Fecundity of the snapping shrimp Alpheus estuariensis (Caridea: Alpheidae) after the oil spill in three mangroves of tropical Brazil

Abstract

This study examined the impacts of oil spills since 2019 by analyzing polycyclic aromatic hydrocarbons (PAHs) in sediments and their effects on the fecundity of the shrimp Alpheus estuariensis. Samples were collected from mangroves in three Pernambuco locations: Catuama, Suape Bay, and Carneiros Beach. Ovigerous females were identified, and their eggs were counted and classified by embryonic stage. Sediment PAH levels were analyzed in freeze-dried and homogenized samples. A total of 107 females were analyzed, with varying distributions across sites. In the dry season, Carneiros showed the highest average fecundity (309 eggs), followed by Suape (238) and Catuama (154), without statistical differences. During the rainy season, Carneiros had significantly higher fecundity (605 eggs) compared to Catuama (176) and Suape (173). PAH concentrations were highest at Catuama (79 ng g⁻¹), followed by Suape (72 ng g⁻¹), and Carneiros (19 ng g⁻¹). Fecundity was inversely related to PAH levels, with Carneiros showing the highest fecundity and lowest PAHs. Four years post-spill, high- molecular- weight PAHs (4–6 rings) were prevalent, posing carcinogenic and mutagenic risks. Diagnostic ratios indicated that PAHs primarily originated from pyrolytic processes, particularly combustion, highlighting biomass burning as a significant source. These findings emphasize the necessity for ongoing monitoring of impacted areas using model species to understand long-term environmental impacts on Brazil's northeastern coast.