"Inuit speak with pride about the skills required to get seals on the ice and in the water, skills which include a profound knowledge of ice, sea state, winds, tides and the habits of the animals being hunted." (Williamson 1997a:44)
Marine mammals, particularly seals, are a major food source for residents of northern Labrador and are culturally important to the Inuit. This chapter discusses ringed seals, harp seals, harbour seals, bearded seals and minke whales. Beluga whales are discussed in Chapter 18 (Species of Special Conservation Status).
Many species of marine mammals are attracted to the coast of Labrador each year by concentrations of crustaceans and schooling fish. Most species of seals, whales, porpoises, and dolphins are migratory and spend only the ice-free months in nearshore waters. The most common marine mammals found along the coast of Labrador year-round are harp seals and ringed seals. Harp, bearded, harbour, and ringed seals and minke whale are common during the summer months. Infrequent visitors to the area include the hooded and grey seal, walrus, humpback, killer whale and narwhal, as well as the white-sided and white-beaked dolphin, and the harbour porpoise.
"We always lived off of the land. Our clothing came from the land. Our boots came from the land, from seal skin. We used other animals to make up our clothing also and this all comes from wildlife." (Tabea Murphy (through interpreter), Panel scoping meeting in Nain, April 17, 1997)
Marine mammals provide the people of northern Labrador with food as well as material for clothing and crafts. Harp seals are primarily hunted in late spring and fall (Figures 13.1 and 13.2), while ringed seals are hunted during late winter and spring (Williamson 1997a; Brice-Bennett 1977). Other seal species and walrus are hunted opportunistically throughout the year. Although Aboriginal subsistence harvesting of whales is permitted, there has not been a dedicated hunt for whales since their decline in the 1960s. Seal hunting in the area is no longer a commercial harvest. Since the collapse of the sealskin market in the late 1970s, seal hunting in Northern Labrador has returned to a subsistence harvest (Williamson 1997a).
Ringed Seals
The Latin name for ringed seal is Phoca hispida.
The Inuktitut name for ringed seal is Natsik.
The Innu-Aimun name for ringed seal is pupunatshuk.
In eastern Canada, ringed seals extend from the Arctic Ocean to northern Newfoundland (Lien et al. 1985). The ringed seal, also known as "jar", is the most numerous and widely distributed marine mammal in the Arctic and the most common pinniped in northern Labrador (Stenson 1994). Ringed seals are most abundant in coastal regions, due to their need for stable fast ice (Smith and Hammill 1981). There is some evidence that ringed seals undergo a small migration (300-500 km) northward in the summer (Schwartz 1977; Boles et al. 1980).
Ringed seals along the entire northern coast of Labrador may interbreed. As well, in some years, individuals normally wintering elsewhere on the coast may congregate within the Landscape Region because of better fast ice or feeding conditions. Individuals within the Landscape Region are therefore considered as part of the northern Labrador population of ringed seals.
During the winter, ringed seals travel between breathing holes, made when the ice is thin and maintained by seals throughout the season (Schwartz 1977; Smith and Stirling 1975). Ringed seals are known to concentrate along the edge of the fast ice, where they feed throughout the winter. Seals spend the winter near polynyas (leads of open water) in the Landscape Region (Brice-Bennett 1977). The breeding and moutling season is from March to May. Boles et al. (1980) found that ringed seals haul out in April and are most abundant on fast ice in May, in the Nain area. Once the ice breaks up, ringed seals move into the bays to feed on cod, capelin, sculpins, and crustacea.
The diet of ringed seals includes Arctic cod, Greenland cod, capelin, sculpins, krill, mysids, shrimps, and other crustacea. There are variations by location; for example, the diet of seals in the Baffin Island area consists mainly of one species of amphipod (Dunbar and Moore 1980) and in the Makkovik area, a species of krill (Northland and Associates Ltd. 1977). There is a seasonal cycle of feeding, with the Arctic and Greenland cod being the preferred food in the winter and spring (Northland and Associates Ltd. 1977; Boles et al. 1980). Young-of-the-year ringed seals feed almost exclusively on mysids and euphausiids in late summer (Boles et al. 1980). Little feeding occurs during moulting (Lien et al. 1985).
Harp Seals
The Latin name for harp seal is Phoca groendlandica.
The Inuktitut name for harp seal is kaigulik.
The Innu-Aimun name for harp seal is pitshuatshuk.
Based on whelping locations, harp seals occur in three populations: northwest Atlantic, White Sea, and Greenland Sea (Stenson et al. 1993). The whelping locations of the northwest Atlantic population occurs from Labrador to the Gulf of St. Lawrence. However, harp seals are highly migratory, spending their summers feeding as far north as the Arctic and then returning each spring to whelp off the southeast coast of Labrador and in the Gulf of St. Lawrence.
Harp seals usually reach the Strait of Belle Isle by late November or December. Before whelping in late February to early March, the population divides into two herds; one establishes itself near the Magdalen Islands and the other drifts on pack ice off the southeast coast of Labrador in early March (Lien et al. 1985; Stenson and Kavanagh 1994). Shortly after whelping, mating occurs in mid-to-late March. The moulting period follows in mid-April through mid-May (Stenson and Kavanagh 1994).
