Central area redd project [Ribble, Hodder and Lune catchments]

Redd counting is an integral part of most Fishery Officers duties. The number and distribution of salmonid redds throughout salmonid catchments provides invaluable information on the range and extent of spawning by both salmon and sea trout. A project was initiated by the Fisheries Science and Management Team of Central Area, North West Region in England in liaison with the Flood Defence function. The main objective of this project was to assess redd count data for Central Area and attempt to quantify these data in order to produce a grading system that would highlight key salmonid spawning areas. By showing which were the main areas for salmon and sea trout spawning, better informed decisions could be made on whether or not in-stream Flood Defence works should be given the go-ahead. The main salmonid catchments in Central Area were broken into individual reaches, approximately 1 km in length. The number of redds in these individual reaches were then calculated and a density per lkm value was obtained for each reach. A grading system was devised which involved looking at the range of density per km values and dividing this by five to produce 5 classes, A - E. A sixth class (F) was used where the density per Ion value was 0.00. This grading system was calculated at two levels of detail. Grades for salmon and sea trout were produced for each individual catchment and also on an Area-wide level. Maps were produced using a range of colours to represent the grade for each reach. These maps provide a highly useful overview of the status of salmonid spawning for each catchment over individual years and highlight the key salmon and sea trout spawning areas in each catchment. These maps and the associated summary data should now provide Flood Defence and Fisheries staff with a fairly detailed overview of the status of spawning in any location within the. main salmonid catchments in Central Area. Although these maps are very useful they should only be used as a guide. The current practice of consulting with the local Fishery Officer should be continued to ensure that expert local knowledge is taken into account.

Field validation of the 'Logie' fish counter at Forge weir on the River Lune, 1992

The stock assessment task group report (1991) mentions that fish counters could play a key role in providing data on the size of the adult stock, and in particular the migratory salmonid stock. This report assesses the performance of the 'logie' fish counter at Forge Weir on the River Lune. Using video surveillance, a total of 1137 hours time lapse and 15 hours real time were used for validation purposes. This report looks at materials and methods, counting accuracy, sizing ability and environmental conditions, performance across the electrode array and salmonid swimming speed.

Description of NRA tracking studies: tracking techniques and fish counter technology

The study began on the 7th January 1991 and was completed in June 1991. Two reports have been produced. This report published as R&D Note 33 describes NRA tracking studies, tracking techniques and fish counter technology. The second report published as R&D Note 34 evaluates NRA tracking studies and recommends future research. The latter will be used solely for NRA management purposes. This report briefly outlines the programme of the NRA, placing the Fisheries programme in the context of the work of the NRA as a whole, and viewing the tracking work against the broader requirements of the NRA Fisheries research programme. Two techniques currently exist for studying the detailed timing and extent of movements of adult salmon: tracking of individually identifiable fish, and counting the numbers of fish moving past a fixed point in the river. Further details of these techniques and their development are given in Sections 2 and 3. Section 4 summarises and assesses completed and current NRA tracking Studies. Complete project descriptions for the studies are contained in Appendix A. Section 5 discusses the scientific content of these studies in relation to similar work carried out elsewhere in the UK. Section 6 details the future development of tracking techniques. Tracking work on migratory salmonids has tended to concentrate largely upon the movements of adult salmon. Much of this report will therefore be concerned with salmon tracking studies. NRA studies involving sea trout are referred to where appropriate. The methodological problems of sea trout tracking studies are summarised in Section 2.1.3.

Comparison of survey methods for estimating abundance of harbor seals (Phoca vitulina) in glacial fjords

The importance of glacial ice habitats to harbor seals (Phoca vitulina) in Alaska has become increasingly apparent. However, enumerating harbor seals hauled out on ice in glacial fjords has been difficult. At Johns Hopkins Inlet in Glacier Bay, Alaska, we compared a shore-based counting method to a large-format aerial photography method to estimate seal abundance. During each aerial survey, shore-based observers simultaneously counted seals from an observation post. Both survey methods incurred errors in double-counting and missing seals, especially when ice movements caused seals to drift between survey zones. Advantages of shore-based counts included the ability to obtain multiple counts for relatively little cost, distinguish pups from adults, and to distinguish mobile seals from shadows or glacial debris of similar size. Aerial photography provided a permanent record of each survey, allowing both a reconciliation of counts in overlapping zones and the documentation of the spatial distribution of seals and ice within the fjord.

