An Integrated Assessment of the Introduction of Lionfish (Pterois volitans/miles complex) to the Western Atlantic Ocean.

Lionfish (Pterois volitans/miles complex) are venomous coral reef fishes from the Indian and western Pacific oceans that are now found in the western Atlantic Ocean. Adult lionfish have been observed from Miami, Florida to Cape Hatteras, North Carolina, and juvenile lionfish have been observed off North Carolina, New York, and Bermuda. The large number of adults observed and the occurrence of juveniles indicate that lionfish are established and reproducing along the southeast United States coast. Introductions of marine species occur in many ways. Ballast water discharge, a very common method of introduction for marine invertebrates, is responsible for many freshwater fish introductions. In contrast, most marine fish introductions result from intentional stocking for fishery purposes. Lionfish, however, likely were introduced via unintentional or intentional aquarium releases, and the introduction of lionfish into United States waters should lead to an assessment of the threat posed by the aquarium trade as a vector for fish introductions. Currently, no management actions are being taken to limit the effect of lionfish on the southeast United States continental shelf ecosystem. Further, only limited funds have been made available for research. Nevertheless, the extent of the introduction has been documented and a forecast of the maximum potential spread of lionfish is being developed. Under a scenario of no management actions and limited research, three predictions are made: ● With no action, the lionfish population will continue to grow along the southeast United States shelf. ● Effects on the marine ecosystem of the southeast United States will become more noticeable as the lionfish population grows. ● There will be incidents of lionfish envenomations of divers and/or fishers along the east coast of the United States. Removing lionfish from the southeast United States continental shelf ecosystem would be expensive and likely impossible. A bounty could be established that would encourage the removal of fish and provide specimens for research. However, the bounty would need to be lower than the price of fish in the aquarium trade (~$25-$50 each) to ensure that captured specimens were from the wild. Such a low bounty may not provide enough incentive for capturing lionfish in the wild. Further, such action would only increase the interaction between the public and lionfish, increasing the risk of lionfish envenomations. As the introduction of lionfish is very likely irreversible, future actions should focus on five areas. 1) The population of lionfish should be tracked. 2) Research should be conducted so that scientists can make better predictions regarding the status of the invasion and the effects on native species, ecosystem function, and ecosystem services. 3) Outreach and education efforts must be increased, both specifically toward lionfish and more generally toward the aquarium trade as a method of fish introductions. 4) Additional regulation should be considered to reduce the frequency of marine fish introduction into U.S. waters. However, the issue is more complicated than simply limiting the import of non-native species, and these complexities need to be considered simultaneously. 5) Health care providers along the east coast of the United States need to be notified that a venomous fish is now resident along the southeast United States. The introduction and spread of lionfish illustrates the difficulty inherent in managing introduced species in marine systems. Introduced species often spread via natural mechanisms after the initial introduction. Efforts to control the introduction of marine fish will fail if managers do not consider the natural dispersal of a species following an introduction. Thus, management strategies limiting marine fish introductions need to be applied over the scale of natural ecological dispersal to be effective, pointing to the need for a regional management approach defined by natural processes not by political boundaries. The introduction and success of lionfish along the east coast should change the long-held perception that marine fish invasions are a minimal threat to marine ecosystems. Research is needed to determine the effects of specific invasive fish species in specific ecosystems. More broadly, a cohesive plan is needed to manage, mitigate and minimize the effects of marine invasive fish species on ecosystems that are already compromised by other human activities. Presently, the magnitude of marine fish introductions as a stressor on marine ecosystems cannot be quantified, but can no longer be dismissed as negligible. (PDF contains 31 pages)

Structure and Historical Changes in the Groundfish Complex of the Eastern Bering Sea

The eastern Bering Sea is a major marine ecosystem containing some of the largest populations of groundfish, crabs, birds, and marine mammals in the world. Commercial catches of groundfish in this region have averaged about 1.6 million tons (t) annually in 1970-86. This report describes the species and relative importance of species in the eastern Bering Sea groundfish complex, the environment in which they live, and the history of the fisheries and management during the years 1954 - 1985. Historical changes in abundance and the condition of the principal species at the end of this first 30 years of exploitation are also examined. Results suggest that the biomass of the groundfish complex is characterized by variability rather than stability. The most reliable data (1979 to 1985) suggests that the biomass of the complex fluctuated between 11.8 and 15.7 million t. Even greater variability is suggested by the less reliable data from earlier years. Because of its dominance in the complex and wide fluctuations in abundance, walleye pollock (Theragra chalcogramma) is primarily responsible for the major variations in abundance of the complex. After 30 years of exploitation, the complex was generally in excellent condition. (PDF file contains 100 pages.)

