second number after decrease in number of whales in Glacier Bay and increase in other areas. The identified whales that left Glacier Bay are not necessarily the same individuals that produced the increased numbers in Lynn Canal and Frederick Sound later.
TABLE 2. Number of humpback whales (individual census) entering Glacier Bay during "influxes". (modified from Jurasz and Jurasz, 1979)
| Year | 1976 | 1977 | 1978 |
| First Influx | 9 | 7 | 7 |
| Second Influx | 11 | 17 | 16 |
| Seasonal Maximum | 20 | 24 | 23 |
TABLE 3. Age composition of humpback whales per year in Glacier Bay (modified from Jurasz and Jurasz, 1979)
| YEAR | 1976 | 1977 | 1978 |
| NO. OF CALVES | 1 | 2 | 4 |
| NO. OF IDENTIFIED ADULTS | 14 | 14 | 18 |
| NO. OF JUVENILES | 6 | 1 | |
| TOTAL NO. OF ADULTS | 19 | 19 | 18 |
Identifiable humpback whales were sighted in Glacier Bay each year, 1976-1977, for a six to twelve week period. In 1978, all but three whales departed the Bay after 16 days. In the summers of 1976-1978 two influxes of whales occurred ([Table 2]). The Juraszs' define an influx of whales as those whales that enter and remain in the Bay for a minimum of three weeks. The second influx arrived 7-14 days after extreme low tides occurred in late June-early July and presumably moved into the Bay on flood tides. In 1979, a single influx comprised of 3 whales entered the Bay. The age composition of identified whales using Glacier Bay was categorized by the Juraszs' for 1976-1978 ([Table 3]).
During the period spent in the Bay, humpback whales have been observed to feed on capelin, euphausiids (Euphausia pacifica), and pandalid shrimp (Pandulus borealis). There appear to be three generalized feeding relationships: 1) early-season feeding on shrimp in the upper Bay; 2) mid-season feeding by concentrations of whales on capelin in the lower Bay; and 3) late-season feeding (around August 5) by concentrations of whales on euphausiids in mid-Bay.
Behaviorally, humpback whales appear to lunge up through concentrated schools of prey during mid-season and use "bubble-netting" as a means of concentrating less dense and/or numerically fewer prey earlier and later in the season. In other areas of southeast Alaska, humpbacks are reported to also feed on herring (Clupea harengus pallasi), shrimp, and possibly other small schooling (swarming) prey. The Juraszs' believe that humpbacks establish feeding territories in the Bay, and have described eight "stress behaviors" associated with violations of those territories ([Table 4]). The data collected by the Juraszs are extensive (including human use of Glacier Bay) but have not yet been completely analyzed.
[3] This summary is based on information provided at the meeting by Charles and Virginia Jurasz.
Human Use of Glacier Bay[4]
John Muir popularized Glacier Bay, leading to tourist activity into the early 1900's, when loose ice resulting from earthquake activity prevented cruise vessels from operating within the Bay. Glacier Bay was designated a National Monument February 26, 1925, the area being added to April 18, 1939.
Vessel and tourist numbers remained low until the late 1960's-early 1970's. Close to 100 percent of the visitors to the Bay use vessels, either entering the Bay aboard them or making use of them to tour the Bay after arriving by aircraft. The Juraszs' developed a classification scheme for vessels and aircraft based upon activities of the craft in the Bay, their size, hull design, and engine characteristics ([Table 5]).
TABLE 4. Juraszs' description of "stress behavior" (Progressing from the least "stressful" to the most "stressful") (modified from Jurasz and Jurasz, 1979.)
| 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.
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 | ||||||
TABLE 8. Average vessel sightings per day in each class as seen from the Juraszs' R/V GINJUR. (Modified from Jurasz and Jurasz, 1979)
| Vessel Class | 1977 | 1978 | Percent Decrease | Percent Increase |
| 1 | 3.90 | 3.20 | 18% | |
| 3 | 5.74 | 13.47 | 135% | |
| 4 | 8.38 | 16.87 | 101% | |
| 5 | 6.93 | 8.19 | 18% | |
| 6 | 1.11 | 3.99 | 259% | |
| 7 | 1.21 | 1.38 | 14% | |
| 8 | 1.24 | 1.18 | 5% | |
Figure 4. COMMERCIAL FISHING VESSEL VISITS TO GLACIER BAY (from Hale and Wright, 1979)
Figure 5. COMMERCIAL FISHING ACTIVITY GLACIER BAY (from Hale and Wright, 1979)
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FIGURE 6. FISHING CHARTER BOATS AND PRIVATE BOAT VISITS TO GLACIER BAY 1970-1977 (from Hale and Wright, 1979)
Natural changes in the environment and/or in the behavior of whales have occurred concurrently with increased human/vessel activity in Glacier Bay. Such natural changes include spatial and temporal trends or cycles in the physical (temperature, tides, currents, turbidity, etc.), chemical (salinity, dissolved gases, inorganic/organic substances—nutrients, etc.) or biological (primary productivity, zooplankton, nekton, benthic species, predators, etc.) properties or characteristics of the waters within and outside the Bay. Temporal and/or spatial differences in relative abundance of three different prey species within and outside the Bay may have occurred and been responsible, at least in part, for the movement of humpbacks from Glacier Bay. At this time, data are inadequate to relate the movement of humpback whales from Glacier Bay in 1978 and 1979 to physical, chemical, or biological factors. Meeting participants felt that physical and chemical factors were unlikely to have changed sufficiently between 1976 and 1978 to affect humpback whales, while biological factors, perhaps as a result of physio-chemical changes, could have changed sufficiently to have caused or contributed to the movement.
