No evidence of bias from fish behavior in the selectivity of size and sex of the protogynous red porgy (Pagrus pagrus, Sparidae) by hook-and-line gear

Most fisheries select the size of fish to be caught (are size selective), and many factors, including gear, market demands, species distributions, fishery laws, and the behavior of both fishermen and fish, can contribute to that selectivity. Most fishing gear is size-selective and some, such as gill nets, are more so than others. The targeting behavior of fishermen is another key reason commercial and recreational fisheries tend to be size-selective. The more successful fishermen constantly seek areas and methods that yield larger or more profitable sizes of fish. Fishery regulations, especially size limits, produce size-selective harvests. Another factor with the potential to cause selectivity in a hook-and-line fishery is the different behavioral responses of fish to the bait or lure, whether the different responses arise among different fish sizes or between the sexes.

Length-weight relationship of fishes from Yemen waters (Gulf of Aden and Red Sea)

The data for this study were gathered between 1993 and 1996 on board commercial trawlers from Somalia, China and Yemen and also from the research vessel Ibn Magid belonging to the Marine Science and Resources Research Centre, Aden, Republic of Yemen. Fish were identified using the FAO species identification literature. All fish were measured to the nearest mm (total length) and weighed to the nearest g. Sex was determined by dissection after the length and weight had been measured. The length-weight relationships were calculated using least-squares regression on log-transformed data and the parameters of the relationship of the form of W=aL super(b) are summarized. Maximum and minimum size of fish sampled are also given. Common names and recent changes in nomenclature were taken from ICLARM's FishBase.

On the Distribution and Fishery Potential of the Japanese Red Crab Chaceon granulatus in the Palauan Archipelago, Western Caroline Islands

A deep-water trapping survey in the Palauan archipelago, Western Caroline Islands, has revealed an abundance of the Japanese red crab, Chaceon granulatus. The recorded depth range (250-900 m) is similar to that of other geryonids, but the large numbers of females caught below 700 m is atypical. Mean yields in excess of 5 kg crabs plus 1 kg shrimp, Heterocarpus laevigatus, by-catch per trap-night were attainable at optimum depths. Chaceon granulatus is apparently a very large geryonid, with maximum weights of 2.02 kg and 1.51 kg recorded for male and female specimens, respectively. A range of body colors was observed: Orange-red shades appear to dominate the deeper waters (below 500 m) while yellow-tan colors are more abundant in the upper reaches. Preliminary evidence suggests that Chaceon granulatus is highly marketable, and the infrastructure in Palau is such that crabs could either be marketed fresh locally or airfreighted to Japan as a quick-frozen product. The high post-trapping survival rates observed indicate that maintaining crabs in live-holding tanks may be a feasible option. The large catches and quality of deep-water crabs taken suggests that the Palauan population of Chaceon granulatus may be able to support a small-scale fishery. It is not yet known whether this population is unusually large or whether these findings typify the deep forereef fauna of the region.

Occurrence of a deeper red colour in prawn pulp prepared from iced-prawns

In commerce, great importance is given to the color of the dry prawn pulp in its quality evaluation. The possible correlation between this color factor to the iced or not iced condition of the raw prawn used, is investigated. The study reveals that as the icing period of the raw material increases the color of the finished product proportionately intensifies to a bright red compared to light brownish yellow or orange color of the product from the not iced prawn, and at the same time the other characteristics like flavor and taste deteriorates as the time of icing advances. This finding tends to show that the color factor does not reflect the true quality of prawn pulp. Based on chemical data it is suggested that "browning" due to Maillard reaction may have an important role in this color phenomena.

Check list of plankton of the northern Red Sea

Qualitative estimation of phytoplankton and zooplankton of the northern Red Sea and Gulf of Aqaba were carried out from four sites: Sharm El-Sheikh, Taba, Hurghada and Safaga. A total of 106 species and varieties of phytoplankton were identified including 41 diatoms, 53 dinoflagellates, 10 cyanophytes and 2 chlorophytes. The highest number of species was recorded at Sharm El-Sheikh (46 spp), followed by Safaga (40 spp), Taba (30 spp), and Hurghada (23 spp). About 95 of the recorded species were previously mentioned by different authors in the Red Sea and Gulf of Suez. Eleven species are considered new to the Red Sea. About 115 species of zooplankton were recorded from the different sites. They were dominated by four main phyla namely: Arthropoda, Protozoa, Mollusca, and Urochordata. Sharm El-Sheikh contributed the highest number of species (91) followed by Safaga (47) and Taba (34). Hurghada contributed the least (26). Copepoda dominated the other groups at the four sites. The appearances of Spirulina platensis, Pediastrum simplex, and Oscillatoria spp. of phytoplankton in addition to the rotifer species and the protozoan Difflugia oblongata of zooplankton impart a characteristic feature of inland freshwater discharge due to wastewater dumping at sea in these regions resulting from the expansion of cities and hotels along the coast.

