Pléneau Island (PLEN)

65˚06’S, 64˚04’W

Magnetic declination: 17.0˚E

Inventory subarea: SW

Inventory acronym: PLEN

Species Diversity: MEDIUM

Site Sensitivity: MODERATE

 

Location — History — Features

This 0.8-mile-long island lies NE of Hovgaard island in the Wilhelm Archipelago, and is very near to Booth Island and the S end of the Lemaire Channel. It was first charted (albeit, incorrectly) as a peninsula of Hovgaard Island during Charcot’s 1903-05 French Antarctic Expedition. The island was named by Charcot for the expedition’s photographer, Paul Pléneau. It was first shown as an island on the Argentine government chart of 1957.

Landing Characteristics

Uncharted water near shore. Hazardous rocks along the shoreline may be exposed, depending on the tide. Landings onto rocks and boulders on the E-NE side, facing Booth Island. May be considerable snow cover, with hidden crevasses. Snow cornices on the shoreline are unstable and treacherous. Pléneau Island is very close to Booth Island at the S end of the Lemaire Passage, and is a site that occasionally has attracted straggler emperor penguins. There are two potential landing sites; one to the N with easy upslope access to gentoo penguins, moss, and scenic views; the other to the S (noted on the appended map), which likely will be closer both to the ship’s anchorage or drifting position, and to nearby Booth Island. Southern elephant seals often haul-out or collect in wallows. The gentoo penguin colonies are scattered and at higher reaches, and care must be taken to avoid trampling the site’s moss beds, which may be hidden by snow cover. On clear days, the top of the island provides excellent views of the glacial and ice scenery to the W.

Antarctic Site Inventory Effort

Visits by Antarctic Site Inventory researchers, 1994-2003:

1.    December 11, 1994    RN              Livonia

2.    January 23, 1996        RD RP        Livonia

3.    February 13, 1996      BH RP        Livonia

4.    February 19, 1997      RN             Explorer

5.    November 28, 1999    LB BP        Cal Star

6.    December 13, 2000    RN             Cal Star

7.    December 27, 2000    SF LF        Cal Star

8.    January 24, 2001        RN RD      Cal Star

9.    January 25, 2001        RD            Cal Star

10.    January 4, 2002        RP            Endeavour

11.    January 15, 2002      RP WT       Endeavour

12.    February 8, 2002      MM            Endeavour

13.     January 3, 2003      RP             Endeavour

14.     January 14, 2003    SF             Endeavour

Assessment and monitoring. Surveyed, mapped, and photodocumented (terrestrial). Aerial photodocumentation needed. Regular, site-wide censusing of gentoo penguins.

Fauna — Flora — Censuses

Penguins & flying birds . Gentoo penguins, kelp gulls, and south polar skuas are confirmed breeders. Gentoo penguin census data reported in Woehler (1993): 500 N1, 1982.

Antarctic Site Inventory censuses:

Gentoo penguin

1,577    N1    1999 Nov

1,579    N1    2000 Dec

1,639    N1    2003 Jan

Blue-eyed shag

    28    N1    2000 Dec

    25    N1    2001 Jan

    53    C1    2001 Jan

    28    N1    2003 Jan

Seals . Southern elephant seals haul-out regularly.

Flora . As the snow cover erodes, patches of Prasiola crispa , crustose lichens Caloplaca , spp., and cushion moss, spp. may be found. At higher reaches, the moss beds appear to be more extensive, but are often snow covered. Snow algae also present.

Conservation Aspects

Site sensitivities. Gentoo penguins in widely scattered colonies are easily approached and disturbed, especially in November and early December when adults will be incubating eggs; subsequently, adults will be guarding and provisioning chicks at the nest, then in crèche. Blue-eyed shags nesting at the NE end are easily approached and disturbed; in November and early December adults will be incubating eggs and, subsequently, guarding and provisioning chicks. As the snow cover recedes, patches of moss and lichens are exposed and readily accessed, and easily may be trampled. Scattered south polar skua territories are easily accessed and disturbed, particularly, later in the season (from mid-January) when adults are fiercely protecting young. Southern elephant seals often haul-out or collect in wallows, and are easily approached and disturbed.

Pointers for avoiding disruptions.

1. Walk slowly and carefully around nesting, crèching, or molting penguins.

2. Walk slowly and carefully around nesting shags.

3. Watch for, and avoid, exposed moss patches.

4. Avoid and stay clear of skua territories.

5. Avoid and stay clear of wallowing southern elephant seals.

6. In deep snow, walk carefully and slowly and beware of crevasses.

7. Stay clear of — and do not hike upon or wander over — snow cornices.

Visitation Aspects

Numbers of tourist zodiac landings and participating visitors, 1989-2003: