Description of economic data collected with a random sample of commercial reef fish boats in the Florida Keys

This study summarizes the results of a survey designed to provide economic information about the financial status of commercial reef fish boats with homeports in the Florida Keys. A survey questionnaire was administered in the summer and fall of 1994 by interviewers in face-to-face meetings with owners or operators of randomly selected boats. Fishermen were asked for background information about themselves and their boats, their capital investments in boats and equipment, and about their average catches, revenues, and costs per trip for their two most important kinds of fishing trips during 1993 for species in the reef fish fishery. Respondents were characterized with regard to their dependence on the reef fish fishery as a source of household income. Boats were described in terms of their physical and financial characteristics. Different kinds of fishing trips were identified by the species that generated the greatest revenue. Trips were grouped into the following categories: yellowtail snapper (Ocyurus chrysurus); mutton snapper (Lutjanus analis), black grouper (Mycteroperca bonaci), or red grouper (Epinephelus morio); gray snapper (Lutjanus griseus); deeper water groupers and tilefishes; greater amberjack (Seriola dumerili); spiny lobster (Panulirus argus); king mackerel (Scomberomorus cavalla); and dolphin (Coryphaena hippurus). Average catches, revenues, routine trip costs, and net operating revenues per boat per trip and per boat per year were estimated for each category of fishing trips. In addition to its descriptive value, data collected during this study will aid in future examinations of the economic effects of various regulations on commercial reef fish fishermen.(PDF file contains 48 pages.)

Estimates of Marine Mammal, Sea Turtle, and Seabird Mortality in the California Drift Gillnet Fishery for Swordfish and Thresher Shark, 1996–2002

Estimates of incidental marine mammal, sea turtle, and seabird mortality in the California drift gillnet fishery for broadbill swordfish, Xiphias gladius, and common thresher shark, Alopias vulpinus, are summarized for the 7-year period, 1996 to 2002. Fishery observer coverage was 19% over the period (3,369 days observed/17,649 days fished). An experiment to test the effectiveness of acoustic pingers on reducing marine mammal entanglements in this fishery began in 1996 and resulted in statistically significant reductions in marine mammal bycatch. The most commonly entangled marine mammal species were the short-beaked common dolphin, Delphinus delphis; California sea lion, Zalophus californianus; and northern right whale dolphin, Lissodelphis borealis. Estimated mortality by species (CV and observed mortality in parentheses) from 1996 to 2002 is 861 (0.11, 133) short-beaked common dolphins; 553 (0.16, 103) California sea lions; 151 (0.25, 31) northern right whale dolphins; 150 (0.21, 27) northern elephant seals, Mirounga angustirostris; 54 (0.41, 10) long-beaked common dolphins, Delphinus capensis; 44 (0.53, 6) Dall’s porpoise, Phocoenoides dalli; 19 (0.60, 5) Risso’s dolphins, Grampus griseus; 11 (0.71, 2) gray whales, Eschrichtius robustus; 7 (0.83, 2) sperm whales, Physeter macrocephalus; 7 (0.96, 1) short-finned pilot whales, Globicephala macrorhychus; 12 (1.06, 1) minke whales, Balaenoptera acutorostrata; 5 (1.05, 1) fin whales, Balaenoptera physalus; 11 (0.68, 2) unidentified pinnipeds; 33 (0.52, 4) leatherback turtles, Dermochelys coriacea; 18 (0.57, 3) loggerhead turtles, Caretta caretta; 13 (0.73, 3) northern fulmars, Fulmarus glacialis; and 6 (0.86, 2) unidentified birds.

The genesis and achievement of a limnologist: George Evelyn Hutchinson, 1903-1991

An obituary of the limnologist G.E. Hutchinson is given.

The fish populations of the River Avon, Hampshire, downstream of Salisbury, in 1987

The objective of this study is to describe the present statu s of the coarse fish populations of the River Avon, Hampshire. The study arose from a widespread concern among anglers and riparian owners that fish numbers had decreased since the early 1970's, and from a scarcity of accurate information on population densities on which to assess this complaint. It was realised at the outset that, without such information from earlier years, the survey would not reveal the extent of any decline in the fisheries. The result s of the survey are compared with available data from other rivers , chiefly the nearby R. Frome and R. Stour. They may be used to assess any futur e changes in population densities and growth rates, and to indicate promising areas for future research. The data were collected from a quantitative survey of twelve river sections along the fifty kilometres of river between Salisbury and Sopley, and a qualitative survey of three weir pools within the same area from 14 September to 9 October, 1987.

The Origins of New Zealand's Chinook Salmon, Oncorhynchus tshawytscha

Chinook salmon, Oncorhynchus tshawytscha, are well established as anadromous and landlocked runs in New Zealand. Ova introductions during the 1870's (probably from the McCloud River, California, U.S.A.), failed to generate anadromous stocks, but further introductions offall-run salmon ova from hatcheries in California's Sacramento River basin in the early 1900's were successful and formed the basis for existing runs. The first batch of ova in the 1900's consignments originated from Battle Creek, a Sacramento River tributary, but the explicit source of later batches is not known. It seems likely that the successful runs stem from the second batch (1903 brood year-1904 consignment in New Zealand), probably augmented by returns from later importations.

A study on length-weight relationship, food and feeding habits of Indian scad, Decapterus russelli (Ruppel, 1830) along the northwest coast of India

Length and weight relationship of Decapterus russelli (Ruppell, 1830) is worked out to be W = 0.00312 L³ which indicates the isometric growth of the fish. Study on food and feeding habits revealed that the species is carnivorous, pelagic, feeding primarily on small crustaceans and small fish species, viz. Acetes indicus, ostracods, Apogon sp., Leiognathus sp., sciaenids, Netnipterus japonicas, Myctophid sp., Trichiurus sp., Therapon sp., D.russelli and occasionally on prawns. It is a selective feeder on Aeetes indicus.

Some aspects of the biology of Johnieops sina (Cuvier, 1830) from Mumbai waters

Investigations on food and feeding of Johnieops sina indicated that it feeds mainly on penaeid prawns, Acetes spp. and fishes. Penaeid prawns were found to be its preferred food item. The spawning activity was observed throughout the year with two peaks in February and August, supported by prominent peaks of gonadosomatic index in the same months. The minimum size at first maturity for females was 153 mm. The absolute fecundity ranged from 28,495 to 135,346 eggs for the ovaries weighing 1.30 to 9.49 g.