Climate change enhances primary production in the western Antarctic Peninsula.

Intense regional warming was observed in the western Antarctic Peninsula (WAP) over the last 50 years. Here, we investigate the impact of climate change on primary production (PP) in this highly productive region. This study is based on temporal data series of ozone thickness (1972-2010), sea ice concentration (1978-2010), sea-surface temperature (1990-2010), incident irradiance (1988-2010) and satellite-derived chlorophyll a concentration (Chl-a, 1997-2010) for the coastal WAP.

The whole is more than the sum of its parts: Modeling community-level effects of UVR in marine ecosystems.

The effect of UVB radiation (UVBR, 290-320 nm) on the dynamics of the lower levels of the marine plankton community was modeled. The model was built using differential equations and shows a good fit to experimental data collected in mesocosms (defined as large enclosures of 1500 L filled with natural marine waters). Some unexpected results appear to be possible by indirect effects in prey (bacteria, phytoplankton and heterotrophic flagellates).

Vertical mixing and ecological effects of ultraviolet radiation in planktonic communities.

We present a mathematical model for a phytoplankton-zooplankton system, based on a predator-prey scheme. The model considers the effects of sinking in the phytoplankton, vertical mixing and attenuation of photosynthetically active radiation (PAR) and ultraviolet radiation (UVR) in the water column. In a first approach, the model was studied under conditions of average PAR irradiance and shows fluctuations and stable equilibrium points.

Ultraviolet-B radiation effects on the structure and function of lower trophic levels of the marine planktonic food web.

The impact of UV-B radiation (UVBR; 280-320 nm) on lower levels of a natural plankton assemblage (bacteria, phytoplankton and microzooplankton) from the St. Lawrence Estuary was studied during 9 days using several immersed outdoor mesocosms. Two exposure treatments were used in triplicate mesocosms: natural UVBR (N treatment, considered as the control treatment) and lamp-enhanced UVBR (H treatment, simulating 60% depletion of the ozone layer).

Photoacclimation to long-term ultraviolet radiation exposure of natural sub-Antarctic phytoplankton communities: Fixed surface incubations versus mixed mesocosms.

Solar UVB radiation (280-320 nm) is known to have detrimental effects on marine phytoplankton. Associated with the seasonal ozone hole in Antarctica, stratospheric ozone depletion occasionally influences the sub-Antarctic (Beagle Channel, Argentina) region, enhancing levels of UVB. The primary objective of this work was to study the effects of several (i.

Mediated modeling of the impacts of enhanced UV-B radiation on ecosystem services.

This article describes the use of group model building to facilitate interaction with stakeholders, synthesize research results and assist in the development of hypotheses about climate change at the global level in relation to UV-B radiation and ecosystem service valuation. The objective was to provide a platform for integration of the various research components within a multidisciplinary research project as a basis for interaction with stakeholders with backgrounds in areas other than science. An integrated summary of the scientific findings, along with stakeholder input, was intended to produce a bridge between science and policymaking.

UV effects on marine planktonic food webs: A synthesis of results from mesocosm studies.

UV irradiance has a broad range of effects on marine planktonic organisms. Direct and indirect effects on individual organisms have complex impacts on food-web structure and dynamics, with implications for carbon and nutrient cycling. Mesocosm experiments are well suited for the study of such complex interrelationships.

TBT toxicity on a natural planktonic assemblage exposed to enhanced ultraviolet-B radiation.

A microcosm approach was designed to study the combined effects of tributyltin (TBT) from antifouling paints and ultraviolet-B radiation (UVBR: 280-320 nm), on a natural planktonic assemblage (<150 microm) isolated from the St. Lawrence Estuary at the end of the springtime. Microcosms (9l, cylindrical Teflon bags, 75 cm heightx25 cm width) were immersed in the water column of mesocosms (1800 l, polyethylene bags, 2.