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ASI Project Design

The major impetus for the Antarctic Site Inventory project is the 1991 Environmental Protocol to the Antarctic Treaty, which entered into force, as a matter of international law, in 1994. There had been no previous effort to catalogue the biological and physical resources of Antarctic Peninsula zodiac landing sites. Thus, an overarching goal is to establish baselines of site-descriptive information and biological data, which will enable environmental changes to be detected and potential causes for such changes to be examined.

Following a year of examining methodologies and logistics, the Antarctic Site Inventory began fieldwork in November 1994; specifically, the project intended to:

• determine whether opportunistic visits can be used to effectively and economically detect possible visitor-caused changes in the physical features, flora, and fauna of sites in the Antarctic Peninsula being visited repeatedly by ship-based tourists;
• begin collecting baseline information necessary to detect possible changes in the physical and biological variables being monitored; and
• determine how best to minimize or avoid possible environmental impacts of tourism and non-governmental activities in the Antarctic Peninsula area.

Theoretically, these data and information will: allow direct and cumulative impacts to be detected; ensure that the best scientific data and descriptive information are available should Antarctic Treaty Parties determine that site management is necessary and appropriate; contribute to a better understanding of biological processes in the entire Antarctic Peninsula region; and suggest additional biological research that might be accomplished with respect to penguins and shags.

From the Inventory’s inception, it was intended that collected data and information be made publicly and routinely available, thus assisting visitors in determining how best to minimize, or potentially avoid, environmental impacts.

Any potential, management efforts by Antarctic Treaty countries inevitably require a consideration of whether or not any detected impacts, direct or cumulative, are naturally occurring, perhaps caused by tourism or other human activities, or result from other causes.

Subareas

The Inventory divides the Antarctic Peninsula into six subareas:

• South Orkney Islands, including Laurie, Coronation, and Signy Islands (SO);
• Elephant Island and nearby islands (EI);
• Northeast Antarctic Peninsula/northwestern Weddell Sea (NE), from Cape Dubouzet (63º16’S  64º00’W) to James Ross Island;
• South Shetland Islands, including Deception, Low, and Smith Islands (SH);
• Northwest Antarctic Peninsula (NW), from Cape Dubouzet (63º16’S  64º00’W) to north end of the Lemaire Channel; and
• Southwest Antarctic Peninsula (SW), from the north end of the Lemaire Channel to the northern part of Marguerite Bay (68º18’S 67º11’W).

Data categories

The Inventory’s methodology involves the collection of three categories of data and information. It is critical that all this data be recorded for each location visited.

The first category, Basic Site Information, includes descriptions of key physical and topographical characteristics; latitude and longitude; distribution of flora, seal haul-out and wallow locations, and discrete groups of breeding penguins and flying birds.

At each site, to evaluate species diversity and site sensitivities, the Inventory collects data regarding the presence or absence of nesting species of penguins and flying birds, wallows of southern elephant seals, and large patches or beds of lichens and mosses at all sites visited. These data are used to rank sites as to their species diversity, based on the number of faunal species and major floral groups recorded. Using these presence/absence data as a base, sites also are ranked as to their potential sensitivity to disruption by visitors, depending on: the number of penguin and seabird species whose nests visitors may access easily, whether or not visitors may access southern elephant seal wallows easily, and whether or not visitors may access easily and possibly trample large patches or beds of lichens and mosses.

Census data collection proceeds according to Standard Methods used in the CCAMLR Ecosystem Monitoring Program, particularly Standard Method A3A (v4), which relates to breeding population size and Standard Method A6 (v5), Procedure A, which relates to breeding success. With respect to blue-eyed shags, data collection follows similar methodologies because, at present, there are no applicable CEMP methods specifically pertaining to blue-eyed shags. The aim is to determine interannual trends in the size of breeding populations. A decline in a breeding population would be one indication that a penguin population at a particular site is being impacted.

 This data collection method specifically pertains only to ground counts of nests in entire colonies. The mandated procedure is to select one or more colonies that are discrete, which separately can be counted as a whole unit, and which will not be affected by other studies or on-site human activities. The census colonies must be well defined and distributed in various parts of the study area. It is important that the same colonies be counted annually and that the counts are made one week after peak egg-laying. The colonies must be clearly marked and mapped. Once established, the same colonies will be used to assess chick numbers under CCAMLR Standard Method A6 (v5), Procedure A, described below.

The nest census procedure requires that three separate counts should be made of each of the selected colonies on the same day; if one of the three counts differs more than 10% from the others, a fourth count should be made on the same day as the other three counts. The total number of birds engaged in breeding activity can be influenced by: cohort size at fledging and rate of recruitment of each cohort to the breeding population; food supply during pre-laying and incubation periods; ages of individual birds (and consequently the age structure of colony); previous breeding experience of the individuals; the length of mate-bond; presence of mate; size and location of colony; and ice conditions prior to colony occupation.

