Spatial distribution patterns of ascidians (Ascidiacea: Tunicata) in combination with information on bathymetry, oceanography, chlorophyll-a, and sea-ice on the continental shelves off the northern Antarctic Peninsula during POLARSTERN cruise ANT-XXIX/3

Ascidians (Ascidiacea: Tunicata) are sessile suspension feeders that represent dominant epifaunal components of the Southern Ocean shelf benthos and play a significant role in the pelagic-benthic coupling. Here, we report the results of a first study on the relationship between the distribution patterns of eight common and/or abundant (putative) ascidian species, and environmental drivers in the waters off the northern Antarctic Peninsula. During RV Polarstern cruise XXIX/3 (PS81) in January-March 2013, we used seabed imaging surveys along 28 photographic transects of 2 km length each at water depths from 70 to 770 m in three regions (northwestern Weddell Sea, southern Bransfield Strait and southern Drake Passage), differing in their general environmental setting, primarily oceanographic characteristics and sea-ice dynamics, to comparatively analyze the spatial patterns in the abundance of the selected ascidians, reliably to be identified in the photographs, at three nested spatial scales. At a regional (100-km) scale, the ascidian assemblages of the Weddell Sea differed significantly from those of the other two regions, whereas at an intermediate 10-km scale no such differences were detected among habitat types (bank, upper slope, slope, deep/canyon) on the shelf and at the shelf break within each region. These spatial patterns were superimposed by a marked small-scale (10-m) patchiness of ascidian distribution within the 2-km-long transects. Among the environmental variables considered in our study, a combination of water-mass characteristics, sea-ice dynamics (approximated by 5-year averages in sea-ice cover in the region of or surrounding the photographic stations), as well as the seabed ruggedness, was identified as explaining best the distribution patterns of the ascidians.

Puerto Rico : update of selected information contained in a 1981 GAO report : fact sheet for the Chairman, Committee on Energy and Natural Resources, U.S. Senate /

"B-234765"--P. 1.

General Library

Albert Kahn, architect. In 1918 the old library was demolished and a new front (north facade) was attached to the 1893 stacks and the stacks built in 1916-1917. This was referred to as the (New) General Library until the south stack addition was built in 1967-1970, when the entire library building was named the Harlan Hatcher Graduate Library.

General Library

Albert Kahn, architect. In 1918 the old library was demolished and a new front (north facade) was attached to the 1893 stacks and the stacks built in 1916-1917. This was referred to as the (New) General Library until the south stack addition was built in 1967-1970, when the entire library building was named the Harlan Hatcher Graduate Library.

General Library

Albert Kahn, architect. In 1918 the old library was demolished and a new front (north facade) was attached to the 1893 stacks and the stacks built in 1916-1917. This was referred to as the (New) General Library until the south stack addition was built in 1967-1970, when the entire library building was named the Harlan Hatcher Graduate Library.

Johnnie Doolittle, General Doolittle's son, in dorm room 5/20/1942

(Ivory took photos for A.P.)

Johnnie Doolittle, General Doolittle's son, in dorm room, r headline of Tokyo raid. 5/20/1942 5/20/1942

(Ivory took photos for A.P.)

Johnnie Doolittle, General Doolittle's son, in dorm room, with newspaper headline of Tokyo raid. 5/20/1942

(Ivory took photos for A.P.)

Need for a Government-wide budget classification structure for Federal research and development information : report to the Congress /

Publication date stamped on cover.

A general charter for trade associations. Correspondence between the attorney general and the secretary of commerce. Permissible activities of trade associations. Text of Supreme court decision condemning certain practices. Text of act legalizing agricultural cooperative marketing associations, together with a treatise on the application of these pronouncements.

Mode of access: Internet.

Utilization of radioisotopes in physical and biological sciences--general topics; a literature search.

At head of title: U.S. Atomic Energy Commission.

A concise answer to the general inquiry, who, or what are the Shakers.

"A hymn. Composed by Samuel Hooser ": p. 11-12.

Drug abuse prevention for the general population /

"Contract number 271-90-2200"--T.p. verso.

Message from the President of the United States communicating in answer to a Senate resolution of December 6, 1877 information in relation to the operation of the Union Pacific Railroad and its branches.

Signed: Charles Devens, Attorney-General.

Impact of the freedom of information and privacy acts on law enforcement agencies.

Mode of access: Internet.