Human activity may have caused changes in the physical, chemical, or biological environment, effecting humpbacks directly or indirectly. Human and vessel activities may have occurred such that the space (vertical and/or horizontal) available to whales for normal activities was less than that necessary (below some threshold level or value). "Too many" vessels may have transited an area and/or approached whales "too closely" for "too long" a period of time, producing visual, acoustic, tactile, chemical, or other as yet unknown stimuli at levels or values (magnitude, intensity, duration, frequency, interval, etc.) greater than the whales would tolerate. The physical-acoustic environment may have changed as a result of sounds produced by vessels. Vessel sounds may be modified, amplified, intensified, etc., as a result of the geological/topographical features of Glacier Bay (and perhaps Lynn Canal as well). Direct interference with the whales' own sounds may have occurred or "environmental" sound levels may have exceeded certain thresholds. Basic data on the acoustic properties and characteristics of Glacier Bay with and in the absence of vessels are lacking.
Changes in water quality may have occurred through pollution. Data are insufficient to document the past or present levels of pollution, but they were thought by meeting participants to be relatively low.
Changes in the biological environment induced by human activity may be contributory to the movement of whales. Movement from Lynn Canal may have resulted from direct competition for the same resource at the same time, by depletion of the resource below levels sufficient to support humpbacks or as a result of noise or the presence of fishing vessels. Fishing activity or overharvesting (depletion of resource) of other species at other trophic levels may indirectly impact humpbacks through the food web/chains. There are insufficient data to prove or disprove such hypotheses at this time.
In summary, a best interpretation of the available data is that uncontrolled increase of vessel traffic, particularly of erratic charter/pleasure craft, may have adversely altered the behavior of humpback whales in Glacier Bay and thus may be implicated in their departure from the Bay the past two years. The causal mechanism of this adverse reaction to increased vessel traffic remains unknown. The effects of increasing vessel traffic apparently are exacerbated by the narrow physical confines of Glacier Bay. This analysis is not clear-cut, however, and may be confounded, at least in 1979, by possible shifts in the occurrence and availability of preferred prey species of humpback whales.
[5] This summary is based on information presented at the meeting and resulting discussions.
ADEQUACY OF EXISTING DATA
In the Background and Possible Cause and Effect sections it was stated that insufficient data exist to indicate cause and effect relationships. Data are not sufficient in many areas, e.g.:
| 1) | environmental baseline data (biological, chemical, and physical) are inadequate; | |
| 2) | data available (i.e., Juraszs') have not been analyzed fully; | |
| 3) | changes in human use of areas are not adequately quantified (e.g., for fishing, cruising, touring, pleasure boating); and | |
| 4) | data on the acoustic characteristics of Glacier Bay or the vessels occurring in the Bay are not available. |
MANAGEMENT AND RESEARCH ACTIVITIES TAKEN OR UNDER CONSIDERATION[6]
The National Park Service (NPS) is responsible for managing and overseeing the use of Glacier Bay National Monument in support of the objectives defined for the Service, when it was established in 1916; an excerpt from the Act creating the Service in 1916 states that the purpose of the Service is:
"To conserve the scenery and the natural and historic objects and the wildlife therein and to provide for the enjoyment of the same in such manner and by such means as will leave them unimpaired for the enjoyment of future generations."
The intent in establishing the Monument is defined in the Proclamations of 1925 and 1939, sections of which are excerpted and presented below.
"Whereas, there are around Glacier Bay ... a number of tide-water glaciers of the first rank in a magnificent setting of lofty peaks, and more accessible to ordinary travel than any similar regions of Alaska,
"And, Whereas, the region is said by the Ecological Society of America to contain a great variety of forest covering consisting of mature areas, bodies of youthful trees which have become established since the retreat of the ice which should be preserved in absolutely natural condition, and great stretches now bare that will become forested in the course of the next century,
"And, Whereas, this area presents a unique opportunity for the scientific study of glacial behavior and of resulting movements and development of flora and fauna and of certain valuable relics of ancient interglacial forests." (Proclamation establishing Glacier Bay National Monument, February 26, 1925.)
