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We studied the influence of the distribution of prey and hydrographic fronts on the spatial distribution of foraging Brunnich's guillemots (Uria lomvia) in Storfjorden, southeastern Svalbard in late July 1992. Two large breeding colonies, comprising a total of 540,000 individuals, were located adjacent to the study area, and large numbers of Brunnich's gullemots from these colonies foraged within the area, as well as to the south, outside of Storfjorden. Within the study area, most guillemots foraged on the west side of the fjord, coincident with a weak subsurface front between warm Atlantic water, which penetrated Storfjorden from the south, and cold Arctic water. Food samples from the guillemots collected in the study area contained primarily crustaceans (Parathemisto spp. and Thysanoessa inermis) and polar cod Boreogadus saida. Acoustic observations of prey were differentiated into two classes of signals, which we interpreted as originating from aggregated and dispersed organisms. The numbers of foraging guillemots were strongly correlated with the strength of echoes of the aggregated type, whereas correlations with dispersed echoes were consistently weaker. The distribution of foraging guillemots showed no significant correlations with either horizontal or vertical gradients of physical properties of the water column. Our finding that guillemots respond differently to aggregated and dispersed prey has important implications both for the interpretation of past work on the foraging ecology of marine birds, and for the management of fisheries.

In order to monitor the recovery of vegetation from pollution and the success of re-seeding efforts, acoustic echoes from the sea floor, covered and uncovered by underwater vegetation, were collected in Puck Bay (southern Baltic sea) using a 208 kHz Biosonics DT 4200 scientific echo sounder. The echo envelopes were examined and several of their parameters were recommended for further analysis. The possibility of using these parameters to distinguish between a bare sea floor and underwater meadows was tested. The parameters may be helpful in the identification of the species composition of the meadows and in accurate biomass assessment. [Copyright &y& Elsevier]

Sea spray aerosols (SSA) are an important part of sea–air interactions. Their emission from the oceans, especially during storms, affects many processes in the air–sea boundary layer environment. Higher concentration of marine aerosols affects cloud condensation nuclei, albedo changes and light scattering (Lewis and Schwartz, 2004). Studying this volatile phenomenon is crucial for a better understanding of our environment, creation of reliable climate models and forecasts, especially in the time of rapid climate changes.It should be noted that sea spray fluxes and the amount of air bubbles beneath the sea surface are correlated (Blanchard, 1963). Hence, here we present the results of connected acoustic and aerosol measurements conducted on-board R/V Oceania during research campaigns on the Southern Baltic Sea. By using the acoustic methods, we were able to estimate how many bubbles were beneath the waves. The acoustic buoy system, with the bandwidth of the tract reduced to the frequency range from 80 Hz to 12.5 kHz, was oriented towards registration of wind/rain components of underwater noise. Simultaneously, we collected the data from the CSAPS_100–HV Particles Measuring System aerosol particles counter, moved vertically between 8, 11, 14, 17 and 20 m asl (Petelski 2014), and the meteorological data to forward analysis. Sea spray fluxes were calculated according to gradient method proposed by Petelski (2003) and compared with data obtained from the acoustic equipment. In the results, we present the outcome of aerosol and acoustic data relation based on underwater sound intensity generated by a local wind dependent on surface sources. Taking into account the applicability, low costs of acoustics measurements in comparison to traditional methods and the possibility of obtaining long series of measurements, we plan to explore this area of research during future field campaigns.Blanchard, D. C. (1963). The electrification of the atmosphere by particles from bubbles in the sea. Progress in Oceanography. https://doi.org/10.1016/0079-6611(63)90004-1Lewis, E. R., & Schwartz, S. E. (2004). Sea salt aerosol production: Mechanisms, methods, measurements and models—A critical review. In Geophysical Monograph Series. https://doi.org/10.1029/152GM01Petelski, T. (2003). Marine aerosol fluxes over open sea calculated from vertical concentration gradients. Journal of Aerosol Science, 34(3), 359–371. https://doi.org/10.1016/S0021-8502(02)00189-1Petelski, T., Markuszewski, P., Makuch, P., Jankowski, A., & Rozwadowska, A. (2014). Studies of vertical coarse aerosol fluxes in the boundary layer over the Baltic Sea. Oceanologia. https://doi.org/10.5697/oc.56-4.697 [ABSTRACT FROM AUTHOR]