A protocol for the aerial survey of penguin colonies using UAVs

Penguins, and many other seabirds, often nest in the open in large colonies, and so are amenable to aerial survey. UAVs offer a flexible and inexpensive method of achieving this but, to date, few published examples are available. We present a protocol for acquiring aerial images of penguin colonies using UAVs and describe simple, open-source tools for processing these into counts. Our approach is demonstrated using a case study for a penguin colony in the Falkland Islands. We discuss the advantages and limitations of UAVs for penguin surveys and make recommendations for their wider application

Assessing the potential of autonomous submarine gliders for ecosystem monitoring across multiple trophic levels (plankton to cetaceans) and pollutants in shallow shelf seas

A combination of scientific, economic, technological and policy drivers is behind a recent upsurge in the use of marine autonomous systems (and accompanying miniaturized sensors) for environmental mapping and monitoring. Increased spatial–temporal resolution and coverage of data, at reduced cost, is particularly vital for effective spatial management of highly dynamic and heterogeneous shelf environments. This proof-of-concept study involves integration of a novel combination of sensors onto buoyancy-driven submarine gliders, in order to assess their suitability for ecosystem monitoring in shelf waters at a variety of trophic levels. Two shallow-water Slocum gliders were equipped with CTD and fluorometer to measure physical properties and chlorophyll, respectively. One glider was also equipped with a single-frequency echosounder to collect information on zooplankton and fish distribution. The other glider carried a Passive Acoustic Monitoring system to detect and record cetacean vocalizations, and a passive sampler to detect chemical contaminants in the water column. The two gliders were deployed together off southwest UK in autumn 2013, and targeted a known tidal-mixing front west of the Isles of Scilly. The gliders’ mission took about 40 days, with each glider travelling distances of >1000 km and undertaking >2500 dives to depths of up to 100 m. Controlling glider flight and alignment of the two glider trajectories proved to be particularly challenging due to strong tidal flows. However, the gliders continued to collect data in poor weather when an accompanying research vessel was unable to operate. In addition, all glider sensors generated useful data, with particularly interesting initial results relating to subsurface chlorophyll maxima and numerous fish/cetacean detections within the water column. The broader implications of this study for marine ecosystem monitoring with submarine gliders are discussed

Ocean processes at the Antarctic continental slope

The Antarctic continental shelves and slopes occupy relatively small areas, but, nevertheless, are important for global climate, biogeochemical cycling and ecosystem functioning. Processes of water mass transformation through sea ice formation/melting and ocean–atmosphere interaction are key to the formation of deep and bottom waters as well as determining the heat flux beneath ice shelves. Climate models, however, struggle to capture these physical processes and are unable to reproduce water mass properties of the region. Dynamics at the continental slope are key for correctly modelling climate, yet their small spatial scale presents challenges both for ocean modelling and for observational studies. Cross-slope exchange processes are also vital for the flux of nutrients such as iron from the continental shelf into the mixed layer of the Southern Ocean. An iron-cycling model embedded in an eddy-permitting ocean model reveals the importance of sedimentary iron in fertilizing parts of the Southern Ocean. Ocean gliders play a key role in improving our ability to observe and understand these small-scale processes at the continental shelf break. The Gliders: Excellent New Tools for Observing the Ocean (GENTOO) project deployed three Seagliders for up to two months in early 2012 to sample the water to the east of the Antarctic Peninsula in unprecedented temporal and spatial detail. The glider data resolve small-scale exchange processes across the shelf-break front (the Antarctic Slope Front) and the front's biogeochemical signature. GENTOO demonstrated the capability of ocean gliders to play a key role in a future multi-disciplinary Southern Ocean observing system

High-resolution acoustic surveys with diving gliders come at a cost of aliasing moving targets.

Underwater gliders are autonomous robots that follow a slow, see-saw path and may be deployed for months on end. Gliders have a dramatically lower payload capacity than research vessels and are thus limited to more simple instrumentation. They have the advantage, however, of being deployable for long periods of time without the high running costs of a ship. Recent years have seen development of the use of gliders to undertake acoustic surveys of biomass in the pelagic environment, highlighting their potential to fill future survey gaps. Here it is shown, using simulation of sampling, that gliders can resolve acoustic targets at greater resolutions than ships, due to their diving pattern, but that survey accuracy is strongly dependent on the speed of the target

The career experiences and aspirations of women deputy head teachers

This article draws on the findings of an in-depth study which sought to explore the career histories and professional aspirations of 12 women deputy head teachers in England. In view of the ongoing underrepresentation of women in secondary headship and the scarcity of literature focusing solely on deputy heads, the study aimed to gain an insight into how female potential aspirants to headship perceive their professional futures. This article explores the heterogeneous ways in which the sample experienced deputy headship and the influence that these experiences had on their career aspirations. The themes that emerged from the women’s narratives highlighted both the enabling and constraining nature of deputy headship. Analysis also revealed that deputies’ day-to-day work had the potential to facilitate or curtail aspirations to headship. This article argues that women’s experiences of deputy headship should be taken into consideration in debates concerning the underrepresentation of women in secondary headship. Implications for leadership development and support as well as avenues for future research are identified