Interactions between marine megafauna and plastic pollution in Southeast Asia

Southeast (SE) Asia is a highly biodiverse region, yet it is also estimated to cumulatively contribute a third of the total global marine plastic pollution. This threat is known to have adverse impacts on marine megafauna, however, understanding of its impacts has recently been highlighted as a priority for research in the region. To address this knowledge gap, a structured literature review was conducted for species of cartilaginous fishes, marine mammals, marine reptiles, and seabirds present in SE Asia, collating cases on a global scale to allow for comparison, coupled with a regional expert elicitation to gather additional published and grey literature cases which would have been omitted during the structured literature review. Of the 380 marine megafauna species present in SE Asia, but also studied elsewhere, we found that 9.1 % and 4.5 % of all publications documenting plastic entanglement (n = 55) and ingestion (n = 291) were conducted in SE Asian countries. At the species level, published cases of entanglement from SE Asian countries were available for 10 % or less of species within each taxonomic group. Additionally, published ingestion cases were available primarily for marine mammals and were lacking entirely for seabirds in the region. The regional expert elicitation led to entanglement and ingestion cases from SE Asian countries being documented in 10 and 15 additional species respectively, highlighting the utility of a broader approach to data synthesis. While the scale of the plastic pollution in SE Asia is of particular concern for marine ecosystems, knowledge of its interactions and impacts on marine megafauna lags behind other areas of the world, even after the inclusion of a regional expert elicitation. Additional funding to help collate baseline data are critically needed to inform policy and solutions towards limiting the interactions of marine megafauna and plastic pollution in SE Asia.

Anthropogenic litter in terrestrial flora and fauna: Is the situation as bad as in the ocean? A field study in Southern Germany on five meadows and 150 ruminants in comparison with marine debris

In contrast to the abundance of research on marine debris, terrestrial anthropogenic litter and its impacts are largely lacking scientific attention. Therefore, the main objective of the present study is to find out whether ingested litter produces pathological consequences to the health of domestic ruminants, as it does in their relatives in the ocean, the cetaceans. For this purpose, five meadows (49°18'N, 10°24'E) with a total survey area of 139,050 m² as well as the gastric content of 100 slaughtered cattle and 50 slaughtered sheep have been examined for persistent man-made debris in Northern Bavaria, Germany. All the five meadows contained garbage, and plastics were always part of it. Including glass and metal, 521 persistent anthropogenic objects were detected altogether, equalling a litter density of 3747 items per km². Of the examined animals, 30.0% of the cattle and 6.0% of the sheep harboured anthropogenic foreign bodies in their gastric tract. As in the case of cetaceans, plastics were the most dominant litter material. Bezoars had formed around plastic fibres of agricultural origin in two young bulls, whereas pointed metal objects were associated in cattle with traumatic lesions in the reticulum and the tongue. Of all the ingested anthropogenic debris, 24 items (26.4%) had direct equivalents in the studied meadows. Comparing with marine litter, 28 items (30.8%) were also present in marine environments and 27 items (29.7%) were previously reported as foreign bodies in marine animals. At least in this study region, waste pollution affected terrestrial environments and domestic animals, with clear equivalents in the marine world. Ingested foreign bodies produced lesions that may have reduced the animals' welfare and, regarding commercial purposes, their productivity.

Spatial, Temporal, and Geographical Factors Associated with Stranded Marine Endangered Species in Thailand during 2006–2015

The stranding of endangered marine animals is cause for concern. We used spatial and temporal analyses to investigate the stranding of endangered marine species (whales, dolphins, dugongs, and sea turtles) in Thailand, based on stranding data and geographical records during 2006–2015. A total of 1988 stranding events were obtained, including 105 whales (5.28%), 714 dolphins (35.92%), 103 dugongs (5.18%), and 1065 sea turtles (53.57%), at an average of 198.80 stranded animals/year (standard deviation = 47.19). Most strandings occurred along the Gulf of Thailand (56.94%), while the rest occurred along the Andaman Sea (43.06%). Cluster and kernel analyses showed that strandings were the most common in Phuket Province. The average number of stranded animals in the rainy season was significantly higher than that in summer and winter (p < 0.05). Our results indicate that the coastline of Thailand was significantly associated with the number of seasonal strandings (p < 0.05). However, there was no significant association between environmental factors and the number of strandings. In conclusion, surveillance systems based on spatial and temporal analyses should be established to monitor stranded animals. This will help relevant authorities to rescue stranded animals more effectively and to study the causes of stranding.