Underwater Exploration Seeks Evidence Of Early Americans; 'We Have Found The Haystack'

ERIE, Pennsylvania -- Where the first Americans came from, when they arrived and how they got here is as lively a debate as ever, only most of the research to date has focused on dry land excavations. But, last summer’s pivotal underwater exploration in the Gulf of Mexico led by Mercyhurst College archaeologist Dr. James Adovasio yielded evidence of inundated terrestrial sites that may well have supported human occupation more than 12,000 years ago, and paved the way for another expedition this July.

As part of their 2008 findings, the researchers located and mapped buried stream and river channels and identified in-filled sinkholes that could potentially help document the late Pleistocene landscape and contain artifacts and associated animal remains from early human occupations. Continued exploration, Adovasio said, will be geared toward assessing a human presence on the now submerged beaches and intersecting river channels.

“There’s no doubt that early North American occupations are underwater, but it’s like looking for a needle in a haystack,” he said. “We have found the haystack; now we’ve got to find the needles.”

That happens July 23-Aug. 7 when Adovasio leads a team of scientists representing leading institutions from government and higher education to St. Petersburg, Fla., where they’ll resume their search for evidence of early Americans in an area 100-to-200 miles off Florida’s west coast, now about 300 feet under water. For the second year, Adovasio will be assisted by co-principal investigator Dr. C. Andrew Hemmings of Mercyhurst College and the Gault School of Archaeological Research in Austin, Texas. This year as last, the primary funding source is the National Oceanic and Atmospheric Administration (NOAA).

The decision to take their expedition underwater in the first place, Adovasio said, stems from the premise that early Americans probably hugged the American coastline, congregating around freshwater rivers, before heading inland. At that time, much of the world’s water was confined to glaciers, causing ocean levels to be lower and exposing more of the continental shelf. As the earth warmed and water levels rose, evidence of past settlements became submerged.

Dredging and storms have turned up artifacts on the Gulf Coast as well as the Atlantic and Pacific coastlines, but Adovasio said this is the first time a group of scientists has staked out a submerged piece of real estate suspected of containing preserved Ice Age beaches and systematically gone in search of early human occupations.

From the University of South Florida’s research boat, the team will use remotely operated vehicles and remote sensing tools to explore the submerged sites. In shallower depths, divers will inspect sites to collect artifacts and animal fossils and recover sediments for geological analysis and possible radiocarbon testing.

“Proof of past human habitation here would reinforce the disintegration of the once prevalent hypothesis about who the first Americans were, how they got here and when they arrived,” said Adovasio, who rose to fame 30 years ago while excavating the Meadowcroft Rockshelter near Pittsburgh, Pa. Radiocarbon dating at Meadowcroft revealed the presence of human campsites as many as 16,000 years ago, which went a long way toward dashing the Clovis-first paradigm, holding that the first humans arrived in the Americas about 12,000 years ago, as revealed by a site near Clovis, New Mexico.

The inaugural expedition confirmed many of the scientists’ original hypotheses and earned second-year funding from NOAA in the amount of $120,000, Adovasio said. Besides NOAA, additional supporters, providing everything from in-kind services to personnel, include the Mercyhurst Archaeological Institute, the Gault School of Archaeological Research, the Florida Bureau of Archaeological Research, the Florida Geological Survey, the University of South Florida, the University of Michigan and the University of Illinois at Chicago Circle, among others, Adovasio noted.

Source: http://www.underwatertimes.com/news.php?article_id=10159703864

Millions Of Pounds Of Trash Found On Ocean Beaches

Trash on a beach. Trash in the ocean kills more than one million seabirds and 100,000 marine mammals and turtles each year through ingestion and entanglement. (Credit: NOAA)

ScienceDaily — Ocean Conservancy released its annual report on trash in the ocean with new data from the 2007 International Coastal Cleanup the most comprehensive snapshot of the harmful impacts of marine debris. The mission of Ocean Conservancy’s International Coastal Cleanup is to engage people to remove trash from the world’s beaches and waterways, to identify the sources of debris and to change the behaviors that cause pollution.

This year, more than 378,000 volunteers participated in cleanups around every major body of water around the globe. Volunteers record the trash found on land and underwater allowing Ocean Conservancy a global snapshot of the problem.