CCAMLR Standard Method A6 (v5), Procedure A will be utilized to estimate breeding success. The aim is to assess productivity by providing an index of relative change in the number of chicks produced one year to the next. A decline in the number of chicks produced per occupied nest would be one indication that a penguin population at a particular site is being impacted.

As with the censusing of occupied nests, Standard Method A6 (v5), Procedure A requires the selection of one or more colonies that are discrete, which separately can be counted as a whole unit, and which will not be affected by other studies or on-site human activities. The census colonies must be well defined, distributed in various parts of the study area, and clearly marked and mapped. It is important that the same colonies be counted annually. The colonies should be the same as those used to assess breeding population size CCAMLR Standard Method A3A (v4), described above.

The chick census procedure requires that three separate counts should be made of each of the selected colonies on the same day, during the peak of chick-créching. The CCAMLR chick censusing methodology states that if one of the three counts differs more than 10% from the others, a fourth count should be made on the same day as the other three counts.

The methodology cautions researchers to walk slowly in performing their work to avoid disruptions that might cause the breakage of eggs or predation by skuas. The methodology provides that results should be analyzed to produce mean numbers of chicks at each colony or breeding area for the number of counts employed (minimum three). These data can be used as an index of breeding success directly by comparing counts for specific colonies or groups of colonies, or indirectly by expressing the results as the mean number of chicks per adult over a group of colonies, yielding an attendant variance. It is important that the colonies or breeding areas, and dates of counts are standardized.

Breeding success will be indicative of many factors, notably adult condition and colony size, food availability, predator pressure, ice conditions and other environmental features. The success of breeding expressed both as total number of chicks raised and number of chicks raised per adult will have important implications for future population size. Season-to-season variation in breeding success can be considerable.

The second category of data and information, Variable Site Information and Data, includes weather and other environmental conditions (sea ice extent, cloud cover, snow cover, temperature, wind direction and speed), biological variables (number of occupied nests, number of chicks per occupied nest, ages of chicks), and the nature and extent of any observed visitor impacts (footprints or paths, cigarette butts, film canisters, and litter). With respect to penguins and flying birds, the focus is collecting data on breeding population size (nest counts) and breeding productivity (number of chicks per active nest), which are the appropriate biological parameters for detecting direct and cumulative impacts on these populations.

The third category of data and information, Maps and Photodocumentation, is an effort to portray major features of each site, particularly the locations of colonies and assemblages of resident fauna and flora. Orientation maps are crafted to assist Inventory researchers in their regular, season-to-season censusing. Oblique aerial photodocumentation has transpired via a cooperative arrangement among Oceanites, the UK Foreign and Commonwealth Office, and the Royal Navy ice patrol ship HMS Endurance. The oblique aerial photodocumentation from HMS Endurance, conducted by helicopter, conforms fully to guidelines established by the UK Foreign and Commonwealth Office to avoid harmful interference with concentrations of Antarctic wildlife.

Inventory researchers use 35mm and digital cameras to photodocument — within a season from season-to-season, and from the same vantage points — flora (lichen, mosses, and grass), penguin and seabird colonies, seal haul-out sites, and other features. Over time, repetitive photodocumentation from the same vantage point potentially may record on-site changes. In the 2001-02 field season, the Inventory experimented with a kite-flown digital camera in order to obtain images of inaccessible penguin nesting groups.

Indicator species

The Inventory considers the following fauna and flora, found variously throughout the Peninsula, to be potential indicators of environmental change:

Census strategies

Taking cues from the literature, the Inventory has focused on censusing four penguin species (gentoo, Adélie, chinstrap, and macaroni) and four species of flying birds (blue-eyed shags, southern giant petrels, kelp gulls, and skuas, spp.). Scree-nesting seabirds (storm-petrels, spp.; Antarctic fulmars; Antarctic petrels; snow petrels) were too difficult to census regularly in the short times expected for Inventory visits because these species’ nests are generally inaccessible and, at times, difficult to discover. Antarctic terns presented a different problem: nesting territories were readily ascertained, but censusing is difficult because of this species’ extraordinary skittishness, and the camouflage of its eggs and young. As a consequence, Inventory researchers note Antarctic tern breeding grounds in field data and orientation maps, but do not expend time trying to achieve censuses.

Regarding penguins, differences in breeding biology led to different Inventory census strategies. Chinstraps and Adélies are site-specific animals, which do not tend to abandon regular nest sites and rookeries if there is a breeding failure in a single season. Gentoos, by contrast, are not as site-tenacious and gentoo-pairs regularly change nesting locations if there are disturbances. The implications for Inventory-like projects are that: gentoo censuses only may have long-term relevance if all gentoos at a particular visitor sites are counted, including all subgroups and small colonies of gentoos found at that site; and censuses of chinstraps and Adélies may have long-term relevance even if all chinstraps or Adélies at a particular location cannot be counted.

