Toxins in the Ocean
A wide range of synthetic chemicals and heavy metals now infuse our oceans worldwide. These create a dangerous condition for both marine wildlife and people through their persistence, toxicity and ability to accumulate. “Bio Magnification” is a term that refers to the dramatic increases in concentration of these compounds up the food chain- often increasing levels by a factor of 15,000 or more from phytoplankton to large predators like tuna. At such levels, they can disrupt hormonal balances, weaken and even kill marine life. Marine debris also plays a surprising and important role in this toxic escalation. Plastic is made of long chain hydrocarbons which are attracted to many of these chemicals. Chemicals like DDT may actually adhere to the surface of the plastic- massively increasing the lethality of these plastic bits if later consumed by fish. Plastic may in some circumstances have 1,000,000x higher levels of these chemicals than ambient seawater.
Toxic chemicals trickle into the environment from various sources such as factories, farms, homes, automobiles, plastics, etc. These chemicals become a part of the plants and animals at the bottom of the food chain. Fish studies are relevant to humans as well as the environment. Toxins make their way up the food chain as the big fish eat the little fish, and humans eat the big fish. The toxins become a part of the human diet, and can cause birth defects in children and toxicity in adults. Every country is a source of the run-off, which is why we need a global solution to reduce these chemicals.
Recent progress has been made at a global level with three important UN Conventions. These seek to increase transparency, restrict trans-boundary movement and eliminate the worst actors.
The Stockholm Convention was first adopted on 22 May 2001 and targets the identification, listing and elimination of “Persistent Organic Pollutants” or POPs. These are particularly dangerous compounds that are both toxic and nearly eternal in their presence. Persistent Organic Pollutants (POPs) are organic chemical substances, that is, they are carbon-based. They possess a particular combination of physical and chemical properties such that, once released into the environment, they:
- remain intact for exceptionally long periods of time (many years);
- become widely distributed throughout the environment as a result of natural processes involving soil, water and, most notably, air;
- accumulate in the fatty tissue of living organisms including humans, and are found at higher concentrations at higher levels in the food chain; and
- are toxic to both humans and wildlife. (source UNEP)
POPs are commonly seen as either pesticides, industrial chemicals or by products. With a carbon backbone, these complex molecules have Chlorine, Bromine and Flourine atoms at their core. DDT and PCB’s are perhaps the two best know POPs.
The Rotterdam Convention entered force in 22 February, 2004 and is focused on the concept of “Prior Informed Consent”. PIC refers to creating a mechanism for individual countries to control movement of listed toxins across borders.This convention requires all party nations to identify, characterize and list import restrictions on listed chemicals. As such, a country will make a legally binding determination that controls movement into their country. As such, this is particularly important to prevent movement of these chemicals into a country with their “Prior Informed Consent”.
There are 40 chemicals listed in Annex III of the Convention and subject to the PIC procedure, including 25 pesticides, 4 severely hazardous pesticide formulations and 11 industrial chemicals. Many more chemicals are expected to be added in the future. These include some of the most dangerous chemicals known to man e.g. – DDT, Mercury, Chlordane and Asbestos.
The Basel Convention was the original platform for the control of environmental toxins. The convention came into force in 1992 and now has 172 member nations. In the late 1980s, a tightening of environmental regulations in industrialized countries led to a dramatic rise in the cost of hazardous waste disposal. Searching for cheaper ways to get rid of the wastes, â€œtoxic tradersâ€ began shipping hazardous waste to developing countries and to Eastern Europe. When this activity was revealed, international outrage led to the drafting and adoption of the Basel Convention.
During its first Decade (1989-1999), the Convention was principally devoted to setting up a framework for controlling the trans-boundary movements of hazardous wastes, that is, the movement of hazardous wastes across international frontiers. It also developed the criteria for â€œenvironmentally sound managementâ€. A Control System, based on prior written notification, was also put into place. This was the basis for the PIC that developed later with the Rotterdam Convention. Recent efforts have focused on developing regional centers of excellence to support individual countries. One example is the Coordinating Center for Latin America in Montevideo. Sea Dragon will visit this site in early 2011. In addition there is an important push to further increase use of “greener” alternative chemicals.
The Pangaea/5 Gyres team is heavily involved in marine toxins on two fronts. First and most prominently, our open ocean debris sampling collects both plastic and marine life samples that are tested for toxin presence – particularly POPs. Upcoming work will look carefully at not only the levels of these chemicals, but attempt to verify a suspected link between the actual debris and fish. Fish eating these small, toxin loaded, plastic particles are expected to have a clear signature of the same chemicals.
Second both at sea and in port, expedition teams are collecting tissue samples from larger fish. These samples can be tested directly to reveal an overall picture of toxins. Many of these fish, like Tuna, Marlin and Jacks become our food. As such they contribute to our own toxin loads- often called our “body burden”
We are now working directly with the Safe Planet: the United Nations Campaign for Responsibility on Hazardous Chemicals and Wastes. Sea Dragon’s upcoming voyages will be tracked and followed by Safe Planet. This will help increase global awareness and provide much needed information on the remote high seas.
Here are just a few of the recent links relating to Ocean Toxins