Diving behaviour of whale sharks in relation to a predictable food pulse

We present diving data for four whale sharks in relation to a predictable food pulse (reef fish spawn) and an analysis of the longest continuous fine-resolution diving record for a planktivorous shark. Fine-resolution pressure data from a recovered pop-up archival satellite tag deployed for 206 days on a whale shark were analysed using the fast Fourier Transform method for frequency domain analysis of time-series. The results demonstrated that a free-ranging whale shark displays ultradian, diel and circa-lunar rhythmicity of diving behaviour. Whale sharks dive to over 979.5 m and can tolerate a temperature range of 26.4 degrees C. The whale sharks made primarily diurnal deep dives and remained in relatively shallow waters at night. Whale shark diving patterns are influenced by a seasonally predictable food source, with shallower dives made during fish spawning periods

Potential techniques and development activities in diver suit heating

A prototype compact reactor suitable for combustion of propane with oxygen under shallow as well as submerged deep submergence diving conditions is reported. The device is used to heat the circulating water in a water tube-type diving suit

Thermal protection of divers

Various diving suit-heating element combinations are evaluated in an effort to achieve a diving capability to depths of 1000 ft in water temperatures down to 29 F. Wet suits, dry suits and suits made of incompressible material are reported, and suit heat replacement by circulation of hot water with heating by cemented electrical elements is described

Shining new light on mammalian diving physiology using wearable near-infrared spectroscopy

Investigation of marine mammal dive-by-dive blood distribution and oxygenation has been limited by a lack of non-invasive technology for use in freely diving animals. Here, we developed a non-invasive near-infrared spectroscopy (NIRS) device to measure relative changes in blood volume and haemoglobin oxygenation continuously in the blubber and brain of voluntarily diving harbour seals. Our results show that seals routinely exhibit preparatory peripheral vasoconstriction accompanied by increased cerebral blood volume approximately 15 s before submersion. These anticipatory adjustments confirm that blood redistribution in seals is under some degree of cognitive control that precedes the mammalian dive response. Seals also routinely increase cerebral oxygenation at a consistent time during each dive, despite a lack of access to ambient air. We suggest that this frequent and reproducible reoxygenation pattern, without access to ambient air, is underpinned by previously unrecognised changes in cerebral drainage. The ability to track blood volume and oxygenation in different tissues using NIRS will facilitate a more accurate understanding of physiological plasticity in diving animals in an increasingly disturbed and exploited environment

Swimming & Diving Teams Claim First Championship and Returning Champs Titles

.Sweeping victory this weekend brings men’s swimming & diving their first-ever championship, while the women’s team defends theirs for the wi

Combating Food Waste: Dumpster Diving as a Form of Consumer Resistance

This paper explores North America’s food waste issue associated with our current industrial globalized food system. Through a sociocultural lens, this essay examines the new social movement of dumpster diving among food waste activists and ‘freegans’ in urban areas. Millions of people are currently unaware as to where their next meal will come from, yet Western households and supermarkets waste massive amounts of edible food. Dumpster divers do not just encourage us to be mindful of the choices we make with respect to food waste; they seek to challenge pre-existing capitalist structures and conventional ways of thinking. Analyzing the counterculture movement of dumpster diving can help us better understand the role food plays in our daily lives, and can provide an important ideological template to follow in order to mitigate this pressing social and environmental injustice

A Single-armed Manta-board as a New Diver-controlled Planing Board and Its Use for Underwater Surveys

Due to inadequacies of previous underwater towing techniques and the special needs of a recent underwater survey, a modified mania-board technique was developed. With this new technique, the diver holds on to the manta-board with one arm; consequently, the board is referred to as a single-armed manta-board (sam-board). The sam-board proved inexpensive and highly maneuverable, allowing the divers to freely collect samples or record information. Through some experimenting with the board and changing some of the variables, such as rope lengths, towing speeds, etc., a highly efficient towing method can be achieved. Preplanning and strict diving safety procedures must, however, be implemented to assure efficiency. This paper presents the materials, guidelines for board construction, equipment, and preplanning and diving safety procedures necessary for the sam-board towing operation