Hawaii and California samples, respectively. From the wide spread 

 of mercury levels encountered in striped marhn, a trend of mercury 

 level with size of fish could not be easily detected. Livers of nine 

 specimens from the Hawaii catch were analyzed: mercury levels 

 ranged from 0.0.5 ppm to 1.53 ppm. 



Three swordfish weighing 6 pounds (2.7 kg). 100 pounds (45.4 

 kg), and an estimated 500 pounds (226.8 kg) contained mercury 

 levels in white muscle of 0.04. 1.71. and 2.10 ppm. respectively. 



(675.) Proceedings of the International Billfish Symposium, 

 KailuaKona, Hawaii, 9-12 August 1972. Part 2. Review 

 and Contributed Papers — Summer Concentration of 

 White Marlin, Tetrapturus albidus. West of the Strait of 

 Gibraltar. By C. Richard Robins. July 1974, p. 164-174. 



ABSTRACT 



Examination of fish catches landed in August 1961 at various 

 ports in southern Portugal and the adjacent coast of Spain 

 demonstrated that the white marlin, Tetrapturus albidus, 

 concentrated in these waters during this month. The coincident 

 absence of white marlin in landings at Sicily make it likely that the 

 species does not enter the Mediterranean in any numbers at least at 

 this season. 



August concentrations of white marlin elsewhere in the Atlantic 

 are discussed along with the implications of the coincident timing of 

 them on population structure of the species. 



Morphometric data are presented on 57 specimens from this 

 eastern Atlantic population to facilitate future comparison with 

 specimens from elsewhere in the range of the species. 



(675.) Proceedings of the International Billfish Symposium, 

 Kailua-Kona, Hawaii, 9-12 August 1972. Part 2. Review 

 and Contributed Papers— The Cape of Good Hope: A 

 Hidden Barrier to Billfishes. By M. J. Penrith and D. L. 

 Cram. July 1974, p. 175-187. 



ABSTRACT 



Since 1838 there have been isolated reports of billfishes from the 

 southern tip of Africa, but only during tne years 1961 64, when a 

 number of Cape Town based boats fished commercially for tuna 

 using longlines. were billfishes found to occur in considerable 

 numbers. 



The waters to the west and south of the Cape of Good Hope were 

 found to be unique in their billfish fauna, no less than six species 

 being represented, comprising Xiphias, Makaira (2 species), and 

 Tetrapturus (3 species). Only two wide-ranging species have not 

 been found. Istiophorus is commonly listed from the area on the 

 basis of Histiopkorus granuUfer. but a reexamination of de 

 Castelnau's type shows it to be a Makaira, while T. angustirostris 

 could occur as it is known from off Durban. 



The billfishes are probably attracted to this limited geographic 

 area by the rich feeding grounds which are the result of the 

 upwelling of nutrient-rich water along the Cape's west coast. It is 

 difficult, however, to suggest reasons why there is an apparent 

 barrier to movement between the Atlantic and Indo-Pacific Oceans 

 for certain species. Hydrographic conditions in the area are 

 discussed, but there are no obvious physical barriers preventing 

 black and .striped marlins from entering the Atlantic nor white 

 marlin and longbill spearfish from moving into the Indo Pacific. 



(675.) Proceedings of the International Billfish Symposium, 

 Kailua-Kona, Hawaii, 9-12 August 1972. Part 2. Review 

 and Contributed papers— Catch Distribution and Related 

 Sea Surface Temperature for Striped Marlin {Tetrapturus 

 audax) Caught Off San Diego, California. By James L. 

 Squire, Jr. July 1974, p. 188-193. 



ABSTRACT 



Records for 4.535 marlin landed at San Diego, California, and 

 related sea surface temperature data were examined for the period 

 1963 through 1970 to determine time space distribution and the 

 relationship of catch and sea surface temperatures. For the period 

 1963 through 1970 the catch of 4. .535 marlin was compared to sea 

 surface temperature conditions relative to increased catches. 



Catch distribution based on 1963 to 1967 data showed that 76.4% 

 were caught within a 35 by 40 nautical-mile area off San Diego, 

 with the maximum catch being made from mid-August to 



mid-September. Catch temperatures off southern California 

 calculated for this area from airborne infrared sea surface 

 temperature survey data ranged from 61 °F (le.l^C) to 73°F 

 (22.8°C): the mean catch temperature was 67.8''F (19.9°C). 



