A non-invasive approach to estimate the energetic requirements of an increasing seabird population in a perturbed marine ecosystem

This is the author accepted manuscript. The final version is available from Springer Nature via the DOI in this record.There is a growing desire to integrate the food requirements of predators living in marine ecosystems impacted by humans into sustainable fisheries management. We used non- invasive video-recording, photography and focal observations to build time-energy budget models and to directly estimate the fish mass delivered to chicks by adult greater crested terns Thalasseus bergii breeding in the Benguela ecosystem. Mean modelled adult daily food intake increased from 140.9 g·d−1 of anchovy Engraulis capensis during incubation to 171.7g·d−1 and 189.2 g·d−1 when provisioning small and large chicks, respectively. Modelled prey intake expected to be returned to chicks was 58.3 g·d−1 (95% credible intervals: 44.9–75.8 g·d−1) over the entire growth period. Based on our observations, chicks were fed 19.9 g·d−1 (17.2–23.0 g·d−1) to 45.1 g·d−1 (34.6–58.7 g·d−1 25 ) of anchovy during early and late provisioning, respectively. Greater crested terns have lower energetic requirements at the individual (range: 15–34%) and population level (range: 1–7%) than the other Benguela endemic seabirds that feed on forage fish. These modest requirements – based on a small body size and low flight costs – coupled with foraging plasticity have allowed greater crested terns to cope with changing prey availability, unlike the other seabirds species using the same exploited prey base.Our research was supported by a Department of Science and Technology-National Research Foundation Centre of Excellence grant to the FitzPatrick Institute of African Ornithology, the Leiden Conservation Foundation (RBS) and our institutes. Robben Island Museum provided logistical support and access to the tern colonies

The costs of kleptoparasitism: a study of mixed-species seabird breeding colonies

This is the author accepted manuscript. The final version is available from OUP via the DOI in this record.Mixed-species assemblages are common in nature, providing mutual benefits to associating species including anti-predator advantages or resource facilitation. However, associating with other species may also impose costs through kleptoparasitism (food theft). Identification of these costs, and how they vary when different species breed alongside one another, is essential to understand the payoffs of mixed-species assemblages. We explore the costs of kleptoparasitism for greater crested terns Thalasseus bergii provisioning offspring at a single-species colony, where individuals suffer kleptoparasitism from conspecifics, and at a mixed colony where terns breed alongside Hartlaub’s gulls Chroicocephalus hartlaubii and are vulnerable to both intra and interspecific kleptoparasitism. Gull presence likely contributes to increases in both kleptoparasitic attacks and the proportion of prey lost or stolen during provisioning, relative to the single-species colony. Provisioning adults suffered additional energetic costs in response to gull kleptoparasitism, requiring more attempts to deliver prey, taking longer to do so, and swallowing more prey (to the detriment of their offspring). Gulls also appear to increase the duration of tern vulnerability to kleptoparasitism, because they continued to steal food from adults and chicks after precocial chicks left the nest, when intraspecific kleptoparasitism is negligible. Terns breeding in a mixed colony, therefore, suffer direct and indirect costs through decreased provisioning and increased provisioning effort, which may ultimately affect reproductive success, resulting in colony decline where kleptoparasitism is frequent. This study illustrates how forming a mixed-species seabird breeding assemblage has costs as well as benefits, potentially fluctuating between a parasitic and a mutualistic relationship.This work was supported by a Department of Science and TechnologyCentre of Excellence grant to the FitzPatrick Institute of African Ornithology. R.B.S.  was supported by a fellowship from the Leiden Conservation Foundation. This research was approved by SANParks (CONM1182), the Department of Environmental Affairs (RES2013/24, RES2014/83, and RES2015/65) and the animal ethics committee of the University of Cape Town (2013/V3/TC)

Effect of opuntia ficus-indica mucilage edible coating on quality, nutraceutical, and sensorial parameters of minimally processed cactus pear fruits

