Movements of migrating green turtles in relation to AVHRR derived sea surface temperature

Previous studies have shown that for some populations of marine turtle, individuals move along narrow migration corridors in the open ocean. It has been suggested that these migration corridors may correspond with nearsurface oceanographic features that can be detected by remote sensing. This idea is examined by superimposing the tracks of green turtles (Chelonia mydas) migrating from Ascension Island to Brazil, on sea surface temperature (SST) data derived from Advanced Very High Resolution Radiometer (AVHRR) images. The turtles did not follow specific isotherms during migration nor make turns en-route where specific thermal cues were encountered. These results suggest that for this population, SST plays a minimal role in influencing the exact route that individuals follow.

A review of long-distance movements by marine turtles, and the possible role of ocean currents

Sea turtle movements often occur in open-sea unsheltered areas, and are therefore likely to be influenced by major oceanographic processes. Only recently has work started to examine the possible relationships of these movements with dynamic oceanic features, and consequently a clear picture of such interaction is only available in a few cases. Newborn sea turtles are thought to rely on oceanic currents to reach their pelagic nursery habitats. The actual extent and timing of these developmental migrations are known for only a few populations, but these movements probably last several years and range over thousands of km. Large juveniles that have been tracked during their pelagic stage were found to make long-distance movements, sometimes swimming against the prevailing currents. Older juveniles of most species leave the pelagic habitat to recruit to neritic developmental habitats. This is a very poorly documented phase of the sea turtle life-cycle, and the few available indications show that turtles may have to swim actively for enormous distances to counterbalance their previous drift with the current. The course and extent of adult postnesting migrations vary greatly among different turtle species, but two main patterns are evident. Some species, like green, hawksbill and loggerhead turtles, shuttle between the nesting beach and a specific feeding area used for the entire inter-reproductive period. In these cases, individuals swim, rather than drift, to complete their journeys, with possible advection due to currents sometimes helping them to quickly reach their target, but sometimes providing navigational challenges. Other species such as the olive ridley and the leatherback turtle, leave the coastal nesting areas to reach the pelagic environment where they forage, and perform wandering movements. Major oceanographic processes (such as main currents and eddies) have been recently shown to have a remarkable influence on leatherback movements, making it questionable whether these journeys are to be considered migrations or, rather, prolonged stays in vast feeding areas.

Long-term satellite telemetry of the movements and habitat utilisation by green turtles in the Mediterranean

There is a relative paucity of data regarding the at-sea distribution and behaviour of marine turtles. This is especially true for the critically endangered green turtle Chelonia mydas population in the Mediterranean. Six adult female green turtles were equipped with satellite transmitters and tracked for periods of between 28 and 293 d following their final nesting of the season in northern Cyprus. Data elucidated hitherto unknown migratory pathways and highlighted the importance of North African coastal waters as feeding habitat for adults of this species. For three individuals, instruments transmitted detailed information on dive depth, dive duration and water temperature which afforded novel insights into behaviour during different stages of migration, feeding in the foraging grounds and most remarkably, during a period of midwinter diapause when water temperatures were generally below 25°C. Turtles showed fidelity to specific shallow inshore feeding areas and moved offshore to deeper wintering sites.

Meta-analysis of movements in Atlantic leatherback turtles during the nesting season : conservation implications

Despite decades of conservation efforts on the nesting beaches, the critical status of leatherback turtles shows that their survival predominantly depends on our ability to reduce at-sea mortality. Although areas where leatherbacks meet fisheries have been identified during the long distance movements between 2 consecutive nesting seasons, hot-spots of lethal interactions are still poorly defined within the nesting season, when individuals concentrate close to land. Here we report movements of satellite-tracked gravid leatherback turtles during the nesting season in Western Central Africa, South America and the Caribbean Sea, which account for about 70% of the world population. We show that during and at the end of the nesting season, leatherback turtles have the propensity to remain over the continental shelf, yet sometimes perform extended movements and may even nest in neighbouring countries. Leatherbacks exploit coastal commercial fishing grounds and face substantial accidental capture by regional coastal fisheries (e.g. at least 10% in French Guiana). This emphasises the need for regional conservation strategies to be developed at the ocean scale—both at sea and on land—to ensure the survival of the last leatherback turtles.

Vertical movements of North Sea Cod

Various air-breathing marine vertebrates such as seals, turtles and seabirds show distinct patterns of diving behaviour. For fish, the distinction between different vertical behaviours is often less clear-cut, as there are no surface intervals to differentiate between dives. Using data from acoustic tags (n = 23) and archival depth recorders attached to cod Gadus morhua (n = 92) in the southern North Sea, we developed a quantitative method of classifying vertical movements in order to facilitate an objective comparison of the behaviour of different individuals. This method expands the utilisation of data from data storage tags, with the potential for a better understanding of fish behaviour and enhanced individual based behaviour for improved ecosystem modelling. We found that cod were closely associated with the seabed for 90% of the time, although they showed distinct seasonal and spatial patterns in behaviour. For example, cod tagged in the southern North Sea exhibited high rates of vertical movement in spring and autumn that were probably associated with migration, while the vertical movements of resident cod in other areas were much less extensive and were probably related to foraging or spawning behaviours. The full reasons underlying spatial and temporal behavioural plasticity by cod in the North Sea warrant further investigation.

