Bunker Fish Kills Reported Locally Since 1679

As reported yesterday in the Asbury Park Press, thousands of adult Atlantic Menhaden were found dead in the Shark River in the early morning. Officials are awaiting test results that may confirm that the bunkers suffocated because there was little or no oxygen in the water due to an algae bloom.

While large fish kills consisting of different species are unusual, bunker fish kills happen locally almost every year. In fact, the first recorded bunker kill in the area was observed by a Dutch settler, Jasper Danckaerts, in a creek in Staten Island in 1679, according to the book Heartbeats In The Muck.

What is unusual about this bunker kill is that is it happened almost a month earlier than the earliest kill recorded on pages 14-16 of this historical report about local fish kills. But algae blooms are early this year as well: a diatom bloom started in Raritan Bay after the sunny Palm Sunday weekend in mid April, as discussed in a previous blog, “Raritan Bay Blooms Brown in the Spring”.

A Typical Bunker Kill

Algae blooms set the stage for a bunker kill. While algae add oxygen to the water during the day, they produce carbon dioxide at night that uses up oxygen. It is not unusual for dissolved oxygen levels to rise into the teens during the day but crash to zero at night during a large algae bloom. Bunker kills indicate that dissolved oxygen has dropped to at least 2.0 mg/l; a good level is 5.0 mg/l, according to this report.

Bunkers are at the base of the food chain. Bluefish, stripers and other predators feast on them. When bunkers are cornered by predators, they pack themselves into tight schools. If you fast forward four minutes into this fishing video, you will see the waves darken as a school of peanut bunkers are driven onto the beach by stripers (peanut bunkers are juvenile menhaden that arrive locally in midsummer). This video shows a “bluefish blitz” at the Jersey shore in 2007, with peanut bunkers littering the beach to escape frenzied bluefish.

Imagine this happening, not in waves on an ocean beach, but in bays like the Shark River, with shallow channels and wide mudflats that have much lower oxygen levels in the water. When bunkers are frightened by predators and ball up into schools, they also defecate. This uses up any remaining oxygen in the water, and they suffocate.

This column in today's Asbury Park Press noted that the blues that were abundant in the ocean off Bradley Beach on Sunday may have driven the bunker into the “refuge” of the Shark River.

Two Other Large Bunker Kills

As summarized on pages 15-16 of this report, the largest fishkill on record in the coastal waters of Monmouth County took place in 2000, when 3.9 million juvenile menhaden (peanut bunkers) suffocated in Little Silver Creek in the Shrewsbury estuary.

Eleven bunker kills occurred in the Bayshore and the Shrewsbury River from mid June through the early fall of 2007. Three of them were estimated in the hundreds of thousands to million dead bunkers. Newspaper pictures showed dead peanut bunker littering the phragmites along Matawan Creek in Keyport like cherry blossoms, in spite of average water quality and dissolved oxygen.

More Bunkers, More Kills

Bunkers that are caught commercially, known as reduction fishing, are “reduced” to fish meal, proteins, and oils (including omega vitamins). They are used as animal feed and in cosmetics, and since colonial days, as fertilizer, according to the book The Most Important Fish in the Sea.

A 2001 law prohibiting reduction fishing by commercial trawlers within 1.2 nautical miles of the NJ shoreline went into effect in 2002. Bunkers reproduce at age three, so there have been at least four full generations of bunkers since then.

Since 2005, the numbers of bunkers have been increasing along NJ, and reached the highest level recorded by NOAA from 1985 through 2008 (slide 16). In 2010, the New Jersey Bureau of Marine Fisheries estimated the East Coast bunker fishery at about 35 billion (Degener, 2010). Legislation passed in 2013 has added quotas and additional restrictions on commercial bunker fishing.

Tidal Flushing and Stormwater

Poor tidal flushing in warm weather can lead to anoxic conditions in estuaries with shallow channels and wide mudflats. Water can turn ink-black because of chemical changes to dissolved sulfur. When oxygen levels fall to zero, natural sulfate in the water turns into sulfide, and the water goes septic. The black water smells like rotten eggs from hydrogen sulfide gas and suffocates any aquatic life that can't swim away in time.

