Tag Archives: mussel

July 11 and 12

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Ecological Notes:

  • I believe most of the gulls eggs have hatched, based on the nests I can see with one to three chicks and discarded empty eggs nearby. The gull parents feed fish to their young. I am impressed how many whole little fish a gull catch then regurgitate for their chicks.
  • I am seeing more nursing harbour seals and pups around the south and east sides of the island. Today, I heard a pup communicating with its mother by little grunting sounds.
  • This afternoon, out of the corner of my eye, I saw a river otter scurry along a path by Tank Shed. I could not see if it was heading for the water or underneath the boardwalk, as they are elusive.
  • See the photo gallery below for more ecological happenings from the past two days.

Weather:

  • Yesterday (July 11):
    • Sky: Clear
    • Wind: W 1-33 kts
    • Sea: rippled, then 2′ chop in evening
    • Temperature Low 11oC, High 20oC
  • Today (July 12):
    • Sky: Clear, fog between 08:45-09:30 with foghorn
    • Wind: W 16-39 kts, gusts up to 44 kts (81 km/h)
    • Sea: 1′ chop in morning, then up to 4′ waves in afternoon and evening
    • Temperature Low 12oC, High 15oC

Visitors:

  • Yesterday, Greg came from the college to refill the diesel tank.

Facility Work:

  • Scrubbed and squeegeed solar panels, routine tidying and checking infrastructure around the island. With the clear days, the solar panels have been fully charging the batteries.

Vessel Traffic:

  • Many Canadian and American ecotour boats have been nearby and heading through the waters of the ecological reserve. There were much fewer boats today, with the high winds.

Here are photo highlights from the past two days. Click on the photos for larger views and captions.

Groundhog Day

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Wind: yesterday 0-52 knots from S to W, today 0-18 knots from W to NE
Sea State: yesterday rippled with waves up to 1 m in afternoon and evening, today rippled
Visibility: yesterday 5-10 NM, today 15 NM
Sky: yesterday rain then patches of sun, today clear
Temperature: yesterday 5-12 °C, today 3-5 °C
Atmospheric CO2: 414.49 ppm (recorded by NOAA at Mauna Loa Observatory, Hawaii)

This morning at sunrise, the elephant seals saw their shadows. As the lore goes for their fellow mammal the groundhog, that means six more weeks of winter. Hard to believe with the crocuses blooming and daffodils buds almost ready to burst. Although, there is snow in the forecast for tonight and tomorrow as the temperature drops to 0 °C.

There were no visitors to the island. Two eco tour boats were seen in the reserve this afternoon.

Here are the results for the weekly census, conducted in the afternoon of Sunday, February 2:
10 elephant seals (3 female adults, 4 male adults, 1 female pup, 1 male pup and 1 unknown gendered pup)
147 steller sea lions
288 california sea lions
104 harbour seals
10 bald eagles (5 adults, 5 juveniles)
1 raven
109 brandt’s cormorants
182 pelagic cormorants
49 double-crested cormorants
24 canada geese
931 gulls (most are thayer’s gulls)
18 black oystercatchers
1 whimbrel
1 surf scoter
8 harlequin ducks
16 black turnstones
1 snow bunting
1 fox sparrow

March 12 – Sunny Census Thursday

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Sunny
Wind: 0-13 knots SW in the morning, NE from mid morning to afternoon and SW in the evening
Air Temperature: Low 9.9°C, High 13.2°C
Ocean Temperature: 9.0°C

Three Pearson students came to Race Rocks this morning. Karen, Sunny and Hanne joined Martin, who has been here since Monday.

The students did some work this afternoon: sweeping all 99 steps of the lighthouse and continuing the process of stowing the chopped wood in all the nooks and crannies of the buildings, to be used next winter to heat the main house.

There was DND blasting happening in the morning and early afternoon on Bentinck Island, less than 1km away from the ecological reserve.

Today’s high temperature of 13.2°C, as measured at the ground weather station, was the highest recorded since 2006, when the weather station was installed. A high of 14°C was recorded by the instruments at the top of the lighthouse.

Three eco tour boats visited the reserve. One boat came very close to a group of sea lions swimming and others hauled out on the South Islands.

The low tide of 1.1m at 13:52, exposed lots of species from the low tide zone into the air. The shore and tidal pools were full of life: mussels, barnacles, limpets and lots of other flora and fauna of the sea. The oystercatchers and shore birds were having a feast.

