ECOHAB crew members Zachary Epperson and Steven Loiacono get ready to deploy the new MLML CTD rosette. Photo credit: Dr. Jason Smith.
This guest post is written by Zachary Epperson whom is a graduate student at MLML and works with the Environmental Biotechnology Lab.
Over the past few weeks, several marine mammals, particularly sea lions, have been exhibiting some haunting symptoms: writhing on the beach, bending back their necks, or lying suspiciously motionless. As the NOAA-NCCOS-funded, collaborative (MLML, UCSC, MBARI, USC, SCCWRP, UCLA, and IOOS) Ecology & Oceanography of Harmful Algal Blooms (ECOHAB) project gears up for its third week of sampling, data-armed scientists are ready with an explanation—toxic algae. Along with an armada of robotic labs and water quality surveillance vehicles roaming the bay, this field effort provides higher temporal and spatial resolution than our weekly shore based monitoring, which detected initiation of a mixed species Pseudo-nitzschia bloom in April (http://oceandatacenter.ucsc.edu/PhytoBlog/).
The diatom Pseudo-nitzschia spp. is known to produce the neurotoxin domoic acid (DA), responsible for cases of domoic acid poisoning (DAP, also known as amnesic shellfish poisoning), when contaminated tissue is consumed in high enough quantities. Symptoms of DAP may include vomiting, diarrhea, abdominal cramps, headache and dizziness; in severe cases the victim may experience difficulty breathing, confusion, disorientation, seizures, permanent loss of short‑term memory, coma and death. For this reason, recreational harvesting of shellfish is usually quarantined from about late April to Halloween.
A light microscope slide from a phytoplankton tow containing Pseudo-nitzschia chains. Photo credit: USCS-Kudela Lab.
Though a spring bloom of Pseudo-nitzschia is typical, what’s surprising this year is the total DA load. According to Dr. Raphe Kudela (UCSC) levels this high haven’t been seen since the year 2000! And ECOHAB is out there to track it. Read the rest of this entry »