Bluefish are not exactly dainty eaters but even they have standards. Known for their voracious appetites, blues are said to sometimes gorge themselves, regurgitate and start all over again.
A disgusting overstatement.
At a seminar last week, Stuart Wilk, the National Maine Fisheries Service bluefish specialist from Sandy Hook, N.J., said observation of blues in a controlled environment indicated this is a myth. He said when observers fed captured blues in a tank the fish would eat only until they were stuffed, then quit.
However, there was a circumstance under which blues could be induced to eat more. "We found if we introduced bait of a larger size, the blues would start eating again," Wilk said.
He said researchers watching blues through a window in the tank fed them small minnows until the predators would take no more. If the scientists threw more minnows in, the blues ignored them. But if they offered a larger size minnow, the eating binge started anew.
Wilk said blues demonstrated a healthy appetite, eating 8 to 12 percent of their body weight per day.
He said their preferred water temperature range is 66-72 degrees. Outside that range, swimming speed increases, indicating a desire to migrate. Temperature thresholds are 53 1/2 degrees and 84 1/2 degrees. In water above or below these temperatures blues show signs of physical stress.
That may explain the mysterious disappearance of bluefish in much of the Chesapeake during high summer. The best fishing seasons are May-June and September-October. During July and August bluefishing can get downright frustrating. Bay water temperatures in high summer often exceed 80 degrees, which would hurry blues on their way.
Wilk said feeding bluefish respond to olfactory stimuli (that means they can smell blood, and who didn't know that?) but generally rely on sight to locate and capture individual prey. He read off a laundry list of food sources that essentially confirmed the suspicion of most anglers that blues will eat anything small that moves.
Research indicates two bluefish spawning periods. In spring, there is a major spawn off the Carolinas, and in late summer another takes place off the mid-Atlantic coast from Maryland to Long Island.
The two spawnings help explain the continued expansion of blues, in that if environmental conditions mitigate against successful reproduction during the spring, they can make up for it in the fall, and vice versa. Most species spawn once a year: if it's a washout, there's no second chance.
Blues generally reach sexual maturity in their first year, and all are mature by age 2. Wilk said they weigh about 1.3 pounds at age 2; 4.8 pounds at age 4; 11.1 pounds at age 7 and 15 pounds at age 10. A 14-year-old blue will weigh about 18.6 pounds, which would be a nice one to catch next May.