Effects of High Dissolved Inorganic and Organic Carbon Availability on the Physiology of the Hard Coral Acropora millepora from the Great Barrier Reef

Coral reefs are facing major global and local threats due to climate change-induced increases in dissolved inorganic carbon (DIC) and because of land-derived increases in organic and inorganic nutrients. Recent research revealed that high availability of labile dissolved organic carbon (DOC) negatively affects scleractinian corals. Studies on the interplay of these factors, however, are lacking, but urgently needed to understand coral reef functioning under present and near future conditions. This experimental study investigated the individual and combined effects of ambient and high DIC (pCO2 403 μatm/ pHTotal 8.2 and 996 μatm/pHTotal 7.8) and DOC (added as Glucose 0 and 294 μmol L-1, background DOC concentration of 83 μmol L-1) availability on the physiology (net and gross photosynthesis, respiration, dark and light calcification, and growth) of the scleractinian coral Acropora millepora (Ehrenberg, 1834) from the Great Barrier Reef over a 16 day interval. High DIC availability did not affect photosynthesis, respiration and light calcification, but significantly reduced dark calcification and growth by 50 and 23%, respectively. High DOC availability reduced net and gross photosynthesis by 51% and 39%, respectively, but did not affect respiration. DOC addition did not influence calcification, but significantly increased growth by 42%. Combination of high DIC and high DOC availability did not affect photosynthesis, light calcification, respiration or growth, but significantly decreased dark calcification when compared to both controls and DIC treatments. On the ecosystem level, high DIC concentrations may lead to reduced accretion and growth of reefs dominated by Acropora that under elevated DOC concentrations will likely exhibit reduced primary production rates, ultimately leading to loss of hard substrate and reef erosion. It is therefore important to consider the potential impacts of elevated DOC and DIC simultaneously to assess real world scenarios, as multiple rather than single factors influence key physiological processes in coral reefs.

William Hope Hodgson's borderlands: monstrosity, other worlds, and the future at the fin de siècle.

William Hope Hodgson has generally been understood as the author of several atmospheric sea-horror stories and two powerful but flawed horror science fiction novels. There has been no substantial study analysing the historical and cultural context of his fiction or its place in the Gothic, horror, and science fiction literary traditions. Through analysing the theme of borderlands, this thesis contextualises Hodgson’s novels and short stories within these traditions and within late Victorian cultural discourse. Liminal other world realms, boundaries of corporeal monstrosity, and the imagined future of the world form key elements of Hodgson’s fiction, reflecting the currents of anxiety and optimism characterising fin-de-siècle British society. Hodgson’s early career as a sailor and his interest in body-building and physical culture colour his fiction. Fin-de-siècle discourses of evolution, entropy, spiritualism, psychical research, and the occult also influence his ideas. In The House on the Borderland (1908) and The Night Land (1912), the known world brushes against other forms of reality, exposing humanity to incomprehensible horrors. In The Ghost Pirates (1909), the sea forms a liminal region on the borderland of materiality and immateriality in which other world encounters can take place. In The Night Land and The Boats of the ‘Glen Carrig’ (1907), evolution gives rise to strange monstrous forms existing on the borderlines of species and identity. In Hodgson’s science fiction—The House on the Borderland and The Night Land—the future of the earth forms a temporal borderland of human existence shaped by fin-de-siècle fears of entropy and the heat-death of the sun. Alongside the work of other writers such as H. G. Wells and Arthur Machen, Hodgson’s four novels respond to the borderland discourses of the fin de siècle, better enabling us to understand the Gothic literature of the period as well as Hodgson’s position as a writer who offers a unique imaginative perspective on his contemporary culture.