One of the great challenges in ocean change research is to understand and forecast the effects of environmental changes on pelagic communities and the associated impacts on biogeochemical cycling. Mesocosms, experimental enclosures designed to approximate natural conditions, and in which environmental factors can be manipulated and closely monitored, provide a powerful tool to close the gap between single species laboratory experiments and observational and correlative approaches applied in field surveys. Existing pelagic mesocosm systems are stationary and/or restricted to well-protected waters. To allow mesocosm experimentation in a range of hydrographic conditions and in areas considered most sensitive to ocean change, we developed a mobile, sea-going mesocosm facility, the Kiel Off-Shore Mesocosms for Future Ocean Simulations (KOSMOS). The KOSMOS platform, which can be transported and deployed by mid-sized research vessels, is designed for operation in moored and free-floating mode under low to moderate wave conditions (up to 2.5 m wave heights). It encloses a water column 2 m in diameter and 15 to 25 m deep (~50–75 m3 in volume) without disrupting the vertical structure or disturbing the enclosed plankton community. Several new developments in mesocosm design and operation were implemented to (i) minimize differences in starting conditions between mesocosms, (ii) allow for extended experimental duration, (iii) precisely determine the mesocosm volume, (iv) determine air–sea gas exchange, and (v) perform mass balance calculations. After multiple test runs in the Baltic Sea, which resulted in continuous improvement of the design and handling, the KOSMOS platform successfully completed its first full-scale experiment in the high Arctic off Svalbard (78° 56.2′ N, 11° 53.6′ E) in June/July 2010. The study, which was conducted in the framework of the European Project on Ocean Acidification (EPOCA), focused on the effects of ocean acidification on a natural plankton community and its impacts on biogeochemical cycling and air/sea exchange of climate relevant gases. This manuscript describes the mesocosm hardware, its deployment and handling, CO2 manipulation, sampling and cleaning, including some further modifications conducted based on the experiences gained during this study.
Archive for September 20th, 2012
Tags: Arctic, biogeochemistry, chemistry, mesocosms, methods
Tags: Arctic, chemistry, mesocosms, methods
The volume of water enclosed inside flexible-wall mesocosm bags is hard to estimate using geometrical calculations and can be strongly variable among bags of the same dimensions. Here we present a method for precise water volume determination in mesocosms using salinity as a tracer. Knowledge of the precise volume of water enclosed allows establishment of exactly planed treatment concentrations and calculation of elemental budgets.
The importance of visitor perceptions in estimating how climate change will affect future tourist flows to the Great Barrier ReefPublished 20 September 2012 Science Leave a Comment
A growing chorus of scientists (Hoegh-Guldberg, Mumby and Hooten 2007, IPCC 2007) are predicting the demise of coral reef systems as a direct consequence of climate change.
IN a bid to raise awareness of the problems that increasing ocean acidity is causing shellfish growers in North America, a number of scientists have shared their research with US politicians about the impending ecological and economic consequences of this trend.
CLEMSON — The drab shell of an oyster is complex and the animal that lives inside can adapt to stressful living conditions, according to a team of marine biologists, including a Clemson University researcher, that identified and catalogued the genes of the Pacific oyster. Their research is published in the journal Nature this week.
If you have been paying attention to environmental news lately you may have read or heard a little bit about this thing called ocean acidification. But what is ocean acidification and why is it such a big deal?
Tags: biological response, corals, prokaryotes, review
Recent research has explored the possibility that increased sea-surface temperatures and decreasing pH (ocean acidification) contribute to the ongoing decline of coral reef ecosystems. Within corals, a diverse microbiome exerts significant influence on biogeochemical and ecological processes, including food webs, organismal life cycles, and chemical and nutrient cycling. Microbes on coral reefs play a critical role in regulating larval recruitment, bacterial colonization, and pathogen abundance under ambient conditions, ultimately governing the overall resilience of coral reef systems. As a result, microbial processes may be involved in reef ecosystem-level responses to climate change. Developments of new molecular technologies, in addition to multidisciplinary collaborative research on coral reefs, have led to the rapid advancement in our understanding of bacterially mediated reef responses to environmental change. Here we review new discoveries regarding (1) the onset of coral-bacterial associations; (2) the functional roles that bacteria play in healthy corals; and (3) how bacteria influence coral reef response to environmental change, leading to a model describing how reef microbiota direct ecosystem-level response to a changing global climate.
FALMOUTH — What is the acidification of the oceans going to do to the scallop population? That’s the question the Woods Hole Oceanographic Institution will try to answer with a $682,000, three-year, federal grant, the National Oceanic and Atmospheric Administration announced Wednesday.
Authors: Katherine Jernigan, Steven Bateman, Daphne Hamilton
Theme: Ocean Acidification and Coral Reefs as related to Food Security and Eco-Tourism
Ocean acidification impacts people and economies through its effects on marine ecosystems. Our topic focuses on the impacts of acidification on coral reefs, and how this in turn affects humans through food security and economic situations. It shows how ecotourism, food security, and the degradation of coral reefs are all intertwined. Our theme does not include all the players that contribute to climate change and ocean acidification, though we will touch slightly on the general causes of ocean acidification.
Carbon dioxide from water pollution, as well as air pollution, may adversely impact oceans
Carbon dioxide (CO2) released into the oceans as a result of water pollution by nutrients — a major source of this greenhouse gas that gets little public attention — is enhancing the unwanted changes in ocean acidity due to atmospheric increases in CO2. The changes may already be impacting commercial fish and shellfish populations, according to new data and model predictions published today in ACS’s journal, Environmental Science & Technology.