Warlen el a\: Recruitment of larval Bievooitia tyi annus to North Carolina and New Jersey estuanes 



619 



6 

 E 



£ 25- 

 c 



0) 

 "O 



ra 20 

 ■o 



c 

 nj 



03 



1990-1991 



NC n=449 

 NJ n=171 



10 20 30 40 50 60 70 80 90 100 110 120 

 3St 



1992-1993 



30- 



-/ 1 



NC n=568 

 NJ n= 86 



10 20 30 40 SO 60 70 80 90 100 110 120 



Estimated age (days) 



Figure 8 



Summary plots of standard length (mm) on estimated age 

 (daysl for larval Atlantic menhaden [Brevoortia tyran- 

 nusi collected at Pivers Island. North Carolina, and Little 

 Sheepshead Creek, New Jersey, in 1989-90, 1990-9, and 

 1992-93. 



o 



789 10 1112 123456 

 IVIonth 



STATION 



o 44025 - Long Island 

 A 44029 - Delaware Bay 

 O CHLV2 - Chesapeake Bay 



Figure 9 



Maximum monthly sea surface temperatures 

 recorded at three NOAA stations in the Middle 

 Atlantic Bight that encompassed the time peri- 

 ods of our three sampling years. Minimum tem- 

 perature that Brevoortia tyrannus eggs had been 

 caught during MARMAP surveys (l.S'C; Steg- 

 mann et al., 1999) are indicated by a horizontal 

 dashed line. In months with maximum tempera- 

 tures below 13°C no spawning of B. tyrannus 

 north of Cape Hatteras was expected. NOAA 

 Data Buoy 4402.5 located -45 km south of Long 

 Island, New York at 40°15'1"N, 73°10'0"W. NOAA 

 Data Buoy 44029 is located -45 km southeast of 

 Delaware Bay at 38''27'49"N, 74°42'7"W. NOAA 

 C-MAN station CHLV2 is located --20km east of 

 Chesapeake Bay at 36°54'18"N, 75°42'48"W. 



Warm core ring streamers and surface intrusions of 

 warmer water could assist in transporting larvae from 

 the Gulf Stream to the MAB continental slope (Hare and 

 Cowen, 1991, 1996). Larvae must then cross the shelf- 

 slope front and once larvae are in shelf waters they may 

 be transported south and westward along the coast and to- 

 ward shore by the predominant winds from the northeast 

 which induce an Eckman drift westward toward shore. 



Biological mechanisms such as vertical migrations and 

 directional swimming behavior, can modulate transport 

 by placing larvae in water masses favorable to cross slope 

 or cross shelf transport (Hare and Cowan, 1996). Cowen et 

 al. (1993) and Hare and Cowen (1993) have described this 

 general scenario for several species that may be trans- 

 ported to the MAB from the SAB. 



Regardless of the type of transport mechanisms, it is 

 clear that larvae of a number of other species are trans- 

 ported from the SAB to the MAB. The larvae ofAnguilla 

 rostrata, which originate in the Sargasso Sea (Schmidt, 



