The Conservation Conversation: A Bumper Crop of Bunker in the Bay, Part II

In my last post, I described the incredible super-abundance of menhaden fish - commonly known as "bunker" - in Little Neck Bay towards the end of this past summer.

By early October, there were so many circling schools of these fish that I couldn't take 10 strokes in my kayak before passing through another "boil" of bunker circling just below the surface. Nobody I've spoken to, including folks who have spent their entire life on the water here and who are even older than I, can remember seeing anything like this.  

Nobody knows exactly why this happened this year. Wildlife populations often rise and fall dramatically over periods of just a few years. This is especially true in predator-prey combinations. Prey animals, which usually have shorter life cycles and faster reproduction rates than their predators, can build up large populations quickly. 

With such large numbers, they often overwhelm the predators' eating capacity, allowing their populations to grow even more. Of course, those predators that are around do very well in a year when the numbers of prey are booming, so the predator population starts to grow. Meanwhile, the large prey population can exceed the available food resources.  

Coupled with increasing predator populations, this can lead to a crash in the prey population, which leads to a subsequent crash in the predator populations. With reduced predation and reduced stress on their food supplies, the prey numbers soon start to rise again, starting the cycle all over. Other factors, such as weather conditions and water quality, can further amplify these natural cycles.   

This year's bunker boom may just be part of one of these cycles, but it may also be attributable, in part, to improved sewage management here at home and more sensible fishing practices in places as far away as Virginia.

Menhaden are in the herring family. They grow to about 14 inches long and are silvery in color. I'm no fish expert, but the bunker in the bay this year had bright yellow tails, so I assume they were Yellowfin rather than Atlantic menhaden (the two species most common here). 

Menhaden were eaten by Native Americans and by colonial settlers, but by the 20th century they fell out of favor as a food fish. Today, they are used primarily to make fish meal and fertilizer. Indeed, the word menhaden means "he enriches the soil" in an Algonquin language.

Bunker are preyed upon by many other fish. In our bay, the most common predators are striped bass and bluefish. They also provide food for many avian predators, including herons, egrets, gulls and osprey.   

Ray Mochizuki, a neighbor who lives at Virginia Point (the northeastern corner of Udalls Cove Park) has taken a number of fantastic photos of osprey perched on a dead branch holding a large bunker in its claws.

Bunker are filter feeders, which means they swim in circles with their mouths open, often in large groups swimming in circular patterns, capturing algae and other phytoplankton. For this reason, they play a vital role in cleaning the water of ocean inlets and embayments like our own. In doing so, they reduce the threat of disastrous, toxic algal blooms that cause red tide or brown tide. 

There is reason to believe that menhaden have been over-fished in recent decades, like so many other fish species. Depleted stocks have probably contributed to poor water quality in our own backyard. Paul Greenberg, author of "Four Fish: The Future of the Last Wild Food," writes:

"The muddy brown color of the Long Island Sound and the growing dead zones in the Chesapeake Bay are the direct result of inadequate water filtration — a job that was once carried out by menhaden. An adult menhaden can rid four to six gallons of water of algae in a minute. Imagine then the water-cleaning capacity of the half-billion menhaden we 'reduce' into oil every year."

I was told by a member of the Bayside Anglers group that a couple of years ago the U.S. government asked the two companies responsible for almost all menhaden fishing to reduce the number of fish they take each year in order to allow the stock to replenish. If so and if those two companies acted on that request, perhaps that is another element that has contributed to this summer's bumper crop of bunker. 

Whatever the reason, it has been good news for our bay and for the many other animals that depend on them.