Subsequent Summers Research Articles

Urticating macromedusae and stinging bathers on the South Atlantic coast: Oceanographic and climatological conditions of Olindias sambaquiensis (Müller, 1861) outbreaks

Incidents of bathers being stung by jellyfish on the coast of southern Brazil have been monitored from 2012 to 2022 to identify the species involved and to search for patterns of behavior in different summer seasons. For 10 years of monitoring, data on occurrence, density and the crossing with the abiotic variables of temperature and salinity of the water and wind direction were obtained. During the investigated period, seven species of macro jellyfish were recorded out, four of them were urticating species, in wich Olindias sambaquiensis was the most frequent and abundant. Based on physical-chemical data on the seawater in this area, the cohorts, and consequently the success in the recruitment and the density of the O. sambaquiensis, may be related with years of low salinity of these Coastal Water. This hydrozoan was also the only species that showed a correlation between average annual density values and incidents of bathers being stung in subsequent summers. Likewise, on a monthly time scale, incidents of stings were correlated with winds from the south quadrant that could promote the transport of organisms to the beach region. A predictive model of the occurrence of jellyfish stinging events is presented and applied for the summer of 2023.

Bluetongue disease in sheep in New South Wales - April 2023.

In 2016, bluetongue virus (BTV), serotype 16 (BTV-16), was detected in New South Wales (NSW) in sentinel cattle for the first time. Over the next 6 years, BTV-16 has been detected regularly and over an increasing area of the BTV zone in NSW. In April 2023, disease was reported in sheep on two farms on the Northern Tablelands of NSW. The consistent clinical signs included reduced exercise tolerance, facial swelling, serous nasal discharges with encrustation of the nasal plane, subcutaneous oedema of the neck and brisket and variable congestion of the coronary band. Affected sheep were mainly mature ewes and rams, with an estimated morbidity of 20% over a period of 6-8 weeks. Although there were several unexpected deaths, no veterinary examination was sought. Predominantly BTV-16 RNA was detected in sick sheep, with an incidence of infection of approximately 40% in a cross section of one flock. These events represent the first confirmation of disease due to bluetongue virus in NSW. As these cases occurred in a region with a high density of sheep, if there is ongoing transmission of BTV-16 during subsequent summers, further disease might be expected.

Role of Winter Soil Moisture in Subsequent Summer Thermal Anomalies on the Tibetan Plateau

Abstract The Tibetan Plateau (TP) exerts strong powerful thermal forcing, which plays a vital role in influencing weather–climate variations in Asia and even the Northern Hemisphere. However, the causes of thermal variation over the TP have not been fully revealed. Here, the role of winter soil moisture (SM) in subsequent summer thermal anomalies on the TP was investigated through multisource datasets for the period 1979–2014. Results indicate a significant positive relationship (r = 0.52) between winter SM and subsequent summer-mean surface air temperature (SAT). Further investigations show that more (less) winter SM results in abundant (deficient) atmospheric water vapor in subsequent summer owing to its persistence. Furthermore, Earth’s surface energy budget equation confirms that strengthened (weakened) surface downward longwave radiation caused by increased (decreased) water vapor is the dominant factor leading to SAT variations, even more significant for nocturnal SAT. The winter SM–atmospheric temperature positive relationship can extend from the surface to 200 hPa over the TP. In addition, the enhanced (weakened) atmospheric latent heat release associated with increased (decreased) water vapor content may be another important factor contributing to changes in atmospheric temperatures over the TP. Therefore, our results contribute to a better understanding of the effect of land–surface processes on thermal anomalies over the TP. Significance Statement Understanding the causes of thermal anomalies over the Tibetan Plateau (TP) is crucial for weather and climate variations, but the role of winter soil moisture (SM) in subsequent summer thermal effects is largely unknown. This study investigated the relationship between winter SM and thermal anomalies in subsequent summers on the TP. Results show that the above (below)-normal winter SM will cause warm (cold) atmospheric temperatures in the subsequent summer. The above (below)-normal winter SM anomalies bring increased (decreased) atmospheric water vapor in summer owing to its persistence, resulting in strengthened (weakened) downward longwave radiation and atmospheric latent heat release to heat (cool) the atmosphere.