Following the one-month moult period, the harp seals disperse and follow the receding pack ice northward to the summer feeding grounds. Harp seals feed along northern Labrador and in the Arctic as far north as Thule in northwest Greenland and west to Hudson Bay (Lien et al. 1985; Stenson and Kavanagh 1994). This northward migration is well underway by July (Stenson and Kavanagh 1994).
Harp seals spend the summer months feeding in coastal waters. Sculpins, Arctic cod, Atlantic cod, and capelin accounted for most of the prey mass consumed by Labrador harp seals (aged one year and older) in the northwest Atlantic (Lawson et al. 1995). Greenland halibut made up most of the prey mass in pup stomachs from Labrador. Capelin, sand lance, and Arctic cod were also contributors to the diet of pups.
Harbour Seals
The Latin name for harbour seal is Phoca vitulina.
The Inuktitut name for harbour seal is Kassigiak.
The Innu-Aimun name for harbour seal is innatshuk kasigiak.
The harbour seal has a widespread distribution, with a number of subspecies worldwide. The eastern North American subspecies occurs from Greenland to the central and eastern Arctic and along the eastern seaboard of Canada (Lien et al. 1985). Harbour seals are seasonally present in most areas of Newfoundland and Labrador, however, the size of the population in the province is not known (Stenson 1994). Harbour seals are nonmigratory and are believed to overwinter in locations where currents maintain open water. Their diet is varied and includes herring, crab, flatfish, cod, and sculpin (Lien et al. 1985).
Harbour seals are known to whelp in rivers and estuaries as well as on offshore rocky islands (Brice-Bennett 1977). The birthing season lasts one to ten days and is reported to occur in June in central Labrador and in April or May in southern Labrador (Boles et al. 1980). Seals become mature at three to six years old and mate during the summer.
Bearded Seals
The Latin name for bearded seal is Erignathus barbatos.
The Inuktitut name for bearded seal is Udjuk.
The Innu-Aimun name for bearded seal is uapistitun.
The bearded seal has a circumpolar distribution. In Canada, this species occurs throughout most of the Arctic, as well as in Hudson Bay, Hudson Strait and Labrador Sea, James Bay, and the Atlantic subarctic (Cleator 1996). Bearded seals are solitary and are considered to be relatively rare on the Labrador coast (Stenson 1994). In many areas, bearded seals are sedentary and make only local movements in response to ice conditions, while in other areas they are migratory and follow the seasonal advance and retreat of ice cover (Cleator 1996). Bearded seals are not common in nearshore central Labrador during the summer; they migrate north in the summer and return in the fall (Schwartz 1977).
Bearded seals occur at relatively low densities near areas of broken-ice and open water in depths of less than 200 m, avoiding thick fast ice. There are indications that the current population of bearded seals in Canadian waters is stable and has been estimated at 190,000 animals (Cleator 1996).
Bearded seals are primarily bottom feeders, using their snouts and flippers to capture benthic fish species like sculpins, flat fish, cod, eelpouts, clams, crabs, and benthic shrimp (McLaren 1958). There are also reports of bearded seals feeding on Arctic cod, sand lance, and smelt (Boles et al. 1980).
Minke Whales
The Latin name for minke whale is Balaenoptera acutorostrata.
The Inuktitut name for minke whale is Pammiuligak.
The most common baleen whale, the minke whale, occurs worldwide. Each summer they undergo extensive migrations from Labrador to winter as far south as the Gulf of Mexico. Minke whales return to the inshore waters of Newfoundland and Labrador in April. Some are known to remain into the winter, as indicated by reports of ice entrapments of minkes (Lien et al. 1985). Minke whales are usually seen individually and close to shore because it is their preferred feeding habitat, but they can form small groups to facilitate feeding. Minke whales have a diet that includes planktonic crustaceans, herring, capelin, mackerel and, occasionally, squid.
Capitalized terms used (such as Landscape Region and VBNC Claim Block) may be defined in other chapters. Some terms and phrases used may have different definitions in other chapters depending upon the context in which they are used; for example, the Assessment Area.
Project shipping activity will take place within ice and open water habitat used by marine mammals. Focused baseline studies were conducted near the shipping route and the inner bays and islands in the vicinity of the Project site. The environmental assessment boundary for marine mammals (Marine Mammal Assessment Area) is the Landscape Region (Figure 13.3). Environmental effects predictions will be made for marine mammals within this Region since the marine mammals breeding population range occurs throughout this Region. The species to be assessed are the ringed seal, harp seal, harbour seal, bearded seal and the minke whale.
Harvesting of marine mammals is controlled by Fisheries and Oceans Canada (DFO) under the Marine Mammals Regulations of the Fisheries Act. The Marine Mammal Assessment Area lies within the Northern Labrador management zone of DFO. No commercial harvesting is permitted for whales within this zone, although Aboriginal subsistence harvesting is permitted. The subsistence harvesting of seals is not included in the quotas established by the Minister for the annual seal hunt and no quota is set for subsistence fisheries of whales or seals.