Possible inclusion of fish waste (scales and fins) in the diet of fishes in aquaculture

The scales and fins of some freshwater fish species (Sarotherodon galilaeus, Oreochromis niloticus, Tilapia zillii, Barbus callipterus, Hemichromis fasciatus) from Kainji Lake, Nigeria were analyzed for their organic and inorganic matter. The aim of such study is to determine the usefulness of these waste parts of the fish in fish feed preparation. In all instances, the inorganic matter was found to be quite high in the fish exoskeleton, and calcium formed the highest element in the scales and the fins. These waste materials are therefore, considered as possible replacement for mineral sources in fish feed and probably the feed for other livestock

Growth performance of Heteroclarias fed maggot meal at varying inclusion levels

70-day growth trial was conducted with Heteroclarias: Heterobranchus bidorsalis X Clarias gariepinus (mean weight 0.64~c0.006g) fed diets based on various inclusion levels of Maggot Meal. The fishmeal in the control diet was replaced with maggot meals at 25%, 50%, 75% and 100% levels to supply 40% crude protein in the final diets. The trails were conducted in glass tanks (60cmx30cmx30cm). Evaluation of growth parameters and nutrient utilization of the fish was based on weight gains, protein intake, protein efficiency ratio, net protein utilization, feed conversion efficiency and carcass analysis. Best growth and feed conversion efficiency were obtained with the 75% dietary inclusion of maggot meal. There was no significant differences (P>0.055) between the group of fish on 50% and 75% dietary inclusion maggot meal in growth performance and protein efficiency ratio but, there was a significant (P<0.05) difference in the NPU (Net Protein Utilization) and protein gain between the control diet and those fed on maggot meals. There was no marked variation in the survival rate of fish on all diets

The aquatic biota of the now extinct lacustrine complex of the Mexico basin

The commonest organisms of the original Mexico lake complex are listed, including those that exist today in the Lago Viejo. In addition, a brief hydraulic history of this endorheic basin is given.

Studies on the complex formation of iron with humic substances [Translation from: Vom Wasser 53, 243-247, 1979]

Most of the humic substances which occur in natural waters have an iron content of a few percent, indicated by the mg/1 content of organically-bonded carbon. This iron is apparently bound in a complex with the humic substances, for it quite plainly differs in its chemical and physico-chemical properties from what one would expect from the purely inorganic iron-water system. The deviations range from the solubility to the redox behaviour, and thus are frequently the basis of analytical and technical difficulties. The key to the solution of most of this problem lies in a better understanding of the aforementioned bonds between the iron and the humic substances. This paper studies the iron content of the humic substance concentration from a bog lake sample and the complexing of iron by humic substances from the surface of the bog lake.

Ceratium hirundinella - ecology of a complex, mobile, and successful plant

Recent work carried out in the English Lake District (Esthwaite Water and Blelham Tarn) is reported. The seasonal growth cycle, diel growth cycle, photosynthesis, vertical distribution and migrations, horizontal distribution, and the interaction of environmental factors, were investigated.

Species of the rougheye rockfish complex: resurrection of Sebastes melanostictus (Matsubara, 1934) and a redescription of Sebastes aleutianus (Jordan and Evermann, 1898)(Teleostei: Scorpaeniformes)

The widespread and commercially important rougheye rockfish, Sebastes aleutianus (Jordan and Evermann, 1898), has been considered a single variable species, with light- and dark-colored forms, found on the outer continental shelf and upper slope of the North Pacific Ocean. Genetic analysis of 124 specimens verified the presence of two species in new specimens collected from Alaska to Oregon, and the two species were analyzed for distinguishing color patterns and morphological characters. Characters distinguishing the two were extended to an analysis of 215 additional formalin-fixed specimens representing their geographic ranges. Sebastes aleutianus is pale, often has dark mottling on the dorsum in diffuse bands, and does not have distinct dark spots on the spinous dorsal fin; it ranges from the eastern Aleutian Islands and southeastern Bering Sea to California. Sebastes melanostictus (Matsubara, 1934), the blackspotted rockfish, ranges from central Japan, through the Aleutian Islands and Bering Sea, to southern California. It is darker overall and spotting is nearly always present on the spinous dorsal fin. Sebastes swifti (Evermann and Goldsborough, 1907) is a synonym of S. aleutianus; S. kawaradae (Matsubara, 1934) is a synonym of S. melanostictus. The subgenus Zalopyr is restricted to S. aleutianus and S. melanostictus. Nomenclatural synonymies, diagnoses, descriptions, and distributions are provided for each species.

Review of the crevalle jacks, Caranx hippos complex (Teleostei: Carangidae), with a description of a new species from West Africa

The Caranx hippos species complex comprises three extant species: crevalle jack (Caranx hippos) (Linnaeus, 1766) from both the western and eastern Atlantic oceans; Pacific crevalle jack (Caranx caninus) Günther, 1868 from the eastern Pacific Ocean; and longfin crevalle jack (Caranx fischeri) new species, from the eastern Atlantic, including the Mediterranean Sea and Ascension Island. Adults of all three species are superficially similar with a black blotch on the lower half of the pectoral fin, a black spot on the upper margin of opercle, one or two pairs of enlarged symphyseal canines on the lower jaw, and a similar pattern of breast squamation. Each species has a different pattern of hyperostotic bone development and anal-fin color. The two sympatric eastern Atlantic species also differ from each other in number of dorsal-and anal-fin rays, and in large adults of C. fischeri the lobes of these fins are longer and the body is deeper. Caranx hippos from opposite sides of the Atlantic are virtually indistinguishable externally but differ consistently in the expression of hyperostosis of the first dorsalfin pterygiophore. The fossil species Caranx carangopsis Steindachner 1859 appears to have been based on composite material of Trachurus sp. and a fourth species of the Caranx hippos complex. Patterns of hyperostotic bone development are compared in the nine (of 15 total) species of Caranx sensu stricto that exhibit hyperostosis.