A 91-year record of seasonal and interannual variability of diatoms from laminated sediments in Saanich Inlet, British Columbia

Diatom seasonal succession and interannual variability werestudied using laminated sediments from Saanich Inlet, BritishColumbia, for the years 1900–1991. Frozen sediment coresallowed fine-scale sampling of laminae for each year. Thus,three ‘seasons’ for each year were identified basedon species composition. Thalassiosira species were indicatorsof spring deposition. Skeletonema costatum was abundant in samplesfollowing Thalassiosira, probably deposited in late spring andsummer. Rhizosolenia sp. was most abundant in fall/winter samples.Diatom stratigraphies were related to sea surface temperature,salinity, sea level and the Pacific North American Index (PNA)using canonical correspondence analysis (CCA). CCA showed thatspecies of a particular season generally had optima for temperatureand salinity characteristic of that time. Interannual changesin diatom species composition and abundance were most prevalentin the decades 1920–1940, with the exception of S.costatumwhich showed cyclic changes in abundance. Skeletonema was moreabundant during periods of cool temperatures, while littoraldiatoms were more abundant during times of heavy winter rains.Sea level was an important variable in CCA and while its relationshipto diatoms is not clear, it may be related to variations innutrient supply to diatoms in surface waters.     

A TRANSIENT BLOOM OF OSTREOCOCCUS (CHLOROPHYTA, PRASINOPHYCEAE) IN WEST NECK BAY, LONG ISLAND, NEW YORK

The smallest known eukaryote, Ostreococcus tauri Courties et Chrétiennot-Dinet, was first reported as the dominant picoplankter in a French lagoon known for its diverse phytoplankton community and high oyster productivity. Long-term seasonal blooms of this picoeukaryote were observed in association with stable plankton communities. On 5 June 2001, a distinctive monotypic picoplankton bloom was detected by flow cytometry as part of an ongoing study of "brown tide" ( Aureococcus anophagefferens ) bloom initiation in Long Island bays. The bloom reached a concentration of 5 × 10⁵ cells·mL⁻¹ in West Neck Bay and lasted less than 2 weeks. Epifluorescence microscopy and TEM indicated that the bloom organism was an Ostreococcus -like picoalga, the first ever observed in a Long Island bay. Many cells of this alga contained numerous virus-like particles. The Ostreococcus -like picoalga, which resembles O. tauri , was rare in samples collected the following week. Instead, a substantial increase in the Synechococcus population was observed. Such rapid population changes have not previously been reported for Ostreococcus . Viral lysis and grazing by heterotrophic nanoflagellates may have contributed to the rapid decline of the Ostreococcus -like cells in West Neck Bay.     

Kinematics of normal locomotion—A statistical study based on T.V. data

A T.V.-computer system for the measurement and analysis of the kinematics of normal and abnormal locomotion has been developed which has the following characteristics: minimum encumberment to the subject or patient, determination of absolute coordinates of anatomical landmarks, analysis of 3 or 4 strides, and automation of data conversion and analysis. Analysis techniques have been developed which take advantage of the accuracy of the marker coordinates, and with suitable application of noise reduction filtering, permit direct calculation of velocities and accelerations (both linear and angular). Examples of some of these derived parameters vs time are presented. The results of a statistical study on a group of normal subjects walking at slow, comfortable and fast cadences yield the ranges of many velocities and accelerations not previously available.     

Flyway population delineation in Taiga Bean Geese Anser fabalis fabalis revealed by multi‐element feather stable isotope analysis

Fundamental to effective management of migratory waterbird populations is an understanding of their flyway delineation. Taiga Bean Geese Anser fabalis fabalis wintering in NW Denmark, Scotland and England are considered to originate from northern and central Sweden, southern and central Norway (‘Western flyway’), those wintering in southern Sweden, NE and southern Denmark are considered to originate from northern Fennoscandia and western Russia (‘Central flyway’), and those wintering in eastern Germany and Poland (which show far less favourable conservation status) are thought to come from western Siberia (‘Eastern 1 flyway’), although evidence to demonstrate this has largely been lacking. Evidence for different natal and moult origins of Taiga Bean Geese was investigated using stable isotope analyses of feathers of four elements (δ²H, δ¹³C, δ¹⁵N and δ³⁴S). There were significant differences in isotopic composition of feathers from Swedish (Central) and German (Eastern 1) wintering populations and those moulting in Sweden in late summer (Western), which validated the three proposed major management flyway units above. The strong continental gradient in the stable hydrogen isotope ratios in precipitation (δ²H_p) across the region was used to assign wintering birds geospatially to natal and moulting origin, indicating separate natal and moulting areas for German (n = 37, from western Siberia) and Swedish (n = 20, Fennoscandia and more western Russia) wintering birds. These results confirm the largely discrete nature of these three flyways and contribute significantly to our ability to deliver effective targeted and appropriate research, monitoring and management actions throughout the ranges of these flyways.