o -4 A--A d *Lb—4k-&4f 



1978 • • 



1979 A A 



SEPTEMBER 



Figure 2.— Abundance of slage I lobster larvae in neuston collections off Hampton. N.H., 1978-79. 



MAT JUNE JU 



Figure 3. —Abundance of stage IV lobster larvae in neuston collections off Hampton. N.H., 1978-79. 



occurred during late August 1978 and late July 1979 and were 

 coincident with large quantities of macroalgae. During 1978, 

 stage IV larvae were collected somewhat more frequently 

 when winds were onshore (Table 1). A total of 169 (1978) and 

 120 (1979) larvae were collected. 



Lobster larvae were also collected during discrete depth 

 plankton sampling conducted in 1978 by Normandeau Assoc, 

 Inc.' 1 A third-stage larva was collected in a mid-depth tow on 7 

 July 1978 indicating that hatching considerably pre-dated the 

 first occurrence of larvae in neuston tows. 



'Normandeau Associaies, Inc., 1981. Plankton studies in the vicinity of Hamp- 

 ton Beach, New Hampshire. Tech. Rep. Xl-3. 147 p. Prepared for Public Service 

 Co. of New Hampshire. 



Table 1. — Frequency of wind directional vectors ('true) and the percent of stage IV 

 lobster larvae, Hampton. N.H., 21 July-18 October 1978. 







Dates stage IV 



Dales stage IV 



Wind 





larvae present 



larvae absent from 



direction 



All dates 



in collections 



collections 



Alongshore 1 



35.2 



33.3 



50.0 



Offshore 1 



40.6 



20.0 



33.3 



Onshore' 



24.2 



46.7 



16.7 





ii = 91 



n = 15 



n = 6 



'Directional vectors 0°-30°, 150 -210°, 330°-360° 

 'Directional vectors 30°-I50°. 



' Directional \ ectors 2 1 L) -330 r . 



Stage Composition 



Stage IV larvae were dominant during 1978. Previous neus- 

 ton sampling conducted off Hampton-Seabrook during 1973 

 also indicated a disproportionate number of stage IV larvae 

 (Normandeau Assoc, Inc. footnote 3). Stage I larvae, how- 

 ever, were dominant during 1979; stage II and III composed 

 <9% of the larvae collected. 



Stage composition in the Hampton-Seabrook area during 

 1973 and 1978 was dissimilar to that of most other areas of 

 New England for which data were available (Fig. 4). Five 

 clusters were distinguished at varying similarities. Clusters 

 A and B were dominated by stage I larvae, but differed in 

 the contribution of stage II and III larvae (Fig. 4). Stage dis- 

 tribution was somewhat more evenly distributed in Cluster C. 

 Clusters D and E (Hampton-Seabrook, 1973 and 1978) were 

 characterized by stage IV dominance but differed in the contri- 

 butions of stage II and III larvae. 



Size of Lobster Larvae 



Mean length of lobster larvae increased almost two-fold 

 from stage I to stage IV (Table 2). At all stages, larvae from 

 New Hampshire appeared to be larger than those reported 

 from areas of Canada and southern New England, with the ex- 



54 