Groundcovers and Rain Shelters Alter Co-Occurrence Patterns among Ground Beetle Communities in an Organic Raspberry Crop.

Simple SummaryRain shelters and reflective groundcovers improve the economic and environmental sustainability of organic fruit crops affected by a number of plant pathogens. In this study, we examined whether these structures also affect the communities of species that inhabit the soil surface, particularly ground beetles, in organic red raspberry crops. Our results indicate that ground beetle species richness, activity and functional traits differed in the presence of rain shelters and reflective groundcovers, but these effects were relatively minor. Thus, this study suggests that these structures, which have known benefits against plant pathogens, had no detrimental impact on ground beetle communities.The use of rain shelters and reflective groundcovers has been shown to improve the economic and environmental sustainability of organic fruit crops prone to rain-driven epidemics of phytopathogens. Here, we tested whether these structures affect communities of epigean species. To this end, we studied rain shelters and white, synthetic reflective groundcovers placed in a red raspberry organic cropping system in New Brunswick, Canada, during two subsequent summers to assess their independent and combined effects on ground beetles (Coleoptera: Carabidae). 18,445 ground beetles belonging to 54 species were collected. Rain shelters and reflective groundcovers altered patterns of ground beetle species richness, activity density and functional diversity compared to the control, but to a limited extent. Thus, this study suggests that these structures, which have known benefits against phytopathogens, have no detrimental impact on epigean fauna.

Extremely wet summer events enhance permafrost thaw for multiple years in Siberian tundra

Permafrost thaw can accelerate climate warming by releasing carbon from previously frozen soil in the form of greenhouse gases. Rainfall extremes have been proposed to increase permafrost thaw, but the magnitude and duration of this effect are poorly understood. Here we present empirical evidence showing that one extremely wet summer (+100 mm; 120% increase relative to average June–August rainfall) enhanced thaw depth by up to 35% in a controlled irrigation experiment in an ice-rich Siberian tundra site. The effect persisted over two subsequent summers, demonstrating a carry-over effect of extremely wet summers. Using soil thermal hydrological modelling, we show that rainfall extremes delayed autumn freeze-up and rainfall-induced increases in thaw were most pronounced for warm summers with mid-summer precipitation rainfall extremes. Our results suggest that, with rainfall and temperature both increasing in the Arctic, permafrost will likely degrade and disappear faster than is currently anticipated based on rising air temperatures alone.

Mugil liza (Valenciennes, 1836) biomarker responses in a hypersaline lagoon in southeastern Brazil before and after a microalgal bloom

Araruama lagoon is one of the largest permanent hypersaline lagoons in the world and has been impacted for twenty years by sewage dumping. In early 2005, a Prasinophyceae (Pseudoscourfieldia sp.) phytoplankton bloom occurred, leading to fish mortality during subsequent summers (2006 and 2007). In this context, the aim of the present study was to accompany this historical period through the use of biochemical biomarkers in mullet (Mugil liza) during and after the algal bloom. Mullet were collected from Araruama Lagoon in June and July 2005 and August 2007, as well as from a reference lagoon with no algal blooms, Saquarema Lagoon. Several enzymatic activities in liver were analyzed, namely glutathione peroxidase (GPX), catalase (CAT), total glutathione S-transferase (GSTt), specific GSTπ (pi) and GSTμ (mi) classes and ethoxyresorufin-O-deethylase (EROD), as well as muscle acetylcholinesterase activity (AChE). In 2005, only EROD activity was significantly increased at Araruama Lagoon, indicating induction of the biotransformation enzyme system (CYP 1A1). GSTπ, on the other hand, was lower in the Araruama Lagoon, especially in 2005, when compared to mullet from Saquarema lagoon (reference area). These results highlight the importance of developing actions that go beyond the physical-chemical monitoring of these environments, since the study of ecological relationships and the physiology of organisms affected by algal blooms also include biochemical parameters to evaluate new approaches to icthyotoxicity.

