By Nika Knight
10 August 2016
(Countercurrents.org) – It’s no secret that we have trashed, poisoned, and warmed oceans at an unprecedented rate via human-caused climate change and pollution.
It seems that oceans may be paying us back in kind, according to a new study that found levels of bacteria responsible for life-threatening illnesses spiking in the North Atlantic region.
The study published Monday in the Proceedings of the National Academy of Sciences of the United States of America (PNAS) discovered that a deadly variety of bacteria known as vibrio is spreading rapidly throughout the Atlantic as a result of hotter ocean temperatures.
Marine ecologist Donald Boesch, president of the University of Maryland Center for Environmental Science, who was not involved in the research, described the shift to the Washington Post as “an ecosystem-level effect of climate change”:
ABSTRACT: Climate change is having a dramatic impact on marine animal and plant communities but little is known of its influence on marine prokaryotes, which represent the largest living biomass in the world oceans and play a fundamental role in maintaining life on our planet. In this study, for the first time to our knowledge, experimental evidence is provided on the link between multidecadal climatic variability in the temperate North Atlantic and the presence and spread of an important group of marine prokaryotes, the vibrios, which are responsible for several infections in both humans and animals. Using archived formalin-preserved plankton samples collected by the Continuous Plankton Recorder survey over the past half-century (1958–2011), we assessed retrospectively the relative abundance of vibrios, including human pathogens, in nine areas of the North Atlantic and North Sea and showed correlation with climate and plankton changes. Generalized additive models revealed that long-term increase in Vibrio abundance is promoted by increasing sea surface temperatures (up to ∼1.5 °C over the past 54 y) and is positively correlated with the Northern Hemisphere Temperature (NHT) and Atlantic Multidecadal Oscillation (AMO) climatic indices (P < 0.001). Such increases are associated with an unprecedented occurrence of environmentally acquired Vibrio infections in the human population of Northern Europe and the Atlantic coast of the United States in recent years.
SIGNIFICANCE: Long-term ecological and paleontological data analyses indicate climate change is having an impact on marine eukaryotic communities. However, little is known about effects of global warming on marine prokaryotes, which are, by far, the largest living biomass in world oceans. Here, we report, for the first time to our knowledge, that a warming trend in sea surface temperature is strongly associated with spread of vibrios, an important group of marine prokaryotes, and emergence of human diseases caused by these pathogens. Our results are based on formalin-preserved plankton samples collected in the past half-century from the temperate North Atlantic.