"Whereas, it appears that certain public lands, part of which are within the Tongass National Forest ... have situated thereon glaciers and geologic features of scientific interest; and
"Whereas, a portion of the aforesaid public lands ... are necessary for the proper care, management, and protection of the objects of scientific interest situated on the lands...." (Proclamation of April 18, 1939, adding lands to the Monument.)
The management plans developed by the National Park Service for the Glacier Bay National Monument did not anticipate, and apparently have not been adequate to deal with, the increased visitor and vessel traffic and their use of the marine environment in the 1970's. Title 36 of the Code of Federal Regulations, under which the National Park Service operates, contains a section requiring any commercial business conducted or operating within the boundaries of Service area to have a permit issued by the Service. The cruise ship industry companies have not as yet been placed under a permit system. However, it is the intent of the Service to establish a regular system in the future. All other commercial ventures operating on lands and waters of the Monument are under contract or permit. Fishing vessel activity is unregulated although the take of Pacific halibut, (Hippoglossus stenolepis) is regulated by the International Pacific Halibut Commission, and the take of salmon and other finfish and shellfish is regulated by the Alaska Department of Fish and Game (ADFG). The need for additional resource/use plans and regulatory programs is recognized by the National Park Service.
The NPS funded field studies of humpback whales by the Juraszs in 1976-1979, analysis of some of the Juraszs' data, and Hale's and Rice's (of the NPS Alaska area office) report, "The Glacier Bay Marine Ecosystem—A Conceptual, Ecological Model" completed in April 1979.
The movement of humpback whales in 1978 from Glacier Bay to surrounding waters and the suggestion by the Juraszs' field observations, that there may be a cause and effect relationship between vessel activity and the whales' movement, led the NPS to restrict some vessel activities in the 1979 season, and to seek Endangered Species Act Section 7 consultations with the National Marine Fisheries Service in August 1979. The Section 7 consultations were not completed at the beginning of the meeting. Based in part upon NMFS's recommendations, the NPS will consider various future management alternatives. Restrictions imposed in 1979 were temporary (emergency closure authority under Title 36 C.F.R.). Any regulations imposed for 1980 cannot be under emergency closure authority (unless an emergency does arise which was unforeseen in setting up regulatory systems). Regulations which can be foreseen at this time as being necessary would have to proceed through the normal Federal Register publication process. Enforcement of all Federal laws and regulations within Glacier Bay is considered to be the responsibility of the NPS.
The National Marine Fisheries Service (NMFS) has overall responsibility, under the Marine Mammal Protection Act of 1972, for the conservation and protection of all whales including humpback whales. The National Marine Fisheries Service in cooperation with the Juraszs has conducted censuses of humpback whales in southeast Alaskan waters in 1975 and 1976, used radio tags to follow individual whales in Alaskan waters in 1976-78, maintains a catalogue of humpback whale photographs and has developed a computerized retrieval photo-identification system. No research was conducted by NMFS in 1979. NMFS enforcement of laws and regulations is conducted by a few people responsible for large areas in southeast Alaska. A contract with the State of Alaska until August 1, 1979, provided a broader presence of enforcement personnel. That contract was not renewed. The NMFS is now fully responsible for enforcement activities relating to humpback whales except in areas such as Glacier Bay where the responsibility is shared.
[6] This summary is based on information presented at the meeting by National Park Service and National Marine Fisheries Service Personnel.
ALTERNATIVE MANAGEMENT ACTIONS
Based on available information, vessel activity may have been a factor contributing to the movement of whales from Glacier Bay in 1978 and 1979. Alternatives available to manage vessel traffic (assuming increased traffic has had or will have an adverse effect on humpback whales) include:
1. Total closure of Glacier Bay to all vessels.
2. Closure to all vessels during the whale season.
3. Closure to all vessels during part of the whale season.
4. Total closure to all but certain classes of vessels—e.g.,
cruise vessels
charter vessels
fishing vessels
5. Seasonal closure to all but certain classes of vessels—e.g.,
cruise vessels
charter vessels
fishing vessels
6. Partial season closure to all but certain classes of vessels—e.g.
cruise vessels
charter vessels
fishing vessels
7. Alternatives 4, 5, or 6 with limitations on total numbers of vessels of various classes given access
8. Alternatives 4, 5, 6 or 7 with restrictions applying only to certain areas of the Bay
9. Establishment of a ceiling for all vessels or certain classes of vessels during all or part of the whale season
10. No restrictions on access but certain activities prohibited or limited to certain areas or vessel classes—e.g.: establish traffic lanes and permit "deliberate" whale-watching only by a few trained and licensed charter-boat operators.
11. No restrictions.