Water Depth Research Papers - Academia.edu (original) (raw)

The spotted dol­ phin (Stenella attenuata) is found throughout much of the eastern tropical Pacific Ocean. A previous study evaluated morphological variation in skull morphology, but now specimens are available for a greater portion of... more

The spotted dol­ phin (Stenella attenuata) is found throughout much of the eastern tropical Pacific Ocean. A previous study evaluated morphological variation in skull morphology, but now specimens are available for a greater portion of the range. Also, corrections have been made in data and an assessment has been made evaluating repeatability of character measurements. We reas­ sessed geographic variation in 30 cranial features (26 morphometric measures and 4 tooth counts) based on 611 museum specimens. All characters except two tooth counts showed statistically signifi­ cant geographic variation, while 21 of the 30 characters exhibited significant sexual dimorphism. Males were larger in most charac­ ters; females were larger in some length measurements involving the rostrum and ramus. As in pre­ vious analyses, inshore S. attenu­ ata were found to be very distinc­ tive, so subsequent analyses fo­ cused on offshore spotted dolphins from 29 50 latitude-longitude blocks. Mantel tests ...

The purpoase of this research was to test the effects of three culture densities on the growth and survival of Octopus vulgaris. A total of 141 sub-adult octopuses (1,175.4 ± 194.9 g) were randomly distributed in nine tanks of 2,000 l... more

The purpoase of this research was to test the effects of three culture densities on the growth and survival of Octopus vulgaris. A total of 141 sub-adult octopuses (1,175.4 ± 194.9 g) were randomly distributed in nine tanks of 2,000 l each (3.6 m × 1.1 m, and 50 cm water depth). Three tanks were stocked with a low initial density of 4 kg/m3, while three other tanks were stocked with an initial density of 8 kg/m3, and the remaining three tanks were stocked at an initial density of 15 kg/m3. Octopuses were all fed frozen squid (Loligo gahi) at 5% body weight per day (%BW/day). The experiment lasted for 70 days. Water temperature varied between 20 ± 2°C, and salinity varied between 36 ± 1 ppt. During the entire experiment, dissolved oxygen was always >75%, and ammonia was always lower than 0.1 mg/l. No differences in growth or growth rates (between 0.9 and 1.1%BW/day for the three densities) were found. Nevertheless, mortality was significantly lower for the low density compared to the other two densities tested. Maximum densities in the culture tanks (>25 kg/m3) were attained in the higher culture densities after 56 days of the experiment.

In the late 1960s oil and gas development became an issue in the northern coastal areas of Alaska and Canada. More lately this has also become an issue in the Euroasian Arctic with the Barents and Kara Seas as example on where offshore... more

In the late 1960s oil and gas development became an issue in the northern coastal areas of Alaska and Canada. More lately this has also become an issue in the Euroasian Arctic with the Barents and Kara Seas as example on where offshore hydrocarbon production now is being planned. In such waters the key questions prior to a development are

Wetlands dominated by Swamp Paperbarks (Melaleuca spp., Myrtaceae) are common in coastal regions across Australia. Many of these wetlands have been filled in for coastal development or otherwise degraded as a consequence of altered water... more

Wetlands dominated by Swamp Paperbarks (Melaleuca spp., Myrtaceae) are common in coastal regions across Australia. Many of these wetlands have been filled in for coastal development or otherwise degraded as a consequence of altered water regimes and increased salinity. Substantial resources, often involving community groups, are now being allocated to revegetating the remaining wetland sites, yet only rarely is the effectiveness of the rehabilitation strategies or on-ground procedures robustly assessed. As part of a larger project investigating the condition and rehabilitation of brackish-water wetlands of the Gippsland Lakes, we overlaid a scientifically informed experimental design on a set of community-based planting trials to test the effects of water depth, microtopography, plant age and planting method on the survival and growth of seedlings of Melaleuca ericifolia Sm. in Dowd Morass, a degraded, Ramsar-listed wetland in south-eastern Australia. Although previous laboratory and greenhouse studies have shown M. ericifolia seedlings to be salt tolerant, the strongly interactive effects of waterlogging and salinity resulted in high seedling mortality (>90%) in the field-based revegetation trials. Seedlings survived best if planted on naturally raised hummocks vegetated with Paspalum distichum L. (Gramineae), but their height was reduced compared with seedlings planted in shallowly flooded environments. Age of plants and depth of water were important factors in the survival and growth of M. ericifolia seedlings, whereas planting method seemed to have little effect on survival. Improved testing of revegetation methods and reporting of success or otherwise of revegetation trials will improve the effectiveness and accountability of projects aiming to rehabilitate degraded coastal wetlands.

Double-ring infiltrometers are routinely used by turfgrass specialists, soil scientists, and other professionals to measure the infiltration rate of field sites. Measurement of infiltration rate is important in proper golf course design... more

Double-ring infiltrometers are routinely used by turfgrass specialists, soil scientists, and other professionals to measure the infiltration rate of field sites. Measurement of infiltration rate is important in proper golf course design development and other scenarios that require estimates of runoff. This study compared several commonly performed double-ring infiltration methods as follows: 30- (inner) and 60-cm (outer) diameter rings with

Deep ocean water (DOW) is commonly referred to as the water below photic zone in the ocean that is typically cold, clean, stable, and rich in nutrients. Japan and the United States have been exploiting the DOW for utilization in water,... more

Deep ocean water (DOW) is commonly referred to as the water below photic zone in the ocean that is typically cold, clean, stable, and rich in nutrients. Japan and the United States have been exploiting the DOW for utilization in water, pharmaceutical, cosmetic, and fishery industries for many years. Since 2000, Taiwan has started the preliminary planning for the exploitation

In marine applications, single point or spread mooring systems are used for providing temporary berthing of vessels. In this investigation, it is suggested that pile anchors and suction anchors can be used depending on the water depth. By... more

In marine applications, single point or spread mooring systems are used for providing temporary berthing of vessels. In this investigation, it is suggested that pile anchors and suction anchors can be used depending on the water depth. By testing a model, the influence of parameters like mooring chain inclination, consistency of the clayey soil in the seabed and anchor embedment ratios on pullout capacity has been brought out. Tests were carried out on single pile, 2-pile, 4-pile anchors made out of pipe piles of 25.4 mm dia with length to diameter ratios, L/DL/D of 10, 14 and 18 and model suction anchors (closed-top caisson) of 113 mm dia with L/D=2L/D=2, 3 and 4. These were installed in a model test bed made out of soft marine clay. The results indicate that in respect of pile anchors as of the chain inclination changes from horizontal to vertical direction, the pullout resistance shifts from passive earth pressure to skin friction. The results in respect of suction anchors can be interpreted in terms of various components proposed.