Ensuring water and food security in a developing Sub-Saharan Africa

Sub-Saharan Africa is changing. Population growth and climate changes have affected food and water available. This, and the expanding urbanisation have put further pressure on food and water security, in a region classified as one of the worlds poorest. Long draught and intense heavy rainfall destroys crops while urbanization leaves more people to be fed and less to produce. Much effort has been put in optimizing agricultural production; restore soil fecundity, and farming efficiency. However, increased agricultural production is not enough to improve and ensure proper food security in the developing countries. More than 50 % of the fruits and vegetables produced those regions are lost during transport. Postharvest handling is of central importance as urbanization and a globalization have changed the world market. Various techniques have been developed to minimize food losses during transportation. However, traditional methods have disadvantages and weaknesses and alternatives are much needed. This paper describes the potential of the ecological approaches. It describes the potential of one ecological and sustainable technique known as Biological control. The method is already widely used in farming practices around the world. The paper is especially focused on the importance of postharvest handling and it outlines the nature of problems associated with postharvest food losses, the causes of losses, and describes the most common methods used today to reduce postharvest loss, and the potential of biological control

Global gradients in intertidal species richness and functional groups.

Funder: Natural Environment Research Council; FundRef: http://dx.doi.org/10.13039/501100000270Whether global latitudinal diversity gradients exist in rocky intertidal α-diversity and across functional groups remains unknown. Using literature data from 433 intertidal sites, we investigated α-diversity patterns across 155° of latitude, and whether local-scale or global-scale structuring processes control α-diversity. We, furthermore, investigated how the relative composition of functional groups changes with latitude. α-Diversity differed among hemispheres with a mid-latitudinal peak in the north, and a non-significant unimodal pattern in the south, but there was no support for a tropical-to-polar decrease in α-diversity. Although global-scale drivers had no discernible effect, the local-scale drivers significantly affected α-diversity, and our results reveal that latitudinal diversity gradients are outweighed by local processes. In contrast to α-diversity patterns, species richness of three functional groups (predators, grazers, and suspension feeders) declined with latitude, coinciding with an inverse gradient in algae. Polar and tropical intertidal data were sparse, and more sampling is required to improve knowledge of marine biodiversity

Blue mussel shell shape plasticity and natural environments: a quantitative approach

Shape variability represents an important direct response of organisms to selective environments. Here, we use a combination of geometric morphometrics and generalised additive mixed models (GAMMs) to identify spatial patterns of natural shell shape variation in the North Atlantic and Arctic blue mussels, Mytilus edulis and M. trossulus, with environmental gradients of temperature, salinity and food availability across 3980 km of coastlines. New statistical methods and multiple study systems at various geographical scales allowed the uncoupling of the developmental and genetic contributions to shell shape and made it possible to identify general relationships between blue mussel shape variation and environment that are independent of age and species influences. We find salinity had the strongest effect on the latitudinal patterns of Mytilus shape, producing shells that were more elongated, narrower and with more parallel dorsoventral margins at lower salinities. Temperature and food supply, however, were the main drivers of mussel shape heterogeneity. Our findings revealed similar shell shape responses in Mytilus to less favourable environmental conditions across the different geographical scales analysed. Our results show how shell shape plasticity represents a powerful indicator to understand the alterations of blue mussel communities in rapidly changing environments.The work was funded by the European Union Seventh Framework Programme, Marie Curie ITN under grant agreement n° 605051

Blue mussel shell shape plasticity and natural environments: a quantitative approach

Shape variability represents an important direct response of organisms to selective environments. Here, we use a combination of geometric morphometrics and generalised additive mixed models (GAMMs) to identify spatial patterns of natural shell shape variation in the North Atlantic and Arctic blue mussels, Mytilus edulis and M. trossulus, with environmental gradients of temperature, salinity and food availability across 3980 km of coastlines. New statistical methods and multiple study systems at various geographical scales allowed the uncoupling of the developmental and genetic contributions to shell shape and made it possible to identify general relationships between blue mussel shape variation and environment that are independent of age and species influences. We find salinity had the strongest effect on the latitudinal patterns of Mytilus shape, producing shells that were more elongated, narrower and with more parallel dorsoventral margins at lower salinities. Temperature and food supply, however, were the main drivers of mussel shape heterogeneity. Our findings revealed similar shell shape responses in Mytilus to less favourable environmental conditions across the different geographical scales analysed. Our results show how shell shape plasticity represents a powerful indicator to understand the alterations of blue mussel communities in rapidly changing environments

