Exploring the association between swordfish catch rates and thermal fronts on U.S. longline grounds in the western North Atlantic

Abstract Associations between ocean surface thermal fronts and the swordfish catch rates of U.S. longline vessels were explored. The study area was the western North Atlantic off the United States, extending from 32°N to 45°N and from 76°W to 63°W. To locate and describe fronts, we used three variables computed from satellite-derived sea surface temperature (SST): horizontal gradient, distance to nearest thermal surface front, and frontal density. Most of the fishing effort analysed occurred along the edge of the continental shelf, where there was a high frequency of frontal presence. Very high catch per unit effort (CPUE) occurred more frequently in the vicinity of fronts than would be expected by chance. The high variability of CPUE that could not be explained by our frontal parameters suggested other, unmeasured, factors also influenced catch rates.

[1]  Robert D. Kenney,et al.  Cetacean biomass densities near submarine canyons compared to adjacent shelf/slope areas , 1987 .

[2]  P. Fiedler,et al.  Tuna aggregation and feeding near fronts observed in satellite imagery , 1987 .

[3]  Paul C. Fiedler,et al.  Albacore tuna catch distributions relative to environmental features observed from satellites , 1984 .

[4]  C. Brown,et al.  Relationship between the distribution pattern of right whales, Eubalaena glacialis, and satellite-derived sea surface thermal structure in the Great South Channel , 1989 .

[5]  Stephen J. Auer.  Five‐year climatological survey of the Gulf Stream system and its associated rings , 1987 .

[6]  S. T. Buckland,et al.  Computer-Intensive Methods for Testing Hypotheses. , 1990 .

[7]  R. Houghton,et al.  Physical/biological structure and exchange across the thermohaline shelf/slope front in the New York Bight , 1983 .

[8]  Peter Cornillon,et al.  Edge detection applied to SST fields , 1990, Defense, Security, and Sensing.

[9]  G. Csanady.  Physical basis of coastal productivity: The SEEP and MASAR experiments , 1990 .

[10]  N. Kohler,et al.  Food and feeding ecology of the sword-fish Xiphias gladius in the western North Atlantic Ocean with estimates of daily ration , 1985 .

[11]  J. Power,et al.  Satellite observed sea-surface temperatures and yellowfin tuna catch and effort in the Gulf of Mexico. , 1991 .

[12]  J. Friedman,et al.  Estimating Optimal Transformations for Multiple Regression and Correlation. , 1985 .

[13]  D. Olson,et al.  The concentrating of organisms at fronts: a cold-water fish and a warm-core Gulf Stream ring , 1985 .

[14]  R. Lynn,et al.  SEASONAL MIGRATION OF NORTH PACIFIC ALBACORE, THUNNUS ALALUNGA, INTO NORTH AMERICAN COASTAL WATERS: DISTRIBUTION, RELATIVE ABUNDANCE, AND ASSOCIATION WITH TRANSITION ZONE WATERS , 1977 .

[15]  M. Healey,et al.  Distribution of Commercial Troll Fishing Vessels off Southwest Vancouver Island in Relation to Fishing Success and Oceanic Water Properties and Circulation , 1990 .

[16]  F. G. Carey,et al.  Daily patterns in the activities of swordfish, Xiphias gladius, observed by acoustic telemetry , 1981 .

[17]  W. J. Richards,et al.  Synopsis of the biology of the swordfish, Xiphias gladius Linnaeus , 1981 .

[18]  W. Cleveland.  Robust Locally Weighted Regression and Smoothing Scatterplots , 1979 .

[19]  T. Leming,et al.  Satellite-detected fronts and butterfish aggregations in the northeastern Gulf of Mexico , 1989 .

[20]  M. Roffer.  Influence Of The Environment On The Distribution And Relative Apparent Abundance Of Juvenile Atlantic Bluefin Tuna Along The United States East Coast , 1987 .

[21]  J. Svejkovsky.  Remotely Sensed Ocean Features and Their Relation to Fish Distributions , 1988 .

[22]  C. Flagg.  Internal waves and mixing along the New England shelf-slope front , 1988 .

[23]  J. Hoey,et al.  A comparative study of the United States and Spanish longline fleets targetting swordfish in the Atlantic Ocean North of 40º N latitude , 1988 .

[24]  F. Sousa,et al.  Remotely sensed oceanographic patterns and variability of bluefin tuna catch in the gulf of mexico , 1984 .

[25]  William G. Pichel,et al.  Comparative performance of AVHRR‐based multichannel sea surface temperatures , 1985 .

[26]  James H. Johnson,et al.  SMALL-SCALE MOVEMENTS OF ALBACORE, THUNNUS ALALUNGA, IN RELATION TO OCEAN FEATURES AS INDICATED BY ULTRASONIC TRACKING AND OCEANOGRAPHIC SAMPLING , 1977 .

[27]  R. Garvine,et al.  Summertime Hydrography at the Shelfbreak Front in the Middle Atlantic Bight , 1988 .

[28]  S. Ramp.  Moored observations of current and temperature on the shelf and upper slope near ring 82B , 1989 .

[29]  J. Tukey,et al.  Variations of Box Plots , 1978 .