Sex differentiation in seasonal distribution of the starry smooth‐hound Mustelus asterias

This mark-recapture study of starry smooth-hound Mustelus asterias tagged during the summer months near the Dutch coast demonstrates a large-scale spatial sex differentiation in their circannual migration patterns and small-scale spatial sex differentiation during summer. Overwintering occurs in the North Sea, English Channel and Bay of Biscay, with significantly more males in the Northern North Sea and more females in the Bay of Biscay. During summer, sheltered sea arms off the Dutch coast were almost exclusively used by adult females. In subsequent summers post-release, both sexes were mostly confined to the Southern North Sea, suggesting philopatry.

Bed-Sediment Transport Conditions along the Sagavanirktok River in Northern Alaska, USA

This manuscript presents a study in predicting bed-sediment transport rates along the Sagavanirktok River in Alaska. Extensive field activities took place to accomplish this goal: four hydro-meteorological stations were installed in a 150 km reach along the river in summer 2015. During the same year, pits were excavated near the stations, and in subsequent summers, the pits were surveyed multiple times in conjunction with taking discharge measurements. Water slope was measured and bed sediment was characterized. Site-specific relationships between water levels and cross-section water depths were developed. Volume change between consecutive surveys was calculated, and main flood events between surveys were identified. Finally, the first bed-sediment transport equations valid for the Sagavanirktok River were developed. Considering the intrinsic error in sediment transport predictions, the agreement between predicted and measured sediment transport values is good. These equations could be used by resource managers when predicting the expected time for an excavated material site in the Sagavanirktok River to refill.

Epidemiological surveillance of schistosomiasis outbreak in Corsica (France): Are animal reservoir hosts implicated in local transmission?

Environmental and anthropogenic changes are expected to promote emergence and spread of pathogens worldwide. Since 2013, human urogenital schistosomiasis is established in Corsica island (France). Schistosomiasis is a parasitic disease affecting both humans and animals. The parasite involved in the Corsican outbreak is a hybrid form between Schistosoma haematobium, a human parasite, and Schistosoma bovis, a livestock parasite. S. bovis has been detected in Corsican livestock few decades ago raising the questions whether hybridization occurred in Corsica and if animals could behave as a reservoir for the recently established parasite lineage. The latter hypothesis has huge epidemiological outcomes since the emergence of a zoonotic lineage of schistosomes would be considerably harder to control and eradicate the disease locally and definitively needs to be verified. In this study we combined a sero-epidemiological survey on ruminants and a rodent trapping campaign to check whether schistosomes could shift on vertebrate hosts other than humans. A total of 3,519 domesticated animals (1,147 cattle; 671 goats and 1,701 sheep) from 160 farms established in 14 municipalities were sampled. From these 3,519 screened animals, 17 were found to be serologically positive but were ultimately considered as false positive after complementary analyses. Additionally, our 7-day extensive rodent trapping (i.e. 1,949 traps placed) resulted in the capture of a total of 34 rats (Rattus rattus) and 4 mice (Mus musculus). Despite the low number of rodents captured, molecular diagnostic tests showed that two of them have been found to be infected by schistosomes. Given the low abundance of rodents and the low parasitic prevalence and intensity among rodents, it is unlikely that neither rats nor ruminants play a significant role in the maintenance of schistosomiasis outbreak in Corsica. Finally, the most likely hypothesis is that local people initially infected in 2013 re-contaminated the river during subsequent summers, however we cannot definitively rule out the possibility of an animal species acting as reservoir host.

Multi-year impacts of permafrost disturbance and thermal perturbation on High Arctic stream chemistry

Permafrost disturbances (such as active layer detachment (ALD) slides) and thermal perturbation (deep ground thaw from high soil temperatures) alter Arctic surface water chemistry. However, the potential multi-year impacts on water chemistry and the ultimate recovery time are not well understood. This study evaluates the impacts on surface waters and recovery following disturbance of a High Arctic catchment in 2007 from ALDs. We measured ion concentrations and stable isotopes in surface waters collected between 2006 and 2014 from paired catchments — one disturbed and the other not. The years 2007 and 2012 were exceptionally warm and represent unusual thermal perturbation for both catchments. Results indicate that the exposure and mobilization of soluble ions in near surface soil is a key control over dissolved ion concentrations and composition following ALDs. Runoff in the disturbed catchment shows increased total dissolved solute (TDS) concentrations and seasonal TDS fluxes and changes to the relative composition of individual ions in surface water. These impacts persisted for the 7 year study duration after disturbance and are consistent with the thawing of the solute-rich transient layer and upper permafrost. Thermal perturbation increased TDS concentrations and seasonal fluxes in runoff for up to 2 years, as ions released from ground thaw appear to be available for flushing in subsequent summers.

