Progress report on identification of "organisms" in Lake Victoria responsible for echosounder traces

Exploratory fishing with midwater trawls in the pelagic zone of Lake Victoria generally yielded low quantities of fish even where dense traces appeared on the echosounder. Efforts to identify the "organisms" met with limited success. Types of gear were tested the midwater trawl, high-speed beam trawl, Lampara net, zooplankton net and SCUBA. This information plus that of earlier investigators indicate that the bulk of the traces are not caused by fish. The evidence however is not conclusive and further studies are warranted. Some recommendations for study are presented

Fish Bulletin 178. History And Status of Introduced Fishes In California, 1871 – 1996

Unlike previous histories on the subject (the last being in 1976), this one is fully documented by primary references to the original publication or other sources. There are also explanations as to why some of the previous errors occurred.The detailed history of each introduction, including the primary references, is given. The subsequent history and status of each species in California is given. The attitude of administrators, ichthyologists, fish culturists, fishery biologists, fishermen, and the public toward each introduction is given, and there is a discussion of their value. There is, with respect to California, a review of the present regulations concerning introduced fishes, and a prognostication of the future concerning them.Approximately 111 full species of freshwater and euryhaline fishes occur in California. (Salton Sea fishes are excluded.) of these, 53 have been introduced from without the state and have been established successfully. Another five subspecies or races have become established. Twelve introduced fishes have uncertain status. Thirty-nine, including one marine fish which was deliberately introduced, have achieved no lasting success. Eight introduced fishes are listed as "hypothetical." Five were scheduled for introduction, but the introductions were never completed. Three species have been listed erroneously in scientific papers as having been introduced. About 26 other species have been formally suggested as introductions. Three species are likely candidates for introduction