Pteropod time series from the North Western Mediterranean (1967 - 2003): impacts of pH and climate variability

International audienceEnvironmental changes resulting from anthropogenic CO2 emissions occur at global and local levels and have potentially harmful effects, particularly for calcifying taxa in the marine environment. A time series of pteropod abundance covering the period 1967-2003 was isolated from the Point B (northwestern Ligurian Sea) zooplankton time series. Inter-and intra-annual changes in the abundance of 3 families (Limacinidae, Cavoliniidae and Creseidae) were compared with the copepod time series to identify any differential effects driven by ocean acidification and temperature. pH values were hind-cast from total alkalinity estimated from local temperature and salinity measurements, and atmospheric CO2 taken from the Mauna Loa time series. Although surface waters were supersaturated with respect to aragonite throughout the study period, it is estimated that pH declined by 0.05 units. All pteropod groups displayed a trend of increasing abundance, suggesting that any deleterious effect of declining pH(T) in the range of 0.05 units has not caused sufficient reductions in fitness as to decrease local abundances between 1967-2003. Pteropod populations are influenced by inter-annual changes in summer temperatures. Spectral analysis identified a similar to 14 yr periodic oscillation in sea surface temperature. Similarly timed oscillations in abundance are present for all pteropod families but not for copepods, indicating a possible influence of the North Atlantic quasi-decadal mode on pteropod populations. While laboratory studies have shown pteropods to be sensitive to changes in pH, this analysis suggests that local and regional scale drivers have had a greater effect on pteropod populations in the northwestern Mediterranean Sea in recent decades. It should be noted that pH changes in laboratory studies exceed 0.05 pH units and that the saturation state with respect to aragonite (Oar) is usually much lower than that of the Mediterranean

Who takes risks at high-risks sports? A typological personality approach.

BACKGROUND: Asthma and allergic diseases have increased in the developed countries. It is important to determine whether the same trends are occurring in the developing countries in Africa. We aimed to determine the time trend in the prevalence of exercise-induced bronchospasm (EIB) and atopic sensitisation over a ten-year period in Ghanaian schoolchildren. METHODS AND FINDINGS: Two surveys conducted using the same methodology ten years apart (1993 and 2003) among schoolchildren aged 9–16 years attending urban rich (UR), urban poor (UP), and rural (R) schools. Exercise provocation consisted of free running for six minutes. Children were skin tested to mite, cat, and dog allergen. 1,095 children were exercised in 1993 and 1,848 in 2003; 916 were skin tested in 1993 and 1,861 in 2003. The prevalence of EIB increased from 3.1% (95% CI 2.2%–4.3%) to 5.2% (4.3%–6.3%); absolute percentage increase 2.1% (95% CI 0.6%–3.5%, p < 0.01); among UR, UP, and R children EIB had approximately doubled from 4.2%, 1.4%, and 2.2% to 8.3%, 3.0% and 3.9% respectively. The prevalence of sensitisation had also doubled from 10.6%, 4.7%, and 4.4% to 20.2%, 10.3%, and 9.9% (UR, UP, and R respectively). Mite sensitisation remained unchanged (5.6% versus 6.4%), but sensitisation to cat and dog increased considerably from 0.7% and 0.3% to 4.6% and 3.1%, respectively. In the multiple logistic regression analysis, sensitisation (odds ratio [OR] 1.77, 95% CI 1.12–2.81), age (OR 0.88, 95% CI 0.79–0.98), school (the risk being was significantly lower in UP and R schools: OR 0.40, 95% CI 0.23–0.68 and OR 0.54, 95% CI 0.34–0.86, respectively) and year of the study (OR 1.73, 95% CI 1.13–2.66) remained significant and independent associates of EIB. CONCLUSIONS: The prevalence of both EIB and sensitisation has approximately doubled over the ten-year period amongst 9- to 16-year-old Ghanaian children irrespective of location, with both EIB and atopy being more common among the UR than the UP and R children