Time lapse sea-bed photos (benthos) with associated current meter data from ROBIO lander deployments during Discovery cruise D297

A baited imaging lander was deployed six times in the Nazare Canyon at depths from 909 to 4361 m during August 2005 to investigate the demersal scavenging fishes. Species observed and lander-derived abundance estimates were similar to previous data from the Porcupine Seabight and abyssal plain, north-east Atlantic Ocean.

Benthos investigations in the Lena Delta

According to monitoring data gained between 1982-1992, macrobenthos in the Tiksi Bay is characterized by low indices of the total abundance, biomass and taxonomic diversity. 30 macrobenthic species have been recorded in the Tiksi Bay. The bottom biocenoses within the estuarine-arctic water mass consist of widespread eurybiontic boreal-arctic and brackish-water species. The maximal number of species was observed at a depth of 8.5 m. The maximum biomass was recorded on muddy grounds. The studied bottom fauna is characterized by a high population density (from 1160-600 ind/m**2) and low biomass of 15.5-22.4 g/m**2. The predominant benthic animals of the main Lena River channel 4.7 km upstream Stolb Island are Chironomidae, Plecoptera and Oligochaeta. In total, 48 species of macrobenthos were registered here. In spring the average density of macrozoobenthos in the channel is 680, in summer 770, in autumn 720 and in winter 380 ind/m**2, with the average biomass varying between 2.9 g/m**2 in spring, 7.06 in summer, 4.4 in autumn, and 2.6 in winter.

Zooplankton abundance for two shelf stations off Galicia (NW Spain) from 1994 to 2006

Zooplankton was sampled by project RADIALES at Vigo (E3VI) and A Coruña (E2CO) between 1994 and 2006. Samples were collected using 50-cm diameter Juday-Bogorov (A Coruña) or 40-cm diameter bongo plankton nets (Vigo) equipped with 200-µm mesh size. Tows were double oblique from surface to near bottom (90 and 70 m in Vigo and A Coruña, respectively). All samples were collected between 10:00 and 14:00 o'clock (local time). Samples were preserved in 2-4% sodium borate-buffered formaldehyde. For the purpose of this study, the original coastal time series were categorized in copepods representative of crustacean zooplankton) and gelatinous plankton (medusae and tunicates). Medusae included Hydrozoans and Scyphozoa, and tunicates included salps, pyrosomes, doliolids, and appendicularia. Plankton identification and counts were performed by Ana Miranda and M. Teresa Álvarez-Ossorio for samples from Vigo and A Coruña, respectively. Different trends were found for gelatinous plankton in the two coastal sites, characterized by increases in either medusae or tunicates. Multiyear periods of relative dominance of gelatinous vs. copepod plankton were evident. In general, copepod periods were observed in positive phases of the main modes of regional climatic variability. Conversely, gelatinous periods occurred during negative climatic phases. However, the low correlations between gelatinous plankton and either climatic, oceanographic, or fishery variables suggest that local factors play a major role in their proliferations.