SoundHAB: Blooms around Vancouver I late May to June 07

[Nicky Haigh]

Hello all
We have indeed lost fish again to suspected Chrysochromulina species in Quatsino Sound - this is the third year in a row.  The blooms started in early May, with detected odd fish behaviour combined with small flagellates in the water.  As happened last year, we saw Dictyocha speculum at the same time, peaking at cell counts of ~700/mL later in the month.  While the Dictyocha was at its peak we saw some mortalities, but the greater number happened a few days later.  Two sites were affected in Quatsino Sound, in addition, fish were affected in Nootka Sound as well.  If anyone has any helpful input in monitoring for and mitigation of Chrysochromulina we'd be overjoyed to get some useful info.  Presently we are only able to assume that mortalities are due to Chrysochromulina species by putting together the clues of the fish behaviour (lethargy combined with extreme skitteriness, leading to nosing into the corners of pens, hanging out in bubbles, and eventually gasping at the surface), presence of small round or teardrop flagellates that swim in a characteristic swim-stop-spin-swim way, that don't stain with Lugol's.  Because they're so small we even have difficulty quantifying them - and of course we can't assume all the nanoflagellates in the samples are toxic species.  Suspected Chrysochromulina blooms that have killed fish in this area have been extremely mixed - as well as the Dictyocha and nanoflagellates we are seeing the typical diatoms for this time of year.  The mortalities dropped off when the Skeletonema returned to dominance with high cell counts.
Heterosigma akashiwo has been blooming in Nanaimo Harbour and across the Strait (I don't know about Vancouver, but I assume the bloom originated over there) since May 27/28.  Cell counts were very high, thick rafts of Heterosigma had levels up to 150,000/mL (150,000,000/L, just in case you think that's a typo!)  I haven't seen it in Nanaimo Harbour this early before - it's about a month earlier than normal.  Luckily there aren't any fish at the research farm at the Pacific Biological Station in Departure Bay.  Early last week concentrations were down to ~30 cells/mL at all depths, but on Thursday it was rafting up again.  
In the past three weeks we have also had reports of thick Noctiluca blooms from Saanich Inlet to Quadra Island.  These haven't caused major problems at any farms affected, although one site did lose some feed days and saw a few mortalities, possibly from anoxia.  Oxygen levels at the site were definitely affected by the bloom. 
That's the status in BC today, who knows what will happen if it ever warms up?  I'll try to remember to post to this website and keep you southerners apprised of the HAB situation in the fun-filled North.
Talk soon,
Nicky
 
Nicky Haigh
Harmful Algae Monitoring Program
Rm 201, Building 373
Malaspina University College
900 Fifth Street
Nanaimo BC V9R 5S5
CANADA
Ph: (250) 740-6354
Cell: (250) 537-7176
haighn at MALA.BC.CA <mailto:haighn at MALA.BC.CA>