Banca de QUALIFICAÇÃO: LARA CUNHA LOPES

Uma banca de QUALIFICAÇÃO de MESTRADO foi cadastrada pelo programa.
STUDENT : LARA CUNHA LOPES
DATE: 30/06/2021
TIME: 09:30
LOCAL: Virtual (google meets)
TITLE:

Distribution of cetacean strandings in relation to seismic surveys and environmental factors in the northeast of Brazil



KEY WORDS:

Seismic research.; Drift simulation; Drift leeway; Carcass; Whale; Dolphin


PAGES: 86
BIG AREA: Ciências Biológicas
AREA: Ecologia
SUMMARY:

Cetaceans are highly dependent on sound for vital activities and have been negatively affected by anthropogenic noise, which causes behavioral change to physical damage. Mass strandings have been linked to active sonars, which seem to mainly affect deep diving species. Another noise source of concern are seismic surveys (SS), an activity that uses compressed airguns to generate high-intensity impulsive sound waves. However, the effect of seismic surveys on the mortality and stranding of cetaceans is still controversial. Thus, we aimed to examine the relationship between pelagic cetacean strandings and 3D seismic surveys in the Equatorial Northeastern Brazil, accounting for the confounding effects of some oceanographic variables. We gathered the strandings registered between 2000 and 2019 in the states of Ceará (CE) and Rio Grande do Norte (RN) and separated the species into 5 ecological groups. Then, we characterized the spatiotemporal occurrence of the records and selected two areas where the search effort was more consistent. For these two areas, we analyzed whether SS and wind and wave conditions affected the probability of stranding of each ecological group. We also simulated the drift of fictitious cetaceans considering a constant mortality rate inside seismic operations ́limits and compared the spatial distribution of these simulated landings to the observed strandings for the same period. In the 20 years considered, 351 strandings were recorded, including 22 species and 5 families. The temporal pattern of the strandings showed a relationship with tourist seasonality (increased in summertime) and with an increase in monitoring effort beginning in 2010, when governmental agencies increased the demand for beach monitoring programs as a condition to environmental licensing. Seismic survey operations also increased in area coverage and duration compared to operations during the first decade of compiled data. Of the 65 strandings that occurred up to one week after an SS operation, 5 records had pathological alterations compatible with gas embolism syndrome associated with exposure to seismic exploration activity. Furthermore, 29% of the observed strandings positions overlap with landings from simulations of drift from seismic operational areas. Drift simulations also showed that beach monitoring programs, required by the environmental regulation of impact, may not cover the areas with highest landing probabilities for animals that died within the seismic operation area. Our simulations showed that animals that could have died in SS of the CE and RN may beach in the North region of Brazil. We recommend that previous drift simulations are carried as a requirement of the licensing process to determine which portion(s) of the coast should be monitored in beach monitoring projects. The results obtained here do not determine the cause of death and strandings of animals in the RN and CE states, they reveal that some strandings can be originated from deaths within the seismic operational area, pointing to an influence of seismic surveys on cetacean strandings in the region. PALAVRAS CHAVE (5-10)



BANKING MEMBERS:
Presidente - 1863735 - RENATA SANTORO DE SOUSA LIMA
Interno - 2319234 - GUILHERME ORTIGARA LONGO
Externo à Instituição - JONATAS HENRIQUE FERNANDES DO PRADO - ICMBio
Notícia cadastrada em: 29/06/2021 10:26
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