Several models were used in assessing the effects of this Project on marine mammals and their environment. Although important in identifying the magnitude and extent of an effect, models use assumptions which limit the extent to which their conclusions may be generalized. Where data are lacking, conservative assumptions have been made so that the magnitude, extent, and duration of effects are not underestimated.
Information regarding marine mammals in the Assessment Area is based upon dedicated quantitative boat-based survey transects during July and August 1996, a dedicated aerial survey during September and October 1996, and incidental observations during marine surveys (June-November 1996). An aerial survey of ringed seal abundance and distribution during the spring was conducted during May of 1996 and 1997. Full details on these surveys are provided in JWEL (1997). As well, Aboriginal knowledge from sources such as Williamson (1997a) and Brice-Bennett (1977) was used extensively to identify marine mammal seasonal distribution patterns.
The purpose of the dedicated marine mammal surveys was to estimate the relative abundance of whales and seals within the Assessment Area during the ice free months.
Quantitative marine mammal surveys were conducted by boat and helicopter from July to November, 1996. Boat surveys were concentrated in each of Anaktalak Bay, Kangeklukuluk Bay, Kangeklualuk Bay, and Voisey's Bay, whereas helicopter-based surveys covered each bay as well as areas up to 65 km seaward of the head of Voisey's Bay. In total, there were 38 boat-based and 68 helicopter-based surveys. All mammal observations were grouped into eight transect survey routes, one for each of the four bays, the shipping route, Paul Island, Kikkertavak Island, and one transect for the route around Nukasusutok Island and Kamutiktalik Island (Figure 13.4).
Marine mammal surveys were conducted only on days which were conducive to observation (i.e., visibility greater than 5 km, light winds and waves less than 0.5 m). This effectively eliminated error due to poor weather. Experimental error due to temporal variability was also reduced because helicopter-based surveys would cover up to all eight transects in one day, usually not less than five. Boat-based surveys were conducted simultaneously from three vessels on separate transects.
Spring ringed seal surveys were conducted by helicopter during May of 1996 and 1997 and included the fast ice of Voisey's Bay, Anaktalak Bay, and part of Nain Bay (Strathcona Run to fast ice edge). The area was bounded by Dog Island to the north, Kasungatak Island to the south and the edge of the fast ice to the east (Figure 13.5). Details on survey methodology may be found in (JWEL 1997).
These surveys were designed to estimate the relative number and density of ringed seals when they are most abundant in the Assessment Area. At this time they are out on the ice to whelp and breed.
Throughout the ice-free season (June-November), incidental observations of marine mammals were made by scientific personnel during their respective field programs. Sightings were recorded from helicopter, boats, and also from the ship Sir John Franklin, which was anchored at Edward's Cove during the summer of 1996. Each field program team was provided with a marine mammal guide and log book to assist in mammal identification and to record any observations. Incidental sightings are not used to estimate species relative abundance.
Data collected during oil industry and mining operations in the Arctic, as well as acoustic modelling, have been used to estimate noise levels (Davis and Malme 1997). The attenuation of sound as it travels outward from a source is estimated using the Weston/Smith Model, a semi-empirical transmission loss model that has been used in other studies of shallow water sound transmission. Noise levels at various distances are compared to the hearing capacity of a ringed seal. The potential noise effect on ringed seals along the shipping route was determined using a human hearing sensitivity model and confirmed by observed responses documented in the scientific literature.
Participant in LIA study: "Voisey's Bay is good for ottuks (seals basking on the spring ice)...there are ottuks everywhere in the spring. In the bay there were always basking seals...we knew that the seals were there all winter...mostly jars [ringed seals], sometimes harps, because the harps got caught in the winter and stayed there." (Williamson 1997a: 30)
Ringed seals are hunted year-round within the Assessment Area, but a dedicated hunt for ringed seals occurs during April and May along the fast ice edge (Williamson 1997a) when the seals gather to whelp and breed. Ringed seals have become more abundant in the Nain area since the commercial seal hunt ended in the late 1970s (Williamson 1997a).
In the summer, the majority of the ringed seal population is thought to move northward a few hundred kilometres (Brice-Bennett 1977; Boleset al. 1980). This was indicated by their relatively low densities during the July-October mammal survey (Appendix 13B). Occasionally, young ringed seals are observed within the bays and near the inner islands during the ice free season.
During a dedicated survey in May of 1996, an area of moderate seal densities (3.41/km2) was observed along the edge of the fast ice (Figure 13.6). In 1997, ringed seal densities along the ice edge were lower, ranging from 0.7-2.2 seals/km2. The highest density during both years was observed in the area of Tunungayualok Island, north to Humbys Island, and west to Kiuvik Island. This area of high density is a suspected nursery area for ringed seals. In 1996, ringed seal densities in this area were estimated at 15.9 seals/km2, which is higher than any ringed seal density reported in the scientific literature.
Densities in 1997 were much less, with a range of 4.2-10.4 seals/km2. Patches of ringed seals were also observed farther from the ice edge to the west, off Kiuvik Island and in the approaches to Voisey's Bay itself. Several smaller patches of ringed seals were observed along the proposed shipping route, with mean densities ranging from 1.15-1.89 seals/km2 in 1997 and 1996, respectively. Ringed seal abundance and distribution fluctuate seasonally and annually in response to ice conditions.
