The Effects of Eutrophication on Jellyfish Populations in New Jersey Waterways How this issue in the Mississippi River delta can be used to predict the effects of eutrophication in New Jersey’s waterways Tag Words: Jellyfish; Eutrophication; New Jersey; CODAR Authors: William Pirl, Emily Pirl with Julie M. Fagan, Ph.D Summary: (WP) What people are doing on land is having a large effect on the coastal ocean waterways. Human beings are introducing excessive amounts of nutrients into these waterways, which is causing biological dead zones that support little productivity. With fewer fish to compete with and hide from, jellyfish are taking over in these areas. This is very true for the New Jersey coastline, specifically in Barnegat Bay. This area is highly enriched from anthropogenic nitrogen sources and there has been an explosion in jellyfish populations in recent years. By coupling research and monitoring programs that have been established in the Gulf of Mexico with CODAR Hf radar it is our goal to allow New Jersey to monitor, study and track these harmful blooms of jellyfish back to the sources of eutrophication in coastal waterways. Video Link: http://youtu.be/S00bAylLd6s ** Listed on You Tube as “Eutrophication in New Jersey” Jellyfish Populations Explode (WP) Jellyfish populations around the world have skyrocketed in recent years. There have been reported increases in jellyfish blooms from Japan to Portugal and most of the areas in between. There is an extensive list of negative consequences that these large increases of jellyfish populations can have on both the environment and its inhabitants. The increase of gelatinous zooplankton directly affects the human population both physically and indirectly. Large populations increase the chances of potential jellyfish encounters by human swimmers. The stinging cells located in the tentacles fire a poisonous thread when it contacts an object. If this object is a human being, the poison will be injected into the victim. Symptoms of jellyfish stings range from mild burning and itching to muscle spasms, coma and death. In addition to having direct contact with the jellyfish, these creatures cause direct decreases in the fishing and tourism industries. Jellyfish blooms in suck massive quantities are capable of breaking through fishing nets of commercial trolling nets. In Japan, swarms of thousands of Normura jellyfish, each being up to 7 feet in diameter and weighing up to 600 pounds, rip through fishing nets ruining both equipment and profits. In fish farming, jellies have invaded fish pens and consumed large amounts of fish decreasing the amount that can be harvested and sold for profit. There are several anthropogenic reasons for these large jellyfish populations. Warmer waters due to climate change and global warming have allowed jellyfish blooms to remain all year long as opposed to dying out during the colder winter months. Also over fishing of many different fish species has caused a steep decline in the natural predators of the jellyfish. Without larger species up the food web, jellyfish have fewer predators and are also not competing with these species for space or resources. Once jellyfish move into an area with little pressure their population explosion and eventually dominance is inevitable. In addition to these stimuli, eutrophication of coastal waterways is a dominant cause of large-scale changes in the dynamic marine food web. http://download.cell.com/trends/ecology- evolution/pdf/PIIS0169534709000883.pdf?intermediate=true http://www.seaturtle.org/PDF/Mills_2001_Hydrobiologia.pdf http://www.nsf.gov/news/special_reports/jellyfish/index.jsp http://blogs.ei.columbia.edu/2011/02/26/giant-jellyfish-swarms-–-are-humans- the- cause/ http://www.dnr.sc.gov/marine/pub/seascience/jellyfi.html Eutrophication (EP) Eutrophication is the process by which a body of water is enriched with nitrogen and phosphorous. Much of the eutrophication of coastal waterways is due to human interactions with the land. This includes the overuse of fertilizers both in commercial agriculture and private landscaping. Golf courses historically use loads of fertilizer to keep their greens and landscaping bright green thought out the season. After heavy rain, the fertilizers runoff into rivers and storm drains that eventually drain to estuary systems. Another source for these inputs is sewage runoff from septic systems and storm drains. These activities increase the amount of nitrogen and phosphorous that the primary producers have to use in the production of oxygen. The high amount of added nutrients disrupts the ecosystem because naturally low levels of both nitrogen and phosphorus keep phytoplankton activity at a level in which it equals consumption, keeling the ecosystem in equilibrium. This increase of nitrogen causes an increase of primary production in photosynthetic phytoplankton and disrupts