Diurnal and nocturnal temperatures for Atlantic salmon postsmolts (Salmo salar L.) during their early marine life

Data storage tags (DSTs) were applied to Atlantic salmon (Salmo salar L.) smolts during their seaward migration in the spring of 2002 at a fish counting fence on Campbellton River, Newfoundland. Our objectives were to discover whether or not salmon smolts could carry DSTs and survive, whether or not useful data on thermal habitat could be obtained and interpreted, and whether or not salmon smolts moved vertically in the water column. Data were downloaded from 15 of the recovered tags and revealed the hourly water temperatures experienced by the fish for periods of 3 to 71 days. The data on the DSTs were analyzed for temperature patterns in relation to migration behavior and diurnal movement of the fish. While in the sea, the DSTs recorded night temperatures of 12.5°C, which were higher than day temperatures of 11.6°C; the record from moored recorders, however, indicated that sea temperatures actually declined at night. It is hypothesized that posts-molts avoid avian predators during daylight hours by positioning themselves deeper in the water column and that they were pursuing prey during the deeper vertical descents or ascents noted during the periods of more rapid changes in temperature.

Age validation, growth modeling, and mortality estimates for striped trumpeter (Latris lineata) from southeastern Australia: making the most of patchy data

Age estimates for striped trumpeter (Latris lineata) from Tasmanian waters were produced by counting annuli on the transverse section of sagittal otoliths and were validated by comparison of growth with known-age individuals and modal progression of a strong recruitment pulse. Estimated ages ranged from one to 43 years; fast growth rates were observed for the first five years. Minimal sexual dimorphism was shown to exist between length, weight, and growth characteristics of striped trumpeter. Seasonal growth variability was strong in individuals up to at least age four, and growth rates peaked approximately one month after the observed peak in sea surface temperature. A modified two-phase von Bertalanffy growth function was fitted to the length-at-age data, and the transition between growth phases was linked to apparent changes in physiological and life history traits, including offshore movement as fish approach maturity. The two-phase curve was found to represent the mean length at age in the data better than the standard von Bertalanffy growth function. Total mortality was estimated by using catch curve analysis based on the standard and two-phase von Bertalanffy growth functions, and estimates of natural mortality were calculated by using two empirical models, one based on longevity and the other based on the parameters L∞ and k from both growth functions. The interactions between an inshore gillnet fishery targeting predominately juveniles and an offshore hook fishery targeting predominately adults highlight the need to use a precautionary approach when developing harvest strategies.

Beluga, Delphinapterus leucas, Group Sizes in Cook Inlet, Alaska, Based on Observer Counts and Aerial Video

Belugas, Delphinapterus leucas, groups were videotaped concurrent to observer counts during annual NMFS aerial surveys of Cook Inlet, Alaska, from 1994 to 2000. The videotapes provided permanent records of whale groups that could be examined and compared to group size estimates ade by aerial observers.Examination of the video recordings resulted in 275 counts of 79 whale groups. The McLaren formula was used to account for whales missed while they were underwater (average correction factor 2.03; SD=0.64). A correction for whales missed due to video resolution was developed by using a second, paired video camera that magnified images relative to the standard video. This analysis showed that some whales were missed either because their image size fell below the resolution of hte standard video recording or because two whales surfaced so close to each other that their images appeared to be one large whale. The correction method that resulted depended on knowing the average whale image size in the videotapes. Image sizes were measured for 2,775 whales from 275 different passes over whale groups. Corrected group sizes were calcualted as the product of the original count from video, the correction factor for whales missed underwater, and the correction factor for whales missed due to video resolution (averaged 1.17; SD=0.06). A regression formula was developed to estimate group sizes from aerial observer counts; independent variables were the aerial counts and an interaction term relative to encounter rate (whales per second during the counting of a group), which were regressed against the respective group sizes as calculated from the videotapes. Significant effects of encounter rate, either positive or negative, were found for several observers. This formula was used to estimate group size when video was not available. The estimated group sizes were used in the annual abundance estimates.

South Lancashire Fisheries Advisory Committee 14th January, 1976.

This is the report from the South Lancashire Fisheries Advisory Committee meeting, which was held on the 14th January 1976. The report contains information on land drainage representation on local committees, fisheries activities report, pollution on Colne water and Trawden water, oil pollution of the feeder stream to Scotman’s flash (Wigan), water bank releases at River Hodder, the progress made in implementing the recommendations contained in the 'Taking Stock' publication and a planning study for the post 1981 period. The section on fisheries activities reported by area fisheries officers looks at fish mortalities, feral mink, fish passing through counting stations at River Ribble and Hodder, and fish propagation plans for Langcliffe and Middleton 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.

South Lancashire Fisheries Advisory Committee 19th October, 1977

This is the report from the South Lancashire Fisheries Advisory Committee meeting, which was held on the 19th October, 1977. It covers fisheries income and expenditure, licence duties, fishing regulations, and information on the pollution of Stock Beck. It also comments on the report by the area fisheries officer on fisheries activities which includes information on fish movement and angling for salmon, sea trout, brown trout and coarse fish. Included in this report is also the numbers of fish passing through counting stations from January to August 1977 at Waddow Weir, Winckley Hall and Locks Weir, poaching, fish mortalities, 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.