In spring, the underside of the fast ice becomes highly productive. As the lower layers of ice melt, detritus and plankton are released into the water, attracting swarms of zooplankton and schools of Arctic cod which, in turn, create an abundant food source for both adult and new-born seals.
These survey results are in general agreement with local knowledge, as compiled by Williamson (1997a). Areas near Iglosiatik Island (House Harbour) and Spracklins Island are favourite ringed seal hunting areas (Williamson 1997a); they are within the area of highest seal densities observed during the 1996 and 1997 ringed seal surveys. Ringed seals were also reported to occur regularly in Voisey's Bay, along the south side of Paul Island, and near Sandy and Skull Islands (Williamson 1997a), which are areas of moderate ringed seal densities (JWEL 1997). An area west of South Aulatsivik Island has also been documented as a core area for ringed seals (Brice-Bennett 1977). These areas are an indicator of productive habitat. Ringed seals in general are opportunistic feeders, concentrating in areas where food is abundant. Although there is no direct evidence from this area, ringed seals are probably feeding on Arctic cod and zooplankton, which are underneath the ice.
Published DFO statistics for the Atlantic region combine catches of seals other than harp seals and hooded seals as ‘others'. In most years, this category consists primarily of ringed seals taken mainly in Labrador. The number of ‘other' seals taken from 1988 to 1992 is shown in Table 13.1. In 1992, 91.8 percent of the catch was reported to be ringed seals, while 5.5 percent and 2.7 percent of the catch consisted of harbour and bearded seals, respectively (Stenson 1994).
Harp seals are the most abundant pinniped species in the northwest Atlantic and were the most common seal observed within the Assessment Area during the ice free season of 1996 (JWEL 1997). The number of adult sightings increased steadily from August to October throughout the assessment area. These individuals are a small portion of the north Atlantic population that whelps off southeastern Labrador which, in 1994, was estimated at 4.3 million seals (Sheldon et al. 1995). In 1994, there were an estimated 446,700 harp seal pups born off southeast Labrador.
Participant in LIA study: "There never used to be any harps up there [Webb's Bay] years ago...now it‘s full of them, great big sculls of them everywhere, gather up in the bay right up in the shoal water, even in the brook, you never used to see that years ago...must of been over 500 in one scull." (Williamson 1997a: 30)
The rate of annual pup production appears to have increased from the early 1980s to the 1990s (Stenson et al. 1995). The effects of a larger population size coinciding with a diminished commercial seal hunt are apparent in the increased number of harp seals throughout the Assessment Area. However, local hunters report that the seals are in a poor condition in recent years. They believe the seals have become thin because there are less capelin and cod available. Furthermore, scarcity of the seals' primary food source has increased pressure on the remaining resources in the area, such as sandlance and molluscs (Williamson 1997a).
During the summer, harp seals can be seen feeding in the bays of the Assessment Area. They are usually seen in groups from 4-5 to several dozen animals. Preferred foods are Arctic and Atlantic cod, sculpin, and capelin. By November, harp seals have begun their migration southward from central and northern Labrador. Traditionally, November has been the time of a dedicated harp seal hunt east of South Aulatsivik and Paul Island (Williamson 1997a). Hunting also occurred in the spring and fall to the east and north of the Okak Islands (Brice-Bennett 1977). However, since the 1950s, harp seals appeared to have altered their migration route and now travel seaward of the outer islands, which is not an area feasible for netting. The change in migration route is apparently due to the early formation of ice inshore but local hunters speculate that motorized boats and guns have kept the seals farther offshore during their fall migration (Brice-Bennett 1977).
Low densities of harp seals were observed within the Assessment Area during the May 1997 seal survey. This is an indication that some harp seals may overwinter in the area. There were no harp seal pups observed during the survey, but their presence would be difficult to confirm against the white fast ice.
Harbour seals have been reported in the assessment area year-round. These seals are considered to be non-migratory. They are reportedly most common in the Assessment Area during the late summer and fall (Brice-Bennett 1977) when they feed in estuaries and shallow coastal areas. Some hunters from the Nain area believe harbour seal numbers in the area have increased, while others believe there recently has been a decrease (Williamson 1997a).
Despite documented regularity of harbour seals in the Assessment Area (Williamson 1997a; Brice-Bennett 1977), they were not commonly encountered during the summer mammal survey of 1996. The only survey record of harbour seals occurred in Anaktalak Bay in August (Figure 13.7). Incidental sightings of harbour seals were reported in Anaktalak Bay during July and August, 1996.
Harbour seals remain in the nearshore year-round, which makes them accessible to hunters. Once plentiful in the bays, hunting has apparently driven harbour seals to the outside islands (Brice-Bennett 1977). Concentrations have been observed near Spracklins Island and Tunungayaulok Island as well as in Garlands Bight in Voisey's Bay. Spracklins Island is reportedly a breeding ground for harbour seals (Williamson 1997a). In the spring and fall, immature harbour seals have also been reported around Hopedale, in Big Bay, and in Flowers Bay (Brice-Bennett 1977).
