Search results for " diving"

The effects of recreational Paracentrotus lividus fishing on distribution patterns of sea urchins at Ustica Island MPA (Western Mediterranean, Italy)

2006

This study evaluated the effects of recreational Paracentrotus lividus fishing on average density and size of this edible sea urchin, and its indirect effects on Arbacia lixula on barren substrates of Ustica Island MPA (SW Italy, Mediterranean Sea). Size, single and pooled species densities, density of large individuals (>40 mm long) and small individuals (<20 mm long) of the two species were estimated by scuba diving in autumn 2003, spring and summer 2004 at two sites impacted by P. lividus fishing (Punta Cavazzi and Pagliaro, take zone C) and one control (Cala Sidoti, no take zone). Two samplings were performed in each season. We found that reduced densities of P. lividus and A. lixula oc…

Scuba diver behaviour and its effects on the biota of a Mediterranean marine protected area

2009

The effects of diving activity in different Mediterranean subtidal habitats are scarcely known. This study evaluates diver behaviour (for example time spent in each habitat), use (contacts made with the substrate) and immediate effects of diver contact on benthic species in a marine protected area (MPA) in Sicily. Over a two-year period, intentions of 105 divers were observed within seven subtidal habitats: algae on horizontal substrate, algae on vertical substrate, Posidonia oceanica, encrusted walls, caves, sand and pebbles. Divers selected a habitat in proportion to its availability along the scuba trail. On average, each diver made 2.52 contacts every seven minutes, and no differences w…

Developing a scuba trail vulnerability index (STVI): a case study from a Mediterranean MPA

2008

Scuba diving is now one of the major form of commercial use of marine protected areas (MPAs) around the world and the control of its potential impacts on the marine environment represents a fundamental key to manage this recreational activity in highly dived areas. A potential tool to tackle such issues has been thought to be the definition of a value of recreational carrying capacity of an area, but this approach has been rarely considered management-effective. Therefore, the first step for effectively managing scuba-diving should be ‘bottom-up’: characterizing the benthic communities potentially affected by diving and evaluating their vulnerability. Aim of this paper is to propose a tool …

Kerguelen, un archipel sous haute surveillance

2016

Avec ses c&ocirc;tes d&eacute;coup&eacute;es et sans cesse battues par les vents, les Kerguelen sont rest&eacute;es longtemps inaccessibles aux biologistes marins. Si sa situation g&eacute;ographique et son isolement exceptionnels rendent cet archipel particuli&egrave;rement vuln&eacute;rable aux changements climatiques, ils en font aussi un laboratoire id&eacute;al pour en &eacute;tudier les effets&hellip;

ROAD -Robotic Assisted Diving: physiology of diving

2014

The operational sex ratio of the sea urchin Paracentrotus lividus populations: the case of the Mediterranean marine protected area of Ustica Island (…

2009

We investigated, with a series of field and laboratory observations, the possible effect of the starfish Marthasteria glacialis predation on the operational sex ratio (OSR), i.e. the number of sexually mature males divided by the total number of sexually mature adults of both sexes at any one time, of the edible sea urchin Paracentrotus lividus. The OSR was estimated three times during the sea urchin summer spawning period (July 2004, June 2005 and July 2006) on barren substrates of Ustica Island Marine Protected Area (Southern Tyrrhenian Sea, Italy). Four sites were selected: two characterized by high M. glacialis density (take zone C) and two controls with low starfish density (no-take zo…

Neurocognitive Markers During Prolonged Breath-Holding in Freedivers: An Event-Related EEG Study

2019

Since little is known concerning the psychological, cognitive, and neurophysiological factors that are involved in and important for phases of prolonged breath-holding (pBH) in freedivers, the present study uses electroencephalography (EEG) to investigate event-related neurocognitive markers during pBH of experienced freedivers that regularly train pBH. The purpose was to determine whether the well-known neurophysiological modulations elicited by hypoxic and hypercapnic conditions can also be detected during pBH induced hypoxic hypercapnia. Ten experienced free-divers (all male, aged 35.10 ± 7.89 years) were asked to hold their breath twice for 4 min per instance. During the first pBH, a ch…

Exploring motivational states in an international sample of competitive springboard and platform divers

2009