Ocean Acidification

The Arctic Ocean is changing faster than any other ocean region in the world. Uptake of anthropogenic carbon, amplified warming, sea ice reduction, coastal erosion, and enhanced riverine runoff are driving important changes in the Arctic Ocean ecosystems through changes in primary production and ocean acidification. However, the current understanding of primary production and ocean acidification in the Arctic remains highly uncertain. Furthermore, projections of both processes by Earth-System Models diverge strongly in this region.

During this webinar, Dr. Terhaar presented:

(1) a modelling study that quantifies the impact of terrigenous nutrients from rivers and coastal erosions on Arctic Ocean primary production, a process that was (wrongly?) neglected so far, and

(2) results from two studies on emergent constraint on ocean acidification in the Arctic Ocean that suggests that projections of Earth-System Models collectively underestimated the extent of future ocean acidification in the Arctic Ocean.

We hope you enjoy this hour-long panel discussion on ocean and coastal acidification’s impact on scallops and softshell clams, methods of remediation, and future projections for the Gulf of Maine.

The talk was moderated by Dr. Libby Jewett, Director of the NOAA Ocean Acidification Program.

Panelists included, Dr. Samantha Siedlecki, University of Connecticut; Dr. Nichole Price, Bigelow Laboratory for Ocean Sciences; and Dr. Robert J Holmberg, Downeast Institute.

Webinar speaker: Dr. Elliot Scanes, Chancellor’s Research Fellow, Climate Change Cluster, The University of Technology, Sydney, Australia

Description:

Climate change is impacting ecosystems and organisms worldwide. Estuaries are diverse and important aquatic ecosystems; and yet until now we have lacked information on the response of estuaries to climate change. In this seminar I will present data from a twelve-year monitoring program, involving 6200 observations of 166 estuaries along ~1100 kilometers of the Australian coastline. Estuary temperatures increased by 2.16 C on average over 12 years, at a rate of 0.2 C/year, with waters acidifying at a rate of 0.09 pH units and freshening at 0.086 PSU/year. Lagoons and rivers are warming and acidifying at the fastest rate because of shallow average depths and limited oceanic exchange. The changes measured are an order of magnitude faster than predicted by global ocean and atmospheric models, indicating that existing global models may not be useful to predict change in estuaries. Estuaries are also home to diverse ecosystems and valuable economies supported by oysters. Oysters rely on bacterial communities forming a microbiome for their health and survival. Oysters are also vulnerable to disease and this is may be exacerbated by climate change in estuaries. We found that warming and acidification can shift the microbiome of Sydney rock oysters (Saccostrea glomerata), however, these effects can be ameliorated by selective breeding. We show that oyster genetic background may influence the microbiome under climate change and that future assisted evolution breeding programs could be used to enhance resilience in the oyster microbiome.

The GOA-ON webinar series has four sponsoring organizations:

(1) GOA-ON, the Global Ocean Acidification Observing Network,

(2) NOAA, the United States National Oceanic & Atmospheric Administration,

(3) IAEA OA-ICC, the International Atomic Energy Agency – Ocean Acidification International Coordination Centre, and

(4) IOC-UNESCO – the Intergovernmental Oceanographic Commission of the United Nations Educational, Scientific and Cultural Organization