Bearded seals may be found in the Assessment Area year-round and usually near the outer islands, but they are considered to be relatively rare on the Labrador coast (Stenson 1994). Nonetheless, local hunters report an increase in the number of bearded seals over the past 20 years (Williamson 1997a).
In the winter, "the small cluster of islands northeast of Dog Island and northeast of Iglosiatik Island are known as the best hunting areas" (Brice-Bennett 1977).
There is a movement of bearded seals out of coastal areas during the summer (Schwartz 1977; Boles et al. 1980). They are thought to migrate north. Bearded seals in the Assessment Area, therefore, likely comprise a portion of a larger population. Bearded seals have traditionally been hunted in the fall in Nain Bay, Tikkoatokak Bay, and Voisey's Bay when they follow the ringed seals into the bays to feed before freeze-up (Brice-Bennett 1977). Bearded seals feed primarily on benthic species such as clams, crab, sculpin, and flatfish.
Bearded seals may be found in spring coastal pack ice in the Hopedale, Nain, and Hebron regions. As the ice breaks up, the young bearded seals move closer to shore with the ringed seals, but the older ones stay near the outside islands. They have also been reported to "follow the routes of the harp seals beyond the outside islands in the southward migration past Hopedale" (Brice-Bennett 1977). Whelping occurs on the ice from late April to the beginning of May, and mating follows from mid-April to mid-May (Lien et al. 1985). A survey conducted near Makkovik over pack ice in 1977 estimated densities at 0.05 bearded seals/km2. Previous estimates of bearded seal density range from 0.01-0.11/km2 (Boles et al. 1980). During the 1996 marine mammal survey, bearded seals were only observed within the Assessment Area during July and August, in moderate densities relative to the other seal species.
Participant in LIA study: "Grumpus [piked whale or minke whale] also seems to be coming back. We never spotted them in big numbers for a long time." (Williamson 1997a: 31)
Minke whales could occur in the Assessment Area anytime during the ice free season, but they are most likely to be present during late summer or early fall. There is some indication from local hunters that the number of minkes in the area has increased recently (Williamson 1997a).
Minke whales are by far the most common whale in the Assessment Area during the ice free season, particularly during September. Each summer, minkes can be spotted in the bays of Labrador.
The expected condition of marine mammals within the Assessment Area, within the expected lifespan of the Project and in the absence of Project, is subject to natural population fluctuations. Natural population fluctuations may be more exaggerated in the future due to climate change and the predicted extreme weather events (Section 8.1.3.1). Extreme storms may result in increased mammal mortality due to exposure, rapid fast ice formation or collapse, or decreases in the availability of food. Marine mammal populations would continue to be subject to variability in hunting pressure and natural mortality.
Noise propagation is highly variable in coastal environments. Since water density varies with depth and season, sound is transmitted differently at different depths. In shallow coastal water, noise propagation is affected by coastal geomorphology and bottom type, as well as season. The distance over which mammals respond to acoustic effects can vary by a factor of ten, depending on these conditions (Malme 1995). Despite the potential for variability, the effects of noise on marine mammals is a concern among local hunters (Williamson 1997a).
The intermittent nature of noise disturbance and the small proportion of any population affected at any one time will result in only a few individual mammals being affected. The effect from noise is considered highly reversible; once the source is removed, displaced mammals would be expected to return.
Participant in LIA study: "It's true that noise can frighten seals when it's newly iced up. When I used to wait for seals in the morning, as soon as dog teams were coming, the seals just splashed and they never poked up after." (Williamson 1997a:70)
After the project has closed and decommissioning is complete, noise levels in the area will return to ambient levels. Any effects of noise on marine mammals, such as avoidance, will be reversed.
Cavitation is a frequent occurrence during ice breaking if a ship has to reverse and repeatedly ram thick ice. Cavitation noise is created when the propeller is switched from astern to forward or when the ship has stalled in the ice after ramming, producing much higher noise levels than continuous forward progress through the ice. (Davis and Malme 1997)
Generally, the level of noise from a ship increases with ship size, speed, and weight of cargo. However, the loudest noise from normal ship operation comes from cavitation of the propeller, which adds 10-15 dBA to the noise level of regular operation (Greene and Moore 1995). Ice breaking noise from theM.V. Arctic was 5-10 dBA higher for ice breaking astern compared to ice breaking ahead. Even though there is a rapid attenuation of noise under heavy sea ice, the noise caused by ice breaking may be detected by ringed seals at ranges of 20-25 km at a water depth of 50 m and at about 25-35 km in water 100 m deep (Davis and Malme 1997).
The reaction of marine mammals to noise from a vessel is species-dependent but can also vary within a species. In one study, ringed seals on ice pans dived into the water in response to a vessel which came within 250-500 m (Bruggeman et al. 1992). In another study, harbour seals on a tidal flat dived into the water when approached by a boat within 100 m. This displaced the seals for one hour to more than three hours. Harbour seals on the ice were displaced by vessels approaching within 100-300 m, depending on vessel type (Calambokidis et al. 1983). In another study, harbour seals did not enter the water until fishing vessels came to within 60 m. Habituation is possible when particular boats visit the same site regularly (Bonner 1982).
