Spring Break
Humans may affect marine eco-systems, says scientist
Betsy Cohen
Issue date: 11/19/08 Section: News
"That is more biomass than the animals in Africa," Jackson said. Today, he said the numbers dwindle at a rate lower than 300,000.
He also discussed how trawling results in the destruction of coral reefs.
"You can see the lines like corn fields" through the traveled area, Jackson said. Off the coast of New Mexico, trawls are conducted twice every year.
"The area of forests deforested by humanity is approximately the same amount as that of the area of trawled ocean floor," he said.
Non-native introduced species like the green algae Caulerpa taxifolia are becoming a serious problem in marine environments. The organism carpets the bottom of the Mediterranean Sea and smothers communities of native species. Caulerpa taxifolia "will soon pave this huge area in the Northwest Mediterranean," Jackson said.
Oceanic acidification results in mass mortalities of coral species because of coral bleaching and negatively affects the skeletal growth of calcifying organisms. Jackson defined coral bleaching as "the breakdown of mutualism between coral and its symbionts caused by high temperatures."
"All over the world, sites like this are becoming very common," he said.
Human activities have also led to the poisoning of food webs. When tested, mercury and other contaminants are frequently found to be present in marine organisms. Higher levels are most commonly observed in apex-level species, including humans. Jackson also noted Inuit mothers' breast milk contains dangerously high concentrations of toxins because of their seafood diet.
In recent years, wild salmon populations have been decreasing at alarming rates because of toxins in the Pacific Northwest waters.
Farmed salmon have even higher concentrations of toxins because of terrestrial feed. Faming deepwater fish is "just dumb, but it tastes good," Jackson joked. "It's an ecological disaster, the amount of blue fin tuna you have to kill to feed the blue fin tuna."
He also discussed how trawling results in the destruction of coral reefs.
"You can see the lines like corn fields" through the traveled area, Jackson said. Off the coast of New Mexico, trawls are conducted twice every year.
"The area of forests deforested by humanity is approximately the same amount as that of the area of trawled ocean floor," he said.
Non-native introduced species like the green algae Caulerpa taxifolia are becoming a serious problem in marine environments. The organism carpets the bottom of the Mediterranean Sea and smothers communities of native species. Caulerpa taxifolia "will soon pave this huge area in the Northwest Mediterranean," Jackson said.
Oceanic acidification results in mass mortalities of coral species because of coral bleaching and negatively affects the skeletal growth of calcifying organisms. Jackson defined coral bleaching as "the breakdown of mutualism between coral and its symbionts caused by high temperatures."
"All over the world, sites like this are becoming very common," he said.
Human activities have also led to the poisoning of food webs. When tested, mercury and other contaminants are frequently found to be present in marine organisms. Higher levels are most commonly observed in apex-level species, including humans. Jackson also noted Inuit mothers' breast milk contains dangerously high concentrations of toxins because of their seafood diet.
In recent years, wild salmon populations have been decreasing at alarming rates because of toxins in the Pacific Northwest waters.
Farmed salmon have even higher concentrations of toxins because of terrestrial feed. Faming deepwater fish is "just dumb, but it tastes good," Jackson joked. "It's an ecological disaster, the amount of blue fin tuna you have to kill to feed the blue fin tuna."
