Multiple pygmy blue whale acoustic populations in the Indian Ocean: whale song identifies a possible new population.

Blue whales were brought to the edge of extinction by commercial whaling in the twentieth century and their recovery rate in the Southern Hemisphere has been slow; they remain endangered. Blue whales, although the largest animals on Earth, are difficult to study in the Southern Hemisphere, thus their population structure, distribution and migration remain poorly known. Fortunately, blue whales produce powerful and stereotyped songs, which prove an effective clue for monitoring their different 'acoustic populations.' The DGD-Chagos song has been previously reported in the central Indian Ocean. A comparison of this song with the pygmy blue and Omura's whale songs shows that the Chagos song are likely produced by a distinct previously unknown pygmy blue whale population. These songs are a large part of the underwater soundscape in the tropical Indian Ocean and have been so for nearly two decades. Seasonal differences in song detections among our six recording sites suggest that the Chagos whales migrate from the eastern to western central Indian Ocean, around the Chagos Archipelago, then further east, up to the north of Western Australia, and possibly further north, as far as Sri Lanka. The Indian Ocean holds a greater diversity of blue whale populations than thought previously.

Microplastic sampling with the AVANI trawl compared to two neuston trawls in the Bay of Bengal and South Pacific.

Many typical neuston trawls can only be used during relatively calm sea states and slow tow speeds. During two expeditions to the Bay of Bengal and the eastern South Pacific we investigated whether the new, high-speed AVANI trawl (All-purpose Velocity Accelerated Net Instrument) collects similar amounts and types of microplastics as two established scientific trawl designs, the manta trawl and the DiSalvo neuston net. Using a 335 µm net, the AVANI trawl can collect microplastics from the sea surface at speeds up to 8 knots as it "skis" across the surface, whereas the manta and DiSalvo neuston trawls must be towed slowly in a less turbulent sea state and often represent shorter tow lengths. Generally, the AVANI trawl collected a greater numerical abundance and weight of plastic particles in most size classes and debris types than the manta trawl and DiSalvo neuston net, likely because these trawls only skim the surface layer while the AVANI trawl, moving vertically in a random fashion, collects a "deeper" sample, capturing the few plastics that float slightly lower in the water column. However, the samples did not differ enough that results were significantly affected, suggesting that studies done with these different trawls are comparable. The advantage of the AVANI trawl over traditional research trawls is that it allows for collection on vessels underway at high speeds and during long transits, allowing for a nearly continuous sampling effort over long distances. As local surface currents make sea surface abundance widely heterogeneous, widely spaced short-tow trawls, such as the manta and DiSalvo trawls, can catch or miss hotspots or meso-scale variability of microplastic accumulations, whereas the AVANI trawl, if utilized for back-to-back tows of intermediate distances (5-10 km), can bridge variable wind conditions and debris concentrations potentially reducing variance and provide a greater resolution of spatial distribution.

Human factor observations of the Biosphere 2, 1991-1993, closed life support human experiment and its application to a long-term manned mission to Mars.

Human factors are a key component to the success of long-term space missions such as those necessitated by the human exploration of Mars and the development of bioregenerative and eventually self-sufficient life support systems for permanent space outposts. Observations by participants living inside the 1991-1993 Biosphere 2 closed system experiment provide the following insights. (1) Crew members should be involved in the design and construction of their life support systems to gain maximum knowledge about the systems. (2) Individuals living in closed life support systems should expect a process of physiological and psychological adaptation to their new environment. (3) Far from simply being a workplace, the participants in such extended missions will discover the importance of creating a cohesive and satisfying life style. (4) The crew will be dependent on the use of varied crops to create satisfying cuisine, a social life with sufficient outlets of expression such as art and music, and to have down-time from purely task-driven work. (5) The success of the Biosphere 2 first 2-year mission suggests that crews with high cultural diversity, high commitment to task, and work democracy principles for individual responsibility may increase the probability of both mission success and personal satisfaction. (6) Remaining challenges are many, including the need for far more comprehensive real-time modeling and information systems (a "cybersphere") operating to provide real-time data necessary for decision-making in a complex life support system. (7) And, the aim will be to create a noosphere, or sphere of intelligence, where the people and their living systems are in sustainable balance.