Estudo da sensibilidade e tolerância ao aumento da concentração de nutrientes em larvas de corais

Abstract

Corals are organisms sensitive to climate change. Increase in temperature and nutrient concentration, local and global impact effects can cause several dysfunctions in these animals, compromising the entire reef ecosystem. The objective of this work was to study the effects of increased nutrients and temperature on coral larvae. A study was carried out bibliographic in order to observe responses to environmental stressors in other parts of the world; in Then, nitrate, nitrite, ammonium, phosphate and chlorophyll a from samples of water from puddles were analyzed. along the Coroa Vermelha reef and subsequent simulation of the minimum and maximum values ​​of the nutrients found in pools in Agaricia humilis coral larvae at different temperatures. Finally, the analysis of lipid peroxidation was performed in order to seek evidence of stress. oxidative in the larvae. It was observed that the nitrogen nutrients, 46 μmol L-1, for ammonia and 8.5 μmol L-1, for nitrate, and chlorophyll a showed high values ​​in the dry period (summer), due to probably due to the increase in the continental contribution at this time of year, due to the increase in tourism in the region. The larvae submitted to the treatments at the highest temperature (32º) presented the highest mortality rates, about 78% and the highest rates of oxidative stress occurred in surviving larvae that were submitted to low temperature treatments and higher nutrient concentrations. The results indicated in this work demonstrate the importance of coral monitoring to assess the effects of environmental stressors on reefs. He was evidence that the increase in temperature in the oceans can increase mortality rates in corals, while the increase in nutrients, even at milder temperatures (26ºC) can cause oxidative stress.