Sentences with phrase «fished marine food webs»

Not exact matches

The researchers looked specifically at the average fishing revenue in 106 Alaskan communities for 10 years before and after 1989, a year when the North Pacific Ocean experienced a significant shift in productivity and abrupt changes in the composition of marine food webs, while at the same time the global price for salmon dropped because of competition from farm - raised fish.

Plankton species, the foundation of the marine food web, have shifted back slightly toward fat - rich, cool - water species that improve the growth and survival of salmon and other fish.

The many marine animals that depend on them would lose their food source, predator fish populations would fall and the effects would likely ripple throughout the entire food web, hurting organisms that don't even rely on those fish directly.

Pauly has documented a persistent pattern of fishing down the marine food web: after prized top predators are hunted out, fishermen turn to increasingly smaller prey, depleting coastlines of marine life.

This «kelp highway hypothesis» suggested that highly productive kelp forests supported rich and diverse marine food webs in nearshore waters, including many types of fish, shellfish, birds, marine mammals, and seaweeds that were similar from Japan to California, Erlandson and his colleagues also argued that coastal kelp forests reduced wave energy and provided a linear dispersal corridor entirely at sea level, with few obstacles to maritime peoples.

«What is important about this study is that while yes, whales eat fish (including baleen whales), whales enhance the production of fish by providing through excretion the nutrients essential for phytoplankton growth at the base of the food web,» said Jim Ruzicka from the Hatfield Marine Science Center at the University of Oregon.

«It could stimulate growth of plankton at the base of the food web, which could impact birds, fish and marine mammals higher up the food chain,» said Dr Hawkings.

Since phytoplankton form the base of marine food webs, the world's most productive fisheries are located in areas of coastal upwelling that bring cold nutrient rich waters to the surface (especially in the eastern boundary regions of the subtropical gyres); about half the world's total fish catch comes from upwelling zones.