Overyielding of temperate deciduous tree mixtures is maintained under throughfall reduction

A changing climate in the future with more severe drought events will affect the conditions for forest growth and vitality. Most knowledge on tree species response to drought is based on monocultures, even though many of the forests in the world consist of mixed stands. We aimed to investigate how trees respond to summer drought when grown in a three species mixture. For two subsequent summers canopy throughfall, and subsequently soil water potential, was reduced using sub-canopy roofs in monocultures and mixtures of Betula pendula, Alnus glutinosa and Fagus sylvatica,. The overyielding of the mixed stand was not affected by the drought using either above or below ground production, standing fine root biomass or soil respiration as parameters. However, Alnus glutinosa was the most negatively affected when growing in monoculture, whereas this species was less affected when growing in mixture. In contrast, Betula pendula was most negatively affected when growing in mixture. Fagus sylvatica was least affected by the drought and maintained growth over the two years. A water demanding species as Alnus glutinosa can perform well in a mixture during drought and not be outcompeted. This is opposite to what is assumed in most models of forest responses to climate change.

Enhancement of Arctic storm activity in relation to permafrost degradation in eastern Siberia

In the last decade, increases in both soil temperature and active layer thickness have been observed in the central Lena River basin, an area located in the centre of continuous permafrost in the Eurasian continent. Increased soil temperatures have been accompanied by corresponding increases in soil moisture within the active layer at many sites throughout the region. These underground hydro-thermal changes are believed to be primarily due to perennially wet climate conditions, rather than the atmospheric warming alone that has resulted in abnormally large amounts of winter snow accumulation and late summer rainfall in the Lena River basin. This study aimed to clarify the linkage between atmospheric and land surface variations in regions of continuous permafrost in eastern Siberia based on in situ observation and atmospheric climatic data analyses. These wet conditions in 2004–2008 were likely caused by the enhancement of cyclones over the Arctic Ocean and eastward propagation of storm activity during late summer and early winter. Water vapour flux was enhanced in conjunction with the manifestation of precipitation in eastern Siberia. As a result, consecutive positive anomalies of winter snow accumulation and precipitation during the subsequent summers effectively humidified land surfaces in the permafrost region from 2005 onwards, which resulted in abrupt soil warming and wetting of both the active layer and the upper part of the permafrost. The positive effects on increasing soil temperatures of both snowfall in winter and rainfall in summer have been observed in eastern Siberia since the 1990s, and have also been demonstrated through land surface simulation. Results of these hydro-climatic changes indicated that the near-surface permafrost in eastern Siberia is vulnerable to the climatic conditions that have arisen due to the acceleration of the hydrological cycle that has resulted from the aforementioned period of warming.

Relationship between cold winters over Northern Asia and the subsequent hot summers over mid‐lower reaches of the Yangtze River valley under global warming

AbstractUnder global warming, cold winters over Northern Asia are highly correlated with the subsequent hot summers over middle and lower reaches of the Yangtze River valley (MLYRV). This high correlation may result from an oceanic bridge's effect in the Western Pacific. The mechanism may be described as follows: the atmospheric circulation anomalies of cold winters corresponds with a simultaneous warmer Western Pacific warm pool (WPWP) by decreasing surface latent heat fluxes. The warmer sea surface temperature (SST) can persist and move eastward gradually to the subsequent summer through the oceanic processes, and thus in turn affect the hot days (HDs) over MLYRV.

