Stranding of Marine Animals: Effects of Environmental Variables

Abstract

Stranded is the term used to refer to a marine animal found on land that does not have the ability to return to the sea (Branco et al. 2015). Stranded marine animals are often observed on beaches around the world, and the reasons for this are varied, ranging from anthropic and fishery interaction to disease, marine pollution, and even due to the occurrence of storms (Barbieri 2009a, b). There are studies that attempt to investigate which are the factors more determinants for the marine animals that end up dead on the beaches. The stranding monitoring is a useful tool to know and learn more about the species and their relationship with the environment. Meteorological and oceanographic phenomena can generate intense winds and wave heights above normal, intensify marine currents, and cause the heating or cooling of sea surface temperatures (Tavares et al. 2016; Melo 2017). These events may affect the survival of a species due to exhaustion, which influences the displacement of individuals and their search for food, as well as the arrival of these animals on the beaches by drifting carcasses (Barbieri et al. 2007). The study of these stranded animals may provide the necessary knowledge to direct conservation efforts and provide data for assessing the mortality rate of taxonomic groups, causes of death, seasonality of events, and associations with oceanographic, meteorological, and anthropogenic variables.

Global assessment of shark strandings

“…Stranded animals may be found dead (either on land or floating) or alive but unable to return to sea due to injury or illness. Broader definitions are also available and do not consider taxonomic groups, but simply the presence of an aquatic animal on land, whether dead or alive (but physiologically/physically unable to return to the sea) (Branco et al, 2015; Brusius et al, 2020; Geraci & Lounsbury, 2005).…”