Oxygen Depletion and Associated Benthic Mortalities 

 in New York Bight, 1976 



Chapter 1. Historical and Regional Perspective 



Carl J. Sindermann' ami R. Lawrence Swanson~ 



CONTENTS 



Page 

 I 



3 

 4 

 9 

 9 



12 



14 

 14 



The 1976 Oxygen Depletion Event 

 Physical Description of the Bight 

 Fish and Shellfish Stocks 

 Organic and Nltrient Loadings 

 Previous Mortalities and Oxygen 



Depletion Events in New York 



Bight 

 Oxygen Depletion in Other Coastal 



Areas of the World 

 Scope of Report 

 References 



' Sandy Hook Laboratory, Northeast Fisheries Cen- 

 ter, National Marine Fisheries Service, NOAA, High- 

 lands, NJ 07732 



' Office of Marine Pollution Assessment, NOAA, 

 Rockville, MD 20852 



THE 1976 OXYGEN DEPLETION EVENT 



In the summer and autumn of 1976. mass mortalities 

 of shellfish and other marine species occurred in the New 

 York Bight, apparently because of extreme oxygen de- 

 pletion and hydrogen sulfide formation in bottom waters. 

 First reports of a developing problem reached the scientific 

 community during the July 4th weekend. Sport divers, 

 lobstermen, and trawler fishermen observed and reported 

 dead and dying animals of all kinds on fishing reefs and 

 wrecks and on fishing grounds off the northern New Jersey 

 coast. Within a few weeks, mortalities were reported 

 southward some 90 km and seaward some 60 km. Planned 

 surveys and monitoring in the Bight by the National 

 Oceanic and Atmospheric Administration (NOAA) were 

 increased in areal coverage and intensity to determine the 

 extent of the problem and to assess the damage. At its 

 maximum extent, oxygen-deficient bottom water — < 2.0 

 ml/I and sometimes with zero values of dissolved oxygen 

 (D.O.) — was found from Sandy Hook to Cape May. a 

 distance of 150 km along the New Jersey coast in a zone 

 or corridor 10 to 100 km off the coast (fig. 1-1). This 

 environmental event of major proportions involved an 

 8,600-km- area of the continental shelf off the coast of 

 New Jersey. 



A mass mortality can be described as an unusual and 

 rapid increase in mortality rate, of sufficient proportions 

 to affect significantly the size of a population and to dis- 

 turb, at least temporarily, the ecosystem of which the 

 population is a part. Mass mortalities may be local, con- 

 fined to a particular cove or estuary, or they may be wide- 

 spread, sometimes affecting hundreds of kilometers of 

 coastline. Causes of mass mortalities may be physical, 

 chemical, or biological — or combinations that produce 

 stress beyond the tolerance limit of individuals in the pop- 

 ulation. Physical causes can include storms, seaquakes, 

 temperature changes and extremes, upwelling. vulcanism, 

 and people-induced changes such as dredging; chemical 

 causes include contaminant chemicals, hydrogen sulfide 

 generation, oxygen depletion, and salinity changes and 



