Proximate composition and fatty acid and cholesterol content of 22 species of northwest Atlantic finfish

The moisture, fat, ash, fatty acid profile, and cholesterol content are reported for cooked and raw fillets from 22 species of finfish found in the Northwest Atlantic. All but nine species had 1%or less fat. Ocean perch and a spring sampling of mackerel and wolffiSh had about 2% fat, followed by yellowfin tuna, whiting, silver hake, butterfish, and a summer -sampling of mackerel and wolffish with a range of 3-7% fat. Herring had a range of 5-12% fat representing a winter sampling on the low end and summer sampling on the high end of the range. Bluefin tuna (a summer sampling) contained the most fat with a high of 23% fat. Omega-3 fatty acids were present in excess of omega-6 fatty acids. The fattier fISh supplied the most omega-3 fatty acids per gram of tissue. The mean cholesterol content for all species was 57 ± 16 mg/l00 g raw tissue. Finfish from the Northwest Atlantic would appear to fit into the regime for a healthy heart, being low in fat and cholesterol and rich in omega-3 fatty acids.(PDF file contains 42 pages.)

The Distribution of Juvenile Fishes in Maryland Coastal Bays in Relation to Environmental Factors: a Multivariate Analysis

Fish assemblage structure of Maryland's coastal lagoon complex was analyzed for spatial and seasonal patterns for the period 1991-2000. Data was made available by Maryland Department of Natural Resources from their MD Coastal Bays Finfish Survey. Dominant species from separate trawl and wiw surveys included blue crab Callinectes sapidus (erroneously included here as a "fish" due to its dominance and commercial importance), bay anchovy Anchoa mitchilli, spot Leiostomous xanthurus, silver perch Bairdiella ehrysoura, and Atlantic menhaden Brevwrtia tyrannus. Ninety-four fish species were identified in the two surveys, a diversity substantially higher than other survey records for Middle Atlantic Bight estuarine and lagoon systems (richness=26 to 78 species). Total species richness for the trawl survey was highest in Chincoteague and lowest in Assawoman and Sinepuxent. On the other hand, mean richness per tow (-area) and related Shannon Weiner Diversity Index were significantly higher in the northern two bays (Assawoman and Isle of Wight Bays) than in the two southern bays (Chincoteague or Sinepuxent Bays). For the seine survey, effort-adjusted diversity indices were significantly lower for Chincoteague Bay than for the other three bays. Higher relative abundances were observed in the northern bays than in the southern bays. The trawl survey exhibited the lowest catch-per-site in Sinepuxent Bay and the highest in Assawoman Bay. The seine survey had the lowest catch-per-site in Chincoteague Bay while the other three embayments were of similar magnitude. There was clear seasonality in assemblage structure with peak abundance and diversity in the summer compared to other seasons. Blue crabs in particular showed a c. 2-fold decline in relative abundance from early summer to fall, which is likely attributable to harvest removals (i.e., an exploitation rate of c. 50%). Seagrass coverage, although increasing over the course of the 10 year survey, did not have obvious effects on species diversity and abundance across or within the embayments, although it did have positive associations with two important species: bay anchovy and summer flounder Pavalich thys dentatus. Atlantic menhaden were most dominant in Assawoman Bay, which could be related to higher primary production typically observed in this Bay in comparison to the other three. (PDF contains 99 pages)

Untersuchungen des Zanderbestandes in den deutschen Küstengewässern der Ostsee von 1992 bis 2002

Pike-perch is an important resource for the coastal fishery in the brackish waters of the eastern part of the coast. For the conservation of the stocks regulation measures (minimum landing size, closed season and minimum mesh size) have been introduced since many years. Basic biological material of the last decade sampled from the commercial fishery and for recruitment by a standard trawl survey. For the “Eastern stock” this paper presents the results concerning age distribution, year-class strengths, growth, proportion spawners, natural mortality and yield-per-recruit analyses.

Einfluss der Verarbeitung auf lipophile chlororganische Rückstände in Fischen

Influence of fish processing methods on changes of chlordane and toxaphene residue concentrations were studied in various fishery products. Investigation included smoking, marinating and canning of fish. Smoking of Greenland halibut and ocean perch led to an increase in chlordane and toxaphene residue amounts in the edible part in relation to the raw material. A similar increase was observed during the marinating process of herring fillets. In both cases, loss of water was responsible for the observed changes in residue contents. The fat and thus the lipophilic organochlorine compounds remained completely in the products. Canning of herring fillets in tomato sauce reduced the residue concentration of the final product due to dilution by the tomato sauce. The concentrations in the fillets kept nearly unchanged even after storage of cans for six months. No equilibration was observed between residue concentrations in fillets and sauce.

