Download or read book Herring Stock Estimates from Diving Surveys of Spawn for the West Coast of Vancouver Island in 1985 written by C. W. Haegele and published by . This book was released on 1987 with total page 73 pages. Available in PDF, EPUB and Kindle. Book excerpt: The abundance of herring spawning on the west coast of Vancouver Islanddeclined over several years to a recent low in 1984. Herring spawns weresurveyed independently in 1985 by Fishery Officers using traditional techniquesand by scuba divers. Data from the traditional surface surveys were collected using various techniques and visual observations were made from thesurface, and from a boat, frequently using a viewing box to increase thevisibility of the bottom, and in some instances, supplemented by snorkeling. Grapples were used to determine the presence of and obtain samples of spawn. From these observaions, the length and width of spawn and the layers ofeggs were estimated. The proportion of the area of the spawn devoid of eggsor vegetation was also estimated.

Download or read book Herring Stock Estimates from Diving Surveys of Spawn on the West Coast of Vancouver Island in 1986 written by C. W. Haegele and published by Nanaimo, B.C. : Fisheries and Oceans, Canada. This book was released on 1987 with total page 63 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Herring Stock Estimates from Diving Surveys of Spawn for the West Coast of Vancouver Island in 1984 written by C. W. Haegele and published by . This book was released on 1985 with total page 67 pages. Available in PDF, EPUB and Kindle. Book excerpt: Diving surveys of spawn estimated herring stocks on the westcoast of Vancouver Island, between Esperanza Inlet and BarkleySound, at 19,710 tonnes in 1984. In two of the three StatisticalAreas, Esperanza Inlet and Barkley Sound, stocks are smaller thancatches in previous years. Stocks have declined throughout thestudy area in recent years and appear to be at a low level. Spawn was distributed shallow in Esperanza Inlet and ClayoquotSound and deep in Barkley Sound.

Download or read book Herring Stock Estimate from a Diving Survey of Spawn in Barkley Sound in 1982 with Comparisons to Other Estimates written by C. W. Haegele and published by . This book was released on 1984 with total page 33 pages. Available in PDF, EPUB and Kindle. Book excerpt: Divers surveyed and sampled herring spawns in Barkley Sound onthe west coast of Vancouver Island, B.C. in 1982 to determine thedistribution of spawn and to estimate the biomass of herring andcompare the results to other estimates. Although spawn wasdeposited to 14 m below Chart Datum, only 10% of spawn was lowerthan 4 m below Chart Datum. The diving survey estimated 23,500tonnes of herring in Barkley Sound, of which 14,300 tonnesspawned in a first wave, 5500 tonnes spawned in a second wave, and 3600 tonnes were caught in fisheries between the two waves. Estimates from population models ranged from 7352 to 25,838tonnes, depending on which assumptions were used. Generally theyunderestimated stocks, probably because Fishery Officer spawnsurvey data, used in all the models, considerably underestimatedthe area of spawn. Hydroacoustic estimates of biomass wereslightly lower and echosounder estimates missed completely thebuild-up of stocks prior to spawning.

Download or read book Herring Stock Estimates from Diving Surveys of Spawn for Georgia and Johnstone Straits in 1985 written by J. F. Schweigert and published by . This book was released on 1988 with total page 63 pages. Available in PDF, EPUB and Kindle. Book excerpt: The abundance of herring spawning in Georgia and Johnstone straits declined over several years to a recent low in 1984. Herring spawns in portions of Georgia Strait were surveyed by divers in 1976 and 1983, but never has there been an attempt by divers to survey all the spawns. Concern about the low levels of herring spawning stocks in Georgia and Johnstone straits in recent years and the potential effects of even moderate herring roe fisheries in these areas on the recovery of these stocks prompted the Department to conduct an intensive diving survey of this area in 1985. The results are summarized in this report.

Download or read book Oceanic Abstracts written by and published by . This book was released on 1995-02 with total page 786 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Perspectives on Canadian Marine Fisheries Management written by Canada. Department of Fisheries and Oceans and published by NRC Research Press. This book was released on 1993 with total page 464 pages. Available in PDF, EPUB and Kindle. Book excerpt: Co-published by: National Research Council of Canada.

Download or read book Herring Stock Estimates from Diving Surveys of Spawn for the Lower East Coast of the Queen Charlotte Islands in 1987 written by C. W. Haegele and published by Nanaimo, B.C. : Fisheries and Oceans, Canada. This book was released on 1987 with total page 41 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Oceanic Abstracts with Indexes written by and published by . This book was released on 1988 with total page 934 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Canadian Journal of Fisheries and Aquatic Sciences written by and published by . This book was released on 2000 with total page 888 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Herring Stock Estimates from Diving Surveys of Spawn for Georgia Strait in 1986 written by C. W. Haegele and published by Nanaimo, B.C. : Fisheries and Oceans, Canada. This book was released on 1988 with total page 65 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Herring Stock Estimates from Diving Surveys of Spawn for the North Coast of British Columbia in 1982 written by J. F. Schweigert and published by . This book was released on 1984 with total page 43 pages. Available in PDF, EPUB and Kindle. Book excerpt: Divers surveyed and sampled major 1982 herring spawns inStatistical Areas 3 to 5. Spawner biomass was estimated at 5700tonnes, which agreed closely with prespawning echosounderestimates, but was considerably lower than the 19,500 to 29,000tonnes estimated with population models. The low estimatedspawner biomass supports the decision to close the sac-roefishery in Chatham Sound from 1979 through 1983 and in PorcherIsland from 1982 through 1983.

Download or read book Herring Stock Estimates from Spawn Surveys for the North Coast of British Columbia in 1986 written by C. W. Haegele and published by Nanaimo, B.C. : Fisheries and Oceans, Canada. This book was released on 1988 with total page 28 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Aquatic Sciences and Fisheries Abstracts written by and published by . This book was released on 1989-05 with total page 768 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Microlog Canadian Research Index written by and published by . This book was released on 1988 with total page 1112 pages. Available in PDF, EPUB and Kindle. Book excerpt: "An index and document delivery service for Canadian report literature".

Download or read book Herring Spawning Stock Biomass Estimates from Diving Surveys for the Central Coast in 1986 written by J. F. Schweigert and published by . This book was released on 1988 with total page 43 pages. Available in PDF, EPUB and Kindle. Book excerpt: Herring abundance in the Central Coast district of British Columbia has recently shown signs of decline. A first attempt to survey spawn in the District (with divers) was made in 1986 to accurately assess the status of the spawning stocks. Herring spawns were surveyed independently with traditional surface survey techniques and by scuba divers. Visual observations were made from a boat and grapples were used to determine the presence of and obtain samples of spawn. From these observations the length and width of spawn and the layers of eggs were estimated. Divers took samples of vegetation with eggs attached, they were weighed, and egg counts were obtained. Eggs on the bottom substrate were calculated from diver estimates of the number of egg layers and percent of the bottom covered by vegetation and then added to eggs on the vegetation.

Download or read book Herring Spawning Stock Biomass Estimates from Diving Surveys for the Central Coast in 1986 written by Canada. Department of Fisheries and Oceans and published by Nanaimo, B.C. : Fisheries and Oceans, Canada. This book was released on 1988 with total page 43 pages. Available in PDF, EPUB and Kindle. Book excerpt: