Agriculture
Seeds of the Future
Protecting Cows—and People—from a Deadly Disease
Watering the Air
Amphibians
Salamanders
Tree Frogs
Toads
Animals
Helping the Cause of Macaws
Putting a Mouse on Pause
Polar Bears in Trouble
Behavior
Taking a Spill for Science
The Colorful World of Synesthesia
From dipping to fishing
Birds
Vultures
Carnivorous Birds
Birds We Eat
Chemistry and Materials
Unscrambling a Gem of a Mystery
Sticking Around with Gecko Tape
Picture the Smell
Computers
Galaxies on the go
Supersonic Splash
The science of disappearing
Dinosaurs and Fossils
A Really Big (but Extinct) Rodent
A Living Fossil
A Rainforest Trapped in Amber
E Learning Jamaica
Results of GSAT are in schools this week
2014 GSAT Results for Jamaican Kids
E Learning in Jamaica WIN PRIZES and try our Fun Animated Games
Earth
On the Trail of America's Next Top Scientists
Warmest Year on Record
Shrinking Glaciers
Environment
A Newspaper's Hidden Cost
Watching for Wildfires in Yellowstone
A Vulture's Hidden Enemy
Finding the Past
Traces of Ancient Campfires
Stone Tablet May Solve Maya Mystery
The Taming of the Cat
Fish
Barracudas
Tilapia
Tiger Sharks
Food and Nutrition
The Color of Health
In Search of the Perfect French Fry
How Super Are Superfruits?
GSAT English Rules
Pronouns
Whoever vs. Whomever
Who vs. That vs. Which
GSAT Exam Preparation Jamaica
Scotiabank Jamaica Foundation Grade Six Achievement Test (GSAT) Scholarships
E Learning in Jamaica WIN PRIZES and try our Fun Animated Games
How are students placed after passing the GSAT exam
GSAT Exams Jamaica Scholarships
Access denied - Disabled boy aces GSAT
GSAT Scholarship
2014 GSAT Results for Jamaican Kids
GSAT Mathematics
Detecting True Art
Math of the World
Losing with Heads or Tails
Human Body
Remembering Facts and Feelings
Taste Messenger
Smiles Turn Away Colds
Invertebrates
Clams
Scorpions
Leeches
Mammals
Golden Retrievers
Whales
Jaguars
Parents
Expert report highlights the importance to parents of reading to children!
Children and Media
The Surprising Meaning and Benefits of Nursery Rhymes
Physics
The Mirror Universe of Antimatter
Spin, Splat, and Scramble
Thinner Air, Less Splatter
Plants
A Giant Flower's New Family
Surprise Visitor
A Change in Leaf Color
Reptiles
Snapping Turtles
Komodo Dragons
Tortoises
Space and Astronomy
A Puffy Planetary Puzzle
Pluto, plutoid: What's in a name?
Chaos Among the Planets
Technology and Engineering
Roll-Up Computer Monitors to Go
Toy Challenge
Squeezing Oil from Old Wells
The Parts of Speech
What is a Verb?
What is a Preposition?
Pronouns
Transportation
Where rivers run uphill
Tinkering With the Basic Bike
How to Fly Like a Bat
Weather
Arctic Melt
Where rivers run uphill
Watering the Air
Add your Article

Food Web Woes

Sharks are scary—no doubt about it. Just ask anyone who's seen Jaws or other films that feature these sharp-toothed creatures. But there's something that might be just as scary as meeting up with a shark—at least from an environmental perspective. It's the thought of what might happen if sharks disappeared from the oceans. That's because sharks are important players in delicate food webs, suggests a new study out of Canada. Fishing companies have been killing large sharks for decades. Sometimes they've done it on purpose, and sometimes they've done it by mistake. Because of these kills, the animals that sharks eat have boomed. And that's bad news for the creatures even lower on the food web. Along the East Coast of the United States, only sharks that are at least 2 meters (6.6 feet) long are tough enough to eat a lot of the medium-size sharks, rays, and skates living in those waters. Eleven large shark species in the region fit into that category. Researchers led by Ransom Myers in Nova Scotia reviewed 17 surveys that counted big sharks and their prey during the past 35 years. They found that numbers of all 11 species have dropped since 1972. As the big sharks disappear, most of the smaller sharks, rays, and skates have increased in number. Surveys have shown increases in 12 of 14 species of these sea creatures over the past 30 years. The populations of some of these species are 10 times as high as they were three decades ago. Researcher Charles H. Peterson recently heard fishermen in North Carolina complaining that cownose rays were eating up all the region's bay scallops. He and his colleagues at the University of North Carolina's Institute of Marine Sciences at Morehead City decided to test whether this was really happening. To keep rays from eating scallops in certain areas, the scientists put a protective ring of poles around the scallops. Rays are wider than most sea creatures and won't usually swim between poles that are spaced closely together. (The rays could turn sideways and fit through, but they don't usually do this.) Other animals, however, swim easily through the gaps between poles. In 2002 and 2003, at the beginning of the fall season, researchers found populations of bay scallops that were healthy and dense. But after rays migrated through, the scallops nearly disappeared in areas that were not surrounded by poles. Within protected areas, only half of the scallops were gone. It's not even certain that the missing ones got eaten, Peterson says, since they might just have swum away. The study suggests that efforts to replace declining populations of shellfish, such as scallops and oysters, might require extra levels of protection against predators. The findings reinforce the message from a 1998 study of a food web in Alaska. In that area, killer whales can normally eat otters. Otters eat sea urchins. And sea urchins eat kelp. When the whales ate more otters, the study found, sea urchins thrived, and the kelp suffered. In food webs, balance is key.—E. Sohn

Food Web Woes
Food Web Woes








Designed and Powered by HBJamaica.com™