How can oil spills affect the ability of sea birds to access resources such as food and shelter? How will other animals that depend on birds for food be affected?

An area affected by an oil spill can become unhabitable for the sea birds' source of food because of toxic poisons and in turn, make it uninhabitable to the sea birds. The animals that depend on the birds for food will have fewer available options for prey and their population may lower. If the area affected by the oil spill has low biodiversity it will have a great effect on the food web.

climate change and pollution

the last one: artificial selection/genetic engineering

plant breeding is modifying the genetic composition of the plant - but this isn't cloning (which is specifically introducing a gene into a genome). but you are artificially selecting for the phenotype that you want.

the second one is literally genetic engineering - the gene would have been cloned first and then inserted or genetically engineered into the new plant cell (the cotton).