There were no small birds perching birds seen today. There are usually a few fox, sparrows, savannah sparrows and occasionally juncos and robins zipping around the island.

Here are the results from today’s Megafauna Census:
Elephant Seal: 1
Steller Sea Lion: 54
California Sea Lion: 43
Harbour Seal: 52
Bald Eagle: 9
Great Blue Heron: 1
Crow: 1
Oystercatcher: 4
Double Crested Cormorant: 12
Brandt’s Cormorant: 21
Gull: 247
Canada Goose: 14
Pigeon Guillemot: 9
Harlequin Duck: 13
Surfbird: 3
Black Turnstone: 10
Rock Sandpiper: 2

Mytilus trossulus: The bay mussel

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musselpool4

These Mytilus trossulus were present in Tidepool 4 at Race Rocks in May, 2004.

 

Physical Description: Mytilus trossulus has a shiny blue-black to black or brownish thin, long shell. Its exterior is smooth with fine lines. The interior of the shell is dull blue with a darker edge. They can be up to 6 to 10 cm long, and 3 to 5 cm high.
Geographical Range: Arctic to Alaska and south to Central California. (approximate)
Habitat: Mussels attach themselves to rocks pilings & other objects in the mid-intertidal zone of shorelines where water is relatively calm. The elevation at which they can be found is limited by the sea stars in the lower intertidal zone and the risk of desiccation in the upper intertidal zone.
Feeding: Mussels are filter-feeders. They filter many litres of water by moving a set of cilia (long hair-like filaments) over their gills to produce a current-like movement and another set of cilia move the trapped food particles (plankton) into food grooves.


Reproduction: Many intertidal organisms’ reproductive cycles are adapted to the tide cycles. For Mytilus trossulus, for example, the gonads mature during the spring tides and they spawn after neap tides. The normal cycle of an invertebrate intertidal organism follows the basic pattern of fertilization and larvae. Fertilization can occur within the adult or in the water itself. A larva then develops in the female parent or in the water and it usually doesn’t look very much like the mature adult. The larvae float in the water for a few minutes up to a few months, depending on the species and reproductive cycle. They feed and grow until the end of their planktonic life, when they settle.
Domain Eukarya
Kingdom Animalia
Phylum Mollusca
Class Bivalvia
Subclass Heterodonta
Order Mytiloida
Family Mytilidae
Genus Mytilus
Species trossulus
Common Name: Bay Mussel
Behaviours: Often found in large aggregations.
Adaptations to environment: To resist to mechanical stress from the wave movement, mussels have developed a strong but not permanent attachment to the rocky substrate: their byssal threads. They anchor the mussel to the rock, but can be broken and remade so it can have limited, slow movement. Mytilus trossulus also naturally has a high tolerance to waves. Most intertidal mollusks have hard shells with simple structures that aren’t likely to break under the pressure from the waves. Mussels such as Mytilus edulis, a closely related species close their valves tightly at low-tide to avoid water loss at low tide. Like all intertidal creatures, mussels must expose their fleshy parts to feed, which also exposes them to the threat of desiccation (drying out) and predators. Almost all diurnal rocky intertidal animals feed only when the tide is high and the water is covering them.

In the early 2000’s the Pearson College students in the Environmental System classes would do a lab on mussel mariculture

References: ( referenced 2005)
Shells and Shellfish of the Pacific Northwest, A Field Guide. Rick. M. Harbo, 1997

Biological Bulletin, Vol. 193, No. 2, Oct., 1997 http://www.jstor.org/stable/1542764
Balanced Environmental – Bay Mussel – Mytilus trossulus http://www.balanced.ca/hd/mussel.html

http://www.wallawalla.edu/academics/departments/biology/rosario/inverts/Mollusca/Bivalvia/Mytiloida/Mytilidae/Mytilus_trossulus.html

Other Members of the Phylum Mollusca at Race Rocks.

taxonomyiconReturn to the Race Rocks Taxonomy
and Image File
pearsonlogo2_f2The Race Rocks taxonomy is a collaborative venture originally started with the Biology and Environmental Systems students of Lester Pearson College UWC. It now also has contributions added by Faculty, Staff, Volunteers and Observers on the remote control webcams.

Sara Correia, PC year 31

Amber O’Reilly, NWT PC 37