Estimation of the relative annual abundance of yellowfin tuna, Thunnus albacares, in the Eastern Pacific Ocean during 1970-1985

ENGLISH: Estimates of relative annual abundance of yellowfin tuna in the eastern Pacific Ocean during 1970-1985 are made using catch rates, measured as tons caught by purse seiners per hour of searching. Catch rates are standardized a weighted generalized linear model. The important standardizing factors are vessel speed, season-area, and whether the yellowfin were caught in association with dolphins, skipjack tuna, or floating objects. Observations are weighted to give equal areas equal weight and to give each unit of fishing effort equal weight within an area. The results indicate that catch per days fishing underestimates abundance during the late 1970's when the fishery shifted some of its effort from dolphin sets to floating object sets, and overestimates abundance when the fishery shifted back to dolphin sets in 1984 and 1985. SPANISH: Se estima la abundancia anual relativa del atún aleta amarilla en el Océano Pacífico oriental (OPO) durante 1970-1985 por medio de tasas de captura, calculadas como toneladas cortas capturadas por barcos cerqueros por hora de búsqueda. Se usa un modelo lineal ponderado generalizado para estandardizar las tasas de captura. Los factores importantes de estandardización son la velocidad del barco, temporada-área, y si se capturaron los aletas amarillas en asociación con delfines, barriletes, o objetos flotantes. Se ponderaron las observaciones para otorgar igual importancia a áreas iguales y a cada unidad de esfuerzo pesquero dentro de un área. Los resultados señalan que la captura por día de pesca estima por bajo la abundancia durante los últimos años de la década de los 70, en cual época la pesquería trasladó parte de su esfuerzo de lances sobre delfines a lances sobre objetos flotantes, y la sobreestima al volver la pesquería a lances sobre delfines en 1984 y 1985. (PDF contains 45 pages.)

1994 annual report on fisheries in the North west incorporating the annual summary of fishery statistics.

This report provides national and regional developments, statistics on fisheries finance, including income and expenditure, salmon and sea trout catches, including rod and line, commercial catches, and angler log book returns, monitoring and special projects, including salmon microtagging, salmon egg survival in Swanside Beck, and fish stock assessments, one with hydroacoustics, and one of surveys of different areas in Cumbria. The appendix includes a summary of fish statistics for 1994.

1995 annual report on fisheries in the North west incorporating the annual summary of fishery statistics.

This fisheries report summarises national and regional developments focussing on the North West region of the Environment Agency. The North West region covers around 14,000 square km, from Cheshire in the south to its northern border with Scotland. The report provides statistics on fisheries finance, including income and expenditure, salmon and sea trout catches, including rod and line and net catches, and special projects, including fish stock assessments, and surveys. The appendix includes a summary of fish statistics for 1995.

1998 annual report on fisheries in the North west incorporating the annual summary of fishery statistics.

This fisheries report summarises national and regional developments focussing on the North West region of the Environment Agency. The North West region covers around 14,000 square km, from Cheshire in the south to its northern border with Scotland. This report provides national and regional developments,and special projects, including fish stocking assessments, radiotracking, and Cumbria surveys. Salmon and sea trout catches, including rod and line and net catches appear in the appendix.

1999 annual report on fisheries in the North west incorporating the annual summary of fishery statistics

This fisheries report summarises national and regional developments focussing on the North West region of the Environment Agency. The North West region covers around 14,000 square km, from Cheshire in the south to its northern border with Scotland. The report provides statistics on fisheries finance, including salmon and sea trout catches, including rod and line and net catches, and special projects, including fish stock assessments, radiotracking, and various surveys. The appendix includes a summary of fish statistics for 1999.

Annual estimates of the unobserved incidental kill of pantropical spotted dolphin (Stenella attenuata attenuata) calves in the tuna purse-seine fishery of the eastern tropical Pacific

We estimated the total number of pantropical spotted dolphin (Stenella attenuata) mothers killed without their calves (“calf deficit”) in all tuna purse-seine sets from 1973– 90 and 1996–2000 in the eastern tropical Pacific. Estimates were based on a tally of the mothers killed as reported by color pattern and gender, several color-pattern-based frequency tables, and a weaning model. Over the time series, there was a decrease in the calf deficit from approximately 2800 for the western-southern stock and 5000 in the northeastern stock to about 60 missing calves per year. The mean deficit per set decreased from approximately 1.5 missing calves per set in the mid-1970s to 0.01 per set in the late-1990s. Over the time series examined, from 75% to 95% of the lactating females killed were killed without a calf. Under the assumption that these orphaned calves did not survive without their mothers, this calf deficit represents an approximately 14% increase in the reported kill of calves, which is relatively constant across the years examined. Because the calf deficit as we have defined it is based on the kill of mothers, the total number of missing calves that we estimate is potentially an underestimate of the actual number killed. Further research on the mechanism by which separation of mother and calf occurs is required to obtain better estimates of the unobserved kill of dolphin calves in this fishery.

The annual course of precipitation over much of the United States: observed versus GCM simulation

General Circulation Models (GCMs) may be useful in estimating the ecological impacts of global climatic change. We analyzed seasonal weather patterns over the conterminous United States and determined that regional patterns of rainfall seasonality appear to control the distributions of the Nation's major biomes. These regional patterns were compared to the output from three GCMs for validation. The models appear to simulate the appropriate seasonal climates in the northern tier of states. However, the spatial extent of these regions is distorted. None of the models accurately portrayed rainfall seasonalities in the southern tier of states, where biomes are primarily influenced by the Bermuda High.