The survey of Lake Victoria's fishers

The findings are presented of a survey conducted regarding the fishers of Lake Victoria, which examined the relationships affecting supply flows of raw material on to the market, and also the characteristics of fishing activities and their effects on fish quality and distribution. Fish marketing plays a vital role in the lives of much of the lake basin's population, both in terms of employment and nutrition. The results of the survey comprise, in part, a base-line data set which will facilitate further research, analysis and management decision-making in relation to stakeholders of the lake's resources. Data collection, methods and research difficulties encountered are described and details given of a profile of a boat owner/renter and aslo of a profile of a crew member. The survey shows that Lake Victoria's fishery is one of very limited diversity. The fishers recount that they consistently target one or more of the 3 most common species within the lake (Nile perch, tilapia and dagaa) and very rarely consider any other species type. The largest proportion of fishers on the lake are Nile perch fishers; there is considerable demand for this species, and hence fishers have little incentive to either target alternative fish species, not to try and establish firm marketing outlets through the creation of arrangements with their principal buyers. In Kenyan waters, however, the number of Nile perch fishers is equaled by the number of dagaa fishers; this fish now commands a considerable portion of the market for fish from Lake Victoria through its availability as well as its relatively low prices. The tilapia fishery is in decline, and all 3 riparian states would not appear to be attracting investment almost certainly as a result of declining catches. For many of those working in Lake Victoria's fishery, the problems faced appear most often to be associated with the vagaries of an unstable market which may rise or fall depending on the state of the international market or the state of access roads to fish landings. (PDF contains 42 pages)

Regulation in Uganda's Lake Victoria fishery: historical and contemporary conditions

This paper sets out to explore how Uganda's lake Victoria fishery has been managed. It explores the management of the fishery during the protectorate period, and argues that the apparent success of regulation during this time may be attributed to the very heightened controls arising from Sleeping Sickness Controls. Once these were removed, entry into the fishery was rapid and uncontrolled, and the resultant impact on fish stocks was quickly felt. With its huge area, considerable shoreline, and innumerable islands, the lake Victoria fisheries service was quickly overwhelmed and disbanded as a result. In the early independence years, the Republic's government focused on developing the fishery, plans thwarted by turmoil of, and following, Idi Amin's reign. More recently, the fishery has prospered from Uganda's entry into the Nile perch fillet export market, which ahs adversely affected stocks. We present and comment on recently collected data that considers fishers' impressions of the status of the fishery, regulations and future managerial possibilities, and comment on these in the light of recent changes to Uganda's fisheries administration

The fish stocks of Lake Victoria, Uganda

An experimental bottom trawl survey was carried out in the Uganda sector of Lake Victoria from November 1997 to December 1998 to estimate the composition, distribution, and abundance of the major fish species. In 12 cruises, 295, thirty-minute hauls were taken in waters from 4-60 m deep. Nile perch, Lates niloticus (L) made up 95% of the catch by weight. Haplochromine cichlids and L. niloticus occurred in all areas sampled while Nile tilapia, Oreochromis niloticus (L.) and other tilapiines were restricted to waters less than 30 m deep. In waters deeper than 40 m, catches were generally near zero. Species diversity and abundance decreased with increasing water depth. In waters less than 30 m deep, the area where the artisanal fishermen operate, the mean catch was 126kg hr super(1)

National report of IFMP catch assessment survey (CAS) for August 2005

The first comprehensive CAS was carried out during the month of July 2005 This is the second report of CAS for the month of August 2005 following the July report. The design and methodology followed was the same as in July. This report highlights the results obtained in August catch assessment survey. The report gives estimates of mean catch rates in Kgs./boat/day, total catches in M.tons and values of the catch by species. The total catch for August was 31,633.0 M. tons. This is lower when compared with the July catch which was 39,745.1 M. tons. In August the catch composed of Dagaa (45%), Nile perch (33%), Haplochromines (16%), Tilapiines (5%) and all other species combined (1%). (PDF contains 14 pages)

The changing ecosystem of Lake Victoria, East Africa

Dramatic changes are occurring in the Lake Victoria ecosystem. Two-thirds of the endemic haplochromine cichlid species, of international interest for studies of evolution, have disappeared, an event associated with the sudden population explosion of piscivorous Nile perch (Lates: order Perciformes, family Centropomidae) introduced to the lake some thirty years ago. The total fish yield has, however, increased 5-fold from 1970 to 1990, but this yield is now dominated by just three fish species: the introduced Nile perch (Lates niloticus), Nile tilapia (Oreochromis niloticus), and a small endemic pelagic cyprinid (Rastrineobola argentea); these three have replaced a multispecies fishery. Contemporaneously the lake is becoming increasingly eutrophic with associated deoxygenation of the bottom waters, thereby reducing fish habitats. Conditions appear to be unstable.

