Funding for this research was provided by:
Fundação para a Ciência e a Tecnologia’ (DL57/2016/CP1440/CT0002)
Received: 19 November 2019
Accepted: 10 June 2020
First Online: 30 June 2020
Compliance with ethical standards
: The authors declare that they have no conflict of interest. This article does not contain any studies with human subjects. Data collection throughout our surveys were performed with permission by the Yemeni Minister of Water and Environment and in collaboration with the Environment Protection Agency of Socotra.