TEMPORAL VARIATION OF NUTRIENTS IN TRANSITIONAL SEASONAL PERIODS (DRY - RAINY) IN THE JAGUARIBE ESTUARY- CEARÁ, BRAZIL

Abstract

This study in the Jaguaribe Estuary aimed toobserve the changes in hydrochemical properties in twoimportant transitional periods i) rainy to dry period in 2007,and ii) dry to rainy, in 2008. This estuary is under shrimpfarms and domestic effluent inputs that contribute withnutrients to the system changing dynamics depending on theseasonal period. Samples of salinity, dissolved oxygen andnutrients (silicate and phosphate) were taken and thetemperature data was recorded in two fixed stations foranalysis. The data showed differences in the two temporalperiods sampled according to fresh water input and marineinfluence, also reflecting on nutrient data. In 2007 theranges went from 2.3-23.3 for salinity, 92.41-232.62  μM forsilicate, and 1.29-2.65  μM for phosphate. In 2008 rangeswent from 18.1-38.2 for salinity, 1.33-74.19  μM for silicate,and 0.19-3.93  μM for phosphate. This study is included in theINCT-TMCOcean Project (CNPq Proc. 573601/2008-9).Index Terms ⎯ Estuary, nutrients, shrimp farms, domesticeffluent.