FOGARTY ET AL.: MOVEMENT OF AMERICAN LOBSTER OFF RHODE ISLAND 



RESULTS 



Inshore Locations 



To date, 450 lobsters tagged and released at 

 coastal sites have been recovered with sufficient 

 information to assess movement patterns (Table 

 1). Due to intensive fishing effort for lobster along 

 the Rhode Island coast, a disproportionate number 

 of tags were returned within 30 d of release (Fig- 

 ure 2); the mean time at large was 48.6, 34.7, and 

 48.6 d for lobsters released in Narragansett Bay, 

 Rhode Island Sound, and the Sakonnet River. Most 

 lobsters tagged at inshore locations were recap- 



tured within 6 km of the release site (Figure 3), 

 possibly reflecting the short time at large. The 

 distance between release and recovery sites aver- 

 aged 6.9, 10.4, and 5.5 km at the Narragansett Bay, 

 Rhode Island Sound, and Sakonnet River loca- 

 tions. Distance travelled tended to increase with 

 time up to 90 d at large at each inshore location 

 although high variability made clear trends diffi- 

 cult to discern (Figure 4). 



An initial examination of straight-line tracks 

 between release and recapture sites revealed a 

 general southerly trend in movements for lobsters 

 released at inshore tagging sites ( Figure 5). These 

 plots also demonstrated that some inshore lobsters 



Table l. — Release and recapture data for American lobsters tagged in 1974 and 1975 off Rhode Island. Locales are 

 given in Figure 1. Number recaptured refers to the number of returns with adequate information to evaluate 

 movements. Cox Ledge-Midshelf indicates lobsters captured on the midcontinental shelf iMidshelf) and released on 

 Cox Ledge. 



70-1 



rn SAKONNET RIVER N=147 

 H NARRAGANSETT BAY N = 188 

  RHODE ISLAND SOUND N = 115 



11-20 21-30 



3i-40 ' 41-50 " 51-60  61-70 71 

 DAYS AT LARGE 



91-100 



>100 



FIGURE 2. — Number of tag returns for 

 American lobster released at inshore lo- 

 cations off Rhode Island as a function of 

 time at large. 



100- 



80- 



z 

 cc 



CD 



s 



z- 



rn SAKONNET RIVER N=147 

 ^ NARRAGANSETT BAY N=188 

  rHODE ISLAND SOUND N = 115 



-8 ' 61-10 

 DISTANCE TRAVELLED (km) 



Figure 3. — Number of tag returns for 

 American lobster released at inshore lo- 

 cations off Rhode Island as a function of 

 distance travelled. 



773 



