Body size, trophic position, and the coupling of different energy pathways across a saltmarsh landscape

Body size is considered an important structuring mechanism of food webs because consumers are usually larger and more mobile than their prey and may couple energy among habitats. We explored the links among trophic position (TP), body size, and the coupling of different energy channels (phytoplankton and C4-marsh plants) in a saltmarsh landscape in the northern Gulf of Mexico—a dynamic system considered weakly shaped by biotic interactions. Body size was positively associated with TP, and this relationship was stronger in the phytoplankton pathway vs. the C4-marsh pathway. There was a gradual increase in the coupling of phytoplankton and C4-marsh plants at larger body sizes and higher TP. Phytoplankton supported longer food chains and larger body sizes than C4-marsh plants. Results support predictions of the landscape theory for food web architecture and indicate that the role of body size in determining trophic interactions may vary across food web compartments

Troubled waters of the gulf of Mexico

The gusher has ended, but before it did, an estimated 206 million gallons of crude oil and methane gas escaped from the Macondo well in lease block Mississippi Canyon 252. We know it better as the BP Deepwater Horizon oil spill that resulted from a series of mechanical and safety failures leading to an explosion, the deaths of 11 workers, and the largest accidental oil spill in history. The well was in the northern Gulf of Mexico in 1500 m of water, not the deepest in this petroleum production fron-tier, but in an otherwise blue-water, pristine ocean home to deep-water corals and pods of sperm whales, and one of two spawning areas for Atlantic bluefin tuna. Satellite images of black oil at the surface marred this picture as the oil continued to spew from the ocean bottom and spread into the northern Gulf of Mexico. Innumerable lives were affected—from microbes to humans—and the world was transfixed by the continuous images of oil and gas blowing from the Gulf bottom while technology raced to catch up with Mother Nature