Size-related Hooking Mortality of Incidentally Caught Chinook Salmon, Oncorhynchus tshawytscha

Mortality associated with the incidental catch and release by commercial trollers of two size classes of chinook salmon, Oncorhynchus tshawytscha, was assessed. Observed cumulative mortality 4-6 days after hooking was 18.3 percent for sublegal-sizefish « 66 cm FL) and 19.0 percent for legal-sizefish. Size of fish was not significantly related to mortality; however, when the results were combined with data from a previous experiment, there was a significant inverse relationship between fish length and mortality. Hooking mortality estimates calculated from tagging experiments and observed relative mortality of legal-and sublegal-size fish held in net pens, were used to derive a range for total hooking mortality of 22.0-26.4 percent for sublegal-size chinook salmon and 18.5-26.4 percent for legal-size chinook salmon.

Gears and craft of Karwar: an overview

An account is given of the different types of gears and craft used to catch the pelagic and demersal fish in the inshore and estuary waters of Karwar, India. The main types of craft used during the fishing season September-May are: rampani boats, yendi boats, out-rigger boats, plank-built and dug-out canoes; important gears include: rampani, yendi, shore-seines, gill nets, boat seines, drift nets and hook and lines. Mechanized fishing, introduced during the sixties and seventies, included trawling and purse-seining. The types of gears used by the traditional fishermen depend on local conditions, seasons and distance covered from the shore. The major share to the total landings of fish in Karwar coast is brought mainly by the mechanized craft.

Mechanization of fishing craft and the use of improved fishing gear

Since the year 1925, attention has been focused periodically on the stagnation in the local fishing industry, and those who have studied the subject have been unanimous about the need to introduce modern fishing craft which are capable of working more fishing gear. This report outlines the stages through which the evolution of more effective fishing operations has progressed, both in the gradually increasing use of mechanical propulsion for boats and in the adoption of more modern gear and techniques by local fishermen. No reference is made in this report to the operation of deep-sea trawlers (Sivalingam, 1956) a phase of development which has hitherto not influenced the local fishing industry to any appreciable extent.

Commercial small craft pair trawling trials Lake Chilwa, Malawi 1971

The results are reported of commercial small craft pair trawling trials conducted on Lake Chilwa from May to August 1971. Type of vessels and equipment used and the fishing method and operation employed are described and design data given for the different trawls used. The effects on catching efficiency of varying amounts of small mesh netting trawls are dealt with and recommendations made for trawls design modifications.