(Press-News.org) The decline of Caribbean coral reefs has been linked to the recent effects of human-induced climate change. However, new research led by scientists at Scripps Institution of Oceanography at UC San Diego suggests an even earlier cause. The bad news – humans are still to blame. The good news – relatively simple policy changes can hinder further coral reef decline.
Employing a novel excavation technique to reconstruct the timeline of historical change in coral reefs located on the Caribbean side of Panama, a team of scientists led by Scripps alumna Katie Cramer and current Scripps Professor of Oceanography and Smithsonian Tropical Research Institute (STRI) Emeritus Staff Scientist Jeremy Jackson has determined that damage to coral reefs from land clearing and overfishing pre-dates damage caused by anthropogenic climate change by at least decades.
"This study is the first to quantitatively show that the cumulative effects of deforestation and possibly overfishing were degrading Caribbean coral and molluscan communities long before climate change impacts began to really devastate reefs," said lead author Cramer, currently based at the Global Coral Reef Monitoring Network at the International Union for Conservation of Nature.
Coral reefs have suffered alarmingly since the 1980s due to coral bleaching and coral disease, thought to stem from the warming of the oceans due to anthropogenic, or human-induced, climate change. However, until recently, the impact of prior human activities on Caribbean coral reefs had not been studied with experimental techniques.
Historical records and qualitative surveys provide hints that declines in corals in some parts of the Caribbean occurred as far back as the early 1900s after coastal lands began to be cleared to make way for plantations. However, the current study is the first to quantify the changes that reef corals and mollusks have undergone as a result of long-term stress caused by the deposition of silt, nutrients, and pollution onto coral reefs from land clearing and the depletion of reef fish that prevent algae from overtaking reefs.
"Because researchers did not really begin to study Caribbean reefs in detail until the late 1970s, we don't have a clear understanding of why these reefs have changed so dramatically since this time," said Cramer. "So, we set out to reconstruct an older timeline of change on reefs by looking at the remains of past reefs – coral skeletons and mollusk shells."
To reconstruct this timeline, the team dug below modern reefs in incremental layers and, using radiocarbon dating of the coral skeletons they found, linked fluctuations in the types and numbers of coral and mollusks over time to historical records of land clearing. Changes in the relative numbers of these various species represent clear indicators of the overall health of the coral reef.
The team also improved upon the standard technique of taking long, narrow core samples of coral fossils that cannot track fluctuations in the numbers of larger species of coral.
"We wanted to look at the whole complement of the coral community," said Cramer.
To catalog the relative numbers of dozens of coral and molluscan species, the researchers dug two-foot-wide by three-foot-deep pits into reefs at several coastal lagoon and offshore sites near Bocas del Toro, Panama, that were heavily affected and less affected by land runoff, respectively. At each of these sites they also conducted surveys and recorded the composition of living corals.
"We dug up over a ton of coral rubble and tens of thousands of shells," said Cramer, who led the fieldwork at STRI and likened the laborious experience to doing underwater construction.
Systematically sifting through the coral and shell fossils, the scientists noted several indicators of environmental stress, including a decrease in the overall size of bivalves such as oysters, clams, and scallops, a transition from branching to non-branching species of coral, and large declines in the staghorn coral and the tree oyster, which were once the dominant coral and bivalve on these reefs.
These indicators were observed in layers of the excavated pits at coastal lagoon sites that were dated before 1960 and as far back as the 1800s, corresponding to a period of extensive deforestation in the Bocas del Toro region. Similar evidence of environmental stress at offshore sites was dated after 1960, indicating that the negative impacts of land clearing have more recently begun to affect reefs further offshore.
With the decline of the branching coral species, the reefs now have fewer nooks and crannies that are used as habitat for reef fish and other organisms. Also, the non-branching species that have taken their place grow at a much slower rate. "Consequently, there is less of a chance that the reefs will be able to keep up with sea level rise from climate change," said Cramer.
"Because the governments of the world have yet to undertake any meaningful efforts to mitigate climate change, it is of the utmost importance that locally caused stressors to reefs such as overfishing and deforestation are minimized," said Cramer. "Advocating for more intelligent use of land as well as implementing sustainable fisheries management, those are things that can be done right now."
