NOAA PROFESSIONAL PAPER 11 



was approximately 600 to 800 km- (Ogren and Chess 

 1969). Mortalities were reported on and near wrecks and 

 reefs from early September until late October 1968. Spe- 

 cies affected were ocean pout, cunner, lobsters, rock 

 crabs, mussels, surf clams, and starfish. More active spe- 

 cies such as tautog. black seabass, squirrel hake, conger 

 eels, and round scad apparently were able to escape and 

 were rarely reported among the mortalities. Fauna on 

 wrecks offshore of Barnegat and Atlantic City was normal. 



Relevant observations made in the mortality area in 

 1968 were: 1) mortalities were restricted to waters less 

 than 30 m deep; 2) bottom water temperatures, principally 

 at wreck sites, were 14° to 16° C; 3) bottom-water dis- 

 solved oxygen values were less than I.U ml/1; 4) a pro- 

 nounced thermocline existed; and 5) a series of phyto- 

 plankton blooms, beginning in July and extending to 

 September, occurred along the New Jersey coast. Reex- 

 amination of the same area in May and July 1969 disclosed 

 that oxygen values near the bottom were more than 7.0 

 ml/1 and that wrecks had been repopulated by fish and 

 crustaceans. 



No reports are available for 1970, but in early October 

 1971 lobsters and rock crabs were reported dead on several 

 wrecks 12 km east of Point Pleasant, N.J., at depths of 

 about 30 m, and also at Shark River Inlet (Young 1973). 

 Bottom water temperatures at the wreck sites were high 

 (18° C) and suspended flocculent material was noted low 

 in the water column. 



Again, no reports are available for 1972 and 1973, but 

 in August 1974 mortalities of ocean pout were observed 

 on several wrecks off Point Pleasant (J. S. Young, per- 

 sonal communication). Bottom-water dissolved oxygen 

 values were 1.0 ml/1, with heavy suspended floccuJent 

 material and bottom water temperatures of 14° to 15° C. 

 In early September 1974 the Subsea Journal of the Manta 

 Ray Diving Club of New Jersey reported dead lobsters 

 and rock crabs on a wreck off Long Beach Island. N.J. 



Thomas et al. (1976) reported that significant summer 

 depletion of bottom dissolved oxygen in the restricted area 

 of the sludge and dredge material disposal sites, and also 

 in an area close to the New Jersey shore off Asbury Park, 

 occurred during summer 1974. Low dissolved oxygen con- 

 centrations have been reported previously in New York 

 Bight dumpsites (Pearce 1972). Dissolved oxygen concen- 

 trations in dumpsites were higher in summer 1975 than in 

 1974 and above the level considered harmful to most ma- 

 rine life. 



OXYGEN DEPLETION IN OTHER 

 COASTAL AREAS OF THE WORLD 



There are other coastal areas in the world where ex- 

 treme oxygen depletion in bottom waters is a frequent. 



sometimes annual, event (fig. 1-8). Deuser (1975) sum- 

 marizes the general problem. To our knowledge, however, 

 the New York Bight incident is the first of such magnitude 

 that has occurred along an open coastal area where clas- 

 sical upwelling is not a major factor. 



Marine fishkills related to oxygen depletion and hydro- 

 gen sulfide buildup have been reported in warm shallow 

 estuaries (May 1973) and in areas of upwelling and mass 

 production of plankton, for example, off South America 

 and Africa (Brongersma-Sanders 1957; Theede et al. 

 1969). 



A coastal upwelling region famous for its low oxygen, 

 hydrogen sulfide production, and periodic mortalities is 

 off the southwest coast of Africa in and near Walvis Bay. 

 Scientific records of mortalities, summarized by Bron- 

 gersma-Sanders (1947, 1957), extend back to 1837. Dead 

 and dying fish, cephalopods, and bivalves have been ob- 

 served with great frequency in December and January in 

 the sea and on the beaches between 21° and 25° south 

 latitude. The sea bottom of the region is highly organic, 

 with high hydrogen sulfide content and anoxic bottom 

 waters. Mass mortalities of fish are more severe in some 

 years than in others and are often preceded by red to 

 brown discoloration of the sea from algal blooms. The 

 anoxic area involved is approximately 17,200 km", but 

 interestingly there is a narrow coastal strip about 6 km 

 wide, extending to a depth of 37 m, where sea life is 

 normal and hydrogen sulfide does not occur. 



Similar mass mortalities of marine animals in a zone of 

 upwelling have been reported by Falke ( 1950) from Con- 

 cepcion Bay, Chile. 



Mass mortalities, particularly of benthic fauna, have 

 occurred in the deeper basins of the Baltic, where anaer- 

 obic conditions may persist for as long as four years (Se- 

 gerstrale 1969). Total absence of oxygen beginning in 1957 

 caused the deeper parts of the Gotland, Gdansk, and 

 Bornholm basins to become lifeless deserts in 1958-59. 

 The total area affected was estimated at 41,200 km-. The 

 stagnation was broken in 1962 by a strong inflow of saline 

 water from the Kattegat. Significantly, great amounts of 

 nutrients accumulated during the stagnation period. These 

 were brought to the surface in 1962, resulting in an enor- 

 mous increase in plankton populations. A similar event 

 occurred in the early 1930s (Kalle 1943; Meyer and Kalle 

 1950). This periodic stagnation, broken by saline inflows 

 and followed by uplift of nutrients, favors periodic in- 

 crease in biological production — unlike other areas of con- 

 tinuous anaerobiasis such as the deep (below 100 m) zones 

 of the Black Sea, which constitute a nutrient sink and are 

 unproductive of sea life. 



Oxygen depletion of bottom waters, with accompanying 

 formation of hydrogen sulfide, occurred in Tokyo Bay in 

 1972 (Tsuji et al. 1973; Seki et al. 1974), presumably re- 

 lated to an extensive red tide. Since red tides are becoming 



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