Cactus pear (Opuntia ficus-indica (L.) Mill.) is a non-climacteric fruit with a relatively short postharvest life span, being very sensitive to water loss, darkening and decay. Cactus pear is a spiny fruit, and the presence of glochids limits fruit consumption and diffusion; therefore, minimally processing, as well as peel removing, could be an opportunity to improve its availability, consumption, and diffusion in national and international markets. In this study, cactus pear minimally processed fruits were treated with a mucilage-based coating extracted from Opuntia ficus-indica cladodes and stored at 5◦C for 9 days. The effect of mucilage edible coating on the postharvest life, qualitative attributes, and nutraceutical value of fruit were evaluated by colors, firmness, total soluble solids content, titratable acidity, ascorbic acid, betalains and DPPH (2,2-diphenyl-1-picrylhydrazyl). Results showed that mucilage-based coating improved the quality and preserves the nutraceutical value of minimally processed cactus pear fruits during storage. The edible coating was effective in maintaining fruit fresh weight, total soluble solids content, fruit firmness, ascorbic acid and betalain content, sensorial traits, and visual score. Coated fruits showed a significantly lower microbiological growth than uncoated control fruits during the entire cold storage period

Effect of Mucilage-Based Edible Coating Enriched with Oregano Essential Oil on Postharvest Quality and Sensorial Attributes of Fresh-Cut Loquat

Due to pulp browning, weight loss, firmness loss, and decay, loquat fruits, and even more minimally processed fruits have a very short post-harvest life. The aim of our study was to evaluate the effect of Opuntia ficus-indica mucilage-based edible coating enriched with oregano oil on postharvest quality, microbial growth, and sensorial attributes of fresh-cut cv Martorana loquat fruit during cold storage. Fresh-cut loquat fruits were dipped in the mucilage-based solution enriched with oregano essential oil (MO-EC) and in distilled water used as control (CTR). According to our results, the mucilage-based edible coating enriched with oregano oil significantly improved the postharvest life of minimally processed loquat fruits by preserving quality, nutraceutical value, and sensory aspects. MO-EC had a barrier effect on fresh-cut loquat fruit, reducing weight and firmness losses, inhibiting TSS, TA, ascorbic acid content decrease, and enhancing the antioxidant activity until the end of the cold storage period (11 days at 5 C). Microbiological analysis revealed that coated loquat fruits were characterized by a cell density of spoilage microorganisms 1 Log cycle lower than control fruits. The mucilage-based coating enriched with OEO positively affects the visual appearance of fresh-cut loquat fruits, at the end of the cold storage period, MO-EC samples did indeed report visual ratings that were five times greater than CTR samples. Our research suggests that applying mucilage-based coating enriched with OEO improves peeled loquat fruit shelf-life and allows the producers to sell products that are usually considered unmarketable (fruit with epicarp with large spot areas) to the market

Effect of Opuntia ficus-indica Mucilage Edible Coating in Combination with Ascorbic Acid, on Strawberry Fruit Quality during Cold Storage

Strawberry fruit is a nonclimacteric fruit and is one of the most consumed berries in the world. It is characterized by high levels of vitamin C, folate, vitamin E, β-carotene, and phenolic constituents as well asanthocyanins that are strictly related to health benefits. Strawberries are highly perishable fruit with a very short postharvest life due to their susceptibility to mechanical injury, rapid texture softening, physiological disorders, and infection caused by several pathogens (yeast and mold) that can rapidly reduce fruit quality. The aim of the present study was to evaluate the effect of the application of Opuntia ficus-indica mucilage in combination with ascorbic acid, as edible coating, on quality, sensorial parameters, and microbiological characteristics of strawberry fruit during cold storage at 4 ± 0.5°C and 85% RH. Strawberries were characterized by a linear increase of weight loss during the storage at 4°C that was significantly higher (+11.3% on average) in the uncoated strawberries. The coating affected the ascorbic acid content of the strawberries that increased by 36.0% in coated strawberries; total soluble solid content and color of the strawberries were only affected by storage. Visual quality and sensorial analysis recorded higher scores in the coated samples at the end of the cold storage period. Furthermore, the mucilage coating did not negatively affect the natural taste of strawberries. The application of O. ficus-indica gel-based edible coating in combination with ascorbic acid, although not able to inhibit the microbial growth, limited significantly their development in coated strawberry fruits. Our results suggest that Opuntia mucilage plus 5% ascorbic acid could be a useful biochemical way of maintaining strawberry fruit quality and extending their postharvest life

Application of hydrogen peroxide to improve the microbiological stability of food ice produced in industrial facilities