Biomineralization plasticity and environmental heterogeneity predict geographical resilience patterns of foundation species to future change

Although geographical patterns of species' sensitivity to environmental changes are defined by interacting multiple stressors, little is known about compensatory processes shaping regional differences in organismal vulnerability. Here, we examine large‐scale spatial variations in biomineralization under heterogeneous environmental gradients of temperature, salinity and food availability across a 30° latitudinal range (3,334 km), to test whether plasticity in calcareous shell production and composition, from juveniles to large adults, mediates geographical patterns of resilience to climate change in critical foundation species, the mussels Mytilus edulis and M. trossulus. We find shell calcification decreased towards high latitude, with mussels producing thinner shells with a higher organic content in polar than temperate regions. Salinity was the best predictor of within‐region differences in mussel shell deposition, mineral and organic composition. In polar, subpolar, and Baltic low‐salinity environments, mussels produced thin shells with a thicker external organic layer (periostracum), and an increased proportion of calcite (prismatic layer, as opposed to aragonite) and organic matrix, providing potentially higher resistance against dissolution in more corrosive waters. Conversely, in temperate, higher salinity regimes, thicker, more calcified shells with a higher aragonite (nacreous layer) proportion were deposited, which suggests enhanced protection under increased predation pressure. Interacting effects of salinity and food availability on mussel shell composition predict the deposition of a thicker periostracum and organic‐enriched prismatic layer under forecasted future environmental conditions, suggesting a capacity for increased protection of high‐latitude populations from ocean acidification. These findings support biomineralization plasticity as a potentially advantageous compensatory mechanism conferring Mytilus species a protective capacity for quantitative and qualitative trade‐offs in shell deposition as a response to regional alterations of abiotic and biotic conditions in future environments. Our work illustrates that compensatory mechanisms, driving plastic responses to the spatial structure of multiple stressors, can define geographical patterns of unanticipated species resilience to global environmental change

Molecular Responses to Thermal and Osmotic Stress in Arctic Intertidal Mussels (Mytilus edulis): The Limits of Resilience.

Increases in Arctic temperatures have accelerated melting of the Greenland icesheet, exposing intertidal organisms, such as the blue mussel Mytilus edulis, to high air temperatures and low salinities in summer. However, the interaction of these combined stressors is poorly described at the transcriptional level. Comparing expression profiles of M. edulis from experimentally warmed (30 °C and 33 °C) animals kept at control (23‱) and low salinities (15‱) revealed a significant lack of enrichment for Gene Ontology terms (GO), indicating that similar processes were active under all conditions. However, there was a progressive increase in the abundance of upregulated genes as each stressor was applied, with synergistic increases at 33 °C and 15‱, suggesting combined stressors push the animal towards their tolerance thresholds. Further analyses comparing the effects of salinity alone (23‱, 15‱ and 5‱) showed high expression of stress and osmoregulatory marker genes at the lowest salinity, implying that the cell is carrying out intracellular osmoregulation to maintain the cytosol as hyperosmotic. Identification of aquaporins and vacuolar-type ATPase transcripts suggested the cell may use fluid-filled cavities to excrete excess intracellular water, as previously identified in embryonic freshwater mussels. These results indicate that M. edulis has considerable resilience to heat stress and highly efficient mechanisms to acclimatise to lowered salinity in a changing world

Freshening increases the susceptibility to heat stress in intertidal mussels (Mytilus edulis) from the Arctic.

