FISHERY BULLETIN: VOL. 80, NO. 2 



growth increments or lamellae in their otoliths, 

 thus providing a detailed chronological record of 

 events in the growth history of an individual fish 

 (Pannella 1971, 1974; Scott 1973; Brothers et al. 

 1976; Struhsaker and Uchiyama 1976; Ralston 

 1976; Taubert and Coble 1977; Barkman 1978; 

 Methot and Kramer 1979; Radtke 1980 5 ; Radtke 

 and Waiwood 1980; Steffensen 1980; Wilson and 

 Larkin 1980; Uchiyama and Struhsaker 1981; 

 Barkman et al. 1981; Brothers 1981; Brothers 

 and McFarland 1981; Methot 1981). Evidence 

 for the presence of apparent daily otolith growth 

 increments in larval herring collected along 

 western Gulf of Maine in October 1976 was given 

 in a preliminary report by Rosenberg and 

 Lough. 6 Further work by Lough et al. 7 led to the 

 development of a growth model extending 

 through the autumn-winter period. Townsend 

 and Graham (1981) recently used otolith aging 

 techniques to examine the age structure of larval 

 herring entering the Sheepscot River, Maine, 

 estuary during autumn-winter 1978-79. 



The objective of this study is to summarize our 

 findings on the age and growth of larval herring 

 otoliths during the first 6 mo of life, from hatch- 

 ing to a length of ca. 31 mm, based on larvae 

 reared in the laboratory and collected in the Gulf 

 of Maine-Georges Bank region. Also, aGompertz 

 growth curve is fitted to the length-at-age data 

 based on "daily" growth increment in their oto- 

 liths to describe the shape of the average larval 

 herring growth curve in this region from Octo- 

 ber through March 1976-77. The present study 

 was initiated by the International Commission 

 for the Northwest Atlantic Fisheries (ICNAF) 

 (Lough et al. 1981) and the U.S. participation 

 was conducted concurrently as part of the MAR- 

 MAP (Marine Resources Monitoring, Assess- 

 ment, and Prediction) program of the Northeast 

 Fisheries Center, which measures long-term 

 changes in the variability of fish stock abun- 

 dance off the northeast coast of the United States 

 (Sherman 1980). 



METHODS 



Larval herring for otolith studies were col- 

 lected at selected stations within a standard grid 



of sampling stations covering the western Gulf of 

 Maine, Georges Bank, and Nantucket Shoals 

 areas on five ICNAF larval herring surveys con- 

 ducted from October 1976 through March 1977 

 (Table 1, Fig. 1). Larvae normally were collected 

 at stations where high densities were encoun- 

 tered. Standard ICNAF double-oblique contin- 

 uous hauls (61 cm bongo net, 0.505 and 0.333 mm 

 mesh nets) were made at each station to a maxi- 

 mum depth of 100 m, or to within 5 m of the bot- 

 tom in shoaler areas, while the vessel was under- 

 way at 3.5 kn. A standard haul ranges in duration 

 from 5 to 25 min; each bongo net filtering be- 

 tween 100 and 1,000 m 3 of water depending on 

 the duration (maximum depth) of the haul. Fur- 

 ther details of the sampling gear and protocols 

 can be found in Lough and Bolz (footnote 2). 

 Immediately after the nets were brought aboard 

 the vessel, larvae were sorted from the untreated 

 0.505 mm mesh plankton sample and frozen in 

 dishes. Extra hauls occasionally were made to 

 collect sufficient numbers of larvae. Tempera- 



5 Radtke, R. L. 1980. The formation and growth of otoliths 

 from redfish (Sebastes spp.) larvae from the Flemish Cap (Di- 

 vision 3M). NAFO SCR Doc. 80/1 X/ 153, 6 p. 



6 Rosenberg, A. S., and R. G. Lough. 1977. A preliminary 

 report on the age and growth of larval herring (Clupea haren- 

 giis) from daily growth increments in otoliths. ICES CM. 

 1977/L:22. 15 p. 



Figure 1.— Station locations in the Gulf of Maine-Georges 

 Bank region where larval herring were collected for otolith 

 aging over the 1976 spawning season. 



7 Lough, R. G., M. R. Pennington, G. R. Bolz, and A. S. Rosen- 

 berg. 1980. A growth model for larval sea herring (Clupea 

 harenyus L.) in the Georges Bank-Gulf of Maine area based on 

 otolith growth increments. ICES CM. 1980/H:65, 22 p. 



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