Aquatic Agricultural Systems: Annual report

The program on aquatic agricultural systems (AAS) aims to change the way the CGIAR engages with aquatic agricultural systems and the poor and vulnerable communities who depend upon them. To do so the program has focused on three primary lines of work in its first six months: (i) preparing for implementation of the program in focal countries and geographical hubs; (ii) harnessing the best of earlier and ongoing research that contributes to the science themes of the program and which we wish to see expanded and integrated into the program as it develops; (iii) establishing innovative governance and management arrangements that will guide and implement the program. This report summaries the achievements and reviews the progress of the AAS program.

Regional variation in the annual feeding cycle of juvenile walleye pollock (Theragra chalcogramma) in the western Gulf of Alaska

Juvenile fish in temperate coastal oceans exhibit an annual cycle of feeding, and within this cycle, poor wintertime feeding can reduce body growth, condition, and perhaps survival, especially in food-poor areas. We examined the stomach contents of juvenile walleye pollock (Theragra chalcogramma) to explain previously observed seasonal and regional variation in juvenile body condition. Juvenile walleye pollock (1732 fish, 37–250 mm standard length) of the 2000 year class were collected from three regions in the Gulf of Alaska (Kodiak, Semidi, and Shumagin) representing an area of the continental shelf of ca. 100,000 km2 during four seasons (August 2000 to September 2001). Mean stomach content weight (SCW, 0.72% somatic body weight) decreased with fish body length except from winter to summer 2001. Euphausiids composed 61% of SCW and were the main determinant of seasonal change in the diets of fish in the Kodiak and Semidi regions. Before and during winter, SCW and the euphausiid dietary component were highest in the Kodiak region. Bioenergetics modeling indicated a relatively high growth rate for Kodiak juveniles during winter (0.33 mm standard length/d). After winter, Shumagin juveniles had relatively high SCW and, unlike the Kodiak and Semidi juveniles, exhibited no reduction in the euphausiid dietary component. These patterns explain previous seasonal and regional differences in body condition. We hypothesize that high-quality feeding locations (and perhaps nursery areas) shift seasonally in response to the availability of euphausiid

Validation of a method for estimating realized annual fecundity in a multiple spawner, the long-snouted seahorse (Hippocampus guttulatus), using underwater visual census

The long-snouted seahorse (Hippocampus guttulatus) (Cuvier, 1829), was used to validate the pre-dictive accuracy of three progressively realistic models for estimating the realized annual fecundity of asyn-chronous, indeterminate, multiple spawners. Underwater surveys and catch data were used to estimate the duration of the reproductive season, female spawning frequency, male brooding frequency, and batch fecun-dity. The most realistic model, a generalization of the spawning fraction method, produced unbiased estimates of male brooding frequency (mean ±standard deviation [SD]=4.2 ±1.6 broods/year). Mean batch fecundity and realized annual fecundity were 213.9 (±110.9) and 903.6 (±522.4), respectively. However, females prepared significantly more clutches than the number of broods produced by males. Thus, methods that infer spawning frequency from patterns in female egg production may lead to significant overestimates of realized annual fecundity. The spawning fraction method is broadly applicable to many taxa that exhibit parental care and can be applied nondestructively to species for which conservation is a concern.

Natural mortality rate, annual fecundity, and maturity at length for Greenland halibut (Reinhardtius hippoglossoides) from the northeastern Pacific Ocean

Mortality, fecundity, and size at maturity are important life history traits, and their interactions determine the evolution of life history strategies (Roff, 1992; Stearns, 1992; Charnov, 2002). These same traits are also important for population dynamics models (Hunter et al., 1992; Clark, 1999). It is increasingly important to accurately determine Greenland halibut (Reinhardtius hippoglossoides) life history traits and to correctly assess the status of its stocks because low recruitment or low biomass estimates have led to catch restrictions in the Bering Sea and Aleutian Islands (Ianelli et al.1), the Northeastern Arctic (Ådlandsvik et al., 2004), and the Northwest Atlantic (Bowering and Nedreaas, 2000).