INFORMATION:
The research team, which also includes Jill Leonard-Pingel of Scripps, Thomas Guilderson of the Lawrence Livermore National Laboratory and the Institute of Marine Sciences at the University of California at Santa Cruz, and Christopher Angioletti, will publish its findings in the April issue of Ecology Letters. An early online version has been released today.
This research was funded by the National Science Foundation, the Smithsonian Institution, the Center for Marine Biodiversity and Conservation at Scripps, the UC San Diego Academic Senate, and the PADI Foundation's Project AWARE.
Declines in Caribbean coral reefs pre-date damage resulting from climate change
Novel excavation technique attributes prior damage to land clearing and overfishing
2012-04-02
ELSE PRESS RELEASES FROM THIS DATE:
Published study finds usage of, reccomendations for dietary supplements high among dietitians
2012-04-02
WASHINGTON, D.C. -- Registered dietitians are one of several groups of healthcare professionals who report using dietary supplements as part of their health regimen, according to a newly published study in Nutrition Journal, a peer-reviewed, online journal that focuses on the field of human nutrition. According to data from the 2009 "Life…supplemented" Healthcare Professionals (HCP) Impact Study, 74 percent of dietitians use dietary supplements regularly while 22 percent reported using them occasionally or seasonally. The data also indicated that an overwhelming percentage ...
Amyloid beta in the brain of individuals with Alzheimer's disease
2012-04-02
The deposition of amyloid beta in the brain of individuals with Alzheimer's disease is the focus of much research into both its cause and treatment.
While there may not be a consensus as to whether the deposition contributes to the disease or is a consequence of the disease, there is agreement that it is not favoured thermodynamically, meaning that something else is promoting the process.
Other proteins are often co-deposited in vivo with amyloid beta and one such protein is serum amyloid P component (or SAP). Recent evidence has suggested that SAP is elevated in Alzheimer's ...
Tales from the crypt lead researchers to cancer discovery
2012-04-02
HUNTSVILLE, Ala – Tales from the crypt are supposed to be scary, but new research from Vanderbilt University, the HudsonAlpha Institute for Biotechnology and colleagues shows that crypts can be places of renewal too: intestinal crypts, that is. Intestinal crypts are small areas of the intestine where new cells are formed to continuously renew the digestive tract. By focusing on one protein expressed in our intestines called Lrig1, the researchers have identified a special population of intestinal stem cells that respond to damage and help to prevent cancer.
The research, ...
Newly discovered foot points to a new kid on the hominin block
2012-04-02
It seems that "Lucy" was not the only hominin on the block in northern Africa about 3 million years ago.
A team of researchers that included Johns Hopkins University geologist Naomi Levin has announced the discovery of a partial foot skeleton with characteristics (such as an opposable big toe bone) that don't match those of Lucy, the human ancestor (or hominin) known to inhabit that region and considered by many to be the ancestor of all modern humans.
The discovery is important because it provides first-ever evidence that at least two pre-human ancestors lived between ...
US stockpile security and international monitoring capabilities strengthened, says new report on technical issues behind the comprehensive nuclear test ban treaty
2012-04-02
WASHINGTON — The United States is now in a better position than at any time in the past to maintain a safe and effective nuclear weapons stockpile without testing and to monitor clandestine nuclear testing abroad, says a new report from the National Research Council. The report, requested by the Office of the Vice President and the White House Office of Science and Technology Policy, reviews and updates a 2002 study that examined the technical concerns raised about the Comprehensive Nuclear Test Ban Treaty (CTBT). The report does not take a position on whether the U.S. ...
Planet under Pressure conference, London: Final statement
2012-04-02
Scientists issued the first "State of the Planet" declaration at a major gathering of experts on global environmental and social issues in advance of the major UN Summit Rio+20 in June.
The declaration opens: "Research now demonstrates that the continued functioning of the Earth system as it has supported the well-being of human civilization in recent centuries is at risk." It states that consensus is growing that we have driven the planet into a new epoch, the Anthropocene, where many planetary-scale processes are dominated by human activities. It concludes society ...
Evolving to fight epidemics: Weakness can be an advantage
2012-04-02
When battling a deadly parasite epidemic, less resistance can sometimes be better than more, a new study suggests.
