Pendrell Sound Monitoring Project – data from 12 August 2010 samples
Report date 16 August 2010
COMMERCIAL-SCALE SPAT SETTLEMENT PREDICTED FOR THIS WEEK AND NEXT WEEK!!!
(SEE DETAILS BELOW)
Note: Many thanks to Joe Sr and Joe Jr. of Baynes Sound Oysters for sending the following samples at the weekend!!
(A) Qualitative Pacific Oyster larval summary (samples were verified by Dr. Neil Bourne – thanks Neil!)
One 5-minute plankton tow at a depth of 1-2 m at each station was collected by plankton net (60µm mesh) from the Station 5 area.
| Biomass (low, medium, high) |
| Station |
Sample 1 |
Sample 2 |
Sample 3 |
| D hinge |
med |
med |
med |
| Umbone |
med |
med |
med |
| Eyed |
low |
low |
low |
In terms of percentages of different stages present:
5% late straight hinge stage
35% early umbo stage (10 to 14 days to settlement = approx 22nd to 26th August)
55% mid umbo stage (6 to 10 days to settlement = approx 18th to 22nd August)
5% late umbo (3 to 4 days to settlement = 15th / 16th August)
0% eyed larvae
So although there may be some settling now, the majority will settle towards the end of this week and during next week. This is also dependent upon the temperature remaining high (around 23 / 24°C) for good settlement. It is also likely that additional spawns may occur which may prolong the settlement season.
The vast majority of bivalves present in the samples were Pacific oyster larvae, with a few mussels and clams also present in small numbers.
This information, previous reports and project details can also be found at
http://www.viu.ca/csr/PendrellSoundMonitoringProject2010.asp
and
http://www.bcsga.ca/
(B) Quantitative plankton results (numbers of individuals per 5 minute tow)*
|
Sample 1 |
Sample 2 |
Sample 3 |
| Zooplankton |
| Cladocerans |
80 |
280 |
800 |
| Copepods |
29920 |
16920 |
28000 |
| Crab Larvae |
1120 |
0 |
2160 |
| Ctenophores |
120 |
40 |
160 |
| Eggs |
0 |
0 |
0 |
| Foraminifera |
0 |
0 |
0 |
| Gastropods |
0 |
120 |
0 |
| Jellyfish |
0 |
0 |
0 |
| Polycheates |
0 |
280 |
0 |
| Rotifers |
0 |
0 |
0 |
| Spirorbis |
0 |
0 |
0 |
| Larvaceans |
80 |
560 |
840 |
| Bryozoan |
|
1080 |
520 |
| Bankia setacea (shipworms) |
| Early |
0 |
0 |
0 |
| Mid |
0 |
0 |
0 |
| Late |
0 |
0 |
0 |
| Mytilus edulis (mussel) |
| Early |
0 |
0 |
0 |
| Mid |
0 |
0 |
0 |
| Late |
40 |
80 |
200 |
| Ostrea lurida (native oyster) |
| Early |
0 |
0 |
0 |
| Mid |
0 |
0 |
0 |
| Late |
0 |
0 |
0 |
| Clams |
| Early |
0 |
0 |
0 |
| Mid |
80 |
40 |
40 |
| Late |
0 |
0 |
0 |
| Crassostrea gigas (Pacific oyster) |
| Straight Hinge |
440 |
0 |
0 |
| Early Umbo |
2880 |
0 |
40 |
| Mid Umbo |
2120 |
1400 |
840 |
| Late Umbo |
120 |
280 |
320 |
| Eyed |
0 |
0 |
0 |
| Biomass (low, medium, high) |
| D hinge |
med |
med |
med |
| Umbone |
med |
med |
med |
| Eyed |
low |
low |
low |
* Please note that only plankton tow samples were taken. No algal identifications or site conditions will accompany this data.
Helen Gurney-Smith, PhD
Research Scientist
Head of Shellfish Health & Husbandry Program
Center for Shellfish Research,
900 5th St,
Nanaimo. BC V9R 5S5
Phone: 250 740-6381
Fax: 250 740-6353
Helen.Gurney-Smith@viu.ca