Annual fecundity, batch fecundity, and oocyte atresia of Atka mackerel (Pleurogrammus monopterygius) in Alaskan waters

Annual potential fecundity, batch fecundity, and oocyte atresia were estimated for Atka mackerel (Pleurogrammus monopterygius) collected in Alaskan waters during 1993−94. Atka mackerel were assumed to be determinate spawners on the basis of decreasing fecundity after batch spawning events. Histological examination of the ovaries indicated that oocytes in the vitellogenic stage and higher had been spawned in the current spawning season. For an average female of 40 cm, potential annual fecundity was estimated to be 41,994 eggs, average batch size (i.e., batch fecundity) was estimated to be 6689 eggs, and there were 6.13 batches per spawning season. Atresia was estimated by examining postspawning specimens and was found to be substantial. The average amount of atresia for a 40-cm fish was estimated to be 11,329 eggs, resulting in an estimated realized fecundity of only 30,664 eggs and 4.64 batches of eggs per spawning season.

Low cost light traps for coral reef fishery research and sustainable ornamental fisheries

Two relatively inexpensive light traps to capture pre-settling reef fish and invertebrates are described. A trap made from a plastic bucket (with plastic bottles, a small plastic waste bin and two sheets of plywood) that costs US$15 appears to be just as effective as a large aluminium and plexiglass trap that costs US$275.

Size-composition of Annual Landings in the White Shrimp, Litopenaeus setiferus, Fishery of the Northern Gulf of Mexico, 1960–2006: Its Trend and Relationships with Other Fishery-dependent Variable

The potential for growth overfishing in the white shrimp, Litopenaeus setiferus, fishery of the northern Gulf of Mexico appears to have been of limited concern to Federal or state shrimp management entities, following the cataclysmic drop in white shrimp abundance in the 1940’s. As expected from surplus production theory, a decrease in size of shrimp in the annual landings accompanies increasing fishing effort, and can eventually reduce the value of the landings. Growth overfishing can exacerbate such decline in value of the annual landings. We characterize trends in size-composition of annual landings and other annual fishery-dependent variables in this fishery to determine relationships between selected pairs of these variables and to determine whether growth overfishing occurred during 1960–2006. Signs of growth overfishing were equivocal. For example, as nominal fishing effort increased, the initially upward, decelerating trend in annual yield approached a local maximum in the 1980’s. However, an accelerating upward trend in yield followed as effort continued to increase. Yield then reached its highest point in the time series in 2006, as nominal fishing effort declined due to exogenous factors outside the control of shrimp fishery managers. The quadratic relationship between annual yield and nominal fishing effort exhibited a local maximum of 5.24(107) pounds (≈ MSY) at a nominal fishing effort level of 1.38(105) days fished. However, annual yield showed a continuous increase with decrease in size of shrimp in the landings. Annual inflation-adjusted ex-vessel value of the landings peaked in 1989, preceded by a peak in annual inflation-adjusted ex-vessel value per pound (i.e. price) in 1983. Changes in size composition of shrimp landings and their economic effects should be included among guidelines for future management of this white shrimp

First Annual Report for the year ended 31st March, 1966

This is the first Annual report of the Cumberland River Authority on information of its activities and responsibilities on river management in its area between the beginning of April 1965, to the end of March 1966. The report contains 5 main sections on water resources, land drainage, fisheries, pollution, and finally the expenditure and income for the 12 month period. The first area that the report deals with is water resources, which includes periodical surveys, hydrometric schemes, acceptable flows, conservation works and a review of rainfall and river flow. The section on land drainage looks at work on improvement schemes, floods, charges and information on maintenance work carried out on rivers including Wampool, Waver, Marron, Irt, Esk, Eden, Caldew, Petteril, Eamont and Annas. The fisheries section covers 5 districts of the River Eden, Esk, Ellen, Derwent, and South West Cumberland. It includes angling information and a general report for salmon and sea trout, brown trout and freshwater fish. It also looks at fish hatchery, fisheries protection and byelaws including licence numbers issued for the different districts. The fourth section on pollution deals with water quality of the rivers and their tributaries from the same 5 areas mentioned above. It also covers information on sewage and trade effluents. The River Authorities preceded the Environment Agency which came into existence in 1996.

