Creaser and Perkins: Distribution, food, and abundance of Pomatomus saltatnx 



499 



Table 1 (Continued) 



Size (mm)' 



Location 



N. Lat. 



E. Long. 



Date of 

 capture 



Oceanic (0 lor 

 estuanne 1E1 



No. 

 captured 



TL 



Method of 

 FL capture- 



Matinicus Rock 24-30 July 1991 



Seal Island (Knox Co.) 



27 Seal Is. 43"53' 68"45' July 1991 



Little Kennebec Bay (Washington Co.) 



28MarstonPt. 44'39' 67'26'15" 25 Aug 1983 



50-60 



50 



100-130 



RT 

 AT 

 HW 



1 TL = total length; FL = fork length. 



; OT = Otter trawl; FN = Fyke net ; HL = Hook and line; - = Unknown; HS = Haul seine , AP = Atlantic puffin, GN = Gill net; AT = Artie tern, DN = Dip net; CT = Common tern , HW = Herring weir; 

 RT = Roseate tern. 



may result from the lack of scientific fish sampling 

 activity and lack of familiarity with the identifica- 

 tion of juvenile bluefish by the sportfishing public 

 and finfish processors. Clark (1973) attributed high 

 densities of juvenile bluefish in areas such as South 

 Carolina and the New York Bight to sampling activ- 

 ity and availability of records from those areas. 



Some published information exists on the distribution 

 of juvenile bluefish in southwestern Maine. They have 

 been reported from Casco Bay (Bigelow and Schroe- 

 der, 1953; Wilk, 1977), Boothbay Harbor (Lund, 1961) 

 and Montsweag Bay (Targett and McCleave, 1974). 



Length-frequency distributions 



Length-frequency distributions of juvenile bluefish 

 captured in the Marsh River (1990-91), Sagadahoc 

 Bay ( 1990 ), and Merepoint Bay ( 199 1 ) varied between 

 8 and 20 cm, 3 and 6 cm, and between 14 and 17 cm 

 respectively (Fig. 2, A-D). Length-frequency data 

 from the Marsh River was combined in 1-cm group- 

 ings and presented as one figure per year because 

 fish were collected for only two months. Although the 

 size range recorded during both 1990 and 1991 was 

 similar, larger juveniles were more prevalent dur- 

 ing 1991 (Fig. 2, A and B). The length-frequency com- 

 position of fish captured by beach seine from 

 Sagadahoc Bay on 10 and 22 August 1990 (Fig. 2C) 

 confirms the presence of small juveniles of 3-6 cm 

 FL in Maine waters. 



Previous reports of juvenile bluefish less than 70 

 mm from Wells Harbor, Winnegance Bay, the mouth 

 of the Abagadasset River, Boothbay Harbor, 

 Matinicus Rock and Seal Island have been presented 

 in Table 1. The overall length-frequency range (8-20 

 cm FL) reported for fish captured in the Marsh River 

 during 1 August-26 September 1990 and 17 July- 

 17 September 1991 was similar to the length-fre- 

 quency range reported from Great South Bay, New 

 York (8-22 cm FL) during 28 May-12 August 1985 



and 10 June-20 August 1986 (Nyman and Conover, 

 1988). Length-frequency distributions generated 

 from gillnet catches (Fig. 2, A, B, D) are biased be- 

 cause panels of individual mesh sizes in gill nets are 

 selective for specific sizes offish. 



Temperature and salinity data collected 

 during gillnet sets 



Juvenile bluefish were captured on both incoming 

 (I) and outgoing (O) tides between 1 August and 26 

 September 1990 and between 17 July and 17 Sep- 

 tember 1991. Specific water temperatures do not 

 appear to be associated with the arrival and depar- 

 ture of juvenile bluefish. Bluefish were first captured 

 at water temperatures of 24.6-27.0°C (1990) and 

 22.8-24.0°C (1991). None were captured when the 

 temperature dropped below 16.0°C ( 1990) and 19.3°C 

 ( 1991 ). Water temperatures varied between 16.0 and 

 27.0°C (1990) and between 19.3 and 27.4 C (1991) 

 when bluefish were present. 



Lund and Maltezos ( 1970) reported that juveniles 

 and adults appear at temperatures of 12-15°C and 

 depart at temperatures of 13-15°C. Oben (1957) re- 

 ported that juveniles appear at temperatures of 18- 

 24.5°C and depart at 13-15°C. Similarly, Nyman and 

 Conover ( 1988) reported that juveniles appear at 20- 

 24°C and depart at water temperatures in the 

 "middle-teens." We believe that juvenile bluefish ar- 

 rived at the mouth of the Sheepscot River when the 

 water temperature was relatively low and they were 

 attracted to the Marsh River, 34.3 km upstream, by 

 the warmer water. These fish appeared to remain in 

 the Marsh River until the water temperature dropped 

 to a temperature range that was lower than the wa- 

 ter temperature at the time of their arrival in the 

 sampling area. 



The salinity of the Marsh River varied between 

 9.5 and 23.3 ppt (1990) and between 9.6 and 26.5 

 ppt (1991) when juvenile bluefish were present. 



