Weddell Seal Science

Weddell Seal Science Videos Now Available at the National Science Digital Library (NSDL)

The Erebus Bay Weddell Seal population study is excited to announce that we now have a good selection of Weddell seal population study videos and our public outreach and education WeddellSealScience.com web portal available through the National Science Digital Library (NSDL) website. The videos are available as Open Educational Resources Commons products allowing video download and educational usage.

To readily get to our products at the NSDL, go to their easy-to-use website and type "Weddell Seal Science" in the main Search field to access, watch, and download our project videos. Viewers can check out and download videos for personal enjoyment and informal science learning and teaching. The videos can be remixed to create new educational products. 

Following is the description of the mission of the National Science Digital Library from their "Overview" section:

Who We Are and What We Do

The National Science Digital Library provides high quality online educational resources for teaching and learning, with current emphasis on the sciences, technology, engineering, and mathematics (STEM) disciplines—both formal and informal, institutional and individual, in local, state, national, and international educational settings. The NSDL collection contains structured descriptive information (metadata) about web-based educational resources held on other sites by their providers. These providers have contribute this metadata to NSDL for organized search and open access to educational resources via this website and its services.

Most resources in the library adhere to principles of Open Educational Resource (OER) access, although some resources are restricted to provider site membership, or may have a cost associated with them (indicated in the full record of the resource).

All WeddellSealScience.com videos and products are free for educational usage! We hope you enjoy watching some of our videos and accessing our web portal, WeddellSealScience.com!

- Mary Lynn Price

 

Animal Neighbors of the Erebus Bay Weddell Seals

During the Weddell seal pupping season in Erebus Bay, Weddell seals can be sighted in pupping colonies scattered throughout the study area. But they are not the only animal species encountered on top of the sea ice in this part of Antarctica. Their animal neighbors can include crabeater seals, emperor penguins, Adélie penguins, south polar skuas, kelp gulls, and snow petrals. 

These two photos show a Weddell seal pup, Leptonychotes weddellii, on top of the ice and breathing at the surface of the icy Antarctic water. Weddells are true seals of the family Phocidae, and spend their entire lives in Antarctica. They are the southernmost breeding population of mammals on Earth, and can be found all around the coast of Antarctica.

Below is a crabeater seal, Lobodon carcinophaga, lounging on the ice near a Weddell seal. Crabeater seals are thought to be the most abundant seals on Earth, and are true seals that can be found all around the coast of Antarctica. They feed primarily on Antarctic krill, and have specialized teeth to assist them in straining krill from the water.

Among the bird species found in the Erebus Bay Weddell seal study area is the kelp gull, Larus dominicanus, a big gull of the Southern Hemisphere as seen in the photo below.

The south polar skua, Stercorarius maccormicki, in the photo below, is a large predatory bird that feeds on fish often stolen from other birds. This bird can often be seen feeding on Weddell seal birth placenta in the pupping colonies.

Emperor penguins, Aptenodytes forsteri, are the tallest and the heaviest of the penguin species and can dive deeper and longer than any other penguin. They breed in large colonies and are often seen in small groups traveling through the Weddell seal study area.

The smaller Adélie penguin, Pygoscelis adeliae, as seen in the photo below, also form large colonies around the coast of Antarctica. These birds can often be seen singly or in small groups traveling about the Erebus Bay Weddell seal study area.

- Mary Lynn Price

Update From The Ice!

So far, this has been a very interesting pupping season for the Weddell seals of Erebus Bay, Antarctica, and the Weddell population study's research field team. There is change this year in both the number of pups born in the study area compared to the past few years, and the location of the sea ice edge this pupping season.

Project lead scientist Dr. Jay Rotella notes, "All continues to go very well with the 2016 season. Most of the pups for the 2016 season have now been born. It appears that the number of pups this year will be quite close to the long-term average. The team has identified and tagged over 400 pups and completed the 1st survey of the population. They will try to obtain 6 surveys between now and Dec 8th to obtain data on the size of the population that’s using the study area this year and to assess the composition of the population." In comparison, last season there were 658 Weddell pups born in the study area.

As for the sea ice edge just beyond the study area, Rotella notes that, "The ice edge is farther north this year than it’s been in recent years. Given that, it will be interesting to see how the numbers of pups and adults that are seen this year compares with what has been seen in other years."

Below are two Sea Ice Maps courtesy Brad Herried of the Polar Geospatial Center (PGS). The maps show in the upper right area where the sea ice edge is this season. In the top map for this year, no sea ice edge can be seen because it is further north beyond the map area. In the 2nd Sea Ice Map from around this same time of year in 2015. In start contrast to this year, the sea ice extent was much further south in McMurdo Sound, and much closer to the study area pupping colonies. Sea ice extent affects the distance the Weddell seals must swim initially to get to the pupping colonies, and how much distance there is between the seals and their predators beyond the sea ice edge. Sea ice extent can also affect how much bio-production is going on under the ice, and how much in the way of food resources might be available for the seals.

Says Rotella, "In addition to understanding the lives of individual seals, the project also seeks to understand how population size and structure varies with environmental conditions. Thus, obtaining data from years with differing conditions is vital, and years such as this are very interesting and help greatly."

In another interesting update from the research field team on the ice, a crabeater seal is photographed lounging on the ice next to a Weddell seal. Crabeater seals are occasionally seen in the study area, and are one of the 4 species of seals that live their entire lives in Antarctica, including the Weddell seal, the Ross seal, and the leopard seal. See if you can spot the differences between the crabeater and the Weddell seal!

- Mary Lynn Price

Pupping Peaks, Team Work Continues

The Antarctica field team is now shifting gears in their field work. Weddell seal pupping has peaked, and the field work is now focusing more on population surveys, and assessing seal mom and pup weights. The number of pups born in the Erebus Bay study area appears to be down some from the last few years when record high numbers of pups were born during the pupping seasons. 

Last season, some 658 pups were born--one of the highest pupping numbers ever for the nearly 50 year old Weddell seal population study. This season the number will be lower. Lead scientist Dr. Jay Rotella, who will soon join Dr. Bob Garrott and the rest of the field team on the ice, noted in a previous post that, "Since 2004, annual population sizes and pup-production levels have ranged from record lows (in 2004, only 169 pups were produced, which is 38% of the long-term average) to the highest level recorded since 1967 (in 2015, 658 pups were produced, which is 149% of the long-term average)."

With the shift in focus at this point in the season, the field team will be conducting more Weddell seal population surveys, and seeking out pups and moms weighed this season to reweigh them at subsequent points during the pup nursing/nurturing period. 

To conduct Weddell seal population surveys, the field team will travel over the entirety of the Erebus Bay Weddell study area counting and identifying every seal. The team will do this between 5 and 8 times over the duration of the pupping and nurturing period in order to account for all the seals that may be in the water on a single survey, maximizing the number of individual seals counted through repeated census surveys.

We'll have further data from the team as the season progresses in November.

-Mary Lynn
 

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