Antarctica -1 Brrrrrrr

Antarctica -1 Brrrrrrrr

I’m McKensie Daugherty, your host for On the Ocean. Feel that chill in the air? It’s getting cold outside. But beware, even now in the midst of summer at bottom of the Earth, it is much colder there. That’s right, this month we are talking about the white continent, and how the Antarctic region uniquely influences the rest of the planet. The Antarctic continent itself covers about 14.1 million square miles, nearly one and a half times larger than the U.S., but its terrain is almost entirely covered by ice. A trans-Antarctic mountain range separates West and East Antarctic Ice Sheets over a mile thick in some areas that weigh down the bedrock to below sea level. Frozen, but not stationary, the Antarctic ice is always on the move. It is discharged into the Southern Ocean by a network of continental ice streams, glaciers, and floating ice shelves. The world’s strongest winds fuel the continuous eastward flow of the Antarctic Circumpolar Current around Antarctica, the largest ocean current on Earth. This swirling current extends throughout the entire water column, and essentially isolates Antarctic glaciers and ice shelves from direct oceanic influences. In some segments of the Antarctic continental shelf, the coldest and densest waters on the planet are produced during wintertime. In summer these areas are home to whales, seals, penguins, exotic cold-water species of algae, and unique invertebrates that thrive in nutrient-rich waters. Antarctica has no permanent human establishments by any nation or ethnic group, but a couple of thousand people live year-round on the continent at research stations established by several countries. In 1961 The Antarctic Treaty System, now involving 52 parties (including the U.S.), was established to ensure that Antarctica is used only for scientific investigation. Researchers study the ocean-ice-atmosphere interactions at key Antarctic locations with global relevance. This has been On the Ocean, a program made possible by the Department of Oceanography and a production of KAMU-FM on the campus of Texas A&M University in College Station. For more information and links, please go to ocean.tamu.edu and click On the Ocean.

 

Contributing Professor: Dr. Alejandro Orsi

Dr. Orsi Bio

More information and links:

http://woceatlas.tamu.edu/

http://sassi.tamu.edu/

Marine Animals: Striped Dolphin

Did you know dolphins have names? Scientists believe that dolphins develop special whistles for other dolphins, which allows them to recognize and communicate with each other in the ocean, the same way humans identify each other.

Striped dolphin jumping out of the water, from https://cff2.earth.com/uploads/2017/04/20122352/striped_dolphin_stenella_coeruleoalba.jpg

The Striped dolphin prefers deep tropical or warm temperate waters, between 52- and 84-degrees Fahrenheit. These dolphins live in social groups called pods, consisting of between 20 and 100 individuals. They are dark blue or dark grey, with two distinctive stripes along the sides of their bodies extending from the eye to the pectoral flipper, and from the eye to the midpoint between their dorsal fin and tail fin. Males of this species of dolphin may grow up to 9 feet long and weigh 350 pounds, while females can grow to be 8 feet and 330 pounds. They may live to be nearly 60 years old. Striped dolphins hunt fish and cephalopods and are capable of diving to 2,300 feet.

Striped dolphin range, Image from: CCARO, http://www.ccaro.org/local-cetacean-striped-dolphin.php

Striped dolphins exhibit remarkable social behavior within their pods. Within a pod, striped dolphins are often organized into smaller groups based on age, sex or breeding status. They do not interact with other dolphins or whales. Many scientists and fishermen have observed stunning displays of acrobatics by these dolphins, spinning at the surface of the ocean or leaping high into the air.

Striped dolphins are not considered endangered or threatened at this time, but they do face several considerable threats to their survival. The main threat to striped dolphins is entanglement in commercial fishing gear. Additionally, dolphins may face challenges from pollution and disease. 1,000 striped dolphins were killed in the Mediterranean Sea due to a disease outbreak related to pollution in the 1990s.

Striped dolphin tangled in fishing gear. Image by Rose Dixon, https://rosedixon.net/2012/12/20/pushing-the-boats-out-again-taiji-terror-tales-1912-201212/striped-dolphin/

This has been On the Ocean, a program made possible by the Department of Oceanography and a production of KAMU-FM on the campus of Texas A&M University in College Station. For more information and links, please go to ocean.tamu.edu and click On the Ocean.