This work was aimed to produce an “active” food ice to preserve its microbiological safety over time. With this in mind, ice cubes were processed with the addition of H2O2 to water before freezing. Four food ice productions were performed at the industrial level: one control trial without the addition of H2O2 (0OX) and three experimental trials obtained by adding 4, 8, and 12 mg/L of H2 O2 (4OX, 8OX, and 12OX), respectively. After production, all food ice trials were artificially contaminated with 102 CFU/100 mL of water-borne pathogenic bacteria (Escherichia coli ATCC 25922, Enteroccus faecalis ATCC 29212, and Pseudomonas aeruginosa ATCC 27853) inoculated individually. Thawed ice samples were then subjected to microbiological analyses performed by the membrane filtration method and the results indicated that only trial 12OX was able to inactivate all bacteria strains. In conclusion, the addition of 12 mg/L H2O2 represents an optimal cost-effective strategy to preserve the microbiological stability of food ice even when it is improperly handled after production

An agent-based system for maritime search and rescue operations.

Maritime search and rescue operations are critical missions involving personnel, boats, helicopter, aircrafts in a struggle against time often worsened by adversary sea and weather conditions. In such a context, telecommunication and in- formation systems may play a crucial role sometimes concurring to successfully accomplish the mission. In this paper we present an application able to localize the vessel who has launched a rescue request and to plan the most effective path for rescue assets. The application has been realised as a distributed and open multi-agent system deployed on rescue vehicles as well as on a land maritime stations of the Italian Coast Guard. The system is going to be tested in real scenarios by the Coast Guard

The migratory birds: novel ecological niche of fungal diversity?

Francesca et al (2010) studied the ecology of wine yeasts associated to birds caught in vineyards. The same authors were able to prove that migratory birds might carry living pro-technological yeasts for about 12 hours from the ingestion of inoculated feed (Francesca et al 2012). In subsequent studies, they tried to demonstrate that microorganisms are not only transported for a short period by birds, but microorganisms might be adapted to the specific conditions (body temperature about 42 °C and low pH) of the intestinal tract of birds. Hence, it was demonstrated that the majority of isolates carried by birds are thermotolerant. The most interesting results were the isolation of two new species of thermotolerant yeasts, isolated from birds (Francesca et al 2013, 2014). Presently, the main scope of this work is to investigate an additional number of seven new species of thermotolerant yeasts isolated from migratory birds. Bird’s cloacae were analyzed for the presence of yeasts (Francesca et al 2012). All isolates were subjected to phylogenetic and phenotypic analyses as reported by Francesca et al (2014). Twenty four cultures belonging to the genera Candida and Aureobasidium were isolated from birds. The phylogenetic analysis of D1/D2 domain of 26S and ITS region of 5.8S rRNA genes placed the cultures of Candida and Aureobasidium in new lineages that differed conspicuously from their closest relatives, C. verbasci and A. pullulans, respectively. For our Candida isolates the phenotypic analyses showed several discrepancies in assimilation tests between our cultures and C. verbasci, as well as represent a novel ecological niche of new species of thermotolerant yeasts gathered

Monitoring commercial starter culture development in presence of red grape pomace powder to produce polyphenol-enriched fresh ovine cheeses at industrial scale level

Red grape Nero d'Avola cultivar grape pomace powder (GPP) was applied during fresh ovine cheese production in order to increase polyphenol content. Before cheeses were produced, the bacteria of a freeze-dried commercial starter culture were isolated and tested in vitro against GPP. Two dominant strains, both resistant to GPP, were identified. Thestarter culture was inoculated in pasteurized ewe's milk and the curd was divided into two bulks, one added with 1% (w/w) GPP and another one GPP-free. GPP did not influence the starter culture development, since lactic acid bacteria (LAB) counts were 109 CFU/g in both cheeses at 30 d. To exclude the interference of indigenous LAB, the pasteurized milk was analyzed, and several colonies of presumptive LAB were isolated, purified and typed. Four strains were allotted into Enterococcus and Lacticaseibacillus genera. The direct comparison of the polymorphic profiles of cheese bacteria evidenced the dominance of the starter culture over milk LAB. The addition of GPP increased cheese total phenolic compounds by 0.42 g GAE/kg. Sensory evaluation indicated that GPP-enriched cheese was well appreciated by the judges, providing evidence that GPP is a suitable substrate to increase the availability of total phenolic content in fresh ovine cheese