A freshwater zooplankton species known as Daphnia dentifera endures periodic epidemics of a virulent yeast parasite that can infect more than 60 percent of the Daphnia population.
During these epidemics, the Daphnia population evolves quickly, balancing infection resistance and reproduction.
A new study reveals that the number of vertebrate predators in the water and the amount of food available for Daphnia to eat influence the size of the epidemics and ...
Lung cancers detected by CT screening grow as fast as those found with traditional methods
2012-04-02
A new study led by researchers at Mount Sinai School of Medicine indicates that CT scans are more effective than traditional lung cancer detection methods at identifying aggressive lung cancers in their most treatable stages. The data, published online March 27 in the journal Radiology, demonstrate that lung cancers found through annual CT screening are similar to those found in routine practice, both in terms of tumor growth rates and cell-type distribution. In fact, the report showed that 79 percent of the cases diagnosed through annual repeat CT scans were detected at ...
Penn biologists identify a key enzyme involved in protecting nerves from degeneration
2012-04-02
PHILADELPHIA –- A new animal model of nerve injury has brought to light a critical role of an enzyme called Nmnat in nerve fiber maintenance and neuroprotection. Understanding biological pathways involved in maintaining healthy nerves and clearing away damaged ones may offer scientists targets for drugs to mitigate neurodegenerative diseases such as Huntington's and Parkinson's, as well as aid in situations of acute nerve damage, such as spinal cord injury.
University of Pennsylvanian biologists developed the model in the adult fruit fly, Drosophila melanogaster.
"We ...
NIH study finds women spend longer in labor now than 50 years ago
2012-04-02
Women take longer to give birth today than did women 50 years ago, according to an analysis of nearly 140,000 deliveries conducted by researchers at the National Institutes of Health. The researchers could not identify all of the factors that accounted for the increase, but concluded that the change is likely due to changes in delivery room practice.
The study authors called for further research to determine whether modern delivery practices are contributing to the increase in labor duration.
The researchers compared data on deliveries in the early 1960s to data gathered ...
LAST 30 PRESS RELEASES:
Program takes aim at drinking, unsafe sex, and sexual assault on college campuses
Inability to pay for healthcare reaches record high in U.S.
Science ‘storytelling’ urgently needed amid climate and biodiversity crisis
KAIST Develops Retinal Therapy to Restore Lost Vision
Adipocyte-hepatocyte signaling mechanism uncovered in endoplasmic reticulum stress response
Mammals were adapting from life in the trees to living on the ground before dinosaur-killing asteroid
Low LDL cholesterol levels linked to reduced risk of dementia
Thickening of the eye’s retina associated with greater risk and severity of postoperative delirium in older patients
Almost one in ten people surveyed report having been harmed by the NHS in the last three years
Enhancing light control with complex frequency excitations
New research finds novel drug target for acute myeloid leukemia, bringing hope for cancer patients
New insight into factors associated with a common disease among dogs and humans
Illuminating single atoms for sustainable propylene production
New study finds Rocky Mountain snow contamination
Study examines lactation in critically ill patients
UVA Engineering Dean Jennifer West earns AIMBE’s 2025 Pierre Galletti Award
Doubling down on metasurfaces
New Cedars-Sinai study shows how specialized diet can improve gut disorders
Making moves and hitting the breaks: Owl journeys surprise researchers in western Montana
PKU Scientists simulate the origin and evolution of the North Atlantic Oscillation
ICRAFT breakthrough: Unlocking A20’s dual role in cancer immunotherapy
How VR technology is changing the game for Alzheimer’s disease
A borrowed bacterial gene allowed some marine diatoms to live on a seaweed diet
Balance between two competing nerve proteins deters symptoms of autism in mice
Use of antifungals in agriculture may increase resistance in an infectious yeast
Awareness grows of cancer risk from alcohol consumption, survey finds
The experts that can outsmart optical illusions
Pregnancy may reduce long COVID risk
Scientists uncover novel immune mechanism in wheat tandem kinase
Three University of Virginia Engineering faculty elected as AAAS Fellows
[Press-News.org] Declines in Caribbean coral reefs pre-date damage resulting from climate changeNovel excavation technique attributes prior damage to land clearing and overfishing