‘We promise you a warm welcome’: tourism to Malta since the 1960s

Tourism is an important element in the Malta economy. This paper traces its development since the 1960s with discussion focussing on the nature of the tourism product, marketing initiatives, arrivals patterns and changes in the accommodation sector. Problems such as an over-dependence on British visitors, the inadequacies of the infrastructure and the limited impact of planning are highlighted. Recent efforts to improve the quality of Maltese tourism are reviewed.     

Near bottom variations of turbidity in the St Lawrence estuary

Observations of the turbidity and velocity fields in the near-bottom waters of the St Lawrence estuary were obtained with a package which includes a self-recording attenuance meter and a currentmeter. The latter also measures salinity and temperature. Time series varying in length between 26 h and 26 days, and with repetition rates between one and 15 min are discussed for 3 typical open-channel and nearshore stations. A high-frequency sampling mode provides a means to observe the passage of a frontal disturbance over the bottom during the semi-diurnal cycle. With lower frequency records having lengths of one week to one month, contributions to the turbidity fluctuations due to the spring-neap oscillations, seasonal changes in run-off, and the sudden rise in solid discharge of local tributaries following storms, can be resolved. From turbidity polar diagrams, local onshore sources of particulate suspended matter can be identified. Among other advantages, it is possible from such records to time precisely the occurrence of turbidity peaks in relation to the ebb and flow velocities, to assess the importance of resuspension, and to specify exactly the time rate of change of the turbidity. On the whole, self-recording equipments provide a wealth of information unavailable from more traditional hydrocast sampling techniques.     

Size partitioning of microbial and meiobenthic biomass and respiration on Brown's Bank, south-west Nova Scotia

Biomass and respiration (oxygen consumption) of bacteria, microfauna, and meiofauna were measured in coarse sand sediment from Brown's Bank (172 m) off Nova Scotia, Canada. Community biomass, excluding macrofauna, had a median value of 35 mg C m⁻², dominated by bacteria (51%), microfauna (25%), and a minor meiofauna component (2·5%). Protozoan microfauna were mostly microflagellates (colourless cryptomonads). The experimental design allowed partitioning of benthic metabolism without using subtraction from whole community rates. Addition-removal experiments with fauna separated into size categories were used to construct a respiration-biomass regression for all taxa. Respiration rates for faunal groups were then calculated from their biomass in the natural sediment. Total microbial and meiofaunal community respiration had a median rate of 0·55 ml O₂ m⁻² h⁻¹ which was partitioned into median proportions of bacteria (50%) microflagellates (27%), and metazoan meiofauna (4%). Correlations among faunal biomass values from incubated vials of sediment suggested that bacteria were important prey for protozoans. With added biomass of meiofauna, protozoans also became a potentially important source of prey. The results demonstrated the significance of microflagellate protozoans in these sediments and their metabolic and trophic importance relative to meiofauna and even bacteria.     

The Effects of Industrial Pollution on the Development and Succession of Marine Fouling Communities I. Analysis of Species Richness and Frequency Data

Abstract. The effects of industrial pollution were determined by comparing the pattern of development of marine fouling communities situated along a pollution gradient within Port Kembla Harbour (Australia) with those from nearby Wollongong Harbour, a relatively unpolluted area. Fifty-three fouling species were found in the communities from Wollongong Harbour compared to only 40 in those from Port Kembla Harbour. Twenty-eight species (including many bryozoans) occurred only in the former, while 15 species occurred solely in the latter. Ten of the 25 species common to both areas were more numerous in Port Kembla Harbour, probably because of the greater availability of free substratum and food in this area. The species richness of fouling communities in Port Kembla Harbour was found to decrease as pollutant concentrations increased. In both study areas, communities established in summer showed significantly higher species richness than those whose development was initiated in winter. This difference was less pronounced in Port Kembla Harbour and was attributed to the effects of pollution on larval settlement. Although species richness increased at all sites through time, Wollongong Harbour communities contained a greater number of species at the end of the experiment than communities from Port Kembla Harbour. Despite this, fewer species were found in the very early developmental stages of the communities from Wollongong Harbour. This result highlights the inherent problems associated with using species richness or diversity measures as a means of determining marine environmental quality.     

Isolated sensor Ocean Bottom Seismometer

In most of the Ocean Bottom Seisometers (OBS) used today, the sensors, electronics, recorders, flotation, and ballast are contained in one rigid package. Usually this configuration requires a large mass, a large vertical cross section in the water, and relatively small bearing surface area in contact with the bottom, resulting in poor seismic characteristics and increased noise sensitivity. An OBS recently developed at the Hawaii Institute of Geophysics (HIG) minimizes these problems by physically separating the sensor from the main OBS package. Direct comparison between signals recorded by a standard HIG configuration Pop-up Ocean Bottom Seismometer (POBS) and signals from the new Isolated Sensor Ocean Bottom Seismometer (ISOBS), deployed near each other in deep water, clearly demonstrates the advantages of the isolated sensor configuration. Although the ISOBS is superior to older OBS designs, recent testing suggests that further improvements can be made.     

Impulsive EUV bursts observed in Civ with OSO-8

Time sequences of profiles of the 1548 line of C iv containing 51 EUV bursts observed in or near active regions are analyzed to determine the brightness, Doppler shift and line broadening characteristics of the bursts. The bursts have mean lifetimes of approximately 150s, and mean increases in brightness at burst maximum of four-fold as observed with a field of view of 2 × 20. Mean burst diameters are estimated to be 3, or smaller. All but three of the bursts show Doppler shifts with velocities sometimes exceeding 75 km s^–1; 31 are dominated by red shifts and 17 are dominated by blue shifts. Approximately half of the latter group have red-shifted precursors. We interpret the bursts as prominence material, such as surges and coronal rain, moving through the field of view of the spectrometer.The National Center for Atmospheric Research is sponsored by the National Science Foundation.