Researchers studying the western coast of the United States have gathered new evidence that sheds light on the complex dynamics of the near-shore environment. The insights provided by this massive new study will help to better manage and conserve sensitive coastal ecosystems and marine species.
What is unusual about the new study is its scope. Jane Lubchenco, from Oregon State University, is principal investigator for PISCO, the Partnership for Interdisciplinary Studies of Coastal Oceans. In that role she coordinates the efforts of a team of 100 scientists from four universities working along the 1,900 kilometer west coast of the United States.
"We have ecologists, oceanographers, geneticists, engineers, molecular biologists and more. And the thing that is unusual about this is that we have agreed to do the same kinds of monitoring and the same kind of experiments all up and down the coast all at the same time," explains Ms. Lubchenco.
The result is a snapshot of the coastal marine zone, an area that extends from the coastline to about 10 kilometers off shore. Ocean scientists refer to this area as the "bad zone" because shallow water, wave action, and currents make it difficult to study.
But an estimated 40 percent of the world's population live within 100 kilometers of a coastline. Human pollution, including toxic run-off from farms, factories and cities, are changing the physical and biological environments off shore. PISCO researchers are studying these pressures and learning how various parts of the ecosystem interact with each other.
"Our team has been trying to understand at very, very small scale - the microscopic scales of larvae, the young that are moving in the ocean - all the way up to the physical oceanographic scales of the system, the big major currents that sweep along the shore, how the system works and how it changes as you go along the shore," says Ms. Lubchenco.
Researchers have developed new tools to track the movement of fish through their lifecycles. Jane Lubchenco says the ear bone, or otolith, in the cranial cavities of fish acts like a mini-flight recorder that scientists can read and interpret.
"These otoliths are structures that add a new layer, sort of like a new layer of a pearl that is formed. Every single day there is a new layer that is added," says Ms. Lubchenco . "When you collect a fish you can extract the ear bone, the otolith, and essentially do a section through it and see rings and essentially do a section through it and see rings, much like the rings of a tree and each one of those rings represents a day and you can do microchemistry to analyze the different heavy metals that are present in these rings and every day the ring that is laid down is a reflection of the chemistry of the water in which that fish existed."
Another finding in the PICSO study uses genetic mapping to show that coastal marine species do not travel such vast distances as previously thought.
Jane Lubchenco: "Instead of envisioning a broad dispersal, everything being mixed up and down the shore, we are finding that for some species, the ones that have been studied so far - and the research is just beginning - there are very distinct neighborhoods like little ghettos or neighborhoods in a city. [They] stay much closer to home than we thought used to be the case for marine critters."
Rosanne Skirble:"Now, once you have this information, what do you do with it?"
Jane Lubchenco: "There is increasing concern that our oceans are not being taken care of, to the extent that they should be. There are many signals that our fisheries are crashing, more and more harmful alga blooms, these 'dead zones.' There are losses of many different species. Lots of our marine species, turtles and other critters are endangered, and there is increased recognition that we should be managing oceans much more responsibly and doing so in a way that is based on an ecosystem approach to oceans."
Using this approach, PISCO researchers are studying the interplay of many factors including the movement of larvae, the importance of preserving habitats, the interaction among species and the impact of shifts in climate and large scale ocean-weather events such as El Nino.
Lead scientist Jane Lubchenco says the PISCO study, still in its infancy, has already produced valuable information that adds to our knowledge of coastal ecosystems in the United States and elsewhere around the globe. She says it remains to be seen whether society will choose to use this new knowledge to better protect the remarkably delicate marine environment.
Photo courtesy of the Partnership for Interdisciplinary Studies of Coastal Oceans