Posts Tagged ‘Crescent gunnel’

What a day in Pedder Bay!

October 2, 2013

Yesterday was the first day of October and there was an incredible amount of animal activity around Pedder Bay.

GBH

GBH on ramp

The first animal of note was a Great Blue Heron (Ardea herodias) on the ramp down to the Pearson College dock.  It was very distracting to Marine Science students…

Distracted

At the same time the heron was making its way down to the dock, three mink also scrambled down towards the water. Since it was difficult to keep the class focused, we went down to the dock and checked the succession substrates that were suspended over one year ago.

Succession1 Succession2

Lots of bryozoans, hydrozoans and several crescent gunnels (Pholis laeta).

While down at the dock, second year marine scientists noticed a hooded nudibranch (Melibe leonina) drifting around at the surface.

Melibe

Not a great photo or video footage but a very cool little watermelon-smelling organism!  Cool enough to have a song written about it by Hanne and Killaq.

Slug song

First year marine scientists measured the variation in temperature and salinity off the Pearson College dock after big rainfall during the weekend.

Depth (m) Temperature (oC) Salinity (ppt)
0 11.3 11.9
0.5 10.7 30.6
1 10.5 30.8
2 10.5 30.9
3 10.4 30.9
4 10.5 31.0
5 10.5 29.7
6 10.5 29.0

While collecting these data we spotted some further animal activity at the mouth of Pedder Bay:

Submarine1

Submarine2

A submarine being escorted to the Navy dock.  What a day!

Early succession – diatoms, shrimp and fish

October 26, 2012

On 10 October 2012, B block marine scientists went down to the Pearson College dock and checked on the substrates that they had suspended in the water on 7 September 2012.

After a month there have been some changes:

 September

A bleach bottle is now covered in benthic diatoms:

 October

So is the piece of cinder block:

 SeptemberOctober

And a glass jar:

 

September

October

The “Kraken” bottle is covered in diatoms too:

September

October

And it is home to at least one dock shrimp:

 

 

 

The tire also housed several shrimp (the photos didn’t turn out though, sorry!)

 

 

And the substrate below…

 

 

…had a crescent gunnel living between the bottle and the mesh covering.