Dolphins Found Washed up on Our Shore

Akira Suwa/ The Philadelphia Inquirer

Since July 9, 2013, there have been a total of 25 dolphin strandings along the Jersey Coast according to the Marine Mammal Stranding Center in Brigantine, NJ. Strandings have been reported along the Atlantic coastline with a total of 124 dolphins washing up along the shores (the majority in Virginia). Pneumonia has beenresponsible for four of the dolphin deaths while another tested positive for Morbillivirus, a measles-like virus.

While although pneumonia and Morbillivirus have been identified as causes, the overall cause of the deaths is unknown.  The Morbillivirus has been known to affectspecies of dolphins in the past 20 years with one notable event occurring inthe 1980s in which 742 dolphins presented with the virus.  This virus has been known to affect species of cetaceans off the coasts of Ireland, France, Italy, Greece, and Turkey.[1]

The macroscopic presentation of this disease involves deteriorating body condition along with prominent lesions on the lungs and central nervous tissues. The Morbillivirus also causes secondary infections, such as pneumonia, due to the “immune suppressive nature of the virus”.[2]  What is concerning most about Morbillivirus is how it is spread. Thevirus is capable of spreading through contact transmission between groups ofdolphins.

The New Jersey Department of Environmental Protection hasbeen informed of the deaths and has stated that there is no correlation betweenthe deaths and the water quality which “has been excellent this summer”.  Instead, it is an indication of a “natural disease cycle.”

The discoveries have led federal agency to declare anunusual mortality event for Bottlenose dolphins. This declaration will provide scientists with additional research funding in order to find the root cause of the deaths.

Perry Habecker, chief of large-animal pathology at the University of Pennsylvania, stated that “’human interaction’- such as aggressive commercial fishing, toxic wastes, and even plastic bags- can contribute to spikes of mortality in marine-mammal populations such as whales, seals and dolphins.”  But, for now, the primary cause of death has yet to be identified. Scientists will know more once they run diagnostic tests on tissue and blood samples.

How can you help? If you see a stranded dolphin, do not touch it. Alert local officials and keep pets away from the animal.

[1] Rubio-Guerri, Consuelo; Melero, Mar; Esperón, Fernando; Belliére, Edqige N.; Arbelo, Manuel; Crespo, Jose L.; Sierra, Eva; García-Párraga, Daniel; Sánchez-Vizcaíno, Jose M. 2013. Unusual striped dolphin mass mortality episode related to cetacean morbillivirus in the Spanish Mediterranean Sea, BMC Veterinary Research, 9:106.

[2] Reidarson, Thomas H.; McBain, Jim; House, Carol; King, Donald P.; Stott, Jeffrey L.; Krafft, Amy; Taubenberger, Jeffrey K.; Heyning, John; Lipscomb, Thomas P. 1998. Morbillivirus Infection in Stranded Common Dolphins from the Pacific Ocean. Journal of Wildlife Diseases. 34(4) 771-776.

Do you know what’s on your plastic?!

Erik Zettler, Sea Education Association

Scientists recently discovered tiny organisms prospering on pieces of plastic that are found in the ocean. Otherwise known as the ‘plastisphere’, these microorganisms have found themselves a home in our ‘garbage’. It is the same garbage that has the potential to make its way into the ocean and possibly be ingested by a multitude of animals. Will these microorganisms have an effect on the marine environment? Will they be able to enter into the food web?

A group of scientists from Sea Education Association, Woods Hole Oceanographic Institution, and the Marine Biological Laboratory, studied these questions while scanning various pieces of marine debris throughout the North Atlantic Ocean.  At the conclusion of their study, they identified over 1000 various colonies of bacterial cells. In contrast to the microorganisms generally found within the seawater, these bacteria were different, raising the possibility that the plastic pieces form an “artificialmicrobial reef” for the microorganisms. Plastic, unlike other material commonly found in the ocean (i.e. feathers, wood, etc.), generally lasts longer creating a permanent residence for the bacteria on the ‘artificial microbial reef’. Because plastic is lightweight and robust, it is able to prevail in the surface waters of the marine environment allowing for the plastisphere to exist.

While these organisms are, in fact, microscopic, they are able to thrive on pieces of plastic of various sizes, some “no bigger than the head of a pin”. With plastic accumulation in the ocean becoming more common, this ‘plastisphere’ can represent a combination of these small fragments.

This discovery opens the door to better understanding the role microorganisms can play in the marine environment and how that role can impact varying types of marine life. The plastisphere represents a new, innovative way that bacteria have evolved transportation from one location to the next. How will this new mode of transmission impact the surrounding communities? Will this increase the presence of water-based pathogens that proliferate and cause disease such as cholera and other gastrointestinal diseases? That is something scientists are still researching.

“Scientists Discover Thriving Colonies of Microbes in Ocean ‘Plastisphere’.” Woods Hole Oceanographic Institute Media Relations Office.  Web.  June 27, 2013.

Wright, S.L., Thompson, R.C., and Galloway, T.S.  The physical impacts of microplastics on marine organisms: A review.  Environmental Pollution 178: 483-492, 2013.