Re-flooding a Historically Drained Wetland Leads to Rapid Sediment Phosphorus Release

Wetland restoration provides many benefits, but re-flooding historically drained land can have unintended negative consequences, including phosphorus (P) release from sediments. To investigate the effects of re-flooding on P cycling, this study monitored a restoration in Michigan that back-flooded old drainage ditches and re-flooded former wetland soils. Immediately after re-flooding, previously exposed sediments released substantial amounts of P to the water column. Soluble reactive phosphorus (SRP) concentrations in re-flooded areas were as high as 750 μg P l−1. At peak P concentrations, there were about 20 times more SRP and 14 times more total P in the surface water than in the much smaller flooded area that existed before re-flooding. Prolific growth of filamentous algae and duckweed was observed in subsequent summers. Sedimental analyses suggest that most of the P released originated from iron-bound fractions. The highest SRP concentrations occurred during the first year when surface water dissolved oxygen was low (<5.5 mg l−1). Similarly low oxygen in the second year after flooding was not associated with such high P concentrations. After 1 year postflooding, SRP concentrations remained below 50 μg P l−1 (but still high enough to produce eutrophic conditions) until the end of sampling about 15 months after re-flooding. When re-flooding historically drained soils, managers should consider the potential for sediment P release to jeopardize restoration goals and therefore should incorporate longer term monitoring of water quality into restoration plans. Knowledge of sediment P amounts and forms can indicate the potential for P release to overlying water.

Movements of Linnets Linaria cannabina in northern Scotland

Linnets Linaria cannabina were caught in northern and eastern Scotland from winter 2003/04 to 2012/13, with the majority of catches in low-lying agricultural areas around the Moray Firth. Although most birds breeding around the Moray Firth were sedentary, birds from further north and west in Highland and Orkney undertook long-distance movements to wintering sites, mainly in the Moray Firth area. Within a winter, movements were short, mostly within 5 km of the original trapping site. There was little variation in the median distance moved as the winter progressed. In subsequent winters, there was a tendency for some birds to switch wintering areas, with significantly fewer being found within 5 km of the original catching site. Catches in northwest Sutherland in spring showed high site fidelity in subsequent summers. During the current study no Scottish birds were recovered abroad and the percentage of long distance movements was not significantly different from birds ringed in other areas of Britain and Ireland.

Consistent plant residue removal causes decrease in minimum soil water content in a Mediterranean environment

Residue retention and no-till farming have been widely adopted to reduce erosion risk, but residue retention in particular is becoming less common due to issues with weed control, and competing markets for residue such as bioenergy production. For this reason, the impact of residue removal on soil water contents in a sandy soil in a Mediterranean-type environment was evaluated. Crop residues were removed by burning or conventional tillage annually in autumn (April or May) from 2008 until 2011. Surface residue cover and soil water contents were measured in summer (February-March) every year from 2008 until 2012, at the time of minimum soil water content (approaching air-dry). After three years of residue removal, average ground cover in the subsequent summers (2011 and 2012) decreased from 78% to 51%, and surface soil water contents decreased from 5.1% to 3.1%. Tillage also significantly decreased ground cover (from 72% to 58%) and soil water (from 4.2% to 3.9%) during the same time period. Changes in surface cover and soil water content indicate that residue removal will have implications for soil health and sustainable crop production.

Thermal Perturbation and Rainfall Runoff have Greater Impact on Seasonal Solute Loads than Physical Disturbance of the Active Layer

ABSTRACTClimate warming in the Arctic will alter hydrological processes and biogeochemical exports from the landscape. Studies have reported that thermokarst disturbances and active‐layer deepening increase solute concentrations in surface waters, but neither the spatial extent nor duration of the impacts of these changes is well understood. We measured total dissolved solute (TDS) concentrations and normalised seasonal TDS fluxes (kg mm‐1) in a series of small headwater catchments in the Canadian High Arctic over three consecutive summers (2007–09) to examine the impact of thermal perturbation (increased soil temperatures) and physical disturbance (active‐layer detachment slides) on solute dynamics in permafrost catchments. We find that usually high July soil temperatures (thermal perturbation) in 2007 resulted in a near‐doubling of solute fluxes during the two subsequent summers, including in a catchment where there was no physical disturbance despite significantly cooler conditions. Solute concentrations increased with the spatial extent of physical disturbances, especially towards the end of the melt season. However, total seasonal solute fluxes did not always increase with the spatial extent of physical disturbances. The results show that the impact of the disturbance area on seasonal solute flux is limited by discharge and hydrological connectivity of the disturbed areas, and that summer rainfall allows for enhanced export of solutes from catchments subject to physical disturbance. Hence, seasonal solute export in these permafrost catchments was more sensitive to thermal perturbations and rainfall runoff than to physical disturbance of the active layer. Copyright © 2013 John Wiley &amp; Sons, Ltd.

