Thursday, July 29, 2010

Most Abundant Food Source Disappearing

In oceans around the world, there has been a surprisingly large and extensive decline in phytoplankton -- the tiny algae that keep marine food webs afloat.

The drifting green flecks have been dying off for at least a century, with a staggering 40 percent decline since 1950, according to a new study.

Phytoplankton make up half of all plant matter around the globe, said marine ecologist Daniel Boyce, whose study appears this week in the journal

Nature. Its disappearance threatens the stability of climate, the well-being of fisheries and the overall health of the oceans.

"It's hard to really imagine phytoplankton could be so important because most people don't see them in their daily lives. They're microscopic and they live out at sea," said Boyce, of Dalhousie University in Halifax, Canada. "But everything that happens to them affects the entire marine food chain, including us."

Some recent satellite images have shown the ocean turning from green to blue as a result of phytoplankton declines, but those data stretch back only 13 years. Other studies have offered mixed results.

To get a more accurate picture and to look further into the past, Boyce and colleagues collected a half-million measurements of ocean clarity from a public data set that dated back to 1899.

Over the last century-plus, analyses showed, phytoplankton levels have dropped by one percent each year in eight out of 10 large ocean regions. The greatest decline occurred in areas around the poles, near the equator and in the open oceans. The rate of disappearance picked up after 1950, totaling a 40 percent drop-off since then.

"It's really big," said David Siegel, a marine scientist at the University of California, Santa Barbara. "I'm a little leery about how big that number is."

The scientists can't yet say what's causing the mass die-off of phytoplankton, but temperature data offer a clue. The declines were worst in places where the surface of the sea has warmed the most. Warmer ocean water limits the amount of nutrients that can get from the depths to the surface. Phytoplankton need those nutrients to live.

With less phytoplankton around, fish have less to eat. As the decline works its way up the food chain, fishermen will have less to catch and fish-eaters less to eat. Phytoplankton even affect climate by taking up carbon dioxide and absorbing heat.

"Everyone looks at blue oceans and goes: 'Isn't that beautiful?'" Siegel said. "But a blue ocean is full of nothing. You really want something, and we're only making more of the blue ocean."

Source: Discovery News
http://news.discovery.com/earth/phytoplankton-oceans-food-web.htmlOcean's

Thursday, July 08, 2010

Adirondack Forum Will Take Aim at Invasive Species

Registration is now open for a free Adirondack Forum on Invasive Species.  The Forum, a one-and-a-half day event, will be held August 10-11 at Paul Smith's College.  You will learn how you and your community can be prepared for harmful invasive species invading Adirondack lands and waters.

Partners of the Adirondack Partnership for Regional Invasive Species Management have organized the Forum to give citizens, community groups, members of governmental and nongovernmental organizations, resource managers, and elected officials from across the region an opportunity to discuss invasive species. The Forum will highlight initiatives underway in the region; showcase local successes and challenges as told by community members; feature up-to-date information about new invasive species; and identify important next steps that groups must collectively take to have a real and lasting impact on this challenging environmental and economic issue. 

The Forum's theme centers on the need to consider all types of invasive species – plants and animals in both aquatic and terrestrial settings – and on ways in which communities can be prepared to address them. Invasive species are a top threat to lands and waters, to favorite outdoor pastimes and cherished traditions, and to forestry, fisheries, and agriculture upon which local economies rely. Some species, like purple loosestrife, have been in New York for hundreds of years, but others, like emerald ash borer, arrived only recently. The explosion in the expansion of species and the rate of new arrivals is alarming and cause for concern.

Each year a greater number of communities are faced with tough decisions about invasive species. In response, groups in the Adirondack region banded together over a decade ago to take aim at this pressing problem. They work together to halt the invasion by focusing on prevention and management. A great deal has been accomplished, but much more has yet to be done.

The Forum is free, and participants may register for all or part of the event. Information about registration, lodging and meals and a draft program are available online at http://adkinvasives.com/Forum.html. The deadline to register is July 28. For more information, contact Hilary Smith at the Adirondack Park Invasive Plant Program,

518-576-2082 or hsmith@tnc.org.