This paper presents results of a study conducted on the trawling industrial fishery fleet of Merluccius gayi in south-central Chile, and the resulting interactions with the South American sea lion (Otaria flavescens). This study is based on observations made during September 2004, when incidental sea lion catch in the trawls was 6.3 sea lions/working day (1.2 sea lions/trawl−1). A total of 82 animals were incidentally caught, of which 12 were found dead, and the 70 remaining suffered from internal bleeding and/or fractures as a result of their capture. 83.3% of the fatalities occurred during nocturnal trawls, which comprise 30% of all observed trawls. Possible mechanisms of sea lion take are discussed. This note presents the first records of sea lions incidental by-catch by the trawler fleet along the south-east Pacific coast of Chile.

To analyse temporal distributions of microplankton populations and relationships to environmental conditions in marine ecosystems, a dataset of microplankton communities was investigated using a range of statistical methods. A total of 164 microplankton species comprising 100 microalgae and 64 ciliates were identified from 120 samples, respectively. Both planktonic microalga and ciliate assemblages showed temporal patterns and were significantly correlated between their temporal variations in abundance. The microplankton communities were characterized by 14 ciliates (e.g. Strombidium sulcatum, Tintinnopsis tubulosoides and Strombidium cheshiri) and 18 microalgae (e.g. Skeletonema costatum and Alexandrium tamarense). Multiple regression analyses showed that the interspecies correlations among these dominant species represented a complex network with a clear seasonal shift. Temporal pattern of microplankton communities was significantly correlated with the environmental variables such as temperature, salinity and nitrate nitrogen. The results suggest the clear species distribution and temporal dynamics of microplankton communities in response to environmental changes, and multivariate statistical approaches were a useful tool to reveal the species distribution patterns and complex microplanktonic interspecies correlations in marine ecosystems.

Mesophotic coral ecosystems (MCEs) are found on the insular and continental slopes of Caribbean islands and comprise mainly scleractinian corals, sponges and macroalgae. These species provide habitat for a highly diverse and specialized crustacean fauna. A new genus and species of the family Louriniidae is described from samples taken from an MCE in south-west Puerto Rico. The new taxa can be diagnosed by: body elongate, almost cylindrical and with inconspicuous podoplean boundary between prosome and urosome; double genital somite with a discontinuous chitinized cuticular ridge; telson short with rectangular anal operculum; furca short; rostrum sinusoidal, well defined at the base; antennules 7-segmented with aesthetasc on the fourth segment; antenna with a brush-like basal seta and an abexopodal seta, exopod 1-segmented with 2 setae; endopod with 7 elements (1 geniculate seta and 1 modified inner spine); maxilliped well developed, prehensile, composed of syncoxa, basis, one segmented endopod and one claw-like apical seta; leg 1 endopod 3-segmented, first segment with a modified inner seta; legs 2, 3 and 4 with 2-segmented endopod with inner seta on the first segment; leg 5 basendopod fused, well developed with 4 setae, exopod well developed, with 5 setae; leg 6 represented by a single seta; and genital slits wide apart. The new genus and species can be confidently assigned to the family Louriniidae on the basis of the following synapomorphies: rostrum well-developed with rounded tip; antennule of female 7-segmented; mandible palp reduced; maxillule endopod and exopod absent; maxillae endopodite 2 represented by 3 setae; leg 5 basoendopod of female confluent, intercoxal sclerite absent, exopod 1-segmented; eggs retained in a single ventral egg sac; telson shorter than last urosomite; and furca short and with 6 setae.

Near-shore benthic sediment samples collected at low tide from the western Atlantic Ocean (Sable Island, Nova Scotia, Canada) and the eastern Pacific Ocean (Haida Gwaii (Queen Charlotte Islands), British Columbia, Canada) were searched for little-known species of the rhizarian (Cercozoa) genera Pinaciophora, Rabdiaster and other related rotosphaerids. Several representatives with complete investitures of silica-scales (the structure of which is taxonomically diagnostic) were studied by transmission and scanning electron microscopy. The validity of the genus Pinaciophora (sensu Penard, 1904) as defined by a single type of plate-scale only, was strengthened by the discovery of Pinaciophora rubicunda and of another previously undescribed entity, both of which lacked spine-scales. Several earlier reports of loose scales from marine habitats, and erroneously identified as the freshwater P. fluviatilis, might be assigned to P. marina sp. nov. The new genus Thomseniophora was erected to include all ‘Pinaciophora' previously known to produce spine-scales and seven new taxa were described. Six other little-known species of Thomseniophora, Pinaciophora and Rabdiaster were described from the Canadian west coast (Pacific Ocean) including one new species of Pinaciophora. The addition of Thomseniophora brings the number of genera assigned to the Rotosphaerida to six: Pinaciophora, Thomseniophora, Rabdiaster, Rabdiophrys and Pompholyxophrys. The presence of several apparently closely related taxa in the same collection (same location and sampling date) strengthens the conclusion that relatively small differences in the morphology of their siliceous scales were more likely caused by genetic differences than by environmental influences.

