Effects of Gear Modifications on the Trawl Performance and Catching Efficiency of the West Coast Upper Continental Slope Groundfish Survey Trawl

Since 1984, annual bottom trawl surveys of the west coast (California–Washington) upper continental slope (WCUCS) have provided information on the abundance, distribution, and biological characteristics of groundfish resources. Slope species of the deep-water complex (DWC) are of particular importance and include Dover sole, Microstomus pacificus; sablefish, Anoplopoma fimbria; shortspine thornyhead, Sebastolobus alascanus; and longspine thornyhead, S. altivelis. In the fall of 1994, we conducted an experimental gear research cruise in lieu of our normal survey because of concerns about the performance of the survey trawl. The experiment was conducted on a soft mud bottom at depths of 460–490 m off the central Oregon coast. Treatments included different combinations of door-bridle rigging, groundgear weight, and scope length. The experimental design was a 2 ´ 2 ´ 2 factorial within a randomized complete-block. Analysis of variance was used to examine the effects of gear modifications on the engineering performance of the trawl (i.e. trawl dimensions, variation in trawl dimensions, and door attitude) and to determine if catch rates in terms of weight and number of DWC species and invertebrates were affected by the gear modifications. Trawl performance was highly variable for the historically used standard trawl configuration. Improvements were observed with the addition of either a 2-bridle door or lighter ground gear. Changes in scope length had relatively little effect on trawl performance. The interaction of door bridle and ground gear weight had the most effect on trawl performance. In spite of the standard trawl’s erratic performance, catch rates of all four DWC species and invertebrates were not significantly different than the 2-bridle/heavy combination, which did the best in terms of engineering performance. The most important factor affecting DWC catch rates was ground gear. Scope length and the type of door bridle had little effect on DWC catch rates. Subsequent revisions to survey gear and towing protocol and their impact on the continuity of the slope survey time series are discussed.

Seasonal Occurrence of the White Shark, Carcharodon carcharias, in Waters off the Florida West Coast, with Notes on its Life History

The white shark, Carcharodon carcharias, is considered rare in the Gulf of Mexico; however, recent longline captures coupled with historical landings information suggest that the species occurs seasonally (winter-spring) within this region. We examined a total of seven adult and juvenile white sharks (185-472 em total length) captured in waters off the west coast of Florida. Commercial longline fisheries were monitored for white sharks during all months (1981-94), but this species was captured only from January to April. All white sharks were captured in continental shelf waters from 37 to 222 km off the west coast of Florida when sea surface temperatures ranged from 18.7° to 21.6°C. Depths at capture locations ranged from 20 to 164 m. Fishing gear typically used in Gulf of Mexico offshore fisheries may not be effective at capturing this species, and the apparent rarity of white sharks in this area may be, in part, a function of gear bias.

South & West Cumberland Fisheries Advisory Committee 3rd June, 1974

This is the first report from the South and West Cumberland Fisheries Advisory Committee meeting, which was held on the 3rd June 1974. The report includes sections on fishery byelaws, estimates for the anticipated income and expenditure on fisheries for the current year, and fish mortality. The section on fish mortality includes the details of a fish kill on the River Marron, gives points along the river where water was sampled, and the results of the analysis. The Fisheries Advisory Committee was part of the Regional Water Authorities, in this case the North West Water Authority. This preceded the Environment Agency which came into existence in 1996.

South & West Cumberland Fisheries Advisory Committee 2nd September, 1974

This is the report from the South and West Cumberland Fisheries Advisory Committee meeting, which was held on the 2nd September 1974. The report looks at comments of the Regional Fisheries Officer on the report 'Taking Stock', and information including the aims of a report entitled 'Coarse Fisheries'. The report also includes sections on the summary of the stocking carried out from Holmewrangle hatchery, biological work undertaken on the Rivers Ellen, Keekle and Thirlmere Reservoir, fishery prosecutions, and fish mortalities. This section includes information on the date, location, extent of the kill and the cause. The Fisheries Advisory Committee was part of the Regional Water Authorities, in this case the North West Water Authority. This preceded the Environment Agency which came into existence in 1996.

