Researchers think they have reason for low oyster production figured out (video)

Tillamook, Ore. — One of the Oregon coast’s biggest industries is being seriously threatened.

Recently, oyster hatcheries have seen a significant drop-off in production. During the last couple of years, researcher Alan Barton with the Whiskey Creek Shellfish Hatchery in Tillamook has been trying to figure out the reason behind the increase the high levels of acidity in the ocean. Oyster larvae are supposed to turn into this adult oyster, but researchers say the acidic ocean is a problem.

University of Miami grad student receives NSF GRF to study impact of ocean acidification

Rachael Heuer to use Gulf toadfish to see how they might cope with increasingly acidic ocean conditions

Rosenstiel School of Marine & Atmospheric Science Marine Biology and Fisheries student, Rachael Heuer, was one of four University of Miami students to receive a National Science Foundation (NSF) Graduate Research Fellowship. The program recognizes and supports outstanding graduate students who are pursuing research-based advanced degrees at accredited U.S. institutions.

Using Gulf toadfish (Opsanus beta) Heuer is studying how these fish might cope with ocean acidification, or changes in ocean chemistry resulting from rising levels of carbon dioxide in the atmosphere that are absorbed by the ocean. Her initial findings indicate that toadfish exposed to elevated CO₂ levels, relevant for the near future and current upwelling regions, lose increased amounts of base from the body through the intestine. This is problematic since toadfish and other marine fishes need to retain bases to help them cope with acidic environments. Heuer’s preliminary findings suggest that this intestinal base loss negatively affects their overall pH balance and health.

Threshold of carbonate saturation state determined by CO2 control experiment (update)

Acidification of the oceans by increasing anthropogenic CO₂ emissions will cause a decrease in biogenic calcification and an increase in carbonate dissolution. Previous studies have suggested that carbonate dissolution will occur in polar regions and in the deep sea where saturation state with respect to carbonate minerals (Ω) will be <1 by 2100. Recent reports demonstrate nocturnal carbonate dissolution of reefs, despite a Ω_a (aragonite saturation state) value of >1. This is probably related to the dissolution of reef carbonate (Mg-calcite), which is more soluble than aragonite. However, the threshold of Ω for the dissolution of natural sediments has not been clearly determined. We designed an experimental dissolution system with conditions mimicking those of a natural coral reef, and measured the dissolution rates of aragonite in corals, and of Mg-calcite excreted by other marine organisms, under conditions of Ω_a > 1, with controlled seawater pCO₂. The experimental data show that dissolution of bulk carbonate sediments sampled from a coral reef occurs at Ω_a values of 3.7 to 3.8. Mg-calcite derived from foraminifera and coralline algae dissolves at Ω_a values between 3.0 and 3.2, and coralline aragonite starts to dissolve when Ω_a = 1.0. We show that nocturnal carbonate dissolution of coral reefs occurs mainly by the dissolution of foraminiferans and coralline algae in reef sediments.

Associate professor – Impacts of ocean acidification and climate change on seaweed based coastal ecosystems

Reference No: HAS 77/12
Type: Academic
Location: Hobart
School/Section: Institute for Marine and Antarctic Studies (IMAS)
Appointment: Tenurable
Availability: Internal & External
Closing Date: Friday, 27 April 2012

This is in an ongoing academic staff appointment in the Institute for Marine and Antarctic Studies (IMAS) at the University of Tasmania. IMAS aspires to become the leading global institution for temperate marine, Southern Ocean, and Antarctic studies, and offers a dynamic and collaborative work environment. Hobart’s marine and Antarctic research community numbers ca 1000 staff at the University of Tasmania, the Commonwealth Scientific and Industrial Research Organisation, and the Australian Antarctic Division. The University provides excellent employment benefits and a pleasant working environment, while Hobart offers an unparalleled lifestyle with a vibrant culture and unique natural environment.

New journal, “Ocean Acidification”

Ocean Acidification (OA) is an international journal devoted to the rapid publication of original and significant studies in all areas of the emerging field of Ocean Acidification:

- biogeochemical and atmospheric processes /interactions;
- biological and ecological response to Ocean Acidification and climate change at cellular to ecosystem scales;
- models and predictions of future change.