The analysis of changes in benthic community structure using multivariate techniques has been successfully applied to the detection and monitoring of impacts caused by oil related activities. A survey to assess the status of the benthos was performed prior to a scheduled exploratory drilling at Banco Sarmiento, a shoal located off the eastern mouth of the Strait of Magellan (south-west Atlantic). The aims of this study are to provide baseline data about the composition and structure of the subtidal macrobenthic assemblages, to analyse the relationships between biodiversity and environmental variables, and to compare its benthic assemblages with those of neighbouring areas. Multivariate analyses classified the stations in two major groups, one composed of relatively shallow stations with coarse sediments dominated by filter-feeders, and the other consisting of stations with a high proportion of sand and mud dominated by deposit-feeders. Poorly sorted sediments had higher species richness than well sorted sediments. Shallow stations showed the lowest taxonomic distinctness due to the occurrence of a high proportion of bryozoans encrusting hard substrata. A five-fold increase in biodiversity can occur at scales of tens of km, suggesting that generalizations on regional biodiversity patterns should be made with caution because of the different gears used during the collection of samples, and should be based on a thorough knowledge about the physical environment.

The ichthyoplankton of Galway Bay was sampled over the spring and summer of 2007 and 2008 to determine what environmental factors influenced the distribution of larval and early juvenile fish. A total of 549 fish representing 27 taxa were caught. Catches decreased throughout each sampling season, and were generally poor in 2007. Catches were numerically dominated by sprat (Sprattus sprattus), dab (Limanda limanda), sand eel (Hyperoplus immaculatus) and whiting (Merlangius merlangus). Environmental factors driving distribution of fish were modelled using a binomial generalized linear model. The strength and direction of wind in the five days preceding sampling was the only significant environmental factor. Sustained onshore winds increased the probability of encountering larval fish in the areas sampled. The rainfall, tidal state, tow depth and wind conditions during sampling were not significant. Among the parameters measured it appears that onshore winds sufficiently strong to overcome the residual circulation are the main physical driver for the distribution of larval fish in Galway Bay.

To enable the study of population dynamics of wild animals the determination of the age, growth rate and maturity status of a sample of the individuals present is required; consequently, obtaining repeated accurate and precise total length (TL) measurements for individuals over time can be especially valuable. However, there are limited easily applied methods to ascertain the TL of large free-swimming fish, especially the largest extant species of fish, the whale shark (Rhincodon typus). This study expands on previous work and presents the results of a robust laser photogrammetry system developed to achieve accurate TL, pre-caudal length (PCL) and further morphometric measurements of whale sharks observed between 2009 and 2011 in seasonal feeding aggregations located in the Seychelles and Djibouti. Calculations for repeatability (r) indicated a high level of precision for the system with r approaching 1 for both TL and PCL, increasing further with the use of morphometric measurements. TL measurements of ‘straight sample sharks’ also provided geometric mean linear regression equations to enable the prediction of TL from defined morphological indices. Continuous validation of the system against objects of a fixed length also indicated a high level of accuracy for the method of measurement. We concluded that the laser photogrammetry system can be confidently employed to obtain accurate in-water TL, PCL and morphometric measurements for R. typus, with wide ranging implications and applications for the study of R. typus, and other large marine fauna.

The morphogenesis and morphology of the marine benthic ciliate Certesia quadrinucleata collected from seawater in Nagasaki Mie Port, Japan, were investigated using microscopic observation of live and protargol-stained specimens. In terms of its morphology, the current isolate possesses diagnostic features of the genus and the species: a row of left marginal cirri, a prominent paroral membrane, 11 frontoventral cirri scattered in frontoventral area, five highly developed transverse cirri, four macronuclear nodules, five dorsal kineties and a caudally located contractile vacuole. Its morphogenesis belongs to the ‘Certesia’ subtype, and main events can be summarized as follow: (1) the oral primordium in the opisthe develops de novo in a subcortical pouch; (2) the old paroral membrane is completely replaced by the new one in the proter, but the parental adoral zone of membranelles is wholly inherited; (3) five streaks of cirral anlagen are formed in a primary mode for the proter and the opisthe, which gives rise to cirri in the pattern of 3:3:3:3:3 from left to right; (4) the leftmost frontoventral cirrus develops de novo on the cell surface in both dividers, and has no connection with the undulating membrane anlage; and (5) the anlagen for marginal cirri and dorsal kineties occur intrakinetally. Current observations confirm the separation of Certesiidae from other euplotids at the familial level.

Rocky banks (i.e. sea mountain-like structures rising from the sea bottom) are hard substrate habitats of high socio-economic value (e.g. for fishermen and divers) and ecological relevance as they often host unusually high density of fish. Here we tested whether the response of fish assemblages to protection (i.e. related to the presence of a Marine Protected Area (MPA)) in rocky banks is comparable with the response of rocky reefs dropping from the coast (hereafter called ‘coastal rocky substrates’), and whether there are differences between fish assemblages associated with protected and unprotected rocky banks. Fish assemblages were assessed in shallow and deep coastal rocky substrates, and in rocky banks, in unprotected and protected conditions at a Mediterranean MPA in north-east Sardinia in August 2007 and 2008. Whole fish assemblage structures (in terms of biomass) differed between protected and unprotected conditions in both study years. Fish assemblages at rocky banks, in addition, differed from those associated with coastal rocky substrates. Total fish biomass (summing contribution of all species) was higher under protected than unprotected condition in 2007, while species richness and total fish density did not demonstrate any significant change related to protection. The responses to protection displayed by the target species Epinephelus marginatus and Diplodus sargus were clear especially in terms of greater frequency of large-sized specimens in both study years. Biomass of E. marginatus in 2007 and density of D. sargus in 2007 and 2008 were significantly higher in protected than unprotected conditions, especially in protected rocky banks. This study emphasizes the ecological and socio-economic role of protection and the potential role of rocky banks within management/conservation programmes in the Mediterranean Sea.