Synthesis and Antifouling Activity Evaluation of Analogs of Bromosphaerol,a Brominated Diterpene Isolated from the Red Alga Sphaerococcus coronopifolius

Marine biofouling is an epibiotic biological process that affects almost any kind of submerged surface, causing globally significant economic problems mainly for the shipping industry and aquaculture companies, and its prevention so far has been associated with adverse environmental effects for non-target organisms. Previously, we have identified bromosphaerol (1), a brominated diterpene isolated from the red alga Sphaerococcus coronopifolius, as a promising agent with significant antifouling activity, exerting strong anti-settlement activity against larvae of Amphibalanus (Balanus) amphitrite and very low toxicity. The significant antifouling activity and low toxicity of bromosphaerol (1) motivated us to explore its chemistry, aiming to optimize its antifouling potential through the preparation of a number of analogs. Following different synthetic routes, we successfully synthesized 15 structural analogs (2–16) of bromosphaerol (1), decorated with different functional groups. The anti-settlement activity (EC₅₀) and the degree of toxicity (LC₅₀) of the bromosphaerol derivatives were evaluated using cyprids and nauplii of the cirriped crustacean A. amphitrite as a model organism. Derivatives 2, 4, and 6–16 showed diverse levels of antifouling activity. Among them, compounds 9 and 13 can be considered as well-performing antifoulants, exerting their activity through a non-toxic mechanism.     

Marine spatial plans focusing on biodiversity conservation: The case of the Aegean Sea

1. The expansion and intensification of marine uses have severe cumulative impacts on marine ecosystems and human well-being, unless they are properly managed with an ecosystem-based management approach.
2. A systematic conservation planning approach, using marxan with zones , was applied to generate alternative marine spatial plans for the Aegean Sea. Relevant human uses were included and their cumulative impact on a wide set of key biodiversity features was considered in the analysis. Different cost scenarios were developed to gain insight on the effects of the approaches used to assess socio-economic factors, and their potential impact on spatial plans.
3. The spatial plans generated differed greatly depending on the method used to estimate opportunity costs and evaluate human activities in monetary terms.
4. The vulnerability weights (the relative vulnerability of ecological features to specific human activities and their impacts) that were estimated based on a cumulative impact assessment, allowed the assessment of each zone in contributing to the achievement of conservation targets, through a transparent planning approach.
5. Results indicate that special care should be given to how socio-economic activities, their impact on the ecosystems, and related costs are incorporated into planning.
6. The proposed approach demonstrates how EU member states may effectively comply with the new Biodiversity Strategy 2030 targets, while planning for the sustainable use of their marine resources.

     

COMPUTED TOMOGRAPHY DIAGNOSIS OF ISOLATED SPLENIC TORSION IN A DOG

Isolated splenic torsion in a dog was diagnosed using computed tomography (CT). The enlarged non enhanced spleen and a twisted soft tissue mass effect represented the rotated pedicle were the main findings. Abdominal radiography and ultrasonography were not conclusive.     

Dissipation of three organochlorine and four pyrethroid pesticides sprayed in a greenhouse environment during hydroponic cultivation of gerbera

A wide range of pesticides (insecticides, acaricides and fungicides) is used in the hydroponic cultivation of gerbera. The fate and behaviour of some of these commonly used pesticides (organochlorine and pyrethroid insecticides/acaricides) in a greenhouse installation was investigated. The concentrations of endosulfan, dicofol, tetradifon, permethrin, bifenthrin, cypermethrin and deltamethrin in the air of the greenhouse were related to their physicochemical properties and respective application rates. Of these compounds, endosulfan exhibited the highest concentration in the greenhouse air 2 h after application (10 microg m(-3)), due to its highest volatility; afterwards, up to 12 h post-application, a rapid decrease was recorded which finally led to a concentration of 0.41 microg m(-3) at 6 days post-application. Dicofol exhibited the same trend of dissipation in the greenhouse air; its concentration decreased from 0.27 microg m(-3) immediately after the application to 0.12 microg m(-3) at 6 days post-application. Tetradifon, bifenthrin and permethrin were found at concentrations lower than 0.1 microg m(-3) at 2 h post-application, and cypermethrin and deltamethrin could not be detected. The concentrations of all the above pesticides in the drain water of the open hydroponic system were relatively high immediately after application and decreased rapidly during the following 3 days. In the closed hydroponic system, all the pesticides accumulated in the nutrient solution during the first 24 h after application and slowly decreased in concentration over the following 3 days. The spray operators applying these pesticides were exposed to rather high concentrations and the spray deposits were monitored on the chest and forehead of the operator. Endosulfan exhibited the highest concentrations of the seven pesticides. The organochlorine pesticides (endosulfan, dicofol and tetradifon) were usually detected at higher concentrations on the chest than on the forehead of the operator; pyrethroids were detected at higher concentrations on the forehead than on the chest of the operator.     