Second Annual Report for the year ended 31st March, 1967

This is the second Annual report of the Cumberland River Authority on information of its activities and responsibilities on river management in its area between the beginning of April 1966, to the end of March 1967. The report contains 5 main sections on water resources, land drainage, fisheries, pollution, and finally the expenditure and income for the 12 month period. The first area that the report deals with is water resources, which includes periodical surveys, hydrometric schemes, acceptable flows, conservation works and a review of rainfall and river flow. The section on land drainage looks at work on improvement schemes, floods, charges and information on maintenance work carried out on rivers including Wampool, Waver, Marron, Ellen, Derwent, Esk, Eden, Caldew, Petteril, Eamont, Gelt and Annas. The fisheries section covers 5 districts of the River Eden, Esk, Ellen, Derwent and South West Cumberland. It includes angling information and a general report for salmon and sea trout, Brown trout and freshwater fish. Fish disease and fish hatchery are also included as well as fisheries protection and byelaws. The fourth section on pollution deals with water quality and the results of samples taken from rivers Eden, Eamont, Caldew, Calder, Derwent, Ehen, Ellen, Wampool and Waver are also given. It also covers information on sewage and trade effluents. The River Authorities preceded the Environment Agency which came into existence in 1996.

Third Annual Report for the year ended 31st March, 1968

This is the third Annual report of the Cumberland River Authority on information of its activities and responsibilities on river management in its area between the beginning of April 1967, to the end of March 1968. The report contains 5 main sections on water resources, land drainage, fisheries, pollution, and finally the expenditure and income for the 12 month period. The first area that the report deals with is water resources, which includes periodical surveys, hydrometric schemes, acceptable flows, conservation works and a review of rainfall and river flow. The section on land drainage looks at work on improvement schemes, floods, charges and information on maintenance work carried out on rivers including Wampool, Waver, Glenderamackin, Marron, Eden, Caldew, and Lyvennet. The fisheries section covers 5 districts of the River Eden, Esk, Ellen, Derwent and South West Cumberland. It includes angling information and a general report for salmon and sea trout, brown trout and freshwater fish. Fish disease and fish hatchery are also covered as well as fisheries protection and licence duties. The fourth section on pollution deals with water quality, and the results of samples taken from rivers Eden, Eamont, Petteril, Caldew, Calder, Derwent, Ehen, Ellen, Wampool and Waver are also given. It also covers information on sewage and trade effluents. The River Authorities preceded the Environment Agency which came into existence in 1996.

Fourth Annual Report for the year ended 31st March, 1969

This is the fourth Annual report of the Cumberland River Authority on information of its activities and responsibilities on river management in its area between the beginning of April 1968, to the end of March 1969. The report contains 5 main sections on water resources, land drainage, fisheries, pollution, and finally the expenditure and income for the 12 month period. The first area that the report deals with is water resources, which includes periodical surveys, hydrometric schemes, acceptable flows, conservation works and a review of rainfall and river flow. The section on land drainage looks at work on improvement schemes, floods, charges and information on maintenance work carried out on rivers including Wampool, Waver, Marron, Ellen, Eden, Caldew, Esk, Annas, Irt and Glenderamackin. The fisheries section covers 5 districts of the River Eden, Esk, Ellen, Derwent and South West Cumberland. It includes angling information and a general report for salmon and sea trout, Brown trout and freshwater fish. Fish disease and fish hatchery are also covered as well as fisheries protection and licence duties. The fourth section on pollution covers water quality, and the results of samples taken from rivers Eden, Eamont, Petteril, Caldew, Calder, Derwent, Ehen, Ellen, Wampool and Waver are also given. It also covers information on sewage and trade effluents. The River Authorities preceded the Environment Agency which came into existence in 1996.

Fifth Annual Report for the year ended 31st March, 1970

This is the fifth Annual report of the Cumberland River Authority on information of its activities and responsibilities on river management in its area between the beginning of April 1969, to the end of March 1970. The report contains 5 main sections on water resources, land drainage, fisheries, pollution, and finally the expenditure and income for the 12 month period. The first area that the report deals with is water resources, wich includes periodical surveys, hydrometric schemes, acceptable flows, conservation works and a review of rainfall and river flow. The section on land drainage looks at work on improvement schemes, floods, charges and information on maintenance work carried out on rivers including Wampool, Waver, Derwent, Ellen, Mite, Bleng, Eden, Caldew and Petteril. The fisheries section covers 5 districts of the River Eden, Esk, Ellen, Derwent and South West Cumberland. It includes angling information and a general report for salmon and sea trout, brown trout and freshwater fish. Fish disease and fish hatchery are also covered as well as fisheries protection and licence duties. The fourth section on pollution deals with water quality, and the results of samples taken from rivers Eden, Eamont, Petteril, Caldew, Calder, Bleng, Derwent, Ehen, Ellen, Wampool and Waver are also given. It also covers information on sewage and trade effluents. The River Authorities preceded the Environment Agency which came into existence in 1996.

