Impact of storm Xynthia in 2010 on coastal agricultural areas: the Saint Laurent de la Prée research farm’s experience

Storm Xynthia crossed France’s western coast between 28th February and 1st March 2010. It hit the Vendée and Charente-Maritime departments hardest, as storm surge flooded up to 23,000 ha of coastal agricultural areas (i.e. polders), causing severe damage to farming operations. However, farm-level damage in the aftermath of seawater flooding is an issue that has rarely been explored in the literature. Here we investigated the effects of storm Xynthia on agriculture at the farm scale. We focused on the case study of Saint Laurent de la Prée research farm, a mixed crop–livestock system that was severely hit. All damages were described and economic losses were quantified for the years 2010 and 2011. The results show numerous consequences of the storm in terms of crop and fodder production losses, but also farm infrastructure repairs, crop restoration and animal health problems. Economic damage costs were high, reaching €71,720 in 2010 (€500/ha flooded) and €56,195 (€390/ha) in 2011 for the case study farm. The discussion highlights the farm-level impacts of seawater flooding and the crucial factors that can explain the damage caused to agriculture by storm events in coastal areas. The results are also discussed in the wider context of global warming which is expected to cause sea level rise and more frequent storm events in the future. The vulnerability of coastal agricultural areas to storms thus exposes broader issues of coastal flooding risk management and specifically the allied protection–remediation–adaptation measures. The conclusions underline the need for future research to address prospective scenarios and subsequent adaptive strategies.     

Solution of fully-coupled shallow water equations and contaminant transport using a primitive-variable Riemann method

A Riemann-solver scheme, using primitive variables rather than conserved variables, is configured and tuned for the solution of the fully-coupled two-dimensional shallow water and contaminant transport equations. This scheme is based on the unstructured finite volume discretization using primitive-variable Roe-flux approximation with an entropy fix. The primitive-variable flux associated with the exact source-term balancing is well-behaved and well-balanced for both still-water and dry regions with arbitrary bed topography. Second-order accuracy is used in space and time. The present study uses a nonlinear implicit scheme based on Newton-iterative algorithm for the time integration. In order to show the accuracy of the scheme, numerical results are verified by different test cases for contaminant advection and diffusion. A scenario of contaminant transport in a complex geometry with wet and dry elements is also simulated to demonstrate that the present work can be implemented on practical applications involving flooding and contaminant transport.     

Supplemental food affects egg size but not hatching asynchrony in rollers

Maternal effects can function as a mechanism of transgenerational plasticity by which the environment experienced by parents is translated into the offspring phenotype and fitness. In birds, parents may affect the competitive ability of their offspring, and hence their fitness, by modifying their hatching pattern and/or egg size. However, little is known about how mothers can modify offspring phenotypes and their fitness in response to a sudden change in environmental conditions during egg-laying. Here, we studied the effect of supplemental food during egg-laying on hatching asynchrony and egg size in the Eurasian roller (Coracias garrulus), a species with marked hatching asynchrony. We also explored the effects of maternal investment on offspring fitness. Food supplementation did not affect hatching asynchrony. However, females in food-supplemented nests laid eggs that increased in size with laying order except for an ultimate small egg. Meanwhile, size of eggs laid by females in control nests did not change with laying order. Supplemental food positively affected hatchability of the egg laid just before the last one and negatively affected hatchability of the last laid egg, which seemed to be a side effect of egg size. Consequently, food-supplemented nests produced fewer fledglings and had higher probabilities of suffering brood reduction than control nests. We conclude that egg size in rollers is a plastic trait, sensitive to short-term changes in food conditions. Furthermore, our results show that maternal investment in egg size may potentially affect offspring fitness.     

Artificial lightweight aggregates as utilization for future ashes - A case study

In the future, more electricity in the Netherlands will be produced using coal with co-combustion. Due to this, the generated annual ash volume will increase and the chemical composition will be influenced. One of the options for utilization if present markets are saturated and for use of fly ashes with different compositions, is as raw material for lightweight aggregates. This was selected as one of the best utilizations options regarding potential ash volume to be applied, environmental aspects and status of technology. Because of this, a study has been performed to assess the potential utilization of fly ash for the production of lightweight aggregate. Lightweight aggregate has been produced in a laboratory scale rotary kiln. The raw material consisted of class F fly ash with high free lime content. An addition of 8% clay was necessary to get green pellets with sufficient green strength. The basic properties of the produced lightweight aggregate and its behaviour in concrete have been investigated. The concrete has a good compressive strength and its leaching behaviour meets the most stringent requirements of Dutch environmental regulations. The carbon foot print of concrete will be negatively influenced if only the concrete itself is taken into account, but the reduction of the volume weight has advantages regarding design, transport emissions and isolation properties which may counteract this. In the Dutch situation the operational costs are higher than expected potential selling price for the LWA, which implies that the gate fee for the fly ash is negative.     