The reaction to the approach of a ship among whales is also quite variable. The narwhal strategy is quite different than other mammals: narwhals remain motionless when frightened by a ship (LGL and Greenridge 1986). Minke whales are known to be curious creatures; they often approach vessels that are stopped or slow moving. However, minkes generally do not approach, and sometimes avoid, faster moving vessels (Richardson et al. 1995).
The comfort level for hearing in seals is exceeded within a distance of about 100m from a vessel which is travelling through ice. Avoidance behaviour would be displayed by seals at a distance of 500-700m from such an activity, consequently hearing damage is unlikely. A similar effect can be expected with respect to whales. Damage to the hearing of these animals could only occur as a result of prolonged exposure close to the noise emitted from a vessel which is breaking ice. For all marine mammals, temporary displacement behaviour and diminished reception of signals are the resulting effects from vessel traffic (Myrberg 1990).
Noise generated from ice breaking would have a similar masking effect as sources of ambient noise such as proximity to a vocalizing fin whale or noise from strong wind and rain or ice movement (Gales 1982). Despite concerns raised by Inuit observers during the Arctic Pilot Project, there have been no scientific reports of mammals being adversely affected by increased ambient noise. Mammals have been known to increase frequency and amplitude of their own signals to compensate for increased ambient noise levels (Evans 1982; Au et al. 1974). However, temporary increases in ambient noise would potentially mask communication between mammals (Richardson et al. 1995).
Several reports have documented the response of marine mammals to low-flying aircraft. The effect is more pronounced in areas where air traffic is uncommon. Flights over ringed seals provoked various responses. Low-flying aircraft and helicopters resulted in frequent diving in the water, however the response was not elicited consistently (Richardson et al. 1995). One study reported that ringed seals left the ice when the helicopter was at an altitude of less than 305 m and within 2 km lateral distance (Kelly et al. 1986). Helicopters and large aircraft are generally more disturbing than small aircraft, especially during calm days and after recent disturbances (Johnson 1977).
Air traffic noise will directly affect seals which are hauled out on the shore or on ice during moulting or pupping. Harbour seals have been observed to abandon their young on the beach when scared by aircraft (Johnson 1977). Aircraft flying below 120 m almost always resulted in dislocation of seals, for up to two hours. Low flying aircraft were estimated to account for about 10 percent of pup deaths in one year. Other studies have not attributed seal pup mortality to low-flying aircraft, and only temporary avoidance behaviour was reported from flights over 76 m (Hoover 1988). Osborn (1985) reported rapid movements in the water by harbour seals in California in two of eleven cases. There are also reports of seals habituating to frequent overflights to the point where there was no reaction (Richardson et al. 1995).
Minke whale have responded to helicopters at an altitude of 230 m by changing course or slowly diving (Leatherwood et al. 1982). Marine mammals in the vicinity of the proposed airstrip location may be affected by air traffic. Seals may exhibit temporary avoidance behaviour at Big Island Cove and the head of Voisey's Bay. These effects will only be experienced by a small portion of any marine mammal population occupying the Assessment Area.
There is evidence of avoidance by whales of areas affected by industrial noise. However, the residual effect of construction noise does not inhibit whales from returning soon after to areas which were previously subject to industrial noise (Davis et al. 1987).
Noise levels will increase in the marine environment near Edward's Cove during on-land construction of the docking facilities. Noise levels in Edward's Cove will be above background levels intermittently, throughout construction. Underwater blasting will not be required during construction of the temporary or permanent docking facilities at Edward's Cove.
Marine mammals that may venture into Edward's Cove will likely respond by decreasing time spent on the surface and, if disturbed, will swim out of the area. Since Anaktalak Bay offers no unique habitat or feeding ground for whales or seals, the normal functioning of any marine mammal species will not be affected. Physiological damage to marine mammals caused by blasting on land is very unlikely. However, if mammals are within the general area of construction, blasting is likely to startle nearby mammals more so than the general noise of construction. A sudden change in frequency orintensity is more alarming than the magnitude of the noise (Gales 1982). Noise generated by construction and blasting will likely cause initial avoidance of the Edward's Cove area; however, this reaction is expected to be temporary.
The effects of ice breaking on marine mammals will be reduced by the ice breaking mitigation measures and shipping schedule discussed in Chapter 9.
There are wide-ranging responses recorded for the reaction of seals to icebreaking activity. A study by DFO in Admiralty Inlet suggests that seals tend to remain on the ice or in their breathing holes just a few tens of meters away from a ship moving through the pack ice. After the ship had passed, seals tended to move into the ship's track, similar to their response to natural openings (Strandberg et al. 1984). There are also reports of ringed and bearded seals hauling out onto the ice when approached by an icebreaker (Fay and Kelly 1982). There are other reports of ringed and bearded seals diving into the water when an icebreaker is 0.93 km away (Brueggeman et al. 1992) but remaining on the ice when the icebreaker was 1-2 km away (Kanik et al. 1980). Seals may also be attracted into the track of an icebreaker because of the ease at which breathing holes can be maintained.
