In situ response of Antarctic under-ice primary producers to experimentally altered pH.

Elevated atmospheric CO concentrations are contributing to ocean acidification (reduced seawater pH and carbonate concentrations), with potentially major ramifications for marine ecosystems and their functioning. Using a novel in situ experiment we examined impacts of reduced seawater pH on Antarctic sea ice-associated microalgal communities, key primary producers and contributors to food webs. pH levels projected for the following decades-to-end of century (7.

Broad-scale patterns of tissue-δ15N and tissue-N indices in frondose Ulva spp.; developing a national baseline indicator of nitrogen-loading for coastal New Zealand.

A survey of tissue-δ(15)N and tissue-N values in the green macroalga, Ulva, was conducted around the coast of New Zealand to determine if these indices could be used as indicators of anthropogenic nutrient loading in coastal waters. In addition, data from four case studies showed temporal and spatial responses of tissue-δ(15)N and tissue-N in Ulva to significant terrestrial nutrient inputs. Tissue-δ(15)N in Ulva from 'natural' exposed coastal sites showed a relatively narrow baseline range of values (6.