There is a need today for accurate understanding of the relationships between economic activities and the environmental realm. In particular, it is urgent from an economic viewpoint to put quantitative meanings upon external, environmental contributions to the economy. Energy analysis and energy externality evaluation procedures are useful in this respect.

This paper examined the relationship between economic development and threats to national parks. Many Authors have suggested that the type and intensity of threats to parks may be influenced by the socio-economic characteristics of the region where the park is located. This idea was tested, using a stratified sample (N=135) of the world's national parks, with data derived from a survey of park managers.

Sand-dune fixation is an important step in the struggle against desertification, which latter is gaining strength in Somalia. The objective is not only to fight erosion and to stabilize the dunes, but also to raise some revenue for residents through reafforestation and agricultural schemes.

The distribution and abundance of gulls were examined on Raritan and Delaware Bays from 20 April to 26 October 1982. Gull numbers were affected by seasonal, tidal, weather-related, and human disturbance, factors on both Bays. Gulls comprised from about 40 to 60% of the avifauna on the census areas, and shorebirds accounted for most of the other individuals. Peak numbers of gulls were present on Delaware Bay from May through July, and on Raritan Bay in September. Laughing Gulls (Larus atricilla) were the dominant species on both Raritan (90%) and Delaware (70%) Bays, with Herring Gulls (L. argentatus) second in abundance.