Impact of early and late winter icing events on sub‐arctic dwarf shrubs

Polar regions are predicted to undergo large increases in winter temperature and an increased frequency of freeze-thaw cycles, which can cause ice layers in the snow pack and ice encasement of vegetation. Early or late winter timing of ice encasement could, however, modify the extent of damage caused to plants. To determine impacts of the date of ice encasement, a novel field experiment was established in sub-arctic Sweden, with icing events simulated in January and March 2008 and 2009. In the subsequent summers, reproduction, phenology, growth and mortality, as well as physiological indicators of leaf damage were measured in the three dominant dwarf shrubs: Vaccinium uliginosum, Vaccinium vitis-idaea and Empetrum nigrum. It was hypothesised that January icing would be more damaging compared to March icing due to the longer duration of ice encasement. Following 2 years of icing, E. nigrum berry production was 83% lower in January-iced plots compared to controls, and V. vitis-idaea electrolyte leakage was increased by 69%. Conversely, electrolyte leakage of E. nigrum was 25% lower and leaf emergence of V. vitis-idaea commenced 11 days earlier in March-iced plots compared to control plots in 2009. There was no effect of icing on any of the other parameters measured, indicating that overall these study species have moderate to high tolerance to ice encasement. Even much longer exposure under the January icing treatment does not clearly increase damage.

Abundance and Distribution of Sharks in Northeast Florida Waters and Identification of Potential Nursery Habitat

AbstractSharks are considered top predators in many marine ecosystems and can play an important role in structuring community ecology. As a result, it is necessary to understand the factors that influence their abundance and distribution. This is particularly important as fishery managers develop management plans for sharks that identify areas that serve as essential fish habitat, especially nursery habitat. However, our understanding of shark habitat use in northeast Florida waters is limited. The goal of this study was to characterize the abundance and distribution of sharks in northeast Florida estuaries and to examine the effect of abiotic factors on shark habitat use. A bottom longline survey conducted from 2009 to 2011 indicated that 11 shark species use the estuarine waters of northeast Florida during the summer months. Atlantic Sharpnose Sharks Rhizoprionodon terraenovae, Blacktip Sharks Carcharhinus limbatus, and Bonnetheads Sphyrna tiburo were the most abundant species and made up 81.4% of the total catch. Site, month, and bottom water temperature were the most important factors determining the presence and abundance of sharks and suggest both regional and seasonal variations in the use of northeast Florida waters. Depth, salinity, and dissolved oxygen were also important factors. Our data show that these waters serve as a nursery for Atlantic Sharpnose and Blacktip Sharks, with young‐of‐the‐year and juveniles being present in the summer months. Limited tag–return data reveal that juvenile sharks remain in these waters throughout the summer and that some return in subsequent summers. This is the first study to characterize the abundance and distribution of sharks and identify potential nursery areas in northeast Florida estuaries.Received October 10, 2012; accepted March 7, 2013

Assessing the Value-Added Effects of Literacy Collaborative Professional Development on Student Learning

This article reports on a 4-year longitudinal study of the effects of Literacy Collaborative (LC), a school-wide reform model that relies primarily on the one-on-one coaching of teachers as a lever for improving student literacy learning. Kindergarten through second-grade students in 17 schools were assessed twice annually with DIBELS and Terra Nova. Scores from the study's first year, before coaching began, offered a baseline for assessing the value added to student learning over the following 3 years. A hierarchical, crossed-level, value-added-effects model compared student literacy learning over 3 years of LC program implementation against observed growth under baseline conditions. Results demonstrated increasing improvements in student literacy learning during LC implementation (standard effect sizes of .22, .37, and .43 in years 1, 2, and 3, respectively), and the benefits persisted through subsequent summers. Findings warrant a claim of substantial effects on student learning for the LC coaching model.