The document summarizes evidence that toxic diatom blooms responsible for sea bird mortality are spreading. Researchers analyzed stomach contents of pelicans and mackerel that died at Cabo San Lucas, Mexico, finding structures resembling the diatom Pseudonitzschia. Extracts from pelican viscera injected in mice showed low levels of the toxin domoic acid, causing diarrhea, convulsions and death. The study identifies Pseudonitzschia blooms as the source of bird toxicity from domoic acid, and recommends monitoring programs to detect future harmful algal blooms.

1. SEA BIRD MORTALITY AT CABO SAN LUCAS, MEXICO:
EVIDENCE THAT TOXIC DIATOM BLOOMS
ARE SPREADING
assignment of Marine Microbiology, Vrije University of Brussels, April 2009
Written by:
A. SIERRA BELTRAN, 1 M. PALAFOX-URIBE, 2
J. GRAJALES-MONTIEL, 3 A. CRUZ-VILLACORTA ~ and J. L.
OCHOA I

2. Lay Out of presentation
• Introduction
• Objective
• Materials and Methods
• Results and Discussions
• Conclusion and Recommendation

3. • Death of Sea Birds cases:
- Monterey Bay in 1991 (Work et al i,1991, 1993)
- Santa Cruz, California, U.S.A. 1992 (Work et al., 1993)
- Ensenada BC, Mexico in 1992
- Baja California peninsula, January 1996
Introduction

5. Introduction
Causes of the death
Domoic acid (DA) toxin

6. Objective
• To explain the death of the sea birds by
determining the presence of such toxic
microorganisms and/or DA in the
stomach content of both mackerel and
pelicans

7. Materials and Methods
Stomach content were observed by light microscopy ( × 400
and x 1000) and extracted, to obtain digestive tract (DT) and
liver (L) extracts
Extract from the viscera of the dead pelicans were made and
injected to the mice and observed for 48 hour
DA analysis was carried out by high-performance liquid
chromatography (HPLC) using the method described by
Quilliam et al. (1995) and IOC (1994)

8. HPLC apparatus
 (1) Solvent reservoirs,
 (2) Solvent degasser,
 (3) Gradient valve,
 (4) Mixing vessel for delivery of the mobile phase,
 (5) High-pressure pump,
 (6) Switching valve in "inject position", (6') Switching valve in "load position“
 (7) Sample injection loop,
 (8) Pre-column,
 (9) Analytical column,
 (10) Detector (i.e. IR, UV),
 (11) Data acquisition,
 (12) Waste or fraction collector.
www.wikipedia.com

9. Results & Discussions
The samples of Cabo San
Lucas pelicans and
mackerel showed some
structures resembling
empty frustules
corresponding to the
diatom Pseudonitzschia

10. Results & Discussions
Most of seabirds extracts
injected into mice
indicated very low
amounts of DA

11. Results & Discussions

12. Results & Discussions
40 min
139 min
DA intoxication such as akinesia, postration and scratching
All the animals had diarrhea
18 hr 1st
animals dead, others showed convulsions, loss of
lateral movement and motor incoordination
20 hr Dead
48 hr Survive mice: slight intoxication, e.g. akinesia, scratching
and lack of motor coordination
 The level action for DA in shellfish is 40 µg/g wet weight
 The upper limit allowed for human consumption of shellfish is 20 µg/g

13. Results & Discussions
DA was first isolated from
Chondria armata ("doumoi" or
"hanayanagi“), in Japan
DA can bioaccumulate in marine
organisms such as shellfish,
anchovies, and sardines
DA acts as an agonist to
glutamate receptors which open
Na+ ion channels in the
pstsynaptic membrane, inducing
depolarization (increasing Ca)
Chondria armata
www.algabase.org

14. Results & Discussions
Is there any correlation between species of Pseudonitschia to
the production DA?
- Blooming of P. Pungens No DA production
- Blooming of P. Pungens + P. Australis YES
• Is it possible to predict HAB

16. Conclussions &
Recommendations
• Pseudonitzschia sp. was identified as the source of the
birds death intoxication by DA
• Diatom blooms have been observed mostly during active
upwelling
• DA is difficult to detect unless a mouse bioassay is
conducted
• A monitoring program is recommended
• New tools should be developed to make economically
feasible a permanent monitoring program

17. Dank u well
Terima kasih
Thank you
Salamat
Gracias
Merci beaucoup

19. • Chromatography is the term used to describe a separation technique in which a
mobile phase carrying a mixture is caused to move in contact with a selectively
absorbent stationary phase. Different components of the sample are carried
forward at different rates by the moving liquid phase, due to their differing
interactions with the stationary and mobile phases.
• In HPLC: The Mobile Phase is a solvent. This solvent is pumped under high
pressure through a column.
• The Stationary Phase is a finely divided solid held inside the column.
• HPLC:It's used to find the amount of a chemical compound within a mixture of
other chemicals