Picture From .. Google Images
In the summer of 2006 my friend and I were getting set to do some travelling on Vancouver Island. While the lure of Vancouver's beauty was compelling I have to admit that the promise of fresh luscious seafood was something we were both looking forward to immensely.
Our first dinner out of town was in a snug comfortable marina on the coast. Upon being seated, to our dismay we were told that there was no scallops or oysters for us to dine on. The waiter explained that there was a red tide alert on the West Coast, an outbreak of paralytic shellfish poisoning (PSP) was reported on the CBC news, and the only seafood that was not affected by these toxins were crab and shrimp. I swallowed my disappointment and proceeded to do justice to a large plate of shrimp and crab. After dinner my curiosity got the better of me and I went off to my room to do some research.
When certain algae go through their growth period, or bloom, "a single cell may replicate itself one million times in two to three weeks", reported the Nova Scotia Museum of Natural History. The algae captures and uses the sun's energy to grow. The growth of algae is an essential life process as it is the first step in transferring solar energy into aquatic food webs. These organisms thrive and multiply primarily during the Spring and Summer in response to the intensity from the sun and nutrients in the ocean water. During bloom reproduction the shallow warm sea water becomes discoloured as a result of various plant pigments used to trap sunlight. Depending on the species the water will reflect many colours including yellow, pink, violet, green, brown, however red is the most common pigment. This is how the name "Red Tide" is obtained.
When the water cools, the red tide can assume its dormant form where preformed cysts fall and accumulate on the ocean floor. Then later when the water is warmer and the sunlight is present, these cysts can germinate causing them to burst open and release swimmer cells into the ocean. These swimmer cells make their way into the marine life and their toxins are stored in the intestinal tracts and guts of most commonly oysters, muscles, clams and scallops.
So this is why I couldn't enjoy oysters on my vacation...interesting!
The most common of the harmful blooms is Alexandrium, which causes PSP via saxitoxin. Saxitoxin is a term used to include up to forty known toxins which disrupt the proper function of ion channels in neurons, which can lead to paralyzes of the respiratory system, and in worst cases death.
Global warming and pollution are on the rise and so is red tide. Not everyone enjoys fresh seafood but the impact of red tide is far more severe than not being able to eat seafood. What are we doing globally to stop these outbreaks? Who's jobs are at risk? Is the research being done? What are the findings? These questions and more must be brought to the forefront of government agencies worldwide. For myself, its not just about oysters anymore.
I'd be interested in hearing from anyone doing research in this area or who has any knowledge or experience with red tides they can share with me.
How a Toxic Algal Bloom Occurs
Northwest Fisheries Science Center and Washington Sea Grant Program