News | December 04, 2014

CT scans of coral skeletons reveal ocean acidity increases reef erosion

Scientists at the University of Hawai'i-Manoa used microCT to generate before and after images

December 4, 2014 — New research from scientists at the Hawai’i Institute of Marine Biology (HIMB) uses micro computed tomography (microCT) to demonstrate that ocean acidification (decreasing ocean pH) not only negatively impacts coral reef growth, but also enhances reef breakdown.

Coral reefs persist in a balance between reef construction and reef breakdown. As corals grow, they construct the complex calcium carbonate framework that provides habitat for fish and other reef organisms. Simultaneously, bioeroders, such as parrotfish and boring marine worms, breakdown the reef structure into rubble and the sand that nourishes our beaches. For reefs to persist, rates of reef construction must exceed reef breakdown. This balance is threatened by increasing atmospheric carbon dioxide, which causes ocean acidification. Prior research has largely focused on the negative impacts of ocean acidification on reef growth, but the new research from HIMB — based at the University of Hawai'i - M?noa (UHM) — demonstrates enhancement of reef breakdown.

To measure bioerosion, researchers deployed small blocks of calcium carbonate (dead coral skeleton) onto the reef for one year. Traditionally, these blocks are weighed before and after deployment on the reef; however, HIMB scientists used microCT (a high-resolution CT scan) to create before and after 3-D images of each block. According to Nyssa Silbiger, lead author of the study and doctoral candidate at HIMB, this novel technique provides a more accurate measurement of accretion and erosion rates.

The researchers placed the bioerosion blocks along a 100-ft transect on shallow coral reef in K?ne'ohe Bay, Hawai'i, taking advantage of natural variability of pH in coastal reefs. The study compared the influence of pH, resource availability, temperature, distance from shore and depth on accretion-erosion balance. Among all measured variables, pH was the strongest predictor of accretion-erosion. Reefs shifted towards higher rates of erosion in more acidic water - a condition that will become increasingly common over the next century of climate change.

Silbiger and colleagues are learning all they can from the microCT scans, as this is the first time before-and-after microCT scans were used as a measure of accretion-erosion on coral reefs. In ongoing work, they are using this technology to distinguish between accretion and erosion and to single out erosion scars from specific bioeroder groups (e.g., holes from boring worms versus bioeroding sponges). The researchers are also using microCT to investigate the drivers of the accretion-erosion balance over the much larger area of the Hawaiian Archipelago.

For more information: www.soest.hawaii.edu

Related Content

Hospital for Special Surgery Invests in Sectra Orthopedic 3-D Planning Software
News | Orthopedic Imaging | January 18, 2018
January 18, 2018 – International medical imaging IT and cybersecurity company Sectra announces that Hospital for Spec
Philips Introduces Technology Maximizer Program for Imaging Equipment Upgrades
Technology | Imaging | January 17, 2018
January 17, 2018 — Philips recently announced the launch of Technology Maximizer, a cross-modality program designed t
Fat Distribution in Women and Men Provides Clues to Heart Attack Risk
News | Women's Health | January 11, 2018
January 11, 2018 – It’s not the amount of fat in your body but where it is stored that may increase your risk for hea
Minimally Invasive Treatment Provides Relief from Back Pain

Lumbar spine MRI showing disc herniation and nerve root at baseline and one month after treatment

News | Interventional Radiology | January 11, 2018
The majority of patients were pain free after receiving a new image-guided pulsed radiofrequency treatment for low back...
Emergency Radiologists See Inner Toll of Opioid Use Disorders

Rates of Imaging Positivity for IV-SUDs Complications. Image courtesy of Efren J. Flores, M.D.

News | Clinical Study | January 11, 2018
January 11, 2018 – Emergency radiologists are seeing a high prevalence of patients with complications related to opio
CT Shows Enlarged Aortas in Former Pro Football Players

3-D rendering from a cardiac CT dataset demonstrating mild dilation of the ascending aorta.

News | Computed Tomography (CT) | January 11, 2018
Former National Football League (NFL) players are more likely to have enlarged aortas, a condition that may put them at...

Size comparison between 3-D printed prosthesis implant and a penny.

News | 3-D Printing | January 11, 2018
January 11, 2018 — Researchers using...
BlueCross BlueShield Companies in Eight States Issue Positive Medical Policies for HeartFlow FFRct Analysis
News | CT Angiography (CTA) | December 28, 2017
HeartFlow Inc. announced that Health Care Service Corp. (HCSC), which operates Blue Cross and Blue Shield plans in five...
Artificial intelligence was the number one topic in radiology in 2017.

Artificial intelligence was the number one topic of interest in radiology in 2017, based on the most popular articles and videos on ITN in 2017.

Feature | Imaging | December 28, 2017
The Imaging Technology News (ITN) website had another record year with more than 1.25 million page views in 2017.
Median Technologies Collaborating With Chinese Hospital for Lung Cancer Screening Programs. Dave Fornell
News | Lung Cancer | December 22, 2017
Median Technologies recently announced a research collaboration agreement with Xingtai People's Hospital, Xingtai City...
Overlay Init