Trawl fishing impacts on the status of seabed fauna in diverse regions of the globe

Bottom trawl fishing is a controversial activity. It yields about a quarter of the world's wild seafood, but also has impacts on the marine environment. Recent advances have quantified and improved understanding of large‐scale impacts of trawling on the seabed. However, such information needs to be coupled with distributions of benthic invertebrates (benthos) to assess whether these populations are being sustained under current trawling regimes. This study collated data from 13 diverse regions of the globe spanning four continents. Within each region, we combined trawl intensity distributions and predicted abundance distributions of benthos groups with impact and recovery parameters for taxonomic classes in a risk assessment model to estimate benthos status. The exposure of 220 predicted benthos‐group distributions to trawling intensity (as swept area ratio) ranged between 0% and 210% (mean = 37%) of abundance. However, benthos status, an indicator of the depleted abundance under chronic trawling pressure as a proportion of untrawled state, ranged between 0.86 and 1 (mean = 0.99), with 78% of benthos groups > 0.95. Mean benthos status was lowest in regions of Europe and Africa, and for taxonomic classes Bivalvia and Gastropoda. Our results demonstrate that while spatial overlap studies can help infer general patterns of potential risk, actual risks cannot be evaluated without using an assessment model that incorporates trawl impact and recovery metrics. These quantitative outputs are essential for sustainability assessments, and together with reference points and thresholds, can help managers ensure use of the marine environment is sustainable under the ecosystem approach to management.     

How is Shrub Cover Related to Soil Moisture and Patch Geometry in the Fragmented Landscape of the Northern Negev desert?

Among the major challenges of landscape ecologists is to develop relatively simple models to quantify ecological processes over large areas. Application of such models can be well demonstrated in fragmented semi-arid ecosystems where competition over resources is intense due to habitat loss, however, only a few studies have done so. Our aim was to model and study the integrated effect of spatial variation in potential soil moisture and patch size and shape on shrub–grass ratio (SGR) in a semi-arid fragmented environment. We specifically ask: (i) what factors most strongly relate to SGR in large remnant patches (> 1.6 ha), and (ii) do different factors more strongly relate to SGR in small patches (< 1.6 ha)? The study was carried out using 60 patches within a semi-arid fragmented environment in the Northern Negev of Israel. Aerial photographs and digital elevation models were used to map six environmental variables: wetness index, aspect, rock cover, rock pattern, patch area, and patch shape. The variables were designed in GIS and were modeled using fuzzy logic procedures to predict SGR, and these predictions were compared to shrub cover maps extracted using maximum likelihood classification of aerial photographs taken in September 2003. We found that in the study area, factors indicating potential soil moisture are most strongly related to SGR in large patches, whereas patch geometric attributes are more strongly relate to SGR in small patches.     

Oscillations and sparsening of odor representations in the mushroom body

In the insect olfactory system, oscillatory synchronization is functionally relevant and reflects the coherent activation of dynamic neural assemblies. We examined the role of such oscillatory synchronization in information transfer between networks in this system. The antennal lobe is the obligatory relay for olfactory afferent signals and generates oscillatory output. The mushroom body is responsible for formation and retrieval of olfactory and other memories. The format of odor representations differs significantly across these structures. Whereas representations are dense, dynamic, and seemingly redundant in the antennal lobe, they are sparse and carried by more selective neurons in the mushroom body. This transformation relies on a combination of oscillatory dynamics and intrinsic and circuit properties that act together to selectively filter and synthesize the output from the antennal lobe. These results provide direct support for the functional relevance of correlation codes and shed some light on the role of oscillatory synchronization in sensory networks.     

Sex pheromone traps as a potential means of improving control programs for the spiny bollworm,Earias insulana

Pheromone traps were reliable for detection and estimation ofEarias insulana (Boisduval) (Lepidoptera: Noctuidae) adult populations in cotton fields. Due to the aggregated distribution in traps, estimates of moth populations were more accurate at low than at high population levels. The relationship betweenE. insulana male catch and larval density could not be assessed because of the numerous chemical treatments applied to the cotton fields. However, when chemical applications were avoided, an increase in male catch was followed by an increase in larval density. SinceE. insulana eggs are difficult to detect and the larvae penetrate the cotton bolls soon after hatching and are therefore hard to control, pheromone traps are particularly useful as a warning device for potential larval infestation.

