ALBERT

Description: An enigma of deep-sea biodiversity research is that the abyss with its low productivity and densities appears to have a biodiversity similar to that of shallower depths. This conceptualization of similarity is based mainly on per-sample estimates (point diversity, within-habitat, or α-diversity). Here, we use a measure of between-sample within-community diversity (β1H) to examine benthic foraminiferal diversity between 333 stations within 49 communties from New Zealand, the South Atlantic, the Gulf of Mexico, the Norwegian Sea, and the Arctic. The communities are grouped into two depth categories: 200–1500 m and 〉1500 m. β1Hdiversity exhibits no evidence of regional differences. Instead, higher values at shallower depths are observed worldwide. At depths of 〉1500 m the average β1His zero, indicating stasis or no biodiversity gradient. The difference in β1H-diversity explains why, despite species richness often being greater per sample at deeper depths, the total number of species is greater at shallower depths. The greater number of communities and higher rate of evolution resulting in shorter species durations at shallower depths is also consistent with higher β1Hvalues.

Description: Many cheilostome bryozoans of diverse phylogenetic origin grow as erect, arborescent colonies with branches of modified planar form composed of two layers of zooids back to back. Regular branching enables a growing colony to expand in surface area, and hence in the number of zooids that feed, reproduce, and perform other vital functions, at an accelerating rate. During growth, branches first all diverge, then increasingly converge, and in late stages of growth begin to interfere with each other's growth and function. Interference can set limits to the width and thickness of branches and hence to the number and size of zooids.Simulation of growth using a 3–dimensional mathematical model shows that a narrow range of possible values of branching angles minimizes branch interference in late growth stages. These values are prevalent in fossil and modern species. Branch spacing at later growth stages is correlated with the distance between branches at first crossing, providing room for feeding organs of the two facing layers of zooids to protrude and function. Interbranch distances dwindle as branches increasingly converge, so emphasis on minimizing interference at a late stage sets a practical limit to growth beyond that stage. To gain this long-term benefit requires adhering to a regular pattern throughout growth. The considerable variation in branching properties in fossil and modern species, and a variability in spacing inherent in the growth pattern itself, limit the amount of usable interbranch space. Despite a higher intraspecific variability, branching properties are as distinctive interspecifically as zooidal properties, and variability is randomly distributed through the colony. A small reduction in variability between fossil and modern species suggests that increasing regularity may provide a selective advantage in the utilization of interbranch space.

Description: Cheilostome bryozoans that grew as rigidly erect arborescent colonies dominate many bryozoan-rich assemblages of Tertiary age, in which they are found most commonly as small dissociated fragments. The regularity with which branching and branch thickening occur in intact colonies of living species provides a basis for quantitative reconstruction of these growth processes in fossils. We propose models to describe branch thickening, develop methods to extend both thickening and branching models to fossils, investigate the thickening and branching properties of four Paleocene and five Oligocene species and compare the properties of these fossils to those of nine living species.The properties investigated are largely mutually independent and species specific irrespective of geologic age and have similar numerical ranges among different assemblages of coeval species. Species are evenly distributed across the range of possible morphologies between observed extremes, without obvious gaps. Statistically significant trends through time are identified in gradients of branch thickening, which have implications for the resistance of colonies to mechanical stress, and in angles of bifurcation, that are important in the way growing colonies occupy space.

Description: An effective protected area system is essential for the long-term conservation of Myanmar's biodiversity. This study examined the attitudes of 2915 residents in 97 communities around three protected areas (PAs) in upper Myanmar: Alaungdaw Kathapa National Park in the western mountains, Htamanthi Wildlife Sanctuary in the hills bordering the Chindwin and Uru rivers, and Chatthin Wildlife Sanctuary in the central dry zone. Logistic regression indicated a positive attitude toward the PAs was most highly correlated with a perception of conservation benefits and benefits resulting from management of the areas. Attitude was also significantly correlated with a perception of extraction benefits, conflicts with PA staff and crop damage by wildlife. Socioeconomic variables were less powerful than perceptions in predicting attitude and, unlike perceptions, their effects varied among the areas. The much greater effect of perceptions, especially positive ones, on people's attitudes indicates that understanding perceptions is important to improving the relationship between local residents and these PAs. This finding underscores the fact that a focus on conflicts to understand people's attitudes toward PAs may undervalue or miss critical positive perceptions that people hold. Understanding local residents' perceptions of PAs makes possible the creation of strategic, place-based management strategies that build on people's positive perceptions and mitigate their negative perceptions.

Description: The lower bathyal Ocean Drilling Program Hole 1261A was sampled near an upper Quaternary oxygen minimum zone (OMZ). Glauconite, the percentage of the foraminiferal assemblage as benthic specimens and assemblage composition were used to investigate the behaviour of the OMZ. Benthic foraminifera and glauconite were comparable with the upper margin of the modern OMZ off California. The percentage abundances of U. peregrina and C. laevigata were on the Demerara Rise negatively correlated, the proportional abundance of U. peregrina increasing upwards through the section. This reflects variations in proximity to the upper margin of the OMZ. This might reflect either crustal subsidence or long-term shallowing of the OMZ during the earlier late Quaternary. Neither hypothesis can be accepted unequivocally. The purported subsidence can be ascribed to crustal loading by the Amazon and Orinoco deep-sea fans, but this would require that the palaeodepth to the top of the OMZ remains constant across several glacial–interglacial cycles. In contrast, it is difficult to envisage any mechanism that could have caused progressive shallowing of the OMZ across several glacial–interglacial cycles. The epifaunal Planulina wuellerstorfi is related to more oxic waters and enhanced current action. This suggests that intervals with more abundant P. wuellerstorfi were somewhat less dysoxic than those with few. These intervals approximate to those with more abundant C. laevigata. Superimposed on this low-frequency signal is a higher-frequency signal, indicated by a between-sample assemblage turnover index (ATIs) that might prove useful for long-range sequence stratigraphic correlation at bathyal depths.