Temperature-dependent development of Sesamia nonagrioides

The effect of various constant temperatures on survival, development and adult longevity of Sesamia nonagrioides Lefébvre (Lepidoptera: Noctuidae) was studied under laboratory conditions. The following temperatures were tested: 14, 17, 21, 25 and 31 °C. The percentage of individuals that completed development at each temperature as well as the days needed for the emergence of the pupa and adult eclosion were measured. Adult longevity was estimated under the same conditions. Development time decreased significantly with increasing temperature within the range 14–25 °C. Survival was higher at medium temperatures (17–25 °C) in comparison with that at more extreme temperature regimens (14 and 31 °C). Egg and first larval instars were the stages where S. nonagrioides suffered the highest mortality levels at all temperatures. The highest survival was recorded with experimental individuals aging between the third and fifth larval instar. Thermal requirements of development (developmental thresholds, thermal constant, optimum temperature) of S. nonagrioides were estimated with application of linear and one nonlinear models (Logan I). Upper and lower developmental thresholds ranged between 31.2 and 36.2 and 7.0 and 10.3 °C, respectively. The optimum temperature for development (where maximum rate of development occurs) was estimated at between 28.1 and 30.3 °C. The thermal constant for total development was estimated at 1,000.0 degree-days. Adult longevity was also affected by temperature, as it was significantly reduced at higher temperatures (21–31 °C) compared to the lower ones (14 and 17 °C). This information would be useful in determining the critical temperatures which may affect the distribution of S. nonagrioides concerning potential climate change.     

Efficacy of the pyrethroid alpha-cypermethrin against Bactrocera oleae populations from Greece, and improved diagnostic for an iAChE mutation

BACKGROUND: The most important pest of olive orchards worldwide is the olive fruit fly Bactrocera oleae (Gmelin). Its control in Greece has been based on organophosphates (OPs), but their intense use has led to the development of resistance. A test previously developed to monitor the trait may not be as robust as originally thought. The pyrethroid alpha-cypermethrin has recently been registered for bait sprays, as an alternative to OPs. RESULTS: The susceptibility of 20 B. oleae populations to alpha-cypermethrin was examined. Variation was observed in their response, with LD(50) ranging from 0.14 to 3.28 ng insect(-1) and resistance factors from 2.3 to 54.7. Resistance mechanisms were investigated. Cytochrome P450 monoxygenase activities showed an association with resistance. Sequences in the domain IIS4-IIS6 of the B. oleae para-type sodium channel were also analysed, but no resistance-associated mutations were identified. Finally, a novel diagnostic assay able to reliably monitor the frequency of the iAChE G488S resistance mutation was developed. CONCLUSION: This is the first attempt to evaluate the efficacy of alpha-cypermethrin against B. oleae from Greece. Data showed that it can be used effectively, but also highlighted the importance of continuous monitoring. The IIS4-IIS6 sodium channel region is the default area in which to look for resistance mutations if target-site resistance to pyrethroids arises. The application of the novel iAChE molecular diagnostic may facilitate the introduction of pyrethroids alongside OPs currently in use.     

Effects of light spectrum on growth and physiological status of gilthead seabream Sparus aurata and rainbow trout Oncorhynchus mykiss reared under recirculating system conditions

Previously reported data clearly indicate that depending on species, ambient light spectrum can affect fish growth, physiology, behaviour, reproduction, etc. Since light spectrum can be easily controlled in intensive indoor fish farming facilities, the present study aimed to investigate the effects of coloured light on growth performance (body weight, growth rate, food utilization, carcass composition, etc.) and physiological status (blood and plasma parameters, brain neurotransmitters, tissue fatty acid composition, etc.) of two widely reared fish species, gilthead seabream Sparus aurata and rainbow trout Oncorhynchus mykiss. For this purpose, 240 specimens of S. aurata (29.8 ± 0.13 g) and 60 specimens of O. mykiss (71.4 ± 0.30 g) were exposed to white (full-spectrum, fluorescent lamps), red (605 nm) and blue (480 nm) light (lamps covered with appropriate filters) for 11 weeks under recirculating water systems. Blue light had a significantly negative impact on O. mykiss growth performance accompanied with reduced liver total lipids and plasma glucose and increased brain serotonergic and dopaminergic activity. In the case of S. aurata, red light significantly increased brain dopaminergic activity, while a tendency towards reduced growth was also observed. Since these results indicated the establishment of stressful conditions, O. mykiss and S. aurata should not be reared under blue and red light, respectively. For each species, the effect of the remaining light colours tested, was not clearly differentiated so that an appropriate light spectrum for the most efficient farming of O. mykiss and S. aurata could not be suggested, at least for the time period examined. Nevertheless, present results suggest that light colour should be regarded as a rearing factor worth to be further investigated, especially when recirculating systems are concerned.     

Could European marine conservation policy benefit from systematic conservation planning?

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