Wednesday, December 14, 2011

Port Townsend Marine Science Center finds unique phytoplankton


Last week Port Townsend Marine Science Center Sound Toxins volunteers Linda Dacon and Darryl Hrenko identified the presence of the relatively rare phytoplankton species, Dinophysis tripos:

Photo of Dinophysis tripos taken by Linda and Darryl on 12/7/2011 in the Discovery Lab at Port Townsend Marine Science Center

The sample containing D. tripos was collected at the Cape George Marina in Discovery Bay of Puget Sound and was an exciting find for our Sound Toxins team. This is the first identification of D. tripos at Port Townsend Marine Science Center since the start of the Sound Toxins program (formerly known as ORHAB) in 1999.
Dinophysis tripos is a type of phytoplankton that falls under the phylum of Dinoflagellata. Some of its defining characteristics are:

  • A toxic marine species that is commonly found in tropical to warm temperate coastal waters
You are probably wondering… what is D. tripos doing in the chilly waters of Puget Sound at Port Townsend Marine Science Center?!?! We consulted our contacts at NOAA and found that as far as distribution goes, it is commonly found in warmer coastal waters but sometimes detected in Puget Sound.

  • D. tripos is found in neritic (coastal), estuarine and oceanic waters
  • It is rather large, measuring in at about 100µm in length

 This little guy (actually it is sexless but we will call it this as a term of endearment) is about 100 µm (micrometers or microns) long! To give us some perspective, that’s equal to one tenth of a millimeter! If you’re wondering how Dinophysis tripos sizes up to some other common miniatures, here are some comparisons for you:

Dinophysis tripos is…
  • About 10 times bigger than a red blood cell 
  • Only 5 to 10 times bigger than most bacteria cells

  • The Genus Dinophysis was discovered in the mid-1800s

  • D. tripos is connected to Diarrhetic Shellfish Poisoning (DSP)

There are many species of Dinophysis connected to historic events of DSP. DSP is one of four recognized symptomatic types of shellfish poisoning (others being paralytic, neurotoxic, and amnesic). D. tripos releases the toxin dinophysistoxin-1 (DTX-1) which is linked to DSP.

Here’s what Brian Bill, a phytoplankton expert at NOAA had to say about the finding:

“As far as toxin content or production from this specific species, not much is known. It is known to produce some amounts of Okadaic acid and Dinophysis toxins, but how much and whether more or less than other species if something we don't know. They are particularly hard to culture in the laboratory because their normal mode of feeding is preying on ciliates such as Mesodinium rubrum, which in turn prey on small cryptophytes for their nutrition. With all those levels of complexity, it's difficult to culture them and find out what conditions facilitate production and what types and ratios of toxins they produce. Hopefully in the near future we can answer some of those questions... the recall of shellfish from Sequim Bay last year and the outbreak in Canada during the same time will hopefully translate into funding so some of those questions can be answered.”

So thanks for checking in with us and stay tuned for more updates on marine science, phytoplankton, coastal issues...

Port Townsend Marine Science Center