compounds down to their low-molecular-weight components 

 and their flushing from the photic layer of the ocean (Tanabe, 

 mSSJzraelera/., 1990). Ontheotherhand.highertemperatures 

 imply reduced absorption of organic pollutants on suspended 

 matter (Pierce et al., 1974), which would have the effect of 

 diminishing the amounts of pollutants deposited in sea-bottom 

 sediments. 



The increased fluxes of U V-B radiation being predicted in 

 connection with the depletion of stratospheric ozone layer 

 would intensify photochemical processes, especially at that 

 ocean-atmosphere interface (Zika, 1989). This would enhance 

 the photodegradation of both chlorinated and petrolic 

 hydrocarbons, possibly reducing this type of pollution of 

 marine environments (Doskey & Andren, 1987). It should be 

 noted, however, that apart from this positive effect of promoting 

 the removal of organic pollutants from seawater, prolonged 

 UV-B irradiation may also prove very detrimental to any 

 number of marine organisms inhabiting the surface layer of the 

 ocean (US EPA, 1987). 



It may be expected that rises in the concentration of 

 atmospheric CO, would produce a certain acidulation of surface 

 waters ( Wilson & Mitchell, 1987). Even though this would not 

 affect the behavior of hydrophobic organic pollutants, the 

 consequences might prove very tangible from the standpoint of 

 ionogenic compounds. Thus, lower pH values would tend to 

 increase the permeability of cell membranes with respect to 

 such compounds, and hence to the accumulation of the latter in 

 marine organisms (Landner, 1989). In addition, higher acidity 

 may reduce the stability of heavy metals hound by compounds 

 ofhumic origin (Mantoura& Riley, 1975; Paxeus, 1985). This 

 process could in turn exacerbate the toxic effects of heavy 

 metals on marine biota (Sunda & Lewis, 1 978; Sedlacek et ai, 

 1983). 



Effects on Environmental Processes 



The predicted changes in the physicochemical parameters 

 of the marine environment as a result of global warming would 

 no doubt have considerable impact on the intensity and balance 

 of the fundamental environmental processes occurring in marine 

 ecosystems, as well as on the condition of biological resources 

 both in coastal waters and in open sea and open ocean areas. 



Changes in the Conditions of Habitation of Marine Organisms 

 As a rule, marine organisms possess considerable 

 environmental (genetic, behavioral, etc.) flexibility, which 

 enables them to adapt to continuously varying environmental 

 conditions. This adaptability of marine organisms accounts for 

 the relative stability of zoogeographic zonation with respect to 

 climatic fluctuations (Odum, 1986). It is to be expected that 

 global warming would be accompanied by directed ecological 

 succession that would enable communities to adapt to a warmer 

 climate; some high-latitude communities may acquire the 

 characteristics of boreal communities, while temperate zone 

 communities might become more like their subtropical 

 counterparts. 



The processes described above could have serious 

 consequences for the formation and distribution of all marine 



biological communities, including those of commercially 

 important fish species. The effect of warming would be 

 especially pronounced in subpolar-front regions ( Roots, 1 989), 

 where increases of even a few tenths of a degree in deep water 

 temperature can lead to a noticeable redistribution of both 

 pelagic and benthic communities. On the other hand, comparable 

 temperature rises in the tropical latitudes would have no 

 significant effect on the functioning of marine organisms. 



It should be noted that temperature is not the only parameter 

 that would be decisive for the state of marine life communities 

 in the higher latitudes under global warming conditions. Another 

 set of factors of considerable importance would be associated 

 with possible changes in oceanic and atmospheric circulation 

 (Bakun, 1990), which is an important influence on the 

 distribution and density of marine populations. 



Changes occurring in the open ocean and in coastal areas 

 might be associated with changes in species diversity. This 

 effect would probably be less in evidence in the open ocean 

 than in estuaries and tidal zones. Polar marine ecosystems in 

 open areas would move more readily into new geographic 

 zones, while coastal ecosystems would be more rigidly restricted 

 by the physical characteristics of the relevant shoreline. 



This leads to the general conclusion that what one may 

 expect in conditions of global warming that can entail 

 considerable changes in the living condition of marine biota is 

 a redistribution of marine life communities with the inevitable 

 consequences for the fishing industry worldwide. 



Changes in Production-Degradation Processes and Biogenic 

 Sedimentation 



In contrast to tropical and temperate regions where 

 productivity is determined largely by biogenic-element levels 

 alone, the chief limiting factors in circumpolar and polar areas 

 are light and temperature. In this connection, the predicted 

 warming of surface waters would lengthen the phytoplankton 

 vegetation season, and therefore increase the productivity of 

 such areas. 



On the other hand, temperature rises would be accompanied 

 by accelerated microbial decomposition of organic matter. 

 The most pronounced intensification of decomposition 

 processes (by a factor from 1.1 to 1.3) might be expected to 

 occur in the higher latitudes and more particularly in the shelf 

 waters and surficial water masses of the boreal zone (Odum, 

 1986;Izrael&Tsyban, 1989). 



The rates of degradation processes in surface waters in the 

 lower latitudes is determined by the influx of organic matter 

 from the Arctic and Antarctic as intermediate and deep waters 

 arrive by meridional transfer. This is why the effect of 

 temperature on the rates of degradation processes in the 

 equatorial and tropical regions is negligible. The changes in 

 production-degradation parameters would have aconsiderable 

 effect on the course biosedimentation proces.ses. 



According to one model ( Suess. 1 980), the magnitude and 

 velocity of the biosedimentary flux is increasing in direct 

 proportion to rising productivity. Given this circumstance, 

 climate warming could increa.se biosedimentary fluxes in coastal 

 upwelling areas where a significant rise in productivity is 

 expected to occur (Bakun, 1990). The same could happen in 



