Cargo Ships: Space Shuttles for Aliens Dayne Buddo Senior Research Officer Natural History Division Institute of Jamaica An alien species is one that originates from another location, usually another country. At times, these alien species cause problems for native species and it is at this point that they are described as being invasive. These invasive species threaten an area s biodiversity, which is the variety of life, as they will tend to outcompete native species and dominate the area. Invasive species are described as being the greatest threat to biodiversity after habitat destruction. The global shipping industry is the major cause for invasion of marine invasive species. Ballast water The global shipping industry comprises of approximately 33,000 large cargo ships. These ships play a crucial role in the transport of these species between different countries. Large cargo ships have ballast tanks that are filled with seawater for stability, which is termed ballast water. These ships are designed to carry enormous weight, and as such, will become unstable if they do not have a particular weight. Therefore, ballast water provides this weight compensation and is absolutely essential for shipping. However, the ballast water that these ships will take up contains organisms including fish, shellfish, worms, algae and dangerous diseases. When the ships arrive to their destination country, such as Jamaica, they will dump this water to take on cargo (see Fig 1). The volume of this water that is arbitrarily released in some countries (including Jamaica) can be as much as 200,000 cubic metres, which is the same amount of water in 2,000 Olympic-sized swimming pools.
Fig. 1 Ship releasing ballast water in Kingston Harbour The International Maritime Organization (IMO) estimates that 10 billion tonnes of water are moved around the world each year. Each day 7,000 to 10,000 species of organisms travel in that water. Every nine weeks, a new invasive species establishes itself somewhere new. Living conditions in these ballast tanks are harsh, such as low oxygen which will kill some of these organisms. Today, ships are becoming faster, which significantly shortens the time for the journey and increases the survivability of these organisms. Some organisms such as barnacles will also be transported to other countries by attaching themselves to the hulls of the ship. The Green Alien invades Jamaica! Jamaica is not excluded from this crisis. In 1998, the green mussel Perna viridis invaded the Kingston Harbour. This oyster-like creature is a very detrimental and resilient invasive species, and has wreaked havoc in every country it has established; no country to date has removed this mussel. The main way that they are transported between countries is via ballast water. The mussel s larval stage is found in the water. Ships will take up the larvae (usually in the hundreds of thousands) in ballast and transport them to another country such as Jamaica, and literally dump them into our waters. The larvae that survive the trip will then develop and attach itself to almost anything present in the water and proliferate. Our harbour will then act as a relay station for the invasion of this mussel to another country. In Jamaica, this mussel has reduced important species from mangrove areas by outcompeting them for space on mangrove roots (see Fig. 2). Roots that were once filled with a variety of organisms such as oysters, sponges, sea squirts and worms, are found to be dominated by the green mussel.
Fig 2: Mangrove root dominated by green mussel They have done very well in Kingston Harbour mainly due to the fact that they feed by filtering microscopic plants called phytoplankton. Phytoplankton levels are very high in Kingston Harbour due to the high levels of organic pollution. The mussels have reached almost 6 inches in length and with densities reaching 1000 mussels per square metre. Apart from the obvious ecological impact on mangroves, the green mussel attaches to anything that is in the water for more than two weeks. These include: wharf pilings, boats, seagrass beds, pier walls, old logs and even plastic buckets. More importantly, the mussel attaches itself to the inner walls of intake pipelines of power companies. There are several companies in Kingston Harbour such as the Jamaica Private Power Company and Hunt s Bay Power Station that use seawater to cool turbines, which is essential to their operation. The mussel will clog the pipelines, significantly reducing the amount of water being pumped in. It costs each company millions of dollars annually to clean the pipelines and rid them of these mussels as well as other biofouling organisms, which has now become a necessary and permanent expenditure for their operations. Of course, this money has to come from revenue generated from their consumers. The IMO estimates that marine invasive species are costing the world tens of billions of US dollars annually.
Human health hazard Ballast water poses tremendous risk to human health. In 1991, a cholera epidemic struck Peru. Millions of people were infected and more than 10,000 died, twice as many as the 9-11 terrorist attacks on the United States. There was an immense economic loss amounting to over US$200 billion in emergency response, loss of seafood exports and loss of tourism. This type of cholera was traced back to ballast water carried from Bangladesh. Ballast water also contains significant amounts of heavy metals, which can be incorporated into fish that humans consume, primarily shellfish which feed by filtering particles from the water column. The US Health Resources and Services Administration states that ballast water is a biological time bomb liable to engender significant disease in vulnerable populations anywhere in the world. This is a fact which is largely ignored. Jamaica s green mussel filters the water in Kingston Harbour to feed. This water is highly polluted and makes the green mussel a potential threat to human health if consumed. It may accumulate heavy metals as well as other agents of disease that can harm persons that consume the mussel. What is Jamaica doing? Jamaica is doing enough to control the importation of plants and animals via our airports and seaports. The Plant Quarantine Division of the Ministry of Agriculture has strict guidelines in place to regulate the importation of plants and plant materials and these may sometimes contain harmful pests and diseases that may threaten our native species. Some plants will displace native and in many occasions impact negatively on our endemic species, those found only here in Jamaica. The Division issues approximately 1,500 permits annually after their rigorous assessment of the risks. Animals are regulated similarly as they may have invasive characteristics, and in addition, contain diseases that may harm humans. However, absolutely nothing is being done to address the problem of organisms coming into our island via ballast water. This is a huge gaping hole in our system. One ship may release millions of organisms into our harbours during one visit that pose a threat to our biodiversity and human health. Jamaica has been very nonchalant about marine invasive species and their introduction via ballast water. The country is growing in trade each year, and as such, more ballast water will be dumped into our harbours at will. Some of the harbours directly influence tourist areas such as those found in Ocho Rios and Montego Bay. There is no policy or legislation in Jamaica to deal with this problem. A pioneering step is now being taken to change this situation by the Natural History Division of the Institute of Jamaica and The Department of Life Sciences (UWI Mona). This project will aim to discover which organisms are being brought into the country by ballast water and use this information to develop management strategies to deal with the problem in Jamaica. It will also involve all the relevant marine interests, both from the public and private sectors. This approach is critical for the success of this massive undertaking.
Ballast water invaders are causing the deaths of many people, the destruction of major fisheries and major changes to ecosystems. Jamaica is at risk as the country does not regulate the release of ballast water. The frail economic situation in this country, which hinges significantly on our tourism product cannot afford a Peru crisis. Procrastination may lead to our detriment, and the country must aim to be more proactive than reactive. Jamaica needs to become more aware of the negative impacts of our activity on the environment and begin to become more responsible citizens. There is a tremendous economic value for conserving our biodiversity, which is often ignored. Organisms in the world adapt themselves to suit a changing environment; humans on the other hand change the environment to suit themselves Dayne Buddo. Dayne Buddo Senior Research Officer Natural History Division Institute of Jamaica 10-16 East Street Kingston, Jamaica Tel #: (876) 922-0620-6 ext 249 Fax #: (876) 922-1147 Website: www.jamaicachm.org.jm Email: chm.nhd@cwjamaica.com