The thin edge of the wedge: Extremely high extinction risk in wedgefishes and giant guitarfishes

1. The process of understanding the rapid global decline of sawfishes (Pristidae) has revealed great concern for their relatives, the wedgefishes (Rhinidae) and giant guitarfishes (Glaucostegidae), not least because all three families are targeted for their high‐value and internationally traded ‘white’ fins.
2. The objective of this study was to assess the extinction risk of all 10 wedgefishes and six giant guitarfishes by applying the International Union for Conservation of Nature (IUCN) Red List Categories and Criteria, and to summarize the latest understanding of their biogeography and habitat, life history, exploitation, use and trade, and population status. Three of the 10 wedgefish species had not been assessed previously for the IUCN Red List.
3. Wedgefishes and giant guitarfishes have overtaken sawfishes as the most imperilled marine fish families globally, with all but one of the 16 species facing an extremely high risk of extinction through a combination of traits: limited biological productivity; presence in shallow waters overlapping with some of the most intense and increasing coastal fisheries in the world; and overexploitation in target and by‐catch fisheries, driven by the need for animal protein and food security in coastal communities and the trade in meat and high‐value fins.
4. Two species with very restricted ranges, the clown wedgefish (Rhynchobatus cooki) of the Malay Archipelago and the false shark ray (Rhynchorhina mauritaniensis) of Mauritania, may be very close to extinction.
5. Only the eyebrow wedgefish (Rhynchobatus palpebratus) is not assessed as Critically Endangered, with it occurring primarily in Australia where fishing pressure is low and some management measures are in place. Australia represents a ‘lifeboat’ for the three wedgefish and one giant guitarfish species occurring there.
6. To conserve populations and permit recovery, a suite of measures will be required that will need to include species protection, spatial management, by‐catch mitigation, and harvest and international trade management, all of which will be dependent on effective enforcement.

     

Einfluss von blattappliziertem Bor auf Boraufnahme und Fruchteigenschaften von Kulturheidelbeeren (Vaccinium corymbosum)

In 2003, highbush blueberry (Vaccinium corymbosum) cultivars ‘Brigitta Blue’ and ‘Nelson’ were treated with a foliar boron-containing, ascofol spray (Wuxal^®). After blossoming, the plants were sprayed three times with 0.5% ascofol solution. Control plants were sprayed with tap water. Fruit harvest of each cultivar was on July 19 and 30, respectively. Leaf samples were taken on June 4 and August 7. The boron content of fruits and leaves was analyzed along with fruit yield and single berry weight. The potential absorption rate of applied boron (boron increase in leaves and fruits) was calculated. Foliarly applied boron was readily taken up by the leaves of both cultivars and translocated to the fruits. A potential boron absorption rate of 2.4% was calculated for ‘Nelson’. Foliar application of boron did not increase fruit yield in either cultivar. However, ‘Nelson’ showed a slight increase of berry weight in the second harvest, associated with the boron treatments.     

Microbiological evaluation of dressing procedures for crocodile carcases in Queensland

SUMMARY Microbiological testing of crocodiles during the dressing procedure has shown that sanitising the skin before skinning reduces the bacterial count on the skin and that dipping crocodile meat in 1.3% acetic acid solution effectively reduces bacterial levels. The total bacterial count on the processed meat sample was comparable with that obtained in the beef, pork and lamb industries. Salmonellae were isolated from 14 of the 72 carcases. Most (65%) of these isolates were in Salmonella subspecies III, formerly classified as Arizona.     

Relations between the concentration of diffusable and extractable gibberellin-like substances and the alternate-bearing behaviour in apple as affected by chemical fruit thinning

The levels of diffusable and extractable gibberellin-like substances (GA_s) of apple fruits were investigated in the alternate-bearing ‘King of the Pippins’ and the regularly fruiting ‘Golden Delicious’, using the barley endosperm bioassay. During 1977 and 1978 there were marked differences between the two cultivars in both the chronological appearance and the absolute amounts of diffusable GA_s. The application of fruit-thinning chemicals (carbaryl, ethephon, NAAm) to ‘King of the Pippins’ suppressed the early increase of GA_s in diffusates, which normally occurs during the second week after full bloom. The following year, the thinned trees exhibited heavy flower- and fruit-set, while the untreated control trees showed a very poor bloom. The later appearance of the GA peak in diffusates from fruits of ‘Golden Delicious’ (5 weeks after full bloom), was not accompanied by a similar inhibitory effect on subsequent flowering.In contrast to their effect on the levels of diffusable GA_s, the thinning-treatments caused no real change in the amount of extractable GA_s, which was very similar in fruits from both cultivars.     

Metolachlor (2-chloro-N-[2-ethyl-6-methylphenyl]-N-[2-methoxy-l-methylethyl] acetamide) and the metolachlor safener CGA 43089 [α-(cyanomethoximino)-benzacetonitrile] in sorghum seedlings: Correlations between morphological effects and ethylene formation

Treatment of germinating sorghum [Sorghum bicolor (L.) Moench] seeds with the grass herbicide, metolachlor (2-chloro-N-[2-ethyl-6-methylphenyl]-N-[2-methoxy-1-methylethyl] acetamide), causes growth retardation, promoted by thickening of the first leaf and thus inhibition of unfolding of secondary leaves, and increased ethylene production. Sorghum seeds pretreated with the safener CGA 43089 [α-(cyanomethoximino)-benzacetonitrile] exhibit neither morphological deformations nor ethylene production upon metolachlor treatment. Aminoethoxyvinylglycine [l-2-amino-4-(2-aminoethoxy)-trans-3-butenoic acid], a specific inhibitor of ethylene formation in higher plants, decreases ethylene formation by metolachlor-treated sorghum seedlings; the observed deformations, however, remain unchanged. Sorghum control seedlings which grow against a covering plate build up ethylene concentrations as after herbicide treatment, but without induction of the morphological symptoms. These observations suggest that the plant hormone ethylene is a symptom and not the inducer of the morphological effects visible after metolachlor treatment of sorghum seedlings.     

Particle nucleation in the tropical boundary layer and its coupling to marine sulfur sources

New particle formation in a tropical marine boundary layer setting was characterized during NASA's Pacific Exploratory Mission-Tropics A program. It represents the clearest demonstration to date of aerosol nucleation and growth being linked to the natural marine sulfur cycle. This conclusion was based on real-time observations of dimethylsulfide, sulfur dioxide, sulfuric acid (gas), hydroxide, ozone, temperature, relative humidity, aerosol size and number distribution, and total aerosol surface area. Classic binary nucleation theory predicts no nucleation under the observed marine boundary layer conditions.