Thermal niche, large-scale movements and implications of climate change for a critically endangered marine vertebrate

Climate change is expected to have a number of impacts on biological communities including range extensions and contractions. Recent analyses of multidecadal data sets have shown such monotonic shifts in the distribution of plankton communities and various fish species, both groups for which there is a large amount of historical data on distribution. However, establishing the implications of climate change for the range of endangered species is problematic as historic data are often lacking. We therefore used a different approach to predict the implications of climate change for the range of the critically endangered planktivourous leatherback turtle (Dermochelys coriacea). We used long-term satellite telemetry to define the habitat utilization of this species. We show that the northerly distribution limit of this species can essentially be encapsulated by the position of the 15°C isotherm and that the summer position of this isotherm has moved north by 330 km in the North Atlantic in the last 17 years. Consequently, conservation measures will need to operate over ever-widening areas to accommodate this range extension.

Flexible foraging movements of Leatherback turtles across the North Atlantic Ocean

Some marine species have been shown to target foraging at particular hotspots of high prey abundance. However, we show here that in the year after a nesting season, female leatherback turtles (Dermochelys coriacea) in the Atlantic generally spend relatively little time in fixed hotspots, especially those with a surface signature revealed in satellite imagery, but rather tend to have a pattern of near continuous traveling. Associated with this traveling, distinct changes in dive behavior indicate that turtles constantly fine tune their foraging behavior and diel activity patterns in association with local conditions. Switches between nocturnal vs. diurnal activity are rare in the animal kingdom but may be essential for survival on a diet of gelatinous zooplankton where patches of high prey availability are rare. These results indicate that in their first year after nesting, leatherback turtles do not fit the general model of migration where responses to resources are suppressed during transit. However, their behavior may be different in their sabbatical years away from nesting beaches. Our results highlight the importance of whole-ocean fishing gear regulations to minimize turtle bycatch.

Building movements: directed improvisation performances : conversing with buildings; assisted falling

For these performances, the new Design Hub building will play the role of architectural surrounds used as spatial research devices, architectural agent and collaborator – by giving the building our attention we aim to bring it and its affordances explicitly into the collective body. In exploring the set of interlinked spaces in the Hub (with an emphasis, we propose, on the stairs) as “elaborately structured pretexts for action” , we anticipate that the beginnings of an approach may emerge and allow us to understand that when a person “flexes her muscles, a person [also] flexes her surroundings”. Arakawa and Gins offer ways to assist us in approaching architecture as a tentative constructing toward a holding in place – in which all modes of sensing and scales of action are exercised – through their notions of ‘architectural surround’ and ‘architectural body’ garnered from chapters ‘Notes for an Architectural Body’ and ‘Architectural Surround’ (Gins and Arakawa, 2002).

Building movements : installations : space-time twister; the rub

The two collaborative installations are part of the Building Movements event and aim to generate a shared ‘body of actions’. We are proposing to emphasise attention to constructed environments (buildings, clothes, landscapes…) as active participants in ecologies of lived experience, with particular interest in how we can more explicitly approach our environments as spatial research devices, i.e. how constructed environments can offer key questions and provocations in any research enquiry.

An eye opening experience: a critical turning point in the life of a young woman with a severe visual impairment

Research on social inclusion often focuses on social exclusion. However, in order to gain greater insights into ways to facilitate social change, it is equally important to research the social inclusion of those normally excluded. Indeed, while one important purpose of studying disabilism is to catalogue and critique all its forms, another critical purpose is to better understand how disabilism can be resisted and/or ameliorated at individual and/or societal levels. Thus, it is equally important to understand when, why and how disabilism does not negatively impact the lives of people with impairments as well as when it does. This paper presents a single case study of Lynette, a young woman with a severe visual impairment who has a life-changing experience in an inclusive environment. In particular, it explores the impact of exclusive and inclusive contexts on Lynette's identity development as she transitions to adulthood. By juxtaposing Lynette's experiences of exclusion with those of inclusion, it highlights contexts in which there is a critical mass of people with impairments living alongside able-bodied people as a possible antecedent/impetus for greater social inclusion of people with impairments in society more generally.

The impact of knowledge and attitudes on access to eye-care services in Cambodia

Purpose: To investigate how knowledge and attitudes influence the access to eye-care services in Takeo Province, Cambodia.

Design: A cross-sectional survey (n=600).

Methods: 30 villages were randomly selected. Groups included: >50 years, 30–49 years, and parents with children <5 years. A newly developed Knowledge, Attitude and Practice in Eye Health (KAP-EH) questionnaire about knowledge and treatment of eye diseases, practices and attitudes to accessing services was used to interview respondents. Descriptive analysis, including Chi square and logistic regression tested for associations with sub-groups of gender, age group, education and self-reported type of disability.

Results: The proportion of respondents who reported having knowledge of specific eye conditions ranged from 97% for eye injury, to 8% for diabetic eye disease. While 509 (85%) people reported knowledge of cataract, 47% did not know how cataract was treated and only 19% listed surgery. The older group (66.5%) were least informed about cataract (p= 0.001) compared to other groups, and were least likely to believe that some blindness could be prevented (p < 0.001). Women (55%) were more likely than men (46%) (p=0 .003) to report that a child with blindness could attend school, as did people without a disability compared to those with a disability (58% vs 34%) (p < 0.001).

Conclusions: The knowledge about cataract and refractive error and what to do to resolve the problems was low among this population and this study suggests that poor knowledge of eye diseases might contribute to the occurrence of un-operated cataract and uncorrected refractive error.