O'CONNELL, C. P., ANn L. P. RAYMOND. 



1970. The effect of food density on survival and growth of 

 early post yolk-sac larvae of the northern anchovy iEn- 

 graulis mordax Girard) in the laboratory. J. Exp. Mar. 

 Biol. Ecol. 5:187-197. 



Edward D. Houde 

 Richard C. Schekter 



Division of Biology and Living Resources 



Rosenstiel School of Marine and Atmospheric Science 



University of Miami 



4600 Rickenbacker Causeway, Miami FL 33149 



DISCOVERY OF JUVENILE PACIFIC SALMON 



(COHO) IN A SMALL COASTAL STREAM 



OF NEW BRUNSWICK 



Three juvenile Pacific salmon (Figure 1) were dis- 

 covered in a small coastal stream in southern New 

 Brunswick (Figure 2) in October 1976 while young 

 Atlantic salmon, Salmo salar, were being col- 

 lected for laboratory experiments. The Pacific 

 salmon were not recognized by the electrofishing 

 team, and their presence among the Atlantic salm- 

 on was not realized until the fish were sorted in 

 the laboratory some days or weeks later. Iden- 

 tification as either coho salmon, Oncorhynchus 

 kisutch, or chinook salmon, O. tshawytscha, was 

 later confirmed by W. B. Scott of Huntsman 

 Marine Laboratory, St. Andrews, N.B. Positive 

 identification to species of these juvenile fish was 

 not possible, but they were almost certainly coho 

 salmon because of recent introductions of this 

 species to the Atlantic coast. 



Coho salmon are not native to the Atlantic, and 

 no populations reproducing in natural streams of 

 the Atlantic coast are known. Two aquaculture 

 operations using coho salmon are under way in 

 Maine, and coho salmon smolts have been released 

 in streams in New Hampshire and Massachusetts 

 since 1969 and 1971, respectively (Figure 2, inset). 

 Presumably, the parents were from one or more of 

 these four operations. No adults have been re- 

 ported from New Brunswick streams. 



When the coho calmon were recognized, further 

 trips were made to obtain an estimate of their 

 numbers in the stream, their size, and habitat 

 preference in comparison with Atlantic salmon 

 and brook trout, Salvelinus fontinalis , which were 

 also present. 



The stream, known locally as Frost Fish Creek, 

 drains into the estuary of the Digdeguash River 

 about 250 m from the Digdeguash Falls. It is a 

 small stream approximately 3 m wide in the lower 

 kilometer where all fishing took place. Its drain- 

 age area is approximately 570 ha. Discharge dur- 

 ing low summer fiow reaches as little as 80 1/s 

 (Symons and Harding 1974). The lowermost 0.25 

 km is steep with cascades and pools. The stream 

 here is either open to the sky or overhung with 

 alders. Most of the Atlantic salmon yearlings 

 occur in this portion of the stream. Through the 

 next 0.25 km upstream the gradient decreases; 

 occasional riffles are separated by pools and slow- 

 flowing water. Bankside cover consists of conifer- 

 ous softwoods partially clearcut. Atlantic salmon 

 yearlings and underyearlings occur in the riffles of 

 this section while the pools and quieter water are 

 inhabited by brook trout. Above this section the 



Figure l.— Underyearling coho salmon captured on 28 October 1976 in Frost Fish Creek, N.B. 



487 