The earliest known report of anoxic conditions in local estuaries dates was recorded by the Shrewsbury Township Board of Health on page 310 of the 1892 “Report of the Board of Health of the State of New Jersey”:

"There is a complaint of tide-water backing up on a tributary of the South Shrewsbury, known as Little Silver Creek, causing decay of vegetable matter and jeopardizing the health of neighbors surrounding it. This Board wishes information as to how it should be opened, and what steps are necessary to be taken in the matter, as all persons owning property adjacent to the creek claim that they have no legal right to proceed in the matter, as it is the bed of the river."

As recently as July 24, 2013, residents left numerous postings on the Oceanport webpage about having to close their windows because the odor was so bad in Blackberry Bay. The hydrogen sulfide odor and black water had followed a heat wave and moderate algae bloom in this poorly flushed area, according to this report in the Asbury Park Press.

Stormwater loaded with nutrients causes algae blooms and fishkills. The effects of stormwater can be diminished by using less fertilizer on your lawn and practicing Low Impact Development, as discussed in this blog, Three Reasons to Reduce Lawn Runoff.

Fun Facts

“Moss bunkers” is derived from marsbanker or horse mackerel, from the early Dutch settlers; menhaden are actually members of the herring family. Bunkers are also called shad, fatback, and pogie or pogy (not porgy), from "pauhagen," the word for fertilizer used by the Abenaki tribe of Maine. The Native Americans of Massachusetts may have taught the Pilgrims to use bunkers as fertilizer when planting corn.

Bunkers also can also die from the bacteria Vibrio ordalii and Photobacterium damselae, which cause respiratory disease in fish, not humans.

Adult bunkers are filter feeders that consume phytoplankton. Like oysters, bunkers may prove to be an important natural Best Management Practice for controlling algae blooms in coastal waters.

The local abundance of bunkers may be attracting more dolphins to the NJ coast, such as the pod of 16 that moved into the Navesink and Shrewsbury estuaries from June 2008 until January 2009. 

ADDITIONAL RESOURCES

Bates, Todd. 7/26/13. Shrewsbury River's rotten-egg odor blamed on algae. Asbury Park Press. http://www.app.com/article/20130727/NJNEWS/307270013/Shrewsbury-River-s-rotten-egg-odor-blamed-algae

Board of Health of the State of New Jersey. Accessed 2/18/10. Annual Report. University Libraries Special Collections New Jersey Health Statistics from 1877 to 2000: An Historical Electronic Compendium of Published Reports. Compiled and Annotated by Mark C. Fulcomer, Ph.D. and Marcia M. Sass, Sc.D. University of Medicine and Dentistry of New Jersey. http://libraries.umdnj.edu/History_of_Medicine/NJHS/statistics.html

Franklin, H. Bruce. 2007. The Most Important Fish in the Sea. Menhaden and America. Island Press, Washington, DC.

Hohn, A. 1/13/09. Worldwide Distribution of Bottlenose Dolphins. Slide 16. NOAA Southeast Fisheries Science Center.Bottlenose Dolphin Seminar. Pollak Theatre. Monmouth University. http://www.nefsc.noaa.gov/njdolphins/SHREWS12/Coastal%20Migratory%20Bottlenose%20Dolphins.pdf

Monmouth County Health Department. 07/29/2013. Natural and Cultural Features Of Monmouth County. http://co.monmouth.nj.us/documents/121/NaturalFeaturesHistory.pdf

Reid, R., Olsen, P., and Mahoney, J. 2002. A compilation of reported fish kills in the Hudson-Raritan Estuary during 1982 through 2001. Northeast Fisheries Science Center Reference Document 02-09. www.nefsc.noaa.gov/nefsc/publications/crd/crd0209/crd0209.pdf

U.S. Fish and Wildlife Services. Accessed 1/29/07. Significant habitats and habitat complexes of the NY Bight watershed. Raritan Bay-Sandy Hook Complex. Complex #17. Southern New England - New York Bight Coastal Ecosystems Program in Charlestown, Rhode Island. ftp://ftp.nodc.noaa.gov/nodc/archive/arc0034/0071981/1.1/data/1-data/dis...

Waldman, J. 1999. Heartbeats in the Muck. The Lyons Press.

Zimmer, K. 1996. How Low Dissolved Oxygen Conditions Affect Marine Life In Long Island Sound. New York Sea Grant Extension Program for the Long Island Sound Study. http://longislandsoundstudy.net/wp-content/uploads/2010/03/lodo.pdf