STATUS OF HABITAT AT SELECTED BREEDING AND STAGING SITES

The above accounts of the damage are necessarily based on longer term studies of systems where both observational and experimental evidence are irrefutable. Studies are now under way on a wider scale, yet there is an immediate need to answer questions about the magnitude and distribution of the problem of high populations and damaged Arctic and sub-Arctic coastal ecosystems (i.e., how much habitat is there and in what condition is it?).

The range of geese in Arctic North America is vast and a comprehensive inventory of the status of habitat at all the important sites is unavailable. Here, we briefly describe conditions at several major breeding or staging sites, with histories of visitation spanning 30-40 years, and all visited within the last 5-10 years. The order of presentation is arbitrarily from south to north and east to west (Fig. 2.2b).

Akimiski Island, NWT

Vegetation damage to the intertidal area along much of the north shore of Akimiski Island is extensive. Mudflats have replaced swards of Puccinellia phryganodes and Carex subspathacea and only patches of vegetation remain. The Festuca rubra and Calamagrostis deschampsioides swards in the upper intertidal zone also are being increasingly grazed and grubbed. Brackish and fresh-water graminoid vegetation immediately inland from the upper limit of spring tides is grazed heavily in summer and shoot pulling is common in spring. Bare peaty areas occur as a result of foraging activities by both lesser snow geese and Canada geese. Dead willow stands occur locally in grubbed areas. Extensive areas are now covered by non-forage plant species, including Glaux maritima and Senecio congestus. Fresh-water sedge meadows show limited signs of damage, but no close examination has been made.

The vegetation in the south-east coastal zone of the island also has been badly damaged by migrating and molting Canada geese. The graminoid cover there has been removed and an extensive moss carpet together with Senecio congestus and Spergularia marina has replaced much of the brackish intertidal vegetation. Large areas of hypersalinity are marked by extensive stands of Salicornia borealis. The south shore of the islands has a steeper gradient, and hence less marsh. In general, it appears to be in good condition, but goose use is limited compared to the north shore.

West coast of James Bay, Ontario

Damage to vegetation as a result of grubbing is localized in salt marshes which occur in embayments or landward of barrier beaches. In general, grubbing is more evident north of Attawapiskat River than south of it. Intensive spring foraging by staging snow and Canada geese has been documented for areas north of Ekwan Point as far as the Lakitusaki River (Wypkema and Ankney 1979, Prevett et al. 1985, Hudson Bay Project, unpublished data). The brackish / freshwater marshes are dominated by Carex aquatilis, C. paleacea and Hippuris tetraphylla. The presence of ice and deep melt water in spring along the shoreline, the extensive spring and autumn hunting carried out by people from coastal settlements and the absence of large breeding colonies of lesser snow geese has resulted in only localized damage to vegetation.

Cape Henrietta Maria, Ontario

The Cape Henrietta Maria region contains an extensive area of intertidal salt marsh that has been severely grubbed and heavily grazed. Inland from the intertidal zone are extensive moss carpets, particularly in the region of the Cape itself. The conditions prevail on the James Bay coast as far south as Hook Point. Between the Cape and the Sutton River to the west, large grubbed areas, degraded salt marsh swards and moss carpets dominate the coastal zone. The salt marshes immediately west of the Sutton River are in relatively good condition, although there are indications of increased grubbing of these marshes. In 1996, the western perimeter of the breeding colony was east of the Sutton River. Tundra areas inland of the inter-tidal areas have extensive fresh-water sedge meadows dominated by Carex aquatilis. These show moderate to heavy grazing by older broods up to 8-10 km from the coast. However, intensive damage, such as the development of peat barrens, has been noted only near the core of the large breeding colony.

The Hudson Bay Coast of Ontario

The stretch of coastline from Sutton River west to the Ontario - Manitoba border shows a diverse geomorphology. Much of the coastline consists of barrier beaches, landward of which are small fringe salt marshes that are both grubbed and heavily grazed by Canada geese and lesser snow geese. Relatively small, but high density colonies of nesting lesser snow geese occur in the vicinity of the more extensive salt marshes east of Winisk River, at Shell Brook and at the Pen Islands. The vegetation at the latter site which is large (20 km x 5 km) is in good condition, possibly protected by deep snow and ice in spring. At the other locations and at the estuaries of the rivers which drain the Hudson Bay Lowlands some damage to the Puccinellia - Carex swards is evident.

The Hudson Bay Coast of Manitoba

The coastline of Manitoba between the Black Duck River in the east and Rupert Creek at the southern end of the Cape Churchill Peninsula has no large colony of breeding lesser snow geese. The area is a major staging region for lesser snow geese and Canada geese in spring. Between the border with Ontario and Cape Tatnum, the coastline consists largely of barrier beaches with heavily grazed/grubbed fringe salt marshes. The vegetation along the remainder of the coastline is dominated by the outflow and mineral sedimentation from the Nelson and Hayes Rivers. This produces freshwater/brackish conditions and rank growth of vegetation which is ungrazed. Staging birds pull shoots in the sedge meadows inland from the coast. There is some moss carpet development and many bare areas in which loose sediment is present on the surface.

