Gulf Shores Alabama

The Age of  Fish

Ever wonder how old that fish you caught was? Dr. Skip, a Gulf Coast marine biologist has written a nice article about that subject :

How to Tell a Fishes’ Age Without Asking

Fish are born, live and die like we do only you can’t ask a fish its age. When a fish is spawned in a hatchery the manager knows how old it is. That’s called a known age fish. If you catch a fish in the wild telling it’s age is a different story.

Fish have bones in their heads called otoliths (oto’ meaning ear and lith’ meaning stone). These bones help the fish to keeping its balance in the water. When an otolith is removed from a fish, sectioned into thin slices and viewed through a microscope, it reveals a pattern of light and dark concentric rings.

When a fishes’ grow slows in the winter a darker denser ring forms. In the warmer months when a fish is growing faster and a clearer ring is formed. These yearly growth rings are called annuli, which are similar to the rings found in tree stumps. You can count the rings in the otolith or stump and determine age. Unfortunately, for the fish it had to die to allow you to determine its age. Other hard parts in a fish’s body can also be aged in a similar way such as fin rays or scales. Unlike bones, scales in a fish tend to get knocked off or fall off over time and have been proven not to be as reliable as otoliths for aging. Otoliths can be small, thin and clear like in marlins or as large as half your thumb and opaque like the red drum (redfish).

A scientific study called “Age and Growth” allows a fishes’ age to be determined without killing it – except for those used in the initial study. For each species otoliths are collected as soon as possible after they are spawned to as old a fish as can be obtained. Data including the gender and length of the fish are collected along with the information from the otoliths. This information is analyzed for each species and gender and an age assigned for a given range of lengths. While not perfect it’s a good indicator of a fish’s age. A separate analysis is done for males and females because in fish, generally speaking, females grow slower, are larger and are longer lived than males. When you hear or read about a large red snapper or king mackerel being caught it’s a good guess it was female.

When age and growth data are combined with commercial and recreational harvest information, the egg producing capacity of the females (fecundity) and other information the result is called a stock assessment. Stock assessments provide regulating agencies with the data necessary to set angler regulations like length limits, number per day and total harvest. The intent of the regulations is to allow for perpetual renewal of the stock.



Fishy Facts

A three foot-long dolphin fish can be less than one year old.

It’s better to throw the big ones back (females) as they produce more eggs a year than the smaller ones.

Otoliths contain heavy metals like lead and can be used as indexes of pollution.

Otoliths from Indian villages thousands of years old can provide insights into the base level of heavy metals like lead.

Back to Gulf Shores Fishing Info

 

 

gulf shores alabama beach photos  ala algulf shores alabama ala
 beach vacation packing list
driving directions al ala
beach condo rentals gulfshoresalabama ala
gulfshoresalabama hotels hotel
fortmorganrental
gulfshores beach photos

gulfshoresalabama map alabama map baldwin county map
fun stuff to do in gulf shores alabama photo photograph alabama ala al
 dolphin boat trips sailing
gulfshoresalabama dining gulf shores restaurant reviews food
gulfshoresalabama hotels hotel
dining out in gulf shores alabama
beach condo rentals gulf shores alabama ala
attractions
fun stuff to do in gulfshoresalabama photo  ala
printable stationery postcards
 beach vacation condo rental
gulfshores reservations

HOME
Traveling Tips
   & Directions
Hotels & Condos
Area Info
Weddings
Restaurants
Coupons
Things to Do
Special Services
Fort Morgan
   & The Ferry
Festivals & Events
Printables
Recipes
Hurricane Facts
Live Beachcams
Gulf Shores -
   Beach Photos
Girl Talk
Gulf Shores Banks
Gulf Shores Condos for Sale
Build a House
Restaurant Menus
Orange Beach Condos for Sale
Drone / UAV Aerial Photography

Bookmark this Site (IE)

Gulf Shores
Orange Beach
Ft Morgan
Alabama

Info, photos, coupons,
maps, driving directions,
& tips for a great
family beach vacation.

For the Gulf Shores Area:
cheap hotel deals

Discount Condo Rentals


Book a CRUISE !
See our photos !

Best
Rates Online ! 

TV Channel Guide

Beach House
Rentals

laser treatments

Hurricane-Proof Construction:
ConcreteCottage.com

Please help support this fun site about Gulf Shores by making Amazon purchases thru us...
Now-a-days Amazon sells almost everything !! Thanks.

Search Now:
gulfshoresalabama gulfshores alabama al ala

email

 

Wednesday July 20, 2016


Copyright 2003-2016 Lundy Wilder
www.Gulf-Shores-Alabama.net

Gulf Shores Area Vacation and Dining Information, Driving Directions, Beach Pictures

Site Map | Privacy Policy | Google+