Refuse

Karachi is the largest metropolitan city of Pakistan with a population of 207,774,520 (Statistics, 2017). Ironically, a megacity of a developing state has its drawbacks and discrepancies in solid waste mechanism being one of them. Karachi has always been the center of businesses and government offices since independence, first as capital of Pakistan and later as a provincial capital. This study evaluates the importance of solid waste management for an urban city such as Karachi, and the steps which have been taken by the successive governments to fulfill the demands of this growing megapolis since independence. In this study, models of solid waste management adopted by different cities will be analyzed and a suitable model for Karachi will be proposed. Needless to say, Karachi has the potential to become an eco-friendly city by adopting the public private partnership. In short, the civil society's role is of paramount importance.

This study evaluates the trophic position of adult Yellow-legged Gulls Larus michahellis atlantis resident in the Azores archipelago in the past (1921–1928) and in the present (2009–2010), and analyses the decadal variation in the diet of breeding birds from the 1990s to the 2000s for three main colonies (Topo Islet, Baixo Islet and Mistério da Prainha). Using mixing models, we compared stable isotope signatures of nitrogen and carbon in adult breast feathers between birds from 1921 to 1928 (held in museum collections) and 2009 to 2010, jointly with both isotopic signatures of their main prey groups (fish, goose barnacles (Lepas anatifera), seabirds, mammals and refuse). The diet of breeding birds was analysed using pellets collected in 1989, 1995, 1996, 2004, 2009 and 2010. Stable isotopes analysis (SIA) results were in accordance with the results provided from the analysis of pellets, showing a relatively recent and significant change in the diet of adult gulls. In particular, SIA revealed a significant decrease in the trophic position of Yellow-legged Gulls in the Azores, over the last 89 years in response to the decrease in the consumption of seabirds and fish and, an increase in the consumption of marine invertebrates (goose barnacles) and refuse. The analysis of pellets confirmed the significant decrease in the fish ingested, whereas the ingestion of lower trophic level prey (i.e. goose barnacles, mammals and refuse) increased. Both methods reflect the feeding plasticity and opportunistic foraging behavior of this species, and are in accordance with patterns described for continental Europe.