The Cape Churchill Region and La Pérouse Bay, Manitoba

The expanding population of lesser snow geese at La Pérouse Bay has resulted in substantial changes to all intertidal habitats. No extensive Puccinellia-Carex swards remain and large areas of dead willows are present in the coastal zone. In addition, nearly all shoots of Carex aquatilis are grazed up to 10 km from the coast. In the vicinity of the coast extensive moss carpets are present. Indicator plants of severe disturbance and hypersalinity, such as Senecio congestus and Salicornia borealis are widespread. In 1996, birds nested from Rupert Creek to Christmas Lake beach ridge and densities of nests at some sites exceeded 2500 km-2.

Knife and Seal Rivers, Manitoba

The extensive braided estuaries of the Knife and Seal Rivers have staging, breeding and post- hatch populations of lesser snow geese and Canada geese. There are a number of Puccinellia-Carex marshes that are badly grubbed and damaged. Moss carpets have developed where Carex aquatilis shoots have been removed.

Tha-Anne River to the Maguse River in the NWT on the west coast of Hudson Bay, NWT

The coastal inter-tidal salt marsh has been replaced by mudflats throughout the entire coastal strip, except at Wolf Creek. Eutrophic, mesotrophic and oligotrophic sedge communities have either been heavily grazed or replaced by peat barrens for distances up to 10 km inland from the coast. At some sites, the peat has been eroded to expose glacial gravels.

Southampton Island, NWT

Although quantitative vegetation surveys have not been carried out on Southampton Island in relation to the effects of foraging by geese, reports from biologists who have visited the breeding colonies of lesser snow geese indicate that there is widespread shoot-pulling of sedges, heavy grazing of shoots of Carex aquatilis / stans and Arctophila fulva and the presence of bare peat areas and moss carpets. At Boas River, formerly extensive salt marshes reported by T. Barry are badly grubbed and reduced to remnant areas. These changes in the vegetation are of particular interest as breeding colonies of Brant, Canada and lesser snow geese are in close proximity to each other. There are virtually no graminoid areas on the southern two-thirds of the island that are not used by broods of snow geese and the other three goose species. Snow goose broods now travel from the East Bay nesting areas all the way westward to the village of Coral Harbour itself, a distance of up to 60 km (K. Abraham, pers. obs).

Southwestern Baffin Island, NWT

This area along the shores of Foxe Basin contains the locations of the first documented lesser snow geese nesting (in the 1920s) and has been occupied continuously since. Several large colonies of lesser snow geese that breed in the coastal marshes and move inland along river valleys to forage on fresh-water graminoids. Again formal vegetation studies of this area have not been done, but damage to salt marshes is evident (D. Caswell, pers. comm.). Examination of photographs indicates widespread destruction of coastal vegetation by geese (grubbing) and the development of moss carpets in the river valleys of the uplands. The lack of quantification is unfortunate because the area may hold as many as one-third of the mid-continent breeding population (D. Caswell, unpublished data).

Bylot Island, NWT

In some areas, there has been deterioration of vegetation in recent years as a result of the foraging activities of a colony of greater snow geese. The birds forage on a range of graminoids, in particular, Dupontia fisheri, Eriophorum angustifolium and Eriophorum scheuchzeri that grow on an organic substratum rather than a mineral substratum. The death or poor growth of individual tussocks/shoot systems following intense foraging has led to the development of sparse growth of graminoids, and the increase of moss. The studies of G. Gauthier and associates show, in prime brood rearing areas: 1) a high impact of grazing, 2) regrowth of plants after grazing and 3) lower production of plants in heavily grazed habitats (Gauthier et al. 1995, Gauthier et al. 1996). However, the long-term ability of the plants to recover is not yet affected because, when geese were excluded, production of Eriophorum tripled after four years (Gauthier et al. 1996).

Queen Maud Gulf, NWT

Extensive studies of the growth and geographical expansion of the colonies of Ross' and lesser snow geese in this region indicate that the birds have expanded beyond prime nesting colony sites, especially where lakes occur, to marginal mainland fresh-water tundra sites. The birds forage in both coastal and inland marshes and travel large distances (over 60 km, R. Alisauskas and S. Slattery, unpublished data) to suitable brood rearing habitats. A number of the vegetation changes reported for the west coast of Hudson Bay occur here, including extensive areas of peat barrens that can be detected from satellite imagery (LANDSAT).

Banks Island, NWT

Formal vegetation studies in relation to the effects of goose grazing are absent. However, the types of changes to vegetation indicated above as a result of goose grazing are expected to occur and can be seen on recent photographs of the area.

North Slope of Alaska, USA

The relatively small breeding colony of lesser snow geese on Howe Island, Sagavanirktok River (<250 pairs) is unlikely to have deleterious effects on the vegetation at this point. However, fall staging of snow geese from the western Canadian Arctic occurs in fresh-water tundra wetlands on the coastal plain. No assessment of damage has been made.

Wrangel Island, Russian Federation

Damage to vegetation at the nesting site in the uplands is minimal and confined to local grubbing. On the coastal Tundra of the Academy there is very heavy grazing of shoots in the vicinity of lakes (<250 m) and moss carpets or swards of Petasites sagittatus (arctic coltsfoot/heliotrope/ butterbur) are common.

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