"Our ocean is sick," says Laura Capps, Senior Vice President at Ocean Conservancy. "And the plain truth is that our ocean ecosystem cannot protect us unless it is healthy and resilient. Harmful impacts like trash in the ocean, pollution, climate change, and habitat destruction are taking its toll. But the good news is that hundreds of thousands of people from around the world are starting a sea change by joining together to clean up the ocean. Trash doesn’t’ fall from the sky it falls from people’s hands. With the International Coastal Cleanup, everyone has an opportunity to make a difference, not just on one day but all year long."

Trash in the ocean kills more than one million seabirds and 100,000 marine mammals and turtles each year through ingestion and entanglement. This year, 81 birds, 63 fish, 49 invertebrates, 30 mammals 11 reptiles and one amphibian were found entangled in debris by volunteers. Some of the debris they were entangled or had ingested include plastic bags, fishing line, fishing nets, six-pack holders, string from a balloon or kite, glass bottles and cans.

Entanglement in Ocean Trash

• Wraps around flippers causing circulation loss and amputations
• Creates wounds and cuts leading to bacterial infections
• Slows animals ability to swim making them more vulnerable to predators
• Smothers or traps animals, causing them to drown
• Causes starvation as animals can no-longer eat or feed its young

Ingestion of Ocean Trash

• Leads to starvation by blocking digestive tracks
• Provides false sense of being full once swallowed, which leads to starvation
• Ingests sharp objects like metal or glass that perforate the stomach, causing internal bleeding
• Becomes lodged in animals windpipes, cutting off airflow and causing suffocation

How Long Does It Take for Trash in the Ocean to Decompose?

• A tin can that entered the ocean in 1986 is still decomposing in 2036
• A plastic bottle that entered the ocean in 1986 is decomposing in 2436
• A glass bottle that entered the ocean in 1986 is decomposing in year 1,001,986

Prevention is the real solution to trash in the ocean. The International Coastal Cleanup volunteers make ocean conservation an everyday priority. Since 1986, more than six million volunteers have removed 116,000,000 pounds of debris across 211,460 miles of shoreline in 127 nations. The 23rd annual Flagship International Coastal Cleanup will be held Sept. 20, 2008.

Evolution Of A Contraceptive For Invasive Sea Lamprey

Lamprey mouth. (Credit: Wikimedia Commons/Pubic Domain Image)
ScienceDaily — In addition to providing fundamental insights into the early evolution of the estrogen receptor, research by a team at the University of California, San Diego School of Medicine may lead to a contraceptive for female lampreys – a jawless fish considered an invasive pest species in the Great Lakes region of the United States. This could prove important to the Great Lakes region, where lampreys aggressively consume trout, salmon, sturgeon and other game fish.

"Since the introduction of sea lamprey to the Great Lakes, the fisheries have been devastated, and as a result, there is much interest in finding new methods to control the lamprey population," said Michael E. Baker, PhD, professor in UC San Diego's Department of Medicine, Division of Nephrology-Hypertension. "Our research could lead to a contraceptive for female lamprey, providing a method to control their reproduction in the Great Lakes." The researchers' findings will be published by PloS ONE on June 25.

Lampreys evolved about 450 million years ago, before the appearance of sharks. In contrast to sharks, fish and land vertebrates, lampreys have no jaw. They feed on fish by attaching themselves to the fish and sucking their body fluids. Their aggressive consumption of game fish has eliminated many natural predators of the alewife, another invasive species on the Great Lakes. This has allowed the alewife population to explode, with adverse effects on many native fish species.

As part of a program to understand the evolution of steroid hormone signaling, the UC San Diego researchers characterized the estrogen-binding site on the estrogen receptor in the sea lamprey. To accomplish this, Baker – along with David Chang, student in the UC San Diego Department of Biology, and Charlie Chandsawangbhuwana, graduate student of Bioengineering in UC San Diego's Jacobs School of Engineering – constructed a 3-D model of the structure of the lamprey estrogen receptor.

The active estrogen in lamprey is unknown, although recent research in the field suggested that lamprey estrogens contain a 15alpha-hydroxyl group, which is lacking in other types of vertebrate estrogen. The model developed by the UC San Diego research team uncovered a unique interaction between 15alpha-hydroxy-estradiol and an amino acid called methionine, found only in lamprey estrogen receptors.

"The unique aspect of this interaction suggests that there are compounds that can bind specifically to the lamprey estrogen receptor, but not to estrogen receptors in other animals," said Baker, adding that some of these compounds could interfere with estrogen action and act as contraceptives in female lamprey, providing a method to control their numbers.

Source: http://www.sciencedaily.com/releases/2009/06/090625074411.htm

Adapted from materials provided by University of California - San Diego, via EurekAlert!, a service of AAAS.