Funder: William Demant FondenFunder: DANCEAFunder: Familien Hede Nielsens Fond; Id: http://dx.doi.org/10.13039/501100007438Funder: Selskabet for Arktisk Forskning og TeknologiFunder: Aage V. Jensens Fond; Id: http://dx.doi.org/10.13039/501100002721Temperatures in the Arctic are increasing at a faster pace than at lower latitudes resulting in range expansion of boreal species. In Greenland, the warming also drives accelerating melt of the Greenland Ice Sheet resulting in more meltwater entering Greenland fjords in summer. Our aim was to determine if increasing summer temperatures combined with lower salinity can induce the expression of stress-related proteins, for example, heat shock protein, in boreal intertidal mussels in Greenland, and whether low salinity reduces the upper thermal limit at which mortality occurs. We conducted a mortality experiment, using 12 different combinations of salinity and air temperature treatments during a simulated tidal regime, and quantified the change in mRNA levels of five stress-related genes (hsp24, hsp70, hsp90, sod and p38) in surviving mussels to discern the level of sublethal stress. Heat-induced mortality occurred in mussels exposed to an air temperature of 30°C and mortality was higher in treatments with lowered salinity (5 and 15‰), which confirms that low habitat salinity decreases the upper thermal limit of Mytilus edulis. The gene expression analysis supported the mortality results, with the highest gene expression found at combinations of high temperature and low salinity. Combined with seasonal measurements of intertidal temperatures in Greenland, we suggest heat stress occurs in low salinity intertidal area, and that further lowered salinity in coastal water due to increased run-off can make intertidal bivalves more susceptible to summer heat stress. This study thus provides an example of how different impacts of climate warming can work synergistically to stress marine organisms

[Book Review] OMURA, Yutaka. 2008. The fundamental study regarding the history of prehistoric archaeology in Japan:The study of Sugao Yamanouchi and those around him Rokuichisyobo, pp.1-215.

大村 裕著『日本先史考古学史の基礎研究-山内清男の学問とその周辺の人々-』A5判 215頁,六一書房,2008年5月刊,本体価格2,500円+税本稿は大村裕氏『日本先史考古学史の基礎研究-山内清男の学問とその周辺の人々-』の書評である。著者はまず日本先史考古学の基盤を築いた山内清男を基軸として、その周囲に展開した研究者の活動を対象としつつ、わが国の先史考古学研究史の再検討を試みる。その中でとくに山内の先人として、その学問形成に直接的な影響を与えたと想定される研究者についてやや予察的な検討を行っている。これは、隣接する学問分野(人類学・歴史学・民俗学・社会学など)の方法論を採り入れたものであり、今後とも斯学に新たな視点を提供していくものと思われる。また、著者は研究史的な検証と併行して、山内の学問的体系とは如何なるものなのかということについても考究した。様々な資料を駆使して、山内が残した論文を詳細に読み解いていく手法は堅実で説得力がある。とくに従来、余りにも素朴に考えられてきた「繩紋」という用語について、原典の丹念な読解によって、その理解に一入の深化を与えたと言える。また文様帯系統論についても、その発想の根源にある生物学的な知見に注目し、難解と言われてきた理論の理解を援ける視点を提供した。さらに、これらを総合し、著者自身が直面する学問的課題に対処するための方法を実際の資料に即して展開したことは、山内の学問に真摯に学んだ研究者のものとして、後学にも資するところ大であると思われる

A marine biodiversity observation network for genetic monitoring of hard-bottom communities (ARMS-MBON)

Marine hard-bottom communities are undergoing severe change under the influence of multiple drivers, notably climate change, extraction of natural resources, pollution and eutrophication, habitat degradation, and invasive species. Monitoring marine biodiversity in such habitats is, however, challenging as it typically involves expensive, non-standardized, and often destructive sampling methods that limit its scalability. Differences in monitoring approaches furthermore hinders inter-comparison among monitoring programs. Here, we announce a Marine Biodiversity Observation Network (MBON) consisting of Autonomous Reef Monitoring Structures (ARMS) with the aim to assess the status and changes in benthic fauna with genomic-based methods, notably DNA metabarcoding, in combination with image-based identifications. This article presents the results of a 30-month pilot phase in which we established an operational and geographically expansive ARMS-MBON. The network currently consists of 20 observatories distributed across European coastal waters and the polar regions, in which 134 ARMS have been deployed to date. Sampling takes place annually, either as short-term deployments during the summer or as long-term deployments starting in spring. The pilot phase was used to establish a common set of standards for field sampling, genetic analysis, data management, and legal compliance, which are presented here. We also tested the potential of ARMS for combining genetic and image-based identification methods in comparative studies of benthic diversity, as well as for detecting non-indigenous species. Results show that ARMS are suitable for monitoring hard-bottom environments as they provide genetic data that can be continuously enriched, re-analyzed, and integrated with conventional data to document benthic community composition and detect non-indigenous species. Finally, we provide guidelines to expand the network and present a sustainability plan as part of the European Marine Biological Resource Centre (www.embrc.eu).Peer reviewe

