on the effects of HA" s on remote sensing of ocean chlorophyll 

 (Carder et al.. 1 986, 1 989) have shown that the lag time could 

 be one or two months. 



Second, the accumulation and distribution of HA's is 

 dependent to a great extent on the mixing and flushing rates for 

 the region. A reduction in the Hushing or mixing rates should 

 allow degradation products to accumulate relative to a well 

 flushed environment. Therefore a bay or stagnant gyre should 

 have more HA per unit of chlorophyll or newly produced 

 organic matter than would a recently upwelled phytoplankton 

 bloom. 



While considering the present results (Fig. 4) it should be 

 stressed that the highest HA concentration is found in the 

 region of the Bering Strait. According to Coachman ( 1 986) the 

 water passing through the strait has three major components. In 

 the west, the tlow is dominated by cold, saline water from the 

 Gulf of Anadyr. In the east, the flow consists of warmer coastal 

 water dominated by the Yukon River discharge. South of 

 St. Lawrence Island, a third water mass is formed of modified 

 shelf water. The Bering Shelf-Anadyr water in the west and the 

 Alaskan Coastal-Yukon River water in the east maintain their 

 identity during passage through the strait. 



The nutrient-laden western Bering Strait tlow is associated 

 with a large standing crop of phytoplankton (Sambrotto et al.. 

 1984). It could be one of the main factors contributing to the 

 local HA maximum. In addition, constant inflow of the 



degradation products from the highly productive waters could 

 promote the synthesis and accumulation of HA's in the strait 

 region as well. These sources include the Gulf of Anadyr, the 

 Bering Sea Shelf, and the coast of Alaska. The lag of HA's 

 behind the chlorophyll distribution and primary production 

 value could be responsible for the observed HA maximum in 

 the southern Chukchi Sea. 



The local HA maximum at Stations 26 and 27 in the Gulf 

 of Anadyr and at Station 1 02 on the Bering Sea Shelf appears 

 to be connected with the freshwater discharges of the Anadyr 

 River and the Yukon River. 



The results showing the high HA distribution in the 

 Chukchi and Bering Seas could be considered as the 

 confirmation of high productivity in the region. 



Taking into consideration the long half-lives of HA's, the 

 HA concentration may be used, in a limited sense, as a quasi- 

 conservative water mass property. Humic acid pools may be 

 interpreted as a measure of primary productivity of a region 

 over the previous one or two months. For this approach to be 

 useful, a better understanding of degradation rates from dead 

 algal cells and newly produced organic matter to HA's is 

 required. In addition, we need to understand the effects of 

 flushing, mixing, and photolysis on the degradation products. 

 Even without these more intense studies, a certain degree of 

 accuracy can be expected from empirical studies of primary 

 productivity and HA's. 



235 



