Rapid worldwide depletion of predatory fish communities.

Guppies (Poecilia reticulatus) were given two prey: Drosophila (on the water surface) and tubificid worms (on the aquarium bottom). The densities of the two prey were varied gradually over 12 days, from 4:1 to 1:4, and we measured the predators'…

Indirect effects of fishing extending 2 or more trophic levels have been observed in a range of ecosystems, but they are not ubiquitously present, and identifying the circumstances in which they occur (or do not occur) is a key challenge for…

Background: Understanding the current status of predatory fish communities, and the effects fishing has on them, is vitally important information for management. However, data are often insufficient at region-wide scales to assess the effects of…

The impact of predation over a 3 week period by the small (mean length 53 mm) salmoniform fish, Galaxias olidus, on the invertebrate communities in the still summer pools of an intermittent stream in southeastern Australia was tested using…

Fish communities over continental shelves are of three types: pelagic, rocky reef and soft substrata. The pelagic community of the South African west coast is dominated by clupeiform fish, which are the principal prey of snoek, the dominant…

This research tested whether limnological conditions, biological characteristics of fish and anthropogenic impacts influenced the assimilation of methylmercury into the muscle of a sedentary piscivorous fish, Cichla spp., from three rivers (Negro,…

Mercury was detected in all analysed samples of swordfish, marlin, shark and tuna purchased from major supermarket outlets and fish retailers in three cities across Canada. Total mercury and methylmercury levels ranged up to 3845 and 2346 ng g(-1),…

In open predation experiments the effects of predators on prey densities can be influenced by predator consumption and by prey movements in to and out of experimental arenas. A published model predicts that the predator effects observed in such…

In enclosed runs in a third-order ephemeral stream in west-central Kentucky, the effects of predatory sunfish (Lepomis) on benthic macroinvertebrates, benthic algae, and detritivory were compared (1) before stream intermittence, (2) after stream…

In the Baltic Sea, increased dominance of ephemeral and bloom-forming algae is presently attributed to increased nutrient loads. Simultaneously, coastal predatory fish are in strong decline. Using field data from nine areas covering a 700-km…