Sea surface temperature conditions based on 2 wk average 

 temperature charts issued by the National Marine Fisheries Service 

 indicate that an initial warming of water to an average temperature 

 of 68° F (20.0°C) or above is related to an increase m eaten. When 

 average temperatures were below 68° F (20.0°C). 931 fish were 

 caught: between 68° (20.0°C) and 70° F (21.1°C) the catch was 1.886 

 fish: and a further increase to 70° F (21.1°C) or above resulted in a 

 catch of 1.718 fish. 



Catch data and isotherm charts, 1%3 through 1970. indicate 

 that the continuity of the 68°F (20.0°C) and 70°F (21.1°C) isotherms 

 from off central Baja California to off southern California is 

 associated with improved fishing. When these isotherms were 

 discontinuous the average catch per biweekly period was 82.0 fish: 

 when these isotherms were continuous the average catch was 146.1 

 fish. The highest average catch per biweekly period (205.3 fish) was 

 recorded when the 70° F (21.1°C) isotherm was continuous. 



(675.) Proceedings of the International Billfish Symposium, 

 Kailua-Kona, Hawaii, 9-12 August 1972. Part 2. Review 

 and Contributed Papers— Results of Sailfish Tagging in 

 the Western North Atlantic Ocean. By Frank J. Mather 

 III, Durbin C. Tabb, John M. Mason, Jr., and H. 

 Lawrence Clark. July 1974, p. 194-210. 



ABSTRACT 



Migrations of sailfish, Istiophorus platypterus (Shaw and 

 Nodder), in the western North Atlantic Ocean are discussed on the 

 basis of results of three cooperative tagging programs. The 

 Rosenstiel School of Marine and .'\tmospheric Sciences (formerly 

 Institute of Marine Science, and Marine Laboratory) of the 

 University of Miami marked and released 1,259 sailfish between 

 1950 and 19.58 and nine tags were returned. Members of the Port 

 Aran.sas (Texas) Rod and Reel Club marked and released 515 sailfish 

 between 1954 and 1962 and obtained three returns. The Cooperative 

 Game Fish Tagging Program of the Woods Hole Oceanographic 

 Institution has marKed and released 12,525 sailfish between 19.54 

 and May 1972, with 97 tags being returned. 



The majority of the returns showed limited movements; most 

 were between localities along the southeast coast of Florida and the 

 Florida Keys. The longer migrations did not follow a distinct 

 pattern, but many of them showed a tendency toward movements 

 between tropical waters (northeast coast of South America, the 

 Lesser Antilles, and the Straits of Florida) in the cold season and 

 temperate waters (the Gulf of Mexico and the United States coast 

 between Jacksonville, Florida and Cape Hatteras. North Carolina) 

 in the warm season. 



Times at liberty, w hich ranged from less than 1 day to over 4 yr, 

 with only nine exceeding 18 mo, are generally consistent with 

 earlier findings that the sailfish is a short lived species. Tag returns 

 give no indication of heavy commercial fishing pressure on the 

 stocks under study. 



(675.) Proceediiigs of the International Billfish Symposium, 

 Kailua-Kona, Hawaii, 9-12 August 1972. Part 2. Review 

 and Contributed Papers— Migrations of White Marlin and 

 Blue Marlin in the Western North Atlantic Ocean- 

 Tagging Results Since May, 1970. By Frank J. Mather III, 

 John M. Mason, Jr., and H. Lawrence Clark. July 1974, 

 p. 211-225. 



ABSTRACT 



Migrations of white marlin, Tetrapturus albidus Poey. and blue 

 marlin. Makaira nigricans Lacepede. in the western North -Atlantic 

 Ocean are discussed in terms of tag returns obtained since the 

 completion of data collection for the paper by Mather. Jones, and 

 Beardsley (1972) in May 1070. 



In the period May 1970 May 1972. 2,039 white marlin and 216 

 blue marlin have been released, and 70 tags from white marlin and 1 

 from a blue marlin have been returned. 



The migratory pattern which had been established for the stock 

 of white marlin summering off the middle Atlantic coast of the 

 United States has been further .supported by 54 of 60 new returns 

 from fish released in this area. The six others deviated from this 

 pattern geographically or chronologically, or in both respects. The 

 ten remaining returns were from releases south of lat. 33°N. Five of 

 these fitted with previously observed patterns or individual 



