The influence of seawater pH on U/ Ca ratios in the scleractinian cold-water coral Lophelia pertusa

The increasing pCO2 in seawater is a serious threat for marine calcifiers and alters the biogeochemistry of the ocean. Therefore, the reconstruction of past-seawater properties and their impact on marine ecosystems is an important way to investigate the underlying mechanisms and to better constrain the effects of possible changes in the future ocean. Cold-water coral (CWC) ecosystems are biodiversity hotspots. Living close to aragonite undersaturation, these corals serve as living laboratories as well as archives to reconstruct the boundary conditions of their calcification under the carbonate system of the ocean. We investigated the reef-building CWC Lophelia pertusa as a recorder of intermediate ocean seawater pH. This species-specific field calibration is based on a unique sample set of live in situ collected L. pertusa and corresponding seawater samples. These data demonstrate that uranium speciation and skeletal incorporation for azooxanthellate scleractinian CWCs is pH dependent and can be reconstructed with an uncertainty of ±0.15. Our Lophelia U / Ca-pH calibration appears to be controlled by the high pH values and thus highlighting the need for future coral and seawater sampling to refine this relationship. However, this study recommends L. pertusa as a new archive for the reconstruction of intermediate water mass pH and hence may help to constrain tipping points for ecosystem dynamics and evolutionary characteristics in a changing ocean.

Notebook, ca. 1714

Paper notebook with Latin text including theses titled "Divisio deber constare partibus paucissimis," "Forma dat esse rei --Theses primae," "Simile non agit in simile probabir à Mr T. Foxcroft in Thesis hâc," and "Lux est Corpus probatur 1712 Thesis." The notebook includes unattached pages of various sizes and a paper fragment.

Notebook, ca. 1714

Paper notebook of Latin grammar including verb conjugations.

Lux est Corpus, ca. 1714

Single folded piece of paper with Latin text titled "Lux est Corpus."

Antithesis: Elementa in propriis..., ca. 1714

Paper notebook comprised of two folded sheets of paper with Latin texts.

Letter from Levi Hedge to President John Kirkland, [ca. 1823]

Levi Hedge, Professor of Logic and Metaphysics, wrote Harvard president John Kirkland requesting renovations to the house which he occupied. Hedge's house was situated on North Street (now Massachusetts Avenue). He notes that the kitchen has a leaky sink, loose and unusable shelves, and is insufficiently insulated.

Glazier's report, [ca. 1765-1775]

On verso: S. Hastings, S. Kendal. This report outlines the glass needed for College buildings in the mid-18th century. Estimates include windows for Hollis, Massachusetts, and Harvard Halls and an unspecified College House.

Measures of hall and chapel, [ca. 1800]

This note, likely in the hand of President Willard, directs Mr. [Josiah] Moore and Mr. [John] Walton measure the length, width, and height of the chapel, hall, and library in Harvard Hall. Includes each room's measurements.

Estimate for shutters for Harvard Hall, [ca. 1806]

Itemized list of cost estimates for shutters for Harvard Hall, compiled circa 1806. Includes supplies needed to install shutters for 24 windows in Harvard Hall. Materials needed include boards, nails, and cross corner hinges.

Outlines of Holden Chapel, [ca. 1801]

Pen and ink drawings with measurements of the interior ground plot, arch, and side of Holden Chapel.

Chamber plan, ca. 1801

Interior floor plan of Hollis Hall. Includes dimensions for student rooms and hallways.

Hollis Hall or Stoughton Hall, ca. 1801

Detailed floor plan of either Hollis Hall or Stoughton Hall, as indicated on drawing. Includes dimensions for student chambers, hallways, and stairs.

Hollis Hall…S.E. [Southeast] view, ca. 1807

Pencil drawing of Hollis Hall, southeast view .