Featured Image from: NOAA https://www.fisheries.noaa.gov/species/striped-dolphin

Script Authors: Karina Carpio and Macy Fidler

Contributing Professor: Dr. Lisa Campbell

Editor: James M. Fiorendino

Marine Animals: Albatross

Large seabirds known as albatrosses were once thought to be an omen of good luck by sailors. Samuel Taylor Coleridge’s famous poem The Rime of the Ancient Mariner recounts the tale of a sailor who shoots an Albatross at sea and brings misfortune to his ship and crew.

A wandering albatross with wings spread wide, from: https://www.dkfindout.com/us/animals-and-nature/birds/wandering-albatross/

The name albatross may refer to several different species of large seabirds in the family Diomedeidae. The largest species, the Wandering albatross Diomedea exulans, has a wingspan of 11 feet, allowing these birds to conserve energy by gliding on gusts of wind for hours without flapping. In calm weather, Albatrosses can be seen floating on the surface of the ocean, where they spend the vast majority of their lives, only returning to land to breed.

Albatross parent and chick, image from naturepl.com/Andy Rouse/ WWF

Albatrosses are primarily found in the Southern Hemisphere around Antarctica, Australia, South Africa, and South America. Only 3 species are found in the North Pacific Ocean. These seabirds can live for 60 years, becoming sexually mature at 5 years, but usually beginning to breed at 7 to 10 years old. Their diet consists of cephalopods like squid and octopus, crustaceans, and fish. They are also known to follow ships to feed on scraps. Albatrosses are capable of diving up to 5 meters to catch their food.

Wingspan of a wandering albatross compared with basketball great Shaquille O’Neal, image from: Discovery https://twitter.com/discovery/status/181491161293275137

Currently, the main threat to the albatross is fisheries; albatrosses are commonly caught on longline hooks when they chase bait meant for large fish before it has sunk. Invasive species are also impacting Albatross breeding sites; rodents often eat the eggs of albatrosses and destroy nesting areas. The Wandering Albatross is currently listed as vulnerable by the International Union for Conservation of Nature.

This has been On the Ocean, a program made possible by the Department of Oceanography and a production of KAMU-FM on the campus of Texas A&M University in College Station. For more information and links, please go to ocean.tamu.edu and click On the Ocean.

Featured image from: Oceanwide Expeditions https://oceanwide-expeditions.com/to-do/wildlife/wandering-albatross

Script Authors: Robert Resha and Mariam Mobarak

Contributing Professor: Dr. Lisa Campbell

Script Author: James M. Fiorendino

Marine Animals: Steller Sea Lion

Have you heard? The Stellar Sea Lion, Eumetopias jubatus, is the largest eared seal. Eared seals, which include sea lions and fur seals, belong to the family Otariidae. As their name suggests, eared seals have a visible ear flap, unlike true seals which have no visible ears. They were named after Georg Wilhelm Steller, a German naturalist who wrote about them while on an expedition in 1742.

Georg Wilhelm Steller, image from University of Tyumen, The Center of Russian-German Cooperation of Georg Wilhelm Steller, https://baynature.org/article/steller-man-behind-name/

The Steller Sea Lion can be found in coastal North Pacific waters. They are similar in appearance to California sea lions, but are much larger and lighter in color, with light tan or reddish-brown fur. Steller Sea Lions are sexually dimorphic; males are larger than females, up to 11 feet long and weighing 2,500 pounds. Females can grow to 9.5 feet long and weigh up to 800 pounds.

Steller Sea Lions, image by Robin Barefield, http://robinbarefield.com/steller-sea-lion/

Steller Sea Lions depend on both land and sea to survive. They forage in coastal and open ocean waters for food. They feed on a wide variety of fish, including salmon, cod, sand lance, and are known to eat cephalopods, as well. On land, Steller sea lions rest, molt, and breed and nurse their young.

Steller Sea Lion range, from NOAA https://www.fisheries.noaa.gov/species/steller-sea-lion

In the past, Steller sea lions have been hunted for meat, fur and oil, as well as being killed to prevent predation on farmed fish. In 1990, they were listed as threated under the Endangered Species Act. Currently, the National Oceanic and Atmospheric Association recognizes two different populations of Steller Sea Lions. The eastern population is considered threatened, while the western is endangered. The greatest threats to Steller sea lions today includes collisions with ships, pollution, and destruction of habitat.

This has been On the Ocean, a program made possible by the Department of Oceanography and a production of KAMU-FM on the campus of Texas A&M University in College Station. For more information and links, please go to ocean.tamu.edu and click On the Ocean.

Featured image from: NOAA

Script Authors: Hannah Hicks and Sam Longridge

Contributing Professor: Dr. Lisa Campbell

Editor: James M. Fiorendino