Gametogenic cycle and size at first maturity of the Patagonic edible snail Buccinanops cochlidium from Argentina

Buccinanops cochlidium is a common edible snail from Argentinean shallow waters, which is being consumed locally in north Patagonia. Nevertheless, there are no policies for their fisheries management. This study provides information about the reproductive cycle and size at first maturity of B. cochlidium from San José Gulf, Argentina. In this species, the testes seemed to develop mature sperm all year round without a resting period although resorption was registered after periods of high evacuation (June–November). The occurrence of parasperm in a nassariid species is reported for the first time in this study. Females showed a clear seasonality, without a resting period, and proliferation of oogonia throughout the year. Evacuation of mature oocytes measuring over 220 μm occurred mainly in October. Oocyte evacuation was associated with minimum seawater temperature and increasing daylength. Males developed a penis of functional size and mature gametes in their testes at 37 mm in shell length (SL) but only began to mate at 65 mm in SL. Females matured at 80 mm in SL, considering gonad maturity, mating behaviour and oviposition altogether. Female SL at first gonadal maturity is close to the male maximum SL. The present results are useful when planning fishery policies aiming to prevent the overexploitation of the resource, if an extensive fishery targeting on this species is developed. In case of this, we propose a fishery based on an artisanal diving collection of individuals over 82 mm in SL, and avoiding to catch gravid females.     

Seasonality and dynamics in coral reef macroalgae: variation in condition and susceptibility to herbivory

Seasonal variation in coral reef macroalgal size and condition is well documented, yet seasonal variability of herbivory on macroalgae by coral reef fishes is unknown. Herbivore feeding intensity was quantified monthly on an inner-shelf reef on the Great Barrier Reef, using Sargassum bioassays. Removal rates of transplants displayed high levels of variation with significantly higher rates of removal during the summer months. Differences in Sargassum plant size and condition suggest that the variability in herbivore feeding intensity is attributed primarily to the variation in the condition of the macroalgae, especially epiphyte loads. The dramatic changes in macroalgal removal reveal a considerable decrease in herbivore activity in the winter. This highlights the clear distinction between ‘summer’ and ‘winter’ months in terms of reef processes, emphasizing the high seasonal variation in macroalgal removal rates at different time of the year.     

Palatability mapping: a koala's eye view of spatial variation in habitat quality

Ecologists trying to understand the value of habitat to animals must first describe the value of resources contained in the habitat to animals and, second, they must describe spatial variation in resource quality at a resolution relevant to individual animal foraging. We addressed these issues in a study of koalas (Phascolarctos cinereus) in a Eucalyptus woodland. We measured beneficial and deterrent chemical characteristics as well as the palatability of trees using a near-infrared spectroscopic model based on direct feeding experiments. Tree use by koalas was influenced by tree size and foliar quality but was also context-dependent: trees were more likely to be visited if they were surrounded by small, unpalatable trees or by large, palatable trees. Spatial autocorrelation analysis and several mapping approaches demonstrated that foliar quality is spatially structured in the woodland at a scale relevant to foraging decisions by koalas and that the spatial structure is an important component of habitat quality.     

Assesment of the response of a shallow macrotidal estuary to changes in hydrological and wastewater inputs through numerical modelling

The aim of this study was to investigate the response to short-term changes in river freshwater discharges and in nutrients loadings (mainly from the treatment of urban wastewater), of the shallow macrotidal Urdaibai estuary (north of Spain), by using numerical tools. A two-dimensional hydrodynamic model and a water quality model were applied to the estuary, in order to better use it as a prediction tool in the study of the effects of variations in hydrodynamic conditions and in waste water inputs. The model was calibrated and verified using data measured under different hydrological conditions (spring and summer). A model calibration was carried out with field data measured during the summer, while the model validation was conducted for spring conditions. The calibration process allowed the model parameter definition, while the model validation permitted the verification of the calibrated parameters under different environmental conditions. The model results were in reasonable agreement with field measurements, in both the calibration and the validation phases. The model showed a significant decrease in phytoplankton concentration with river input increase. A study on the effects of nutrient input reduction from the Gernika Waste Water Treatment Plant (WWTP) was conducted. It showed a decrease in phytoplankton concentration with decreasing levels of nutrient discharge. This reduction was more pronounced in conjunction with the highest river discharge. In that case, a 50% decrease for the elimination of the WWTP discharge was observed.