A reparação do dano causado por membro indeterminado de um grupo: por uma relação de complementaridade entre o seguro e a responsabilidade civil

O dano e sua causa apresentam-se, em conjunto, como um dilema inerente a uma sociedade que incorporou o risco como produto do seu próprio desenvolvimento. Desde tempos imemoriais a solidariedade figura como instrumento imprescindível à composição das diferentes formas possíveis para minimizar os efeitos negativos do implemento de um risco seja através da transferência de suas consequências econômicas para quem, por sua atividade o produziu ou, esteja melhor preparado para suportá-lo. Entretanto, as formas privadas tradicionais, isoladamente mostram-se insuficientes para responder satisfatoriamente à necessidade de reparação dos danos na atualidade. Isto porque, via de regra, os instrumentos para tal foram desenvolvidas em uma perspectiva individual, tendo como premissa a identificação da causa do dano e, a partir daí, a possibilidade de imputação de responsabilidade. Contemporaneamente, contudo, os danos usualmente resultam de causas múltiplas e, mesmo quando decorrem de causa única, essa pode estar relacionada a um conjunto de agentes, de forma a não ser possível a individuação do ofensor. Neste contexto, torna-se imprescindível a construção de uma noção jurídica de causalidade, apta a solucionar questões críticas, tais como a do dano causado por membro indeterminado de um grupo. Esta noção, por seu turno, requer uma base solidária mais aprofundada, de sorte a permitir a reparação do dano injusto sofrido pela vítima, sem arruinar o ofensor. Afirma-se, então, que a reparação integral dos danos em uma sociedade de risco depende de uma nova concepção acerca da solidariedade: a solidariedade global. E, indo além, a fase atual impõe a necessidade de se repensar a própria base do sistema de responsabilidade civil, como decorrência necessária de uma nova orientação jus-filosófica, inspirada por valores personalistas e solidaristas e também em razão da própria evolução social que potencializou os problemas que gravitam em torno da solidariedade e do risco, notadamente em razão da coletivização das causas dos danos. Assim, se há cada vez mais solidariedade nas causas e nos danos, deve haver também solidariedade na reparação. Nessa perspectiva, a presente dissertação tratará da coletivização da responsabilidade civil em relação à causa dos danos, na hipótese de responsabilidade grupal, e em referência à reparação dos danos em uma perspectiva convergente dos institutos do seguro e da responsabilidade civil.

Mortality, growth and growth rate variability of striped bass larvae in Chesapeake Subestuaries

In this report we develop age-length keys and derive age-frequency data. We estimate striped bass and white perch mortality and growth rates, based on the otolith-aging analysis. We also report on hatch-date frequencies of striped bass and white perch larvae, and we discuss environmental effects on recruitment potential.

The design of multimesh, multidepth gillnet fleets for use in the Lake Victoria Fisheries Research Project

Multimesh, multidepth gillnet fleets are useful in assessing fish stock abundance, size distribution and depth distribution. Using data collected on net mesh selectivity for Nile perch, Lates niloticus (L.), in the Kenyan waters of Lake Victoria, suitable mesh sizes for gillnet fleets for use in the Lake Victoria Fisheries Research Project were determined. The modal selection length for Nile perch in the mesh sized used in the earlier experiment were determined, as was the size range vulnerable to capture. Initial trials suggest 60% of the Nile perch swim within 5 m of the bottom. Setting and hauling of the nets is simple and quick, allowing the nets to be used at the same time as other sampling programmes.

Current status of the fish stocks of Lake Victoria (Uganda)

A total of 457 hauls were taken during experimental bottom trawl surveys in the Uganda sector of Lake Victoria between November 1997 and June 1999 to estimate composition, distribution and abundance of the major fish species in waters 4-60 m deep. Fifteen fish groups were caught with Nile perch, Lates niloticus (L.), constituting 94% by weight. Haplochromines and L. niloticus occurred in all areas sampled, while Nile tilapia, Oreochromis niloticus (L.) and other tilapiines were restricted to waters 30 m deep or less. The mean trawl catch rate in the zone where artisanal fishermen operate (i.e. in waters less deep than 30 m was 165 kg hr, of which 93.6% comprised L. niloticus. Species diversity and relative abundance decreased with increasing water depth.

The status of the artisanal fishery of Lake Victoria, Kenya, with notes on improvements to the catch data collection system

Catch and effort assessment surveys have been used to assess trends in fish landings in Kenyan waters of Lake Victoria since 1976. Landings reached a maximum of 200000 t annually in 1989-1991 as Nile perch, Lates niloticus (L.), catches increased due to an expansion in stock size and increased fishing effort. CPUE peaked at 180 kg boat day-1 in 1989 and decreased thereafter with increasing effort. By 1998 total Nile perch catches were half those at the beginning of the decade despite increased effort. Catches of Rastrineobola argentea (Pellegrin) have levelled off despite increased effort.

Catch trends from Lake Victoria - Tanzanian waters

Catch trends from Fisheries Department reports from the last eleven years (1985-1995) were analyzed. These showed a shift in the fishery from a cichlid-based system to one dominated by Nile perch and tilapias. In recent years, catches have declined from a peak in the early 1990s. Catch per unit effort appears to have remained stable except for a drop in 1995, however, this is considered dubious because the effort showed a doubling in that year. Limitations of the fisheries data collection system for the Tanzanian sector of Lake Victoria are highlighted and discussed.