Sedimentation in the Chesapeake - look at the brown toward the headwaters. Found at nasa.gov
Rocks erode, travel down rivers and eventually in the form of small particles, settle in river deltas and estuaries. Even smaller pieces can be carried hundreds of miles into the ocean. It’s all part of the natural process of sedimentation, but like many other natural cycles, this one has been hijacked by human activities. Development, agriculture, channelization of streams, damming and many other practices change the natural course of sediment in the coastal oceans more than the ecosystem can handle.
These changes can either be a drastic increase in sediment runoff from upstream sources or a complete deprivation of naturally occurring deltas. In addition, many pollutants cling to these sediment particles so that changing the location of the sediment also shifts the location of pollution.
Sea Otters are turning up dead in central California. In 2007, 11 sea otters were recovered from Monterrey Bay. Over the last three years, dead otters washing up on beaches has reached a record high?
What could be causing all these otter deaths? Are there new predators in the area? Is there some kind of disease? Could increased otter deaths reflect an increase in otter populations, indicating not otter population decline, but otter population growth? The answer turns out to be even more surprising – freshwater algae.
The Great Big Blue looks like it contains nothing but water and maybe a little salt, especially out in the open ocean. However, this kind of sparse environment is exactly where the chemistry matters the most – it’s a fine line between not enough, too much, and just right. Given this, there’s no distinct myth here but an underlying unresolved question: what is the limiting factor that keeps the open ocean at low productivity?
The ocean is full of metals and minerals that naturally occur such as zinc, copper, and cobalt and many marine organisms therefore depend upon access to those metals in small concentrations. However, inshore marine systems receive inputs from industrial, mining, and stormwater runoff that far exceed what these organisms can use. So what’s the effect? There was recently a good review article by Mayer-Pinto et al describings the effects of these metals at the assemblage level that basically did my job for me, research-wise, covering both marine and freshwater systems.
In light of the BP oil spill, this week’s installment of Chemistry of the Great Big Blue will be particularly relevant to current events and hopefully already on the minds of everyone reading. Where do petrochemicals in the marine environment come from other than oil spills? Road runoff, refineries, plastic production, plastic degradation, atmospheric deposition and ocean circulation from other parts of the world, natural seeps, and the list goes on and on. It is important to note, however, that oil spills are not necessarily the predominant source of petrochemicals. So what exactly is a petrochemical and what does it do?
Dr. Tyrone Hayes is a professor of Biology at UC Berkley who has been at the forefront of some groundbreaking research into the developmental effects of the pesticide Atrazine on amphibians and mammals. Dr. Hayes runs the Atrazinelovers homepage, a site dedicated to educating the public about the effects of the pesticide on our environment and human health. His research and outreach have earned him the ire of many in the pesticide industry, especially from Syngenta, the company that manufactures Atrazine. The Oyster’s Garter provides a good introduction to his research here.
Below is a video of one of his talks, summarizing his research:
Remember when I promised to profile chemicals in the ocean as a New Year’s resolution? If not, here‘s my first in the series of one posts that resulted, reposted here as a reminder. As always, I encourage checking out the old comments. From now on, I still hope to give the series a second shot at life, so keep checking back for more installments of the series.
As my fellow fry-entists can attest, we know so little about the oceans that every deep sea expedition yields a handful of new species to describe, focus on saving one species may come at the demise of another, and people still won’t go swimming in some areas for fear Jaws will eat them. And that’s just a quick sampling of what we’ve written so far. The depth of our societal ignorance about the ocean and how it functions is enormous. Just as the fishermen of days gone by used to think that the sea offered God’s unlimited bounty, modern day people don’t seem to understand that the ocean isn’t an endlessly large dumping ground for all things undesired in our terrestrial lives. From trash to carbon dioxide to birth control pills, our oceans are the unfortunate downstream victims of human decisions. We don’t understand the impacts, sources, or even types of chemicals that are ending up flushed to the seas. One of my new year’s resolutions is to become more acquainted with the chemicals of the great big sea. Today’s profiled chemical: the unknown. Read More
With seafood season in full swing, I thought I’d repost this review of certification programs. I’ve learned lots since writing this article, most notably that the compiled data from the EDF study comes from a huge database of government sources. This gives me more confidence in their truth, but the areas tested are still light on estuaries. Everything else still stands. Please check back at the old site for comments.
Another thought process to add to the many considerations of food ethics: if you choose to eat seafood, which fisheries are sustainable and eco-friendly? For those of us who live on the coast, seafood represents local food that supports local businesses and helps make the connection between producer and consumer. So step one, deciding to eat seafood, has been taken. But then what? A number of nonprofits have taken on that burden and created seafood guides and certification to help you as an informed consumer. Only problem is, they sometimes differ in their listings based on what criteria they use and how they weight those criteria. Read More