Paper 17 



PREVIOUS FISH KILLS 



In the same area as the fish kill and anoxia aevelopment of 1976^ 

 three previous fish kills have been reported: September through 

 early October 1968 (Ogren and Ch^ss 1969)/ October 1971 (Young 

 1973)/ and August 1974.' Aoparently none of these earlier fish 

 kills was as extensive or enduring as the 1976 kill. Low oxygen 

 conditions in the bottom i^aters accompanied all of the fish 

 kills. C I i mat o log i ca I records of sea surface temperature from 

 shore station reports and discharge rates for the Hudson River 

 for the last iO years (19A7-76) were examined for conditions 

 similar to those of 1976. During this 3u-yr period/ high 

 discharge (arbitrarily defined as >150% of the monthly mean) 

 occurred five times in January (1949/ 1950/ 1952/ 1973/ and 

 1974)/ and three times in February (1951/ 1954/ and 1976). Shore 

 station temperature records for Sandy Hook and Atlantic City 

 indicated early warming of the water (monthly mean for February 

 warmer than for January) occurring 12 times at Sandy Hook and 9 

 times at Atlantic City. No observations were made in 1970 and 

 1971 at Atlantic City/ which were two of the years of early 

 warming at Sandy Hook. Coincidence of early warming and high 

 discharge occurred in 1949/ 1952/ 1954/ 1974/ and 1976. 

 Therefore/ these five years had the potential to develop low 

 oxygen conditions as a result of early stratification. For the 

 30-yr record/ the highest warming rates and record highest 

 discharge in February all occurred in 1976. Included in the 

 years of potential early stratification is 1974/ one of the times 

 of a reported fish kill/ but not incLuaed are the other two 

 instances. 



A sign 

 o c c u r r 

 fall, 

 result 



which 

 temper 

 be caus 

 (the 

 than t 

 the h 

 means 

 temper 

 t y pi c ^ 

 only 

 S ept em 

 1968/ 



if i can 



ed du r 

 The i 

 f rom 

 wou Id 

 3tu res 

 e rive 

 h i ghe s 

 he mon 

 ig hest 



for 

 atu re 

 lly th 

 seven 

 be r t e 

 and 



t po 

 ing 

 mp I i 



e i 

 leng 



we 

 r di 

 t d 

 th Ly 



di 

 De ce 

 r e c 

 e wa 

 t i m 

 mpe r 

 1971 



int 

 summ 

 cat i 

 t he r 

 then 

 re e 

 sch a 

 i s ch 

 me a 

 scha 

 mbe r 

 ords 

 rme s 

 es 

 at ur 



here 

 er / 

 on i 

 an 

 the 

 xami 

 rge 

 arqe 

 ns f 

 rge 

 / J 

 fr 

 t mo 

 f rom 

 es w 

 Of 



is t 



but 1 



s t ha 



ear 



peri 

 ned t 

 in su 



of 

 or De 



for 

 anua r 

 om A 

 nt h a 

 194 

 ere i 

 these 



hat th 

 n 1968 

 t very 

 ly sp 

 od of 

 o det e 

 Timer a 



the 3 

 cember 



Septe 

 y/ an 

 t lanti 

 nd Sep 

 7 to 

 n 194 

 year 



e fi 

 and 

 lo 

 ring 

 st r a 

 rmi n 

 nd 



0-y r 

 / J a 

 mbe r 

 d F 

 c C 

 t emb 

 1976 

 8/ 

 s t 



sh k i 

 1971 

 w ox 

 or a 

 t i f i c 

 e the 

 fall 



r eco 

 nuar y 



i s 

 ebrua 

 ity 

 er wa 

 . Th 

 1957/ 

 he hi 



Us o 



they 

 ygen 



late 

 at i on 



late 



1 s 

 rd f o 

 / and 

 about 

 ry) . 

 s how 

 s war 

 e ins 

 195 

 ohes t 



f 19 

 oc c 

 con 

 fal 



. 

 a r r 



typi 



r Au 



Fe 



the 



S 



t ha 



mer 



t an c 



9/ 

 rat 



74 an 

 ur r ed 

 di t i o 

 1/ ei 

 nly 

 i va I 

 ca I ly 

 gust 

 bruar 

 same 

 ea 



t Aug 

 than 

 es of 

 1965/ 

 e of 



d 1976 



during 



ns may 



t her of 



surface 



of fall 



s!tia 1 1 



is less 



y / and 



as the 



surface 



us t was 



August 



higher 



1966/ 



wa rm ino 



"C. J. Sindermann/ Northeast Fisheries Center/ NMFS/ 

 NJ 07732. Pers. commun./ November 1976. 



Highlands/ 



294 



