Ocean Acidification: An Emerging Threat to our Marine Environment

This report aims to provide a concise overview of the present state of scientific knowledge of ocean acidification and its likely impacts on organisms and ocean ecosystems. This is particularly relevant in the context of the possible implications and ramifications of ocean acidification for Irish marine areas. Discussion on how mankind’s CO2 emissions are changing ocean chemistry; consequences of ocean acidification; ocean acidification as an emerging cause for concern; international policy drivers, strategies and necessary actions; and research and information needs are presented. Ireland’s marine location and extensive marine resources in our shelf seas, Atlantic waters and habitats of the west coast mean we are uniquely positioned to contribute to international scientific efforts to monitor and understand the impacts of ocean acidification. Monitoring and research of key biological, chemical and physical factors in these regions will allow us to determine the current status of Irish Marine waters, the rate of change in the carbonate cycle and the influence of this change on natural communities and ecosystems. The Marine Institute’s SSTI funded Sea Change programme includes a Rapid Climate Change programme. Under this, a two year collaborative project between NUI Galway and Marine Institute ‘Impacts of increased atmospheric CO2 on ocean chemistry and ecosystems’ is developing capabilities for measuring pCO2 fluxes, inorganic carbon chemistry and pH and is initiating baseline measurements of these parameters in coastal and offshore waters. This report summarises the issues and state of knowledge and communicates ongoing monitoring and research needs into acidification.Funder: Marine Institut

Microphytobenthos of Arctic Kongsfjorden (Svalbard, Norway): biomass and potential primary production along the shore line

During summer 2007, Arctic microphytobenthic potential primary production was measured at several stations around the coastline of Kongsfjorden (Svalbard, Norway) at ?5 m water depth and at two stations at five different water depths (5, 10, 15, 20, 30 m). Oxygen planar optode sensor spots were used ex situ to determine oxygen exchange in the overlying water of intact sediment cores under controlled light (ca. 100 ?mol photons m?2 s?1) and temperature (2–4°C) conditions. Patches of microalgae (mainly diatoms) covering sandy sediments at water depths down to 30 m showed high biomass of up to 317 mg chl a m?2. In spite of increasing water depth, no significant trend in “photoautotrophic active biomass” (chl a, ratio living/dead cells, cell sizes) and, thus, in primary production was measured at both stations. All sites from ?5 to 30 m water depth exhibited variable rates of net production from ?19 to +40 mg O2 m?2 h?1 (?168 to +360 mg C m?2 day?1) and gross production of about 2–62 mg O2 m?2 h?1 (17–554 mg C m?2 day?1), which is comparable to other polar as well as temperate regions. No relation between photoautotrophic biomass and gross/net production values was found. Microphytobenthos demonstrated significant rates of primary production that is comparable to pelagic production of Kongsfjorden and, hence, emphasised the importance as C source for the zoobenthos