ships’ ballast water has apparently enabled numerous species to expand their ranges to environments in which they did not evolve (Carlton 1998; Cohen and Carlton, 1998; Ruiz et al., 2000). In normal trading operations, ships load seawater ballast in one port, then discard it at another in exchange for cargo. Modern international voyages span just a few days or weeks, affording entrained organis...

BACKGROUND In a "wasp-waist" ecosystem, an intermediate trophic level is expected to control the abundance of predators through a bottom-up interaction and the abundance of prey through a top-down interaction. Previous studies suggest that the North Sea is mainly governed by bottom-up interactions driven by climate perturbations. However, few studies have investigated the importance of the inte...

Recruitment success of roach varied dramatically between 1979 and 1982 in Alderfen Broad, a small lake in eastern England. When fry were abundant (in 1979 and 198 1, but not in 1980 or 1982) the summer zooplankton became sparse and was dominated by copepods and rotifers. In years of good recruitment, as each of the preferred cladoceran prey species entered the diet of underyearling roach, its d...

Methylmercury (MeHg) concentrations can increase by 100 000 times between seawater and marine phytoplankton, but levels vary across sites. To better understand how ecosystem properties affect variability in planktonic MeHg concentrations, we develop a model for MeHg uptake and trophic transfer at the base of marine food webs. The model successfully reproduces measured concentrations in phytopla...

Toxic cyanobacterial blooms can strongly affect freshwater food web structures. However, little is known about how the patchy occurrence of blooms within systems affects the spatial distribution of zooplankton communities. We studied this by analysing zooplankton community structures in comparison with the spatially distinct distribution of a toxic Microcystis bloom in a small, shallow, eutroph...

We studied the seasonal dynamics of zooplanktivory by the major zooplanktivores (sprat Sprattus sprattus, herring Clupea harengus and the mysid shrimp Mysis mrxta) in 3 coastal areas of the northern Baltic Sea proper from the beginning of July through the end of October, 1985. The 3 areas are within 30 km of each other and dffer in nutrient loading and primary productivity. Consumption rates we...

A combination of stable isotope measurements and gut contents analysis was used to determine the major food sources of the sergestid crustacean Acetes sibogae, in commercial shrimp ponds at two farms in southeast Queensland, Australia. Slight differences were observed between farms but overall the results were consistent. Although gut contents analysis gave a good indication of the range and te...

Cold-water corals (CWC) are frequently reported from deep sites with locally accelerated currents that enhance seabed food particle supply. Moreover, zooplankton likely account for ecologically important prey items, but their contribution to CWC diet remains unquantified. We investigated the benthic food web structure of the recently discovered Santa Maria di Leuca (SML) CWC province (300 to 11...

We examined the spatial and temporal linkage between primary production, zooplankton distribution and density, and bowhead whale Balaena mysticetus foraging behavior in Disko Bay, West Greenland using concurrent ship-based oceanographic and net sampling together with instrumentation of whales with satellite-linked transmitters and dive recorders. Estimates of bowhead whale abundance were used i...

The present study uses bioenergetics modeling to estimate the annual consumption of the main zooplankton groups by some of the most commercially important planktivorous fish stocks in the Northeast Atlantic, namely Norwegian spring-spawning (NSS) herring (Clupea harengus), blue whiting (Micromesistius poutassou) and NEA mackerel (Scomber scombrus). The data was obtained from scientific surveys ...