The declining health of coral reefs is intensifying worldwide at an alarming rate, due to the combined effects of land-based sources of pollution and climate change. Despite the persistent use of mosquito-control pesticides in populated coastal areas, studies examining the survival and physiological impacts on the early life stages of foundation species, like corals, are limited.
In order to better understand the combined effects of mosquito pesticides and rising sea-surface temperatures, Dr. Cliff Ross, an associate professor of biology at the University of North Florida, along with scientists from Mote Marine Laboratory, exposed larvae from the coral, Porites astreoides, to selected concentrations of pesticides and temperatures.
In this pioneer study, recently published in Ecotoxicology, Ross and his colleagues—Kevin Olsen, Michael Henry and Dr. Richard Pierce—uncovered that this particular coral larvae were shown to have a moderate degree of resistance against short-term exposure to ecologically relevant concentrations of pesticides, even in the presence of elevated temperature.
“The significance of this work is that coral reefs across the globe are declining at an alarming rate due to climate change (warming ocean temperatures) and pollution. If baby corals don’t survive exposure to these stressors, then you won’t have adults, which are needed to reproduce and maintain the populations,” said Ross, who is focusing his current research at UNF on understanding the effects of climate change and environmental stressors on marine organisms, such as corals and sea grasses.
One big issue in the Florida Keys and many other coastal environments, Ross noted, is the use of mosquito-control pesticides. The Florida Keys relies heavily upon tourism. Unfortunately, the same beautiful habitat is conducive towards mosquito growth. According to Ross, the Florida Keys Mosquito Control district does an excellent job controlling mosquito populations by applying pesticides. Unfortunately, he said, some of these pesticides can inadvertently end up in the ocean and have a negative effect on marine life.
What kind of possible negative effects? In order to better understand the combined effects of mosquito pesticides and rising sea-surface temperatures, Ross collected and exposed coral larvae to selected concentrations of two major mosquito pesticide ingredients, naled and permethrin, and seawater elevated to +3.5 degrees Celsius. After 18 to 20 hours of exposure, larvae subjected to high naled concentrations had significantly reduced survivorship compared to controls. These effects weren’t detected in the presence of permethrin or elevated temperature.
Additionally, larval settlement, post-settlement survival and bleaching weren’t impacted by any treatment. To evaluate the sub-lethal stress response of larvae, several cellular and molecular assays were run. These assays determine if the larvae are stressed, much like a human blood test. The molecular responses to pesticide exposure were variable and contingent upon pesticide type, as well as the specific biomarker being employed.
In some cases, such as with the protein carbonylation and catalase gene expression, the effects of naled exposure and temperature were interactive. In other cases, pesticide exposure failed to induce any sub-lethal stress response.
Overall, these results demonstrate that Porites astreoides larvae have a moderate degree of resistance against short-term exposure to ecologically relevant concentrations of pesticides, even in the presence of elevated temperature. However, Ross notes much more work is needed on this topic, since there are many different types of environmental stressors that can interact with pesticides to cause damage to corals.
“With the onset of increasing stress to coral reefs, via direct human activities, or indirectly through effects associated with climate change, a more complete understanding of how stress impacts corals is essential,” said Ross. “In particular, as the use of pesticides increases in coastal communities there is a need to investigate the negative effects on early life stages of foundation species like corals.”
The full study, to be published in the February 2015 issue, can be found at http://link.springer.com/article/10.1007/s10646-014-1402-8
The University of North Florida in Jacksonville is a nationally ranked university located on an environmentally beautiful campus, offers students who are dedicated to enriching the lives of others the opportunity to build their own futures through a well-rounded education.
Public Relations Director
Joanna Norris | newswise
Upcycling 'fast fashion' to reduce waste and pollution
03.04.2017 | American Chemical Society
Litter is present throughout the world’s oceans: 1,220 species affected
27.03.2017 | Alfred-Wegener-Institut, Helmholtz-Zentrum für Polar- und Meeresforschung
More and more automobile companies are focusing on body parts made of carbon fiber reinforced plastics (CFRP). However, manufacturing and repair costs must be further reduced in order to make CFRP more economical in use. Together with the Volkswagen AG and five other partners in the project HolQueSt 3D, the Laser Zentrum Hannover e.V. (LZH) has developed laser processes for the automatic trimming, drilling and repair of three-dimensional components.
Automated manufacturing processes are the basis for ultimately establishing the series production of CFRP components. In the project HolQueSt 3D, the LZH has...
Reflecting the structure of composites found in nature and the ancient world, researchers at the University of Illinois at Urbana-Champaign have synthesized thin carbon nanotube (CNT) textiles that exhibit both high electrical conductivity and a level of toughness that is about fifty times higher than copper films, currently used in electronics.
"The structural robustness of thin metal films has significant importance for the reliable operation of smart skin and flexible electronics including...
The nearby, giant radio galaxy M87 hosts a supermassive black hole (BH) and is well-known for its bright jet dominating the spectrum over ten orders of magnitude in frequency. Due to its proximity, jet prominence, and the large black hole mass, M87 is the best laboratory for investigating the formation, acceleration, and collimation of relativistic jets. A research team led by Silke Britzen from the Max Planck Institute for Radio Astronomy in Bonn, Germany, has found strong indication for turbulent processes connecting the accretion disk and the jet of that galaxy providing insights into the longstanding problem of the origin of astrophysical jets.
Supermassive black holes form some of the most enigmatic phenomena in astrophysics. Their enormous energy output is supposed to be generated by the...
The probability to find a certain number of photons inside a laser pulse usually corresponds to a classical distribution of independent events, the so-called...
Microprocessors based on atomically thin materials hold the promise of the evolution of traditional processors as well as new applications in the field of flexible electronics. Now, a TU Wien research team led by Thomas Müller has made a breakthrough in this field as part of an ongoing research project.
Two-dimensional materials, or 2D materials for short, are extremely versatile, although – or often more precisely because – they are made up of just one or a...
20.04.2017 | Event News
18.04.2017 | Event News
03.04.2017 | Event News
27.04.2017 | Life Sciences
27.04.2017 | Physics and Astronomy
27.04.2017 | Earth Sciences