Identifying drivers controlling the distribution of a keystone species in a changing Arctic

Current climate change as a consequence of large-scale global emissions of greenhouse gases results in an unsurpassed warming of the Arctic, leading to melting of sea ice and glaciers. This results in an increased freshening of the ocean that, in combination with warming, affects the unique features of the Arctic environment and biodiversity. While the impact of changes in ice and temperatures on physical and chemical processes is well documented, the effects on the marine biology in the Arctic remain largely understudied. Greenland is the world's largest island stretching from 59°N to 83 °N, en-compassing 12% of the world's coastline. The largely north-south orientated coastlines of Greenland constitute a unique climate gradient from the subarctic to the High Arctic, along which multiple species meet their distribution limits. However, the biology of Greenland's coastal and intertidal systems has received limited attention and remains poorly understood. Therefore, by linking ecology, physiology and genetics of a keystone species, the blue mussel, this thesis aims at increasing knowledge of the Greenland intertidal zone by specifically studying what climatic and physiological factors determine the distribution and polarward limits of intertidal species. Hitherto, it has been commonly accepted that only one blue mussel species (Mytilus edulis) inhabited the Arctic. However, by utilizing genetic tools, we revealed that three blue mussel species inhabit the Arctic, and that the blue mussel M. edulis dominates in Southwest Greenland, while the congener M. trossulus dominates in the North (Paper I). Historically, work on the distribution of blue mussels in West Greenland has only been descriptive, but I quantified the abundance and population dynamics of the genus as far north as 77°N (Paper II). In doing so, I found that sub-zero air temperatures and air exposure time are of central importance for the distribution, and that abundances are controlled at the earliest life stage, not during adulthood. In addition, I performed a series of laboratory experiments to elucidate the importance of the physiology to the distribution. One proposed hypothesis was that polar-ward distribution is controlled by failed gonad maturation and reproduction. However, I showed that blue mussels at their northernmost limit in North Greenland are capable of producing mature gonads and spawn, and that spat settles annually (Paper III). Thus, I conclude suppressed gonadal development is not a key factor in shaping polar-ward distribution limits. Another tested hypothesis is the oxygen- and capacity-limited thermal tolerance hypothesis, which suggests that low temperatures control species distribution through failed aerobic metabolism. I studied this in Paper IV but found no indications of limited aerobic performance in populations from either South or North Greenland (Paper IV). Instead, it seems that blue mussels are capable of adjusting their aerobic performance on both temporal and spatial scales (Paper V). Furthermore, blue mussels at their polar-ward limit are facing prolonged winters with limited pelagic primary production. To investigate how they survive the prolonged winter, I used fatty acids to study their food preferences, both while ice-covered and during summer (Paper VI). I found, that the population feeds extensively on diatoms while covered by intertidal sea ice, but after the ice breaks up, food consists mainly of pelagic dinoflagellates. Thus, this population likely does not face severe starvation during ice cover, as long as ice-algae growth is sustained. Finally, I exposed the blue mussel Mytilus edulis simultaneously to a natural (sub-zero air temperatures) and a chemical stressor (lead, Pb) to investigate the effects of multiple stressors on survival (Paper VII). These two stressors were chosen, because natural Greenlandic M. edulis populations are exposed to both stressors near their polar-ward limit. Chemical stress has been found to decrease thermal tolerance of some ectotherms, thus making them vulnerable to sub-zero air temperatures. I found no interacting effects in the study, but since natural populations are commonly exposed to multiple stressors in their environment, acknowledging the potential importance of such interactions are necessary to understand species ecology and distribution and should be studied further. In conclusion, the drivers of species distribution in the Greenland intertidal zone are complex, and much remains to be done. However, by combining field and laboratory work within ecology, physiology and genetics, this thesis contributes new knowledge of processes and traits determining the distribution and distribution limits of intertidal species in the Arctic. This knowledge is important for our understanding of climate change impacts - now and in the future