South & West Cumberland Fisheries Advisory Committee 13th October, 1975.

This is the report from the South and West Cumberland Fisheries Advisory Committee meeting, which was held on the 13th October 1975. The report contains information on the impact of work on the A66 Penrith to Workington road, brown trout fishing, the development of the Ehen as a fishery, reports of fisheries activities, Holmwrangle hatchery, land drainage representation, new fishery byelaws and fishing licence duties. The section on fisheries activities includes runs of fish, stocking, poaching and biological work. The section on Holmwrangle hatchery includes mortality numbers and possible solutions to avoid future pipe chokes and to improve the pumping system. The section on land drainage is purely for an up-to-date picture of developments. The Fisheries Advisory Committee was part of the Regional Water Authorities, in this case the North West Water Authority. This preceded the Environment Agency which came into existence in 1996.

South & West Cumberland Fisheries Advisory Committee 2nd December, 1974

This is the report from the South and West Cumberland Fisheries Advisory Committee meeting, which was held on the 2nd December 1974. The report looks at the Water Bailiffs establishment, including the organisation and the duties of both the Fisheries Inspector and the Senior Bailiff. The report also covers the report by the Unit Fisheries Officer on fisheries activities. This includes stocking on Devoke Water, biological work carried out in the Greta and Glenderamackin tributaries, information on the fishing of migratory fish, trout and coarse fish and fisheries prosecutions. The Fisheries Advisory Committee was part of the Regional Water Authorities, in this case the North West Water Authority. This preceded the Environment Agency which came into existence in 1996.

South & West Cumberland Fisheries Advisory Committee 12th January, 1976.

This is the report from the South and West Cumberland Fisheries Advisory Committee meeting, which was held on the 12th January 1976. The report contains sections on land drainage representation on local committees, actions to be taken to solve problems with Braithwaite Weir, Enneralde compensation flow, fisheries activities report, recommendations for future policy by association hatcheries and progress made in implementing the recommendations contained in 'Taking Stock' publication. The section on fisheries activities reported by area fisheries officers looks at migratory fishing and spawning, U.D.N. disease appearance, poaching and prosecutions, biological work at Mockerkin Tarn and the River Calder. The Fisheries Advisory Committee was part of the Regional Water Authorities, in this case the North West Water Authority. This preceded the Environment Agency which came into existence in 1996.

South & West Cumberland Fisheries Advisory Committee 13th January, 1975

This is the report from the South and West Cumberland Fisheries Advisory Committee meeting, which was held on the 13th January, 1975. It covers information on the proposed regional fishing licence duties, the report of the Working Party on future regional hatchery requirements, and the Unit Fisheries Officer's report on fisheries activities. This section includes biological work undertaken on Chapel House Reservoir, information on the fishing of migratory fish, trout and coarse fish, hatchery work and prosecutions. The Fisheries Advisory Committee was part of the Regional Water Authorities, in this case the North West Water Authority. This preceded the Environment Agency which came into existence in 1996.

South & West Cumberland Fisheries Advisory Committee 28th April, 1975

This is the report from the South and West Cumberland Fisheries Advisory Committee meeting, which was held on the 28th April, 1975. It covers information on fishery byelaws, and a report by Unit Fisheries Officer on fisheries activities. This section includes work on stocking, biological work carried out, fish surveys, fishing information for migratory fish, trout, and coarse fish, and hatchery work. Other areas looked at include licence duties, inportation of live freshwater fish, and a pollution incident on the River Ellen. The Fisheries Advisory Committee was part of the Regional Water Authorities, in this case the North West Water Authority. This preceded the Environment Agency which came into existence in 1996.

South & West Cumberland Fisheries Advisory Committee 27th June, 1977.

