Tag Archives: coastal eutrophication

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Short Links: Gorillas, drunky shrews, and jellyfish

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Three nature stories from the New York Times:

In the Congo Republic a survey has discovered a large population (125 000) of Western lowland gorillas.

Trove of Endangered Gorillas Found in Africa

The survey was conducted by the Wildlife Conservation Society and local researchers in largely unstudied terrain, including a swampy region nicknamed the “green abyss” by the first biologists to cross it. Dr. Steven E. Sanderson, the president of the society, marveled at the scope of what the survey revealed. “The message from our community is so often one of despair,” he said. “While we don’t want to relax our concern, it’s just great to discover that these animals are doing well.”

It’s Always Happy Hour for Several Species in Malaysian Rain Forest

German scientists have discovered that seven species of small mammals in the rain forests of western Malaysia drink fermented palm nectar on a regular basis. For several of the species, including the pen-tailed tree shrew, the nectar, which can have an alcohol content approaching that of beer, is the major food source — meaning they are chronic drinkers.

Oceanic food webs shifting to dominance by jellyfish, due to overfishing of top predators, and likely coastal eutrophication and climate change.

Stinging Tentacles Offer Hint of Oceans’ Decline

From Spain to New York, to Australia, Japan and Hawaii, jellyfish are becoming more numerous and more widespread, and they are showing up in places where they have rarely been seen before, scientists say. The faceless marauders are stinging children blithely bathing on summer vacations, forcing beaches to close and clogging fishing nets.

But while jellyfish invasions are a nuisance to tourists and a hardship to fishermen, for scientists they are a source of more profound alarm, a signal of the declining health of the world’s oceans.

“These jellyfish near shore are a message the sea is sending us saying, ‘Look how badly you are treating me,’ ” said Dr. Josep-María Gili, a leading jellyfish expert, who has studied them at the Institute of Marine Sciences of the Spanish National Research Council in Barcelona for more than 20 years.

Ecosystem services, Greenlash, Regime Shifts

Biofuel production vs. Aquatic ecosystems

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Simon Donner writes about his new paper Corn-based ethanol production compromises goal of reducing nitrogen export by the Mississippi River (Proc. Natl. Acad. Sci. USA, 10.1073/pnas.0708300105) on his weblog maribo:

A new paper by my colleague Chris Kucharik and I looks at the new US Energy Policy, will calls for growing more corn to produce ethanol, will affect the “Dead Zone” in the Gulf of Mexico. For a quick summary, see Reuters, the CBC or AFP.

The Mississippi dumps a massive amount of nitrogen, largely in the form of the soluble ion nitrate, into the Gulf each spring. It promotes the growth of a lot of algae, which eventually sinks to the bottom and decomposes. This consumes much of the oxygen in the bottom waters, making life tough for bottom-dwelling fish and creatures like shrimp. The Dead Zone has reached over 20,000 km2 in recent years.

The primary source of all that nitrogen is fertilizer applied to corn grown in the Midwest and Central US. Reducing the Dead Zone to less than 5000 km2 in size, as is suggested in US policy, will require up to a 55% decrease in nitrogen levels in the Mississippi.

The new US Energy Policy calls for 36 billion gallons of renewable fuels by the year 2022. Of that, 15 billion can be produced from corn starch. Our study found meeting those would cause a 10-34% increase in nitrogen loading to the Gulf of Mexico.

Meeting the hypoxia reduction goal was already a difficult challenge. If the US pursues this biofuels strategy, it will be impossible to shrink the Dead Zone without radically changing the US food production system. The one option would be to dramatically reduce the non-ethanol uses of corn. Since the majority of corn grain is used as animal feed, a trade-off between using corn to fuel animals and using corn to fuel cars could emerge.