Larval transport during winter in the SABRE study area: results of a coupled vertical larval behaviour–three-dimensional circulation model

A three-dimensional circulation model was used in conjunction with larval fish vertical behaviour models to study the interaction between larval vertical distribution, advection and the outcome of larval transport along the central portion of the east coast of the United States. The circulation model was forced by tides, a northern boundary inflow, and winds. Vertical behaviour models were developed for Atlantic menhaden ( Brevoortia tyrannus ) and spot ( Leiostomus xanthurus ). The purpose of this modelling effort was to investigate the transport pathways of Atlantic menhaden and spot larvae from offshore spawning grounds to estuarine nursery habitats. The coupled circulation and behavioural model demonstrated the importance of along-shelf transport in what is generally thought to be a 'cross-shelf' problem. Cross-shelf transport was associated with bathymetric features, such as shoals. Both physical (e.g. wind) and biological (e.g. changes in larval behaviour) events were responsible for many of the observed patterns in larval transport. Overall, larval transport was determined by circulation but was modified by larval vertical distributions.     

Use of the space shuttle for remote sensing research: recent results and future prospects

Routine access to low earth orbit provided by the space shuttle holds great potential for global studies of the earth's resources and its environment. A successful test flight of the Columbia orbiter in November 1981 demonstrated the utility and versatility of the shuttle for earth-related research. A series of remote sensing experiments is currently planned for the mid-1980's that will more fully exploit the shuttle's earth observation capabilities.     

Determination of Surrogate Indicators for Phosphorus and Solids in Urban Stormwater: Application of Multivariate Data Analysis Techniques

Solids and phosphorus found within urban stormwater have the potential to cause environmental damage to ecological systems in receiving waters. The evaluation of these pollutants in urban stormwater is usually undertaken by physico-chemical monitoring programs which sample streamflow for laboratory assessment. In this study, data from two such monitoring programs have been examined for the catchment characteristics which influence solids and phosphorus discharge behaviour and the potential for the use of surrogate indicators to predict streamflow concentrations. The study involved partitioning of the components on the basis of the dissolved and particulate fractions. Investigation of the physical and chemical behaviour of solids and phosphorus by univariate and multivariate data analysis techniques led to the identification of interrelationships among the measured parameters. Thus, using turbidity and conductivity, relationships were developed for suspended and dissolved solids. Similarly, relationships were developed for dissolved and particulate phosphorus using suspended and dissolved solids. These relationships have the potential to enhance rapid generation of vital information from site-based measurements and to reduce the requirements for laboratory-based analysis of indicator concentrations in urban stormwater.     

Space shuttle: a new era in terrestrial remote sensing

The space shuttle will carry its first scientific cargo into orbit on its second test flight. The seven experiments to be conducted during this flight-investigations related to continental geology, atmospheric chemistry, meteorology, marine biology, and plant physiology-will demonstrate the potential usefulness of the shuttle for research in the earth and life sciences.     

Spawning habitat of the Atlantic menhaden in Onslow Bay, North Carolina

The Continuous, Underway Fish Egg Sampler (CUFES) was used to sample pelagic eggs of the Atlantic menhaden ( Brevoortia tyrannus ) from 3-m depth off North Carolina in winter 1993–94 and 1994–95. Simultaneous measurements were made of temperature, salinity, and the concentration of chlorophyll a . The maximal concentration of eggs was 346 eggs m⁻³. Eggs were highly aggregated in patches which occurred between the Gulf Stream and mid-shelf fronts (17–23°C, 36.0–36.4‰). Unexpectedly, eggs were found almost exclusively in water of 20–60 m (mode 20 m) bottom depth. Thus, spawning appears related to bathymetry as well as hydrography. Variograms for egg concentration indicated a mean (± SE) patch scale of 3.6 ± 1.7 km and a high degree of spatial variance explained by CUFES sampling. Lagrangian modelling of particles moving in response to tides, winds, and a prescribed flow from the north indicated that the region of observed, maximal occurrence of eggs is favourable for the retention of eggs and larvae on the shelf adjacent to inlets used to enter nursery areas.     

Overview of the shuttle imaging radar-B preliminary scientific results

The Shuttle Imaging Radar-B experiment consisted of a large number of scientific investigations in the earth sciences. Nine oceanographic experiments were conducted to study the generation and propagation of surface waves, the dynamics of internal waves, oil slick detection, and the properties of southern polar ice. Stereo imaging from space allowed three-dimensional viewing of surface features. Geologic experiments were conducted to study subsurface penetration, structural mapping, and lithologic classification. Imaging radar angular scatterometry was used in the vegetation cover, forest type, and urban areas classification experiments. This article provides an overview of the scientific results, some of which are also presented in this issue.     

The 1978 epornitic of avian cholera on the Chesapeake Bay

In an outbreak of avian cholera (Pasteurella multocida infection) in wildfowl on and around Chesapeake Bay during March and April of 1978, 31,295 carcasses were retrieved from Maryland and Virginia. Although other birds were involved, mortality was heavy among diving ducks (90% of the total), especially oldsquaw ducks (80% of the total). This is the second outbreak involving primarily diving ducks to be reported from this area of the Atlantic Flyway. It mimics in many respects the epornitic that occurred in 1970. Although mortality was heavy then, this occurrence appears much more severe and could be the largest recorded outbreak of avian cholera in North America.     

Pesticide contamination of water rats in the Murrumbidgee Irrigation Areas, New South Wales, Australia, 1970-72.

Organochlorine pesticides were found in all samples of livers, kidneys, mammary glands, and fetuses of eastern water rats (Hydromys chrysogaster) collected in the Murrumbidgee irrigation areas of New South Wales in 1970 and 1972. DDE was the predominant residue. Livers contained 0.01--3.10 ppm sigma DDT air-dried weight; kidneys, less than 0.01--1.12 ppm; mammary glands, 0.14--23.75 ppm; fetal liver, 0.28--0.66 ppm. Variations in residue levels are discussed in relation to the possible effects of environmental and physiological factors.