Cleaning Up Fish Farms
Middle school science adventures
Fast-flying fungal spores
Tree Frogs
Frogs and Toads
New Mammals
Missing Moose
Moss Echoes of Hunting
World’s largest lizard is venomous too
Slumber by the numbers
A Global Warming Flap
Chemistry and Materials
Screaming for Ice Cream
Gooey Secrets of Mussel Power
Cooking Up Superhard Diamonds
Look into My Eyes
Middle school science adventures
Music of the Future
Dinosaurs and Fossils
An Ancient Spider's Web
Mammals in the Shadow of Dinosaurs
E Learning Jamaica
Results of GSAT are in schools this week
E Learning in Jamaica WIN PRIZES and try our Fun Animated Games
2014 GSAT Results for Jamaican Kids
Life trapped under a glacier
Explorer of the Extreme Deep
Warmest Year on Record
Sounds and Silence
Nanosponges Soak Up Pollutants
The Wolf and the Cow
Finding the Past
Words of the Distant Past
Preserving Ancient Warrior Paint
Chicken of the Sea
Food and Nutrition
Turning to Sweets, Fats to Calm the Brain
In Search of the Perfect French Fry
Moving Good Fats from Fish to Mice
GSAT English Rules
Order of Adjectives
Who vs. That vs. Which
Capitalization Rules
GSAT Exam Preparation Jamaica
Ministry of Education Announces 82 GSAT Scholarships for 2010
GSAT stars reap scholarship glory
E Learning in Jamaica WIN PRIZES and try our Fun Animated Games
GSAT Exams Jamaica Scholarships
GSAT Exam Preparation
Access denied - Disabled boy aces GSAT
GSAT stars reap scholarship glory
GSAT Mathematics
A Sweet Advance in Candy Packing
Setting a Prime Number Record
E Learning in Jamaica WIN PRIZES and try our Fun Animated Games
Human Body
Taking the sting out of scorpion venom
From Stem Cell to Any Cell
Running with Sneaker Science
Guinea Pigs
Blue Whales
African Leopards
What Not to Say to Emerging Readers
Raise a Lifelong Reader by Reading Aloud
How children learn
Project Music
Road Bumps
Spin, Splat, and Scramble
Hungry bug seeks hot meal
White fuzzy mold not as friendly as it looks
Surprise Visitor
Boa Constrictors
Snapping Turtles
Space and Astronomy
Mercury's magnetic twisters
Rover Makes Splash on Mars
World of Three Suns
Technology and Engineering
Machine Copy
Are Propellers Fin-ished?
A Clean Getaway
The Parts of Speech
Problems with Prepositions
What is a Noun
Troubles with Hubble
Where rivers run uphill
Seen on the Science Fair Scene
A Change in Climate
Arctic Melt
Warmest Year on Record
Add your Article

Shrinking Fish

You've probably heard the story about "the big one that got away." Someone goes out fishing and claims to have caught a monster fish. There's no proof, though, because the fish managed to free itself before it could be landed. Whether or not the story is true, the chances of catching "the big one" seem to be getting worse and worse. In response to fishing pressures, fish are becoming smaller, growing more slowly, and having a harder time reproducing, says David O. Conover of the State University of New York at Stony Brook. The average size of fish of many species has declined in recent years. That's not surprising. Smaller fish are more likely to squirm out of nets than larger ones. And laws often require that fish smaller than a certain size be returned to the sea. People tend to catch and keep the bigger, meatier ones. Fishing can also induce changes in fish that are passed on from generation to generation. To check this idea out, Conover grew several generations of Atlantic silversides in six aquarium tanks. In two of the tanks, he kept removing the biggest fish, to copy what commercial fishermen do in the ocean. He found that this caused each generation of fish to grow more slowly than the one that came before it. When Conover repeatedly removed the smallest fish from two other tanks, each generation grew more quickly than the previous one. When he removed fish at random, there was no change in how fast the fish of each generation grew. Taking only big fish penalizes fish that grow quickly. Removing these animals from the gene pool leads to breeds that grow more slowly and don't grow to be as large. To see if the trend is reversible, Conover then stopped fishing from his tanks. So far, it seems to take longer than expected for the fish to recover their earlier growth patterns. It's not practical to stop fishing altogether. Instead, Conover proposes that fishing boats be required to throw back the biggest fish along with the smallest ones. This would help preserve fast-growing fish. And your chances of catching "the big one" might actually improve.—E. Sohn

Shrinking Fish
Shrinking Fish

Designed and Powered by™