     

Efficacy of 1 alpha hydroxyvitamin D3 in the prevention of bovine parturient paresis

One hundred and seventeen Israeli-Friesian cows from herds with a milk fever incidence of more than 15 per cent were injected intramuscularly with either 350 micrograms 1 alpha hydroxyvitamin D3 (1 alpha OHD3) in propylene glycol or with the vehicle alone, close to calving. If parturition had not occurred within 72 hours a second injection was administered; parturition was induced two days after the second injection if necessary. There were 10 cases of milk fever among 57 control cows as opposed to two cases among the 60 animals treated with 1 alpha OHD3. In an attempt to prolong the effect of the drug, Israeli-Friesian cows were injected intramuscularly with 350 micrograms 1 alpha OHD3 in either 10 ml propylene glycol or arachis oil. 1 alpha OHD3 in arachis oil did not prolong the effect of the drug. 1 alpha OHD3 in propylene glycol increased plasma calcium concentrations more rapidly than when the drug was administered in oil. Additional cows of the same breed and age were injected intramuscularly with 350 micrograms 1 alpha OHD3 in propylene glycol. Five of the animals received a second dose four days, and five received a second dose five days after the first injection. Five animals served as uninjected controls. The plasma calcium levels of the injected cows were significantly higher (P less than 0.01) than those of the controls from the second until the 14th day after the first injection. Based on these results 451 Israeli-Friesian cows from herds with a milk fever incidence of more than 15 per cent were injected intramuscularly with 1 alpha OHD3 close to calving.(ABSTRACT TRUNCATED AT 250 WORDS)     

The role of acetic acid in the attraction of the Mediterranean fruit fly <Emphasis Type="Italic">Ceratitis capitata</Emphasis> to ammonium acetate

Ammonium acetate is a well-known and widely-used attractant, primarily as the main and essential component of the dry bait BioLure, in many fruit fly control systems. The integrated attractiveness of ammonium acetate and the attractiveness of its two volatile components were studied in laboratory experiments on both females and males of the Mediterranean fruit fly, Ceratitis capitata. Acetic acid was barely attractive for females and was very attractive for the males. Ammonia was significantly more attractive to females and the integrated attractiveness of ammonium acetate was higher for males than females.     

Choosing best practices for managing impacts of trawl fishing on seabed habitats and biota

Bottom trawling accounts for almost one quarter of global fish landings but may also have significant and unwanted impacts on seabed habitats and biota. Management measures and voluntary industry actions can reduce these impacts, helping to meet sustainability objectives for fisheries, conservation and environmental management. These include changes in gear design and operation of trawls, spatial controls, impact quotas and effort controls. We review nine different measures and actions and use published studies and a simple conceptual model to evaluate and compare their performance. The risks and benefits of these management measures depend on the extent to which the fishery is already achieving management objectives for target stocks and the characteristics of the management system that is already in place. We offer guidance on identifying best practices for trawl‐fisheries management and show that best practices and their likelihood of reducing trawling impacts depend on local, national and regional management objectives and priorities, societal values and resources for implementation. There is no universal best practice, and multiple management measures and industry actions are required to meet sustainability objectives and improve trade‐offs between food production and environmental protection.     

Primordial rare gases in unequilibrated ordinary chondrites

The primordial gases of eight unequilibrated ordinary chondrites are strongly fractionated with respect to" cosmic" proportions. The absolute amounts are roughly proportional to the degree of disequilibration. Apparently, ordinary chondrites originally contained considerably larger amounts of primordial rare gases.     

Production,size, and germination of broad‐leaved dock seeds collected from mother plants grown under different nitrogen,phosphorus, and potassium supplies

Rumex obtusifolius is believed to be a nitrophilous weedy species that spreads mainly by seed. However, the effects of nutrient availability on seed production never have been investigated. In this study, how the amount of seed production per plant, the chemical composition of the seeds, and their size and germination are affected by the supply of N, P, and K was investigated. A pot fertilizer experiment with 10 treatments (combinations of 0, 150 [N1], and 300 [N2] kg N ha^?1, 0, 40 [P1], and 80 [P2] kg P ha^?1, and 0 and 100 [K] kg K ha^?1 applied twice per vegetation season) was carried out in Prague, Czech Republic, in 2008 and 2009. The seeds from plants that were cultivated since the spring were collected each August. The germination of the seeds was determined in long‐daylight conditions at a stable temperature of 20°C. The number of seeds per plant ranged from 0 in the P1 and P2 treatments and <200 in the control and K treatments to almost 9000 in the N2P2K treatment. The number of seeds per plant was positively correlated with the number of stems per plant and the number of seeds per stem. The relationship between the amount of seeds per plant and the individual seed weight was positive. The concentration of N, P, and K in the seeds was affected by the treatments. The weight of 1000 seeds ranged from 1.3 to 1.7 g. The seed length ranged from 2.11 to 2.34 mm and the seed width varied from 1.26 to 1.42 mm. With the exception of the control (with 94% germination), the amount of seed germination was >98% in all the other treatments in 2008. In 2009, the amount of seed germination was >95% in all the treatments, except N1 and N2, where 93% and 89% germination, respectively, was recorded. The germination rate was positively related to the P concentration in the seeds. The amount of time that was necessary for 50% seed germination ranged from 1.53 to 2.89 days and was not related to the N concentration in the seeds, but it was negatively related to the P and K concentrations. A balanced N, P, and K supply to the mother plant strongly affected the number of produced seeds and their chemical composition and germination ability.