Table 7. — Xumber of Irout-perch taken in 10-minute trawl lows al various depths, February IS to November 4, 19S4 



* No trout-peich were caught deeper than 30 fathoms. 



- No data. 



Dryer (19(56) reported that trout-perch in the 

 Apostle Islands region of Lake Superior were 

 widel_y distributed down to 49 fathoms, were most 

 abundant at 10 to 19 and 30 to 39 fathoms, and 

 exhibited no seasonal changes in distribution. 



YELLOW PERCH 



Yellow perch in their first 2 years of life in 

 southeastern Lake Michigan are in water shallower 

 than 3 fathoms, as indicated by their presence in 

 shore seines and scarcity in trawls fished as shal- 

 low as 3 fathoms. No young-of-the-year ( O group) 

 yellow perch and only 23 yearlings (I group) , dis- 

 tinguished by size, were caught in the 11 standard 

 series. Extensive trawling oft' Grand Haven, Midi. 

 (23 nautical miles north of Saugatuck), in 1954 

 and 1960 produced only one large catch of young- 

 of-the-year perch (4 fathoms, November 20, 1954) 

 and two of yearlings (5 and 7 fathoms, June 20, 

 1960). The yearlings were caught during a mild 

 upwelling. The depth distribution of small yellow 

 perch in southeastern Lake Michigan contrasts 

 strikingly with that in Lake Erie, where research 

 vessels of the Bureau of Commercial Fisheries 

 regularly have found large numbers of young of 

 the year (as small as 1.2 inches or 3.0 cm.) in 

 depths to 6 fathoms and yearlings commonly to 

 17 fathoms. Young-of-the-year perch in Saginaw- 

 Bay (Lake Huron) strongly preferred water shal- 

 lower than 2 fathoms in summer, but many moved 

 several fathoms deeper in October (R/V O/.sco 

 trawling and shore-seining records, 1956). Year- 



lings were distributed at least as deep as 7 fathoms 

 in summer. 



Adult yellow perch (defined here as those older 

 than 2 years) in southeastern Lake Michigan in- 

 habit shallow and intermediate depths. Most are 

 on the bottom, but appreciable numbers may be at 

 midlevels in summer. Greatest numbers in Feb- 

 ruary to early May were at 10 to 12 fathoms, and 

 the extreme depth range was 5 to 25 fathoms (table 

 8) . A movement into shallower water was in prog- 

 ress by May 26. Yellow perch congregate in middle 

 and late May for spawning at depths less than 8 

 fathoms on rocky bottom about 2 miles south of 

 the trawling area. Most adult yellow perch were 

 at 7 fathoms or less during summer. Substantial 

 numbers probably were often shallower than 3 

 fathoms; the maximum depth was 10 to 12 fath- 

 oms. Perch have been abundant as deep as 12 to 17 

 fathoms during occasional periods in Augu.st of 

 other years when warm water reached unusual 

 depths. Adult yellow perch moved into deeper 

 water in fall. None were taken at depths shallower 

 than 10 fathoms in the October 14 and November 

 4 standard series. The largest catch on November 

 4 was at 20 fathoms, but no fish were caught 

 deeper. The fall movement of yellow perch into 

 greater depths in Lake Michigan can be more pro- 

 nounced than the catches of the standard series in- 

 dicate. An extremely heavy catch was made otf 

 Charlevoix, Mich., on October 17, 1955 in a gill net 

 at 25 fathoms (bottom temperature 15.1° C), 

 where none had been taken in several sets in spring 

 and summer. 



FISH DISTRIBUTION IN SOUTHEASTERN LAKE MICHIGAN 