Lune Wyre & Furness Fisheries Advisory Committee 24th October, 1977

This is the report from the Lune, Wyre and Furness Fisheries Advisory Committee meeting, which was held on the 24th October, 1977. It covers fisheries income and expenditure, licence duties, and information on possible reasons for the apparent depletion of fish stocks on the River Leven. It also comments on the progress report on goosanders and mergansers and the consequent effect they were having on fisheries, net licences, erosion and a brief summary of the present situation of the development of coarse angling on Halton Fishery. Also covered is the report by the area fisheries officer on fisheries activities which includes information on fishing conditions, Skerton Weir, Forge Weir Fish Counter, fish mortalities and the construction of the fishery groynes in the River Lune. The report also includes the numbers of fish passing through counting stations at Haverthwaite and Halton, migratory fish propagation and information on the stocking of salmon and sea trout into the Kent, Leven, Crake, Duddon, Keer, Wyre and Lune watershed, and the Lakes of Windermere, Esthwaite and Grasmere watersheds. 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.

Eden & District Fisheries Advisory Committee 10th January, 1978

This is the report from the Eden and District Fisheries Advisory Committee meeting, which was held on the 10th January, 1978. It covers information of fisheries income and expenditure, licence duties, regional water resources study, salmon fishing, radioactive discharge in relation to fishery interests and a brief mention about the possibilities of opening Castle Carrock reservoir for public angling. It also includes the report by the area fisheries officer on river conditions and fishing, Holmwrangle Hatchery and stocking. Included in this report is a note on the survey work carried out on the Upper Eden and Eamont regarding brown trout, the collection of fish for hatcheries, Redd counting and the transfer of coarse fish. 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.

Lune, Wyre & Furness Fisheries Advisory Committee 3rd July, 1978

This is the report from the Lune, Wyre and Furness Fisheries Advisory Committee meeting, which was held on the 3rd July, 1978. It covers information on the monitoring of radioactivity in migratory fish, fishing offences and prosecutions, the income from sale of rod and line licences, the review of discharge consent conditions, illegal netting, the Morecambe and Heysham sewerage scheme and fish counting work. It also covers the report by the area fisheries officer on river conditions and fishing for Lune, Furness, Wyre and tributaries. Also covered in the report is information on migratory fish movements, fish monitoring stations, Middleton hatchery, fish mortalities, fish diseases, biological work and stocking numbers of brown trout, rainbow trout and coarse fish by the Angling Associations. 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 June, 1976.

This is the report from the South and West Cumberland Fisheries Advisory Committee meeting, which was held on the 28th June, 1976. The report contains sections on Branthwaite Weir and fisheries activities. The section on fisheries activities during the period 13th January-2nd March includes stocking; biological surveys; fish mortalities; hatcheries and redd counting. The section on fisheries activities during the period 2nd March-20th May includes a general report of the area; fry stocking/rearing; River works (River Ehen, Calder, Derwent, and Glenderamackin); coarse fish removal; and fish transfers. 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.

Gunnislake Fish Counter. Annual Report 1999

This is the Gunnislake Fish Counter, Annual Report 1999 produced by the Environment Agency South West Region on March 2000. The report presents the daily upstream counts of migratory salmonids recorded at Gunnislake Weir fish counting station (SX 435 713) situated on the River Tamar in 1999. The counter data contained within this report covers the period of the commercial migratory salmonid net buy-back scheme and the implementation of the National Spring Salmon Byelaws. The fish counter at Gunnislake is a resistivity based system (Logie 2100A – Aquantic limited) and is installed in the fish pass on the Cornish bank of the River Tamar at the head of the tide. The minimum salmon count for 1999 was 2691. The run pattern observed for salmon and sea trout in 1999 was generally consistent with that of previous years. However, the total combined annual count of salmon and sea trout migrating upstream on the River Tamar in 1999 was 25% higher than the 5 year average (1994 - 1998).

Restormel Fish Counter Annual Report 1999

This is the Restormel Fish Counter, Annual Report 1999 produced by the Environment Agency South West Region on March 2000. The report presents the daily upstream counts of migratory salmonids recorded at Restormel Weir counting station (SX 107 613) River Fowey in 1999. The counter data covers the period of the commercial migratory salmonid net buy-back scheme, which was in operation between March and June 1999. The fish counter is a resistivity based system (Logie 2100 A - Aquantic limited) and operates over all three channels of the weir at Restormel. The minimum salmon count estimate was 497, and the 1999 upstream count for sea trout was 6590. The run pattern observed for salmon and sea trout in 1999 was generally consistent with that of previous years. Flows on average were half those of 1998 during September, October, and November.