Location

Palmer Station is located at 64°46' S, 64°03' W, on a protected harbor on the southwestern coast of Anvers Island off the Antarctica Peninsula. The Palmer Weather Station was constructed in 1968 and consists of two major buildings, three smaller buildings, two large fuel tanks, a helicopter pad and a dock. The location of the station was choosen for its proximity to birds, seals and other components of the marine ecosystem, including Adelie Penguins.

Research

In 1990 it was designated by the National Science Foundation as a long term ecological research (LTER) site. From the about section of PAL LTER's website 'The PALmer (PAL) LTER seeks to build on three decades of long-term research along the western side of the Antarctic Peninsula (WAP) to gain new mechanistic and predictive understanding of ecosystem changes in response to disturbances spanning long-term, decadal, and higher-frequency “pulse” changes driven by a range of processes, including natural climate variability, long-term climate warming, resiliency/recovery in the face of press versus pulse forcing, transformed spatial landscapes, and food-web alterations.'.

Wind Speed and Direction

Zoom + Pan

Daily Average Temperature

The annual average temperature is a cold -3°C with the warmer summer months from December to February averaging 2°C and the colder winter months from July to August averaging -10°C. There is a general trend of winter starting and ending later each year.

Sea Ice Extent

The fundamental long-term objective of the seabird component of the Palmer LTER has been to identify and understand the processes that influence the average population growth rate of various penguin populations. Two proposed mechanisms are changes in the regional krill biomass, and the long term changes in sea ice extent as it affects the balance of species due to the affitinty to sea ice that different species have developed over time. Later we will investigate krill abundance. The different ice attributes, formation, age, land type, edge, and condition trend, are classified by the World Meteorological Organization (WMO). A full list is available here (https://artefacts.ceda.ac.uk/badc_datadocs/ surface/code.html). In 2015, the ice age observed was mostly young and predominantly new ice corresponding to an id of 2 and 3. The land ice type was predominantly a large number of icebergs with growlers and bergy bits, corresponding to an id of 7, 8, 9. There was a range of different ice conditions observed, from easily penetrable ice with conditions improving to difficult to penetrate ice withconditions not changing.

The interactive map to the left shows the movement of penguins over time. The map is divided up into a grid, and then each pixel is coloured based on the number of penguins inside that grid square. The values are then normalised so a squares represents the proportion of the total penguin population present in the square that year.

Diet Composition

The fundamental long-term objective of the seabird component of the Palmer LTER has been to identify and understand the processes that influence the average population growth rate of various penguin populations. Two proposed mechanisms are changes in the regional krill biomass, and the long term changes in sea ice extent as it affects the balance of species due to the affitinty to sea ice that different species have developed over time. Previously we saw the changes in sea ice extent over time, now we investigate krill abundance.

Adelie Penguins have a varied diet, consisting of primary prey, including krill and fish, and secondary prey, including octopus, squid amphipods, mysid shrip, limpets and small clams. Krill makes up the bulk of the diet for each of the three penguin species, Adelie, Gentoo and Chinstrap, during the summer months. There are 3 main types of krill in the penguin diet, Antarctic krill (Euphausia superba), crystal krill (E. crystallorophias) and Thysanoessa macrura (no common name).

The process for collecting samples is outlined on the PAL LTER website 'Adelie penguin diet samples obtained in the field are initially drained and weighed and returned to laboratories for further processing. This includes resuspension of the samples in fresh water to release fish otoliths, squid beaks and other prey hard parts, and then draining to a consistency that facilitates separating the diet samples into componenets. Each prey component is weighed (total weight) and, if possible, sorted according to species for further analyses.'.

Krill Abundance

Islands

How Big Are Adelie Penguins?

The map to the left shows the location of a number of key islands in the Anvers region. Charcot island is located further south of Biscoe island. The chart to the right compares the average penguin attributes for different species on various islands. The culmen is the upper ridge of a penguins beak. The depth measures the vertical height of the beak, while the length is the horizontal length. The dot plot to the right shows the average measurements for foraging adult male and female penguins for each species and island from 2007 to 2009.

Annual Penguin Population Count per Species

How Have Adelie Penguin Populations Changed?

The chart to the left shows the annual penguin population. The data was collected by the Southwest Fisheries Science Center from the Anvers Region of Antarctica. Previously we saw the krill abundance has remained relatively high, in contrast the Adelie penguin population has steadily declined over the past 30 years. This is contrary to the hypothesis that krill abundance has an effect on penguin population health. The chart to the right show the number of adelie penguin chicks for a number of different islands in the Anvers region. We can the number of chicks has been declining since 1998 with a sharp decrease in 2002, which reflects the overall population decline.

Number of Adelie Penguin Chicks per Island

Author: Joshua Childs

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