The residue measurment of pesticide in water and biota of the Sorkhrood River in the south of the Caspian Sea

Pesticide residue is considered as a crucial factor in the fresh water ecosystem pollution of north Iran (Esp. Gillan and Mazandaran provinces). It is also regarded dangerous to the health of human being and animals. In this research , pesticide residue in 3 species of fish was gauged in stations of the Haraz river , the Sorkhrood river , and the Caspian sea. The sampeles were taken during 27 mounths (started in April 97 and ended to June 99). The maximum level of pesticide in water was found in July 98 for lindine at 12.4 ppb. The level of chlorinated pesticide residue recorded at 63 ppb in April 98. The level of. organophosphorus pesticides residue in water was at 1.75 ppb in Aug 97. The toxicity of the mentioned pesticide and bioaccomulation were taken into account in conducting this researched.

Aquaculture of the mangrove red snapper

Mangrove red snapper (Lutjanus argentimaculatus) is an important marketable species throughout the Indo-Pacific region. It is a euryhaline species; it can tolerate freshwater, brackishwater and marine water. Modular culture is the common system in snapper production in the Philippines. Stocking density is 4,000 fry per cropping; there could be 2 croppings per year. Brief details are given of investment costs and returns for culture in brackishwater pens.

Application of gel-casting to the fabrication of 1-3 piezoelectric ceramic-polymer composites for high-frequency ultrasound devices

A modified gel-casting technique was used to fabricate a 1-3 piezoelectric ceramic/polymer composite substrate formed by irregular-shaped pillar arrays of small dimensions and kerfs. This technique involves the polymerization of aqueous piezoelectric (PZT) suspensions with added water-soluble epoxy resin and polyamine-based hardener that lead to high strength, high density and resilient ceramic bodies. Soft micromoulding was used to shape the ceramic segments, and micropillars with lateral features down to 4 m and height-to-width aspect ratios of ∼10 were achieved. The composite exhibited a clear thickness resonance mode at approximately 70 MHz and a k eff ∼ 0.51, demonstrating that the ceramic micropillars possess good electrical properties. Furthermore, gel-casting allows the fabrication of ceramic structures with non-conventional shapes; hence, device design is not limited by the standard fabrication methods. This is of particular benefit for high-frequency transducers where the critical design dimensions are reduced. © 2012 IOP Publishing Ltd.

Effects of solar ultraviolet radiation on photosynthesis of the marine red tide alga Heterosigma akashiwo (Raphidophyceae)

In order to assess the short- and long-term impacts of UV radiation (LTVR, 280-400 nm) on the red tide alga, Heterosigma akashiwo, we exposed the cells to three different solar radiation treatments (PAB: 280-700 rim, PA: 320-700 nm, R 400-700 nm) under both solar and artificial radiation. A significant decrease in the effective quantum yield () during high irradiance periods (i.e., local noon) was observed, but the cells partially recovered during the evening hours. Exposure to high irradiances for 15, 30, and 60 min under a solar simulator followed by the recovery (8 h) under dark, 9 and 100 mu mol photons m(-2) s(-1) of PAR, highlighted the importance of the irradiance level during the recovery period. Regardless the radiation treatments, the highest recovery (both in rate and total Y) was found at a PAR irradiance of 9 mu mol photons m(-2) s(-1), while the lowest was observed at 100 mu mol photons m(-2) s(-1). In all experiments, PAR was responsible for most of the observed inhibition; nevertheless, the cells exposed only to PAR had the highest recovery in any condition, as compared to the other radiation treatments. In long-term experiments (10 days) using semi-continuous cultures, there was a significant increase of UV-absorbing compounds (UVabc) per cell from 1.2 to > 4 x 10(-6) mu g UVabc cell(-1) during the first 3-5 days of exposure to solar radiation. The highest concentration of UVabc was found in samples exposed in the PAB as compared to PA and P treatments. Growth rates (mu) mimic the behavior of UV-absorbing compounds, and during the first 5 days mu increased from < 0.2 to ca. 0.8, and stayed relatively constant at this value during the rest of the experiment. The inhibition of the Y decreased with increasing acclimation of cells. All our data indicates that H. akashiwo is a sensitive species, but was able acclimate relatively fast (3-5 days) synthesizing UV-absorbing compounds and thus reducing any impact either on photosystem 11 or on growth. (c) 2006 Published by Elsevier B.V.