This is the report from the South and West Cumberland Fisheries Advisory Committee meeting, which was held on the 27th June, 1977. The report contains sections on water resources development in West Cumbria which includes essential short and long term requirements for conservation of migratory fish stocks in the River Ehen. The section on fisheries activities includes salmon, sea trout and brown trout catches; restocking; fish mortalities; fisheries investigations/gravel abstractions in Rivers Annas, Calder, Esk, Newlands Beck, St. John's Beck, Trout Beck and Caldew; and general activities held in Holmwrange Hatchery. It also covers prosecutions and electrofishing carried out in Rivers Cocker, Marron, Ellen, Glenderaterra, Ehen, Calder, Irt, Esk and Annas. The Fisheries Advisory Committee was part of the Regional Water Authorities, in this case the North West Water Authority. This preceded the Environment Agency which came into existence in 1996.

South & West Cumberland Fisheries Advisory Committee 17th October, 1977

This is the report from the South & West Cumberland Fisheries Advisory Committee meeting, which was held on the 17th October, 1977. It covers fisheries income and expenditure, licence duties, and information on the River Marron at Lostrigg Beck in connection with opencast coal workings in the area. It also looks at the proposal for the development of the Eskett Quarries and the likely effect on the River Ehen, and the possible development of Rivers Waver and Wampool as a sea trout fishery. The report for that covers the physical descriptions of the catchments, abstractions, discharges, biological aspects, chemical aspects and the present situation regarding fisheries. Also included is the report by the area fisheries officer on fisheries activities which includes information on river improvement works on the River Calder, Branthwaite Weir Fish Pass, a fish kill on the tributary of the River Calder, stock numbers, and an update on Holmwrangle hatchery. The Fisheries Advisory Committee was part of the Regional Water Authorities, in this case the North West Water Authority. This preceded the Environment Agency which came into existence in 1996.

South & West Cumberland Fisheries Advisory Committee 28th March, 1977.

This is the report from the South and West Cumberland Fisheries Advisory Committee meeting, which was held on the 28th March, 1977. The report contains sections on fisheries income and expenditure, licensing of salmon dealers, sea patrol of estuaries, proposed fish pass at Branthwaite Weir, and fisheries activities. The section on sea patrol of estuaries looks at the possibility of bailiffs in Derwent, Ehen/Calder and Esk estuaries carrying out sea patrols in places where salmon netting takes place. The section on fisheries activities includes information on the spawning season in 1976; salmon and sea trout catches; restocking and fisheries investigations regarding water quality. The Fisheries Advisory Committee was part of the Regional Water Authorities, in this case the North West Water Authority. This preceded the Environment Agency which came into existence in 1996.

South & West Cumberland Fisheries Advisory Committee 9th November, 1977

This is the report from the South and West Cumberland Fisheries Advisory Committee meeting, which was held on the 9th November, 1977. It covers fisheries income and expenditure, re-structuring of the licence system, sales of fishing licences and information on assessed fisheries. The Fisheries Advisory Committee was part of the Regional Water Authorities, in this case the North West Water Authority. This preceded the Environment Agency which came into existence in 1996.

South & West Cumberland Fisheries Advisory Committee 9th January, 1978

This is the report from the South and West Cumberland Fisheries Advisory Committee meeting, which was held on the 9th January, 1978. It covers information on water resource development for West Cumbria which includes details on the River Derwent and Ennerdale schemes, fisheries income and expenditure, licence duties, Eskett Quarries and radioactive discharge in relation to fishery interests. It also looks at the report by the area fisheries officer on river conditions and fishing, Holmwrangle Hatchery and stocking. Included in this report is a note on survey work carried out on Braystones Tarn, resources and the collection of fish for hatcheries. The Fisheries Advisory Committee was part of the Regional Water Authorities, in this case the North West Water Authority. This preceded the Environment Agency which came into existence in 1996.