Most ringed seals are believed to follow the ice edge as it progresses seaward. However, some seals usually stay within the bays throughout the winter. Shipping activity within Edward's Cove may deter seals from remaining in this area during the winter. Ringed seal abundance was not adversely affected during ice breaking in a study in the Northwest Territories (Alliston 1980) and another in Lake Melville, Labrador (Alliston 1981).
Mortality will only result from collision with a vessel if the seal has nowhere to escape. However, this is not likely given the agility of seals and the fact that adult ringed seals use an average of 3.4 holes per seal for breathing (Hammill and Smith 1989). If one breathing hole is threatened, they may escape through another hole. As well, ringed seal pups (25-57 days old) use an average of 8.7 breathing holes, up to 900 m apart (Lyderson and Hammill 1993).
Areas along the shipping route are recognized as whelping grounds for ringed seals (Williamson 1997a). Ringed seals congregate on fast ice in the Assessment Area during April and May. Because shipping through ice will cease during early spring when most seal hunting occurs, ringed seal pups should not be affected by shipping.
"Seal meat is essential to the diet of Aboriginal people. Ice breaking activities will disturb and have negative effects on seal populations especially the harbour seal or the jar seal. These species use the bays throughout the year giving birth to their young between the ice in the spring." (Ronald Webb, Panel scoping meeting in Nain, April 17, 1997)
Section 9.1.3.5 (in the chapter on ice) defines and discusses hinge ice, which has the potential to form along a small section of the shoreline within the Assessment Area. Only a small portion of any mammal population would be affected by any collapse of hinge ice. Of these potential hinge ice areas, few are closer than 1 km to the shipping route, further reducing the possibility of hinge ice collapse. Because ice re-forms a short time after ice breaking has ceased and the sea ice is not a year-round occurrence, the reversibility of the effects of ice breaking is high.
Marine mammals are air-breathing and, therefore, do not have the same exposure to dissolved or precipitated contaminants from the marine environment as other marine organisms like filter feeding molluscs or finfish. Marine mammals may avoid an area if a contaminant is offensive. However, marine mammals have been known to feed in potentially harmful environments (Béland, P. pers. comm.).
Marine mammals uptake metals primarily through ingestion (Wagemann and Stewart 1994). Mammals may also take up metals by accidental ingestion of sediment during bottom feeding, but they do not commonly drink seawater. Ingestion of metal-contaminated sediment could result in the liberation of metal ions in the acidic conditions of the stomach. Metals in a free ionic form are considered bioavailable and may therefore be absorbed into the digestive tract. In practice, it has proven extraordinarily difficult to identify sources of heavy metal contamination in marine situations (Gaskin 1982). To illustrate this point, the exchange of metals in the marine food chain is depicted in Figure 13.7. In seemingly uncontaminated areas far from industrial sources (the Canadian Arctic and Greenland), reports indicate that lead, mercury, and cadmium are relatively high in some marine mammals (Wagemann et al. 1983; Hansen et al. 1990).
Since the majority of contaminants in marine mammals are accumulated through food, the rate and level of bioaccumulation depends on the trophic level at which the marine mammal feeds. For instance, bearded seals primarily feed on benthic invertebrates. Therefore, they will accumulate contaminants more slowly than ringed seals, which feed at higher levels in the food chain, where some bioaccumulation has already taken place.
Effects on marine mammals associated with the uptake and bioaccumulation of metals has been further evaluated through the use of a risk assessment model (Beak International Incorporated 1997). Ringed seal were modelled as a representative species of local marine mammals. The model considered six metals (nickel, copper, cobalt, zinc, lead and cadmium) based on contaminant source characterizations (Senes 1997a; 1997b; 1997c) and biological sensitivity. Ringed seal were considered to potentially uptake these elements through eating fish, invertebrates, and ingestion of sediment. Inhalation (breathing) of metals was not included as a pathway for seal as air contaminants from the Project do not extend to the marine areas where the seals reside.
For modelling purposes, three areas of ringed seal habitat were modelled: Kangeklualuk Bay, Voisey's Bay, and Anaktalak Bay. It was assumed that the seals reside in these bays throughout the year and obtain all of their food from within these bays. Ringed seal was modelled with a diet that consisted of 75 percent fish and 25 percent mussel. The fish portion of their diet consisted of Arctic charr and sculpin.
The uptake and bioaccumulation of metals from dietary sources is based on ingestion transfer factors from established literature values. These factors determine the efficiency that metals are transferred from a food source to the seal.
Based on exposure, diet and ingestion transfer, the bioaccumulation of metals in seals was modelled over 140 years. The model provided estimates of the incremental dose (mg/kg/day) for each of the metals modelled. The predicted dose concentrations were compared to lowest observed effect level (LOEL) which are toxicological benchmark concentrations. Species specific LOEL (benchmark doses) were calculated based on weight. The LOEL represent the concentration at which some effect on the animal (e.g., weight loss) was observed. These values do not represent acute toxicological thresholds, which would be substantially higher. The predicted dose was compared to the benchmark dose (LOEL) to produce hazard quotients (HQ) for each of the metals modelled. The HQ represents the ratio of the predicted does to the benchmark dose. An HQ of less than one reflects a dose which is not expected to have an observable effect on seals.