With respect to chinstraps and Adélies, Inventory personnel generally selected census colonies of fewer than 300 active nests. Colonies with more than 300 active nests (e.g. at Baily Head and Hannah Point) consistently proved to be more difficult to census. With respect to macaroni penguins, Hannah Point is the only Peninsula visitor site where this species is regularly encountered, and the small numbers of nests, adults, and chicks are readily tracked. While some studies have shown that the cumulative effect of repeated visits to penguin colonies over many years has caused no significant decline in colony size or reproductive performance, and that penguins tend to become habituated to the presence of humans and human disturbances near their nest sites, other studies indicate potential effects on recruitment by new breeding pairs to heavily-visited colonies, which may cause a population decline over time, especially to small colonies. At this stage, it is unclear whether the Hannah Point macaroni population is growing, declining, or remaining steady.

In the first edition of the Compendium, regarding the relevance of Inventory census data for reproductive comparisons, Oceanites recommended a need for correlation studies to determine how close opportunistic Inventory nest and chick counts are to the peaks of egg-laying and chick-créching, respectively. Alternatively, in this second edition, Oceanites recommends long-term monitoring of a few select sites that are heavily visited, diverse in species composition, and sensitive to potential environmental impacts; at select sites where this long-term monitoring is realized, data will be collected according to CCAMLR Standard Methods and, thus, be fully comparable with data collected elsewhere in the Antarctic.

Preaching extreme care in the use of Inventory-collected data does not and should not suggest a lack of usefulness. For example, note that historical compilations of minimum penguin breeding reflect nest counts obtained at various times and in varying fashions. No filter insures that these data reflect nest counts achieved at the peak of egg-laying. The only filter applied to these data relates to the exactitude of the counts themselves (i.e. whether they represent actual nest counts or estimates with varying degrees of accuracy). These compilations are valuable sources of information about penguin distribution, often reflect more detailed work being done at various locations, and if repeated may suggest trends. In other words, “one-off” counts that are carefully accomplished during each breeding season are useful and should be repeated as often as possible.

The Inventory has achieved flying bird censuses (blue-eyed shags, southern giant petrels, kelp gulls, and skuas, spp.), but not in as much detail as with similar censuses of penguin colonies. Shag nests, adults, and chicks are regularly censused at eight sites. Kelp gull and skua nests at various locations were readily noted and marked both in Inventory data sheets and on Inventory orientation maps. Both species readily take flight on close approaches and, thus, Inventory personnel give them a wide berth, confining notes and data to the location of nests, numbers of adults tending nests, and numbers of chicks observed at a distance. Censuses of the southern giant petrels were consistently difficult to accomplish, being perhaps the most skittish of these flying birds, nesting in scrapes on the ground and easily agitated. The standard Inventory modus operandii is to walk the far perimeter of giant petrel nesting areas to reduce potential disturbances to an absolute minimum.

With respect to non-avian fauna, Inventory personnel regularly census seals on the landing beaches of Peninsula visitor sites, and track numbers of southern elephant seals in easily accessed wallows.

With respect to Antarctic Peninsula flora communities, Inventory researchers record the presence of lichens, mosses, Deschampsia, and Colobanthus, and there is an effort to photodocument as much of this vegetation as possible. Specific identifications are coordinated with British Antarctic Survey personnel. Some locations have readily accessed and often extensive moss beds (the Aitcho Islands, Penguin Island, the upper slopes of Cuverville Island, the vicinity of the Ferraz Station, Pléneau Island). Other sites present easily accessed Usnea lichens and Deschampsia (inland of the beach walk at Arctowski Station, Whalers Bay).

To avoid duplication of effort, the principal investigator of the Inventory coordinates with other national Antarctic programs and their scientists, and with representatives of the Scientific Committee on Antarctic Research (SCAR) and its specialist groups, regarding ongoing and previous scientific effort that relates directly to sites being surveyed. At sites where on-site flora have been photographed, identification of such flora is made in coordination with the British Antarctic Survey.

No Inventory effort takes place at sites where national Antarctic programs are operating research stations. However, five of these sites — Ferraz Station (SH), Arctowski Station (SH), Half Moon Island (SH), Bernardo O’Higgins Station (NW), and Vernadsky Station (SW) — are included in the compendium for reference, because they are relatively, frequently visited by tourists. The recently restored (and frequently visited) hut at Goudier Island is referenced in the site description of Jougla Point, Port Lockroy (NW).