Long-term and trans-life-cycle effects of exposure to ocean acidification in the green sea urchin Strongylocentrotus droebachiensis

Anthropogenic CO2 emissions are acidifying the world’s oceans. A growing body of evidence demonstrates that ocean acidification can impact survival, growth, development and physiology of marine invertebrates. Here, we tested the impact of long-term (up to 16 months) and trans-life-cycle (adult, embryo/larvae and juvenile) exposure to elevated pCO2 (1,200 μatm, compared to control 400 μatm) on the green sea urchin Strongylocentrotus droebachiensis. Female fecundity was decreased 4.5-fold when acclimated to elevated pCO2 for 4 months during reproductive conditioning, while no difference was observed in females acclimated for 16 months. Moreover, adult pre-exposure for 4 months to elevated pCO2 had a direct negative impact on subsequent larval settlement success. Five to nine times fewer offspring reached the juvenile stage in cultures using gametes collected from adults previously acclimated to high pCO2 for 4 months. However, no difference in larval survival was observed when adults were pre-exposed for 16 months to elevated pCO2. pCO2 had no direct negative impact on juvenile survival except when both larvae and juveniles were raised in elevated pCO2. These negative effects on settlement success and juvenile survival can be attributed to carry-over effects from adults to larvae and from larvae to juveniles. Our results support the contention that adult sea urchins can acclimate to moderately elevated pCO2 in a matter of a few months and that carry-over effects can exacerbate the negative impact of ocean acidification on larvae and juveniles

Ocean community warming responses explained by thermal affinities and temperature gradients

As ocean temperatures rise, species distributions are tracking towards historically cooler regions in line with their thermal affinity. However, different responses of species to warming and changed species interactions make predicting biodiversity redistribution and relative abundance a challenge. Here, we use three decades of fish and plankton survey data to assess how warming changes the relative dominance of warm-affinity and cold-affinity species. Regions with stable temperatures (for example, the Northeast Pacific and Gulf of Mexico) show little change in dominance structure, while areas with warming (for example, the North Atlantic) see strong shifts towards warm-water species dominance. Importantly, communities whose species pools had diverse thermal affinities and a narrower range of thermal tolerance showed greater sensitivity, as anticipated from simulations. The composition of fish communities changed less than expected in regions with strong temperature depth gradients. There, species track temperatures by moving deeper, rather than horizontally, analogous to elevation shifts in land plants. Temperature thus emerges as a fundamental driver for change in marine systems, with predictable restructuring of communities in the most rapidly warming areas using metrics based on species thermal affinities. The ready and predictable dominance shifts suggest a strong prognosis of resilience to climate change for these communities

Decreased motility of flagellated microalgae long-term acclimated to CO2-induced acidified waters

Motility plays a critical role in algal survival and reproduction, with implications for aquatic ecosystem stability. However, the effect of elevated CO2 on marine, brackish and freshwater algal motility is unclear. Here we show, using laboratory microscale and field mesoscale experiments, that three typical phytoplankton species had decreased motility with increased CO2. Polar marine Microglena sp., euryhaline Dunaliella salina and freshwater Chlamydomonas reinhardtii were grown under different CO2 concentrations for 5 years. Long-term acclimated Microglena sp. showed substantially decreased photo-responses in all treatments, with a photophobic reaction affecting intracellular calcium concentration. Genes regulating flagellar movement were significantly downregulated (P P D. salina and C. reinhardtii showed similar results, suggesting that motility changes are common across flagellated species. As the flagella structure and bending mechanism are conserved from unicellular organisms to vertebrates, these results suggest that increasing surface water CO2 concentrations may affect flagellated cells from algae to fish

Incidence and pattern of injuries among adolescent basketball players in Nigeria

<p>Abstract</p> <p>Background</p> <p>Basketball is the second most popular sport in Nigeria after football and is commonly played by adolescents. Prospective studies on adolescent basketball players in Nigeria are lacking. Such studies will help to develop injury counter-measures. Hence, this study aimed at determining the incidence and pattern of injuries among adolescent basketball players in Nigeria.</p> <p>Methods</p> <p>A prospective observational study involving 141 adolescent basketball players (75 boys and 66 girls; with age range 15 – 18 years) who participated in the 2010 National Finals of the Nigeria Nestlé Milo Basketball Competition. Basketball-related injury data were collected by an assessor during the competition using a standardized basketball injury report form. Data were analyzed using descriptive and inferential statistics.</p> <p>Results</p> <p>A total of 32 injuries were recorded with an incidence of 22.7 injuries per 100 participants same for boys and girls. This is equivalent to 1.1 injury per match for boys and 0.9 injuries per match for girls. Jumping/landing was the most common cause of injury (28.1%, N = 9). Most of the injuries were at the lower extremities (75%, N = 24); with majority at the knee joint (40.6%, N = 13). Ligament sprain was the most common types of injury. The pattern of injuries among boys did not significantly differ from that of girls (P > 0.05). Most injuries (N = 13, 41%) occurred in the offensive half of the court and cryotherapy was the most frequently used treatment modality.</p> <p>Conclusion</p> <p>The overall incidence of match injury among adolescent amateur basketball players during a national competition in Nigeria was 22.7 injuries per 100 participants; equivalence of 1.0 injury per match. The pattern of injuries was similar in both genders and consistent with what has been previously reported in literature for adolescent basketball players. Exercise-based injury prevention programmes aimed at improving core strength and neuromuscular control at the lower limbs may help reduce the incidence of injuries.</p

Community-level influences on women's experience of intimate partner violence and terminated pregnancy in Nigeria: a multilevel analysis

<p>Abstract</p> <p>Background</p> <p>Intimate partner violence (IPV) is a major public health problem with serious consequences for women’s physical, mental, sexual and reproductive health. Reproductive health outcomes such as unwanted and terminated pregnancies, fetal loss or child loss during infancy, non-use of family planning methods, and high fertility are increasingly recognized. However, little is known about the role of community influences on women's experience of IPV and its effect on terminated pregnancy, given the increased awareness of IPV being a product of social context. This study sought to examine the role of community-level norms and characteristics in the association between IPV and terminated pregnancy in Nigeria.</p> <p>Methods</p> <p>Multilevel logistic regression analyses were performed on nationally-representative cross-sectional data including 19,226 women aged 15–49 years in Nigeria. Data were collected by a stratified two-stage sampling technique, with 888 primary sampling units (PSUs) selected in the first sampling stage, and 7,864 households selected through probability sampling in the second sampling stage.</p> <p>Results</p> <p>Women who had experienced physical IPV, sexual IPV, and any IPV were more likely to have terminated a pregnancy compared to women who had not experienced these IPV types.</p> <p>IPV types were significantly associated with factors reflecting relationship control, relationship inequalities, and socio-demographic characteristics. Characteristics of the women aggregated at the community level (mean education, justifying wife beating, mean age at first marriage, and contraceptive use) were significantly associated with IPV types and terminated pregnancy.</p> <p>Conclusion</p> <p>Findings indicate the role of community influence in the association between IPV-exposure and terminated pregnancy, and stress the need for screening women seeking abortions for a history of abuse.</p