Sixth Annual Report for the year ended 31st March, 1971

This is the sixth Annual report of the Cumberland River Authority on information of its activities and responsibilities on river management in its area between the beginning of April 1970, to the end of March 1971. The report contains 5 main sections on water resources, land drainage, fisheries, pollution, and finally the expenditure and income for the 12 month period. The first area that the report deals with is water resources, which includes periodical surveys, hydrometric schemes, acceptable flows, conservation works and a review of rainfall and river flow. The section on land drainage looks at work on improvement schemes, floods, charges and information on maintenance work carried out on rivers including Wampool, Waver, Derwent, Eden, Mite, Bleng, Annas and Irt. The fisheries section covers 5 districts of the River Eden, Esk, Ellen, Derwent and South West Cumberland. It includes angling information and a general report for salmon and sea trout, brown trout and freshwater fish. Fish disease and fish hatchery are also covered as well as fisheries protection and licence duties. The fourth section on pollution deals with water quality, and the results of samples taken from rivers Eden, Eamont, Petteril, Caldew, Calder, Irt, Derwent, Ehen, Ellen, Wampool and Waver are also given. It also covers information on sewage and trade effluents. The River Authorities preceded the Environment Agency which came into existence in 1996.

Seventh Annual Report for year ended 31st March, 1972

This is the seventh Annual report of the Cumberland River Authority on information of its activities and responsibilities on river management in its area between the beginning of April 1971, to the end of March 1972. The report contains 5 main sections on water resources, land drainage, fisheries, pollution, and finally the expenditure and income for the 12 month period. The first area that the report deals with is water resources, which includes periodical surveys, hydrometric schemes, acceptable flows, conservation works and a review of rainfall and river flow. The section on land drainage looks at work on improvement schemes, floods, charges and information on maintenance work carried out on rivers including Wampool, Waver, Derwent and Eden. The fisheries section covers 5 districts of the River Eden, Esk, Ellen, Derwent and South West Cumberland. It includes angling information and a general report for salmon and sea trout, brown trout and freshwater fish. Fish disease and fish hatchery are also covered as well as fisheries protection and licence duties. The fourth section on pollution deals with water quality, and the results of samples taken for chemical analysis from rivers Eden, Eamont, Petteril, Caldew, Calder, Irthing, Esk, Irt, Mite, Derwent, Ehen, Wampool and Waver are also given. It also covers information on sewage and trade effluents. The River Authorities preceded the Environment Agency which came into existence in 1996.

Eighth Annual Report for year ended 31st March, 1973

This is the eighth Annual report of the Cumberland River Authority on information of its activities and responsibilities on river management in its area between the beginning of April 1972, to the end of March 1973. The report contains 5 main sections on water resources, land drainage, fisheries, pollution, and finally the expenditure and income for the 12 month period. The first area that the report deals with is water resources, including periodical surveys, hydrometric schemes, acceptable flows, conservation works and a review of rainfall and river flow. The section on land drainage looks at work on improvement schemes, floods, charges and information on maintenance work carried out on rivers including Wampool, Waver, Derwent, Eden and Caldew. The fisheries section covers 5 districts of the River Eden, Esk, Ellen, Derwent and South West Cumberland. It includes angling information and a general report for salmon and sea trout, brown trout and freshwater fish. Fish disease and fish hatchery are also covered as well as fisheries protection and licence duties. The fourth section on pollution deals with water quality, and the results of samples taken for chemical analysis from rivers Eden, Eamont, Leith, Lowther, Lyne, Petteril, Caldew, Calder, Irthing, Esk, Irt, Mite, Derwent, Ehen, Ellen, Annas, Wampool and Waver are also given. It also covers information on sewage and trade effluents. The River Authorities preceded the Environment Agency which came into existence in 1996.