All HQ values derived from the modelling were well below one (and thus below the benchmark dose) for all metals in the seals in the three areas. All results were several orders of magnitude lower than doses that are expected to show any effect on seals.
Therefore, the ringed seal is not expected to bioaccumulate metals to a dose which would cause an adverse effect.
The oil spill modelling is discussed in Section 3.12, Volume 2.
To assess the effects of an oil spill within the Assessment Area, spill scenarios were developed for areas of increased risk of an oil spill (Edward's Cove and the southeast corner of Paul Island).
Marine mammals may also be exposed to oil through feeding on oiled prey. Zooplankton may engulf petroleum droplets when in direct contact and retain metabolized and unmetabolized petroleum for 7-10 days (Geraci and St. Aubin 1990). Similarly, marine fish are able to metabolize hydrocarbons and are therefore not a source of hydrocarbon contamination for marine mammals during extended periods. Bivalve molluscs however, tend to accumulate hydrocarbons from prolonged or repeated exposure, posing a threat to benthic-feeding seals. Ingestion of small quantities of oil through feeding or grooming is usually not harmful to marine mammals since they are able to metabolize hydrocarbons and the whale's baleen function is not impaired by ingesting oiled food (Payne 1992).
The oil spill trajectory modelling (Section 3.12, Volume 2) demonstrates very different patterns of oil dispersion in the open water and ice covered seasons. The effects of an oil spill on marine mammals will depend largely upon season as well as location of the spill. If a spill were to occur during the ice free season, a number of seal species and minke whales would be prone to oil exposure through feeding, grooming, or direct contact. The effects are not likely to be lethal, however, given the ability of marine mammals to metabolize hydrocarbons and to maintain body temperature through the insulation capacity of their blubber. The species most vulnerable to oil along the shoreline would be the harbour seal, since it frequently hauls out on beaches. Harbour seals therefore are more likely to become coated in oil than other marine mammal species.
In contrast to open water conditions, ice cover restricts oil dispersion, thereby limiting the area affected. Thus, fewer marine mammals would be expected to come into direct contact with an oil spill during the period of ice cover. There are few marine mammal species in the area during the winter, but by early spring, ringed seals have begun to congregate in the area to whelp and breed. Seals within the immediate area of the spill will become oiled and prone to exposure. Ringed seal pups would be especially vulnerable to the cold if they become oiled because they have not yet established adequate fat reserves. Oil trapped underneath the pack ice may also decrease the ringed seal food supply in the immediate area by depleting zooplankton and Arctic cod availability. The potential for adverse effects on ringed seal pups due to an oil spill is limited due to the halt in shipping during the period when seal pups are most vulnerable to the effects of oiling.
The effect of an accidental oil spill during any time of year is small, considering the portion of any mammal population at risk. Any effect would be reversible because of the limited physiological effects of oil on mammals. The only other seal species known to whelp in the area are harbour seals. Since harbour seals usually give birth near river banks and on the outer islands off Voisey's Bay (Williamson 1997a), they are not expected to be affected by a marine oil spill.
Concentrate spill trajectory modelling was conducted to simulate accidental events at Edward's Cove and Paul Island (Hatch 1997). A spill at Paul Island would dissipate much more quickly than a concentrate spill at Edward's Cove because of the strong currents outside Anaktalak Bay.
Concentrate within the water column may increase the bioavailability of copper and nickel in the water column. Mammals may be exposed to increased levels of copper and nickel through the ingestion of plankton, fish or shellfish. Marine mammals ability to regulate their levels of copper and nickel will prevent any deleterious biological effects. The effect of a concentrate spill on marine mammals is therefore considered reversible.
Exploration and drilling programs conducted by other companies have little or no interaction with marine mammals. Therefore, no cumulative effects are expected from other exploration activities.
Other resource development activities, particularly the quarry operation in Ten Mile Bay and potential quarries at Pearly Gates and Tabor Island, may result in the release of quarry drainage into the marine environment. Quarry drainage may contain elevated levels of suspended solids, but because the quantity of drainage will be restricted to run-off and the quarries are relatively small, no cumulative effect on marine mammals is expected. Small amounts of shipping are also associated with quarry operations. Quarry shipping is not year-round and would not involve any ice breaking. No cumulative effect on marine mammals due to quarry operations and the Project are expected.
The relocation of Utshimassits will result in a short term increase in marine traffic as relocation takes place, but it will be local and temporary and will not affect marine mammals.
The predicted climate change events of increased variability in the weather, a temperature decrease of less than 1°
C and possible rise in sea level of 12 cm (Section 8.1.3.1) are not predicted to have any cumulative effect on marine mammals.
The following is a list of environmental design and mitigation features specific to marine mammals:
site personnel will be directed in proper procedures for managing encounters with marine mammals so as to reduce disturbances;
the shipping route will have appropriate levels of traffic control and navigational aids to ensure safe passage, which will reduce the risk of an accidental event affecting marine mammals; and
a marine mammal survey of Edward's Cove will be conducted prior to construction blasting at the port site during periods of mammal abundance in Edward's Cove.
