OLLA ET AL.: SEASONAL DISPERSAL OF CUNNER AND TAUTOC, 



tautog and cunner observed within each transect 

 with the sum of the six transects being the total 

 count. 



Cunner and tautog ( 314.0 cm) trapped at Sites 

 A, B, C, D, and E were tagged throughout the 

 study with Floy-67C^anchor tags. Tags were con- 

 secutively numbered allowing identification of in- 

 dividual fish and their release site. Each tag was 

 printed with a request for fishermen catching 

 tagged fish to return the tag, accompanied by in- 

 formation as to the location and date the fish was 

 caught. Fish were recaptured either in our traps or 

 by recreational fishermen. 



Ultrasonic tracking was employed for short- 

 term monitoring of movement and cover associa- 

 tion of young tautog residing at both a perennial 

 (Site A) and seasonal (Sites B and F) habitats. 

 Four fish (two at Site A, one at Site B, and one at 

 Site F) were individually tracked using the same 

 procedures previously described by 011a et al. 

 (1974, 1975) for capturing, handling, and track- 

 ing. 



A series of transfer experiments was conducted 

 to examine habitat selection in young tautog. All 

 fish were captured at Site A and released at either 

 existing, seasonal habitats (Sites B and C) or at 

 experimental habitats which we established (see 

 below). Fish were transferredby boat in 100-1 bar- 

 rels of aerated seawater with the time to travel 

 from capture to release sites ranging from 5 to 15 

 min. Four fish (three at Site B and one at Site C) 

 were separately released at the seasonal habitats 

 and tracked ultrasonically. Five transfers were 

 made to the experimental habitats. One transfer 

 was a single fish, released and monitored ultrason- 

 ically. The other transfers consisted of four group 

 releases with 10 fish/group. The response of the 

 fish in these releases was monitored directly using 

 scuba. While lying motionless, 5 m from the re- 

 lease site, the observer recorded at 1-min intervals 

 the number offish present. Cover abthe experi- 

 mental habitats consisted of masonry structures 

 constructed from standard cement blocks (20 x 20 

 X 40 cm) positioned in a manner which laterally 

 exposed the central cavities (7 « 13 > 20 cm) ol 

 each block. Cement blocks had been shown to be 

 readily acceptable as cover by young tautog in the 

 laboratory (OUa and Bejda unpubl. obs.). The 

 structure for the single fish release was a four- 



block cube (40 X 40 x 40 cm). Two structures were 

 used in the group releases. They were identical 

 12-block rectangular prisms ( 120 x 40 « 40 cm). 



RESULTS 



Catch and Direct Sightings at 

 Seasonal and Perennial Habitats 



It was apparent from catch data and direct un 

 derwater sightings that a majority of the habitat 

 sites were utilized only seasonally by both cunner 

 and young tautog. Throughout the summer, sub- 

 stantial numbers of fish were captured at Sites 

 A-E (Table 1) or sighted directly at Site F (Table 

 2). In September, there was a gradual decline in 

 the catch of cunner and in October a sharp decline 

 in both cunner and tautog at Sites B-E (Table 1). 

 At Site F, direct visual counts indicated the same 

 general trend (Table 2). However at Site A, while 

 there was little change in catch during September, 

 the catch of both species increased in October (Ta- 

 ble 1). In November, Sites B-F were observed di- 

 rectly with scuba and no fish were sighted. At Site 



Table 1. — Mean monthly catch of cunner and young tautog at 

 perennial (A) and seasonal (B-E) sites. 



'Unit eftorl = one trap fished 1 wk, 

 -ND ^ no data 



Table 2.— Visual counts using scuba or mask and snorkel ot 

 cunner and young tautog at seasonal Site F. 



^Reference to trade names does not imply endorsement nt 

 commercial products by the National Marine Fisheries Service, 

 NOAA. 



25; 



