Agriculture
Treating peanut allergy bit by bit
Springing forward
Getting the dirt on carbon
Amphibians
Frogs and Toads
Toads
Salamanders and Newts
Animals
Navigating by the Light of the Moon
Life on the Down Low
Ants on Stilts
Behavior
Newly named fish crawls and hops
Hitting the redo button on evolution
Dino-bite!
Birds
Nightingales
Falcons
Peafowl
Chemistry and Materials
Sugary Survival Skill
Atom Hauler
Moon Crash, Splash
Computers
New eyes to scan the skies
Hitting the redo button on evolution
Games with a Purpose
Dinosaurs and Fossils
A Big, Weird Dino
Fossil Forests
Winged Insects May Go Way Back
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
Hints of Life in Ancient Lava
Quick Quake Alerts
Earth's Poles in Peril
Environment
Plant Gas
Shrinking Fish
What is groundwater
Finding the Past
Settling the Americas
A Human Migration Fueled by Dung?
Stone Tablet May Solve Maya Mystery
Fish
Bull Sharks
Sting Ray
Flounder
Food and Nutrition
Chocolate Rules
The Essence of Celery
Chew for Health
GSAT English Rules
Who vs. Whom
Order of Adjectives
Whoever vs. Whomever
GSAT Exam Preparation Jamaica
Mastering The GSAT Exam
The Annual GSAT Scholarships
Results of GSAT are in schools this week
GSAT Exams Jamaica Scholarships
Results of GSAT are in schools this week
42,000 students will sit for the GSAT Exam in two weeks
GSAT Practice Papers | GSAT Mathematics | Maths
GSAT Mathematics
Monkeys Count
Math is a real brain bender
Math and our number sense: PassGSAT.com
Human Body
Sea Kids See Clearly Underwater
Disease Detectives
Running with Sneaker Science
Invertebrates
Centipedes
Praying Mantis
Tapeworms
Mammals
Wolverines
Cougars
Elk
Parents
Raise a Lifelong Reader by Reading Aloud
Expert report highlights the importance to parents of reading to children!
The Surprising Meaning and Benefits of Nursery Rhymes
Physics
Black Hole Journey
One ring around them all
The Particle Zoo
Plants
City Trees Beat Country Trees
Fastest Plant on Earth
Nature's Alphabet
Reptiles
Gila Monsters
Geckos
Copperhead Snakes
Space and Astronomy
Saturn's Spongy Moon
Black Holes That Burp
Baby Star
Technology and Engineering
Morphing a Wing to Save Fuel
Are Propellers Fin-ished?
Reach for the Sky
The Parts of Speech
What is a Preposition?
Problems with Prepositions
Pronouns
Transportation
Tinkering With the Basic Bike
Flying the Hyper Skies
Robots on the Road, Again
Weather
In Antarctica watch the heat (and your step)
The Best Defense Is a Good Snow Fence
Polar Ice Feels the Heat
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™