the delicate balance between the marine organisms in the trophic food web. This leads to high amounts of oxygen production as well as more detritus from dying phytoplankton that sinks to the lower layers in the ocean. Bacteria at depths utilize oxygen in order to metabolize the sinking detritus particles. Their rapid consumption of oxygen to keep up with the falling detritus exceeds the production of oxygen. This creates zones of low or even no oxygen. Large blooms of phytoplankton have other negative effects on the ecosystem and lead to many hazardous consequences for the rest of the food web. Some species of phytoplankton release harmful and toxic chemicals into the water when they bloom in large quantities, proving to be lethal for many organisms. The large, dense blooms of phytoplankton also pose a problem for those below them. The thick and dense blooms of phytoplankton prohibit light from reaching far into the surface waters causing the photoic zone to be shortened, and not providing light to those who require it. This diminishes the amount of total photosynthesis for the area. Phytoplankton need light to produce oxygen and less light in the water column means a thinner layer of oxygen producing phytoplankton. http://www.eoearth.org/article/Eutrophication http://lepo.it.da.ut.ee/~olli/eutr/html/htmlBook_4.html http://www.state.nj.us/dep/wms//Estuarine%20nutrient%20eutrophication%20r ev- %20noaa.pdf http://people.oregonstate.edu/~muirp/eutrophi.htm Coastal Dead Zones (EP) Coastal dead zones occur as a result of a disruption of the nutrient cycling in the marine food web. These areas are the areas usually at the end of he watershed where rivers and lakes drain to the ocean. This is because of the accumulation of high nutrients from many tributaries come to gather in these Back Bay and coastal regions. They are created when eutrophication creates a large bloom of phytoplankton. As these organisms die, their bodies sink to the deep parts of the area where they are decomposed by bacteria and other organisms. These bacteria need a large amount of oxygen to be able to work so as their supply of detritus increases so will their respiration to keep up with it. They also are consuming this oxygen at a fast rate and the production of new oxygen cannot keep up. When this level gets so low that the water can no longer sustain life, it becomes a dead zone. The lack of oxygen is detrimental to the inhabitants of these areas. Motile creatures such as fish and crabs, have the ability to move out of the area and find new niches to inhabit. Other organisms that are sessile are not so lucky and they will die in these hypoxic conditions. This leads to a decrease in species richness of the area, which causes a decline of the overall health of the ecosystem. There are several areas that have shown signs of low or no oxygen all around the world and many right here in the Untied States. A very large and notable dead zone is located at the mouth of the Mississippi River delta where the majority of the water from the United States drains to the ocean. This dead zone reaches out into the gulf and is said to be about the size of New Jersey and it is growing. All of the fertilizers used on the nearby farming land coupled with sewage both human and animal, this area has become a dead zone. Other dead zones are becoming more common in coastal water along every coastline in the United States from Florida to Maine and lining the Gulf of Mexico. http://www.grinningplanet.com/2005/05-17/gulf-of-mexico-dead-zone-usa- global- article.htm http://people.oregonstate.edu/~muirp/eutrophi.htm http://www.allgov.com/Top_Stories/ViewNews/US_Coastal_Dead_Zones_Grow_100911 Jellyfish Thrive in Low Dissolved Oxygen (WP) The low oxygen levels in dead zones creates by eutrophication do not support very much life. Many species either die out or are forces to move into new niches when oxygen levels in the water plummet. Larger consumers such as fish, sea turtles and even marine mammals are not supported because of food scarcity and higher levers of competition. However these conditions are suitable for jellyfish populations for many reasons. First, with larger organisms that prey on jellyfish such as sea turtles and sunfish jellyfish populations are not being controlled by the preditors-prey relationship and the jellyfish are able to increase their population size. When the sea turtles and sunfish die or vacate the area, they are no longer a threat to the jellyfish because they do not inhabit the same area in the water to consume jellyfish as prey. Also the limited food supply, due to low oxygen levels, is not an issue for jellyfish because their diet is so varied that they are able to feed on something else if what it prefers takes a population dip. They feed almost by accident as their tentacles as run across their prey as they are freely floating in the water column.