|Notes on the Peruvian coastal current. 1. An introduction to the ecology of Pisco Bay|
Sears, M. (1954). Notes on the Peruvian coastal current. 1. An introduction to the ecology of Pisco Bay. Deep Sea Res. (1977) 1(3): 141-169
In: Deep Sea Research (1977). Elsevier Science: Oxford; New York. ISSN 0146-6291, more
Coastal currents; Coastal upwelling; El Nino phenomena; Marine ecology; Phytoplankton; Marine
Biological calamities of the Peruvian Coastal Current have long been associated with undue warming of the surface water. These high water temperatures have most frequently been attributed to an incursion of fresher water from the north ("El Nino"). More recently they have also been ascribed to the intrusion of wedges of saltier, warm offshore water and even to the discharge from local streams. Re-examination of the warming processes in Pisco Bay indicates that solar radiation probably accounts for a large proportion of the high temperatures observed there. Such warming can occur whenever upwelling, the only effective source of cooling, ceases for any appreciable period. From available evidence, there appears to be an annual temperature range of about 7° C. Salinities of the current as a whole do not normally vary by as much as 2ppt whether the water be derived from upwelling, from offshore or from "El Nino." The ranges of these characteristics are much more limited than in some coastal waters and about the same as for others. The actual temperature limits are very nearly the same as for the cycle in the Mediterranean. Consequently, before the relationship between temperature and the recurrent biological disasters can be understood, it is suggested that two peculiarities of the area should be studied in detail: (1) the process of upwelling which provides nutrient salts for the growth of phytoplankton and (2) the effect, if any, of that fraction of the birds' excreta dropped in the water on the nutrient cycle and on the character of the phytoplankton (DBO).