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.

When the spring bloom swamped the study area with fresh phytoplankton, cross-reef distinctions in particle quality disappeared. In spring 2007, near-bottom suspended particles were collected with submersible pumps during one part of a tidal cycle.Analysis revealed a difference in composition of suspended particulate matter along the reef, with highest quality at the northwest edge where particles were delivered, and lower quality at the middle and southeast edge of the reef. Results from both cruises show that particles passing over Tisler reef are subject to preferential removal of nitrogen, indicating that even a relatively small reef such as Tisler has an impact on the biochemistry of its environment. This evidence suggests that, globally, CWC reefs are hotspots of mineralization activity in the ocean.

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.

Damien Guihen is now at the British Antarctic SurveyContinuous long-term measurements of temperature, salinity and current velocity, have been recorded over 44 months at the Tisler Reef. The Tisler Reef is a 2 km long cold-water coral reef on the sill of the Kosterfjord, located in the north-eastern Skagerrak, Norway. The reef comprises principally Lophelia pertusa, at depths between 70 and 160 m, and is an important habitat for sponge, crustacean and fish species including a number of species of commercial importance. Analysis of the current velocity data has identified a number of features such as flow reversals. These reversals in flow direction are often associated with significant changes in bottom temperature. During the autumn months of 2006 and 2008, a series of large and rapid increases in bottom temperature were observed, with temperatures seen to rise by approximately 48C in a 24 hour period on both occasions. The occurrence of the 2006 and 2008 events corresponded with the observation of mass mortality in the long-lived sponge Geodia baretti. Historical temperature records from the region suggest that these temperature shocks are uncharacteristically high. The temperatures observed at the reef exceed the typical short-term physiological limits of L. pertusa thus future temperature shock events may have a swift and negative impact on the cold-water coral reef ecosystems of the Skagerrak.

A calibrated 120 kHz single-beam echo-sounder was integrated into an ocean glider and deployed in the Weddell Sea, Southern Ocean. The glider was deployed for two short periods in January 2012, in separate survey boxes on the continental shelf to the east of the Antarctic Peninsula, to assess the distribution of Antarctic krill (Euphausia superba). During the glider missions, a research vessel undertook acoustic transects using a calibrated, hull-mounted, multi-frequency echo-sounder. Net hauls were taken to validate acoustic targets and parameterize acoustic models. Krill targets were identified using a thresholded schools analysis technique (SHAPES), and acoustic data were converted to krill density using the stochastic distorted-wave Born approximation (SDWBA) target strength model. A sensitivity analysis of glider pitch and roll indicated that, if not taken into account, glider orientation can impact density estimates by up to 8-fold. Glider-based, echo-sounder-derived krill density profiles for the two survey boxes showed features coherent with ship-borne measurements, with peak densities in both boxes around a depth of 60 m. Monte Carlo simulation of glider subsampling of ship-borne data showed no significant difference from observed profiles. Simulated glider dives required at least an order of magnitude more time than the ship to similarly estimate the abundance of krill within the sample regions. These analyses highlight the need for suitable sampling strategies for glider-based observations and are our first steps toward using autonomous underwater vehicles for ecosystem assessment and long-term monitoring. With appropriate survey design, gliders can be used for estimating krill distribution and abundance.