Elephant Seal Moulting

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Race Rocks is at the northern limit of distribution of the Elephant Seal. They often number from 2 to 3 large males and 4 or 5 females. Arriving in January, they usually stay through the summer on the middle island and then leave for several months in the winter. Elephant seals often undergo a juvenile moult on the local beaches of Victoria when several years old. This individual may be at the end of such a moult as it still has a few sore spots on it’s coat. They end up on beaches where they wallow in the sand to keep the flies off. Members of the public often report them to the “authorities” as being diseased in appearance as their skin is blistered and raw. There has even been an example in the past few years in the local Victoria area when an animal in such condition was reported to the authorities as sick and due to ignorance, the animal was shot by an animal control officer. Of course this outraged some of some local residents who had been observing it for weeks as it was going through the moult, but the mistake had been made. So humans — leave well enough alone. Misguided intervention is not helpful for this rather rare pinniped

The video of this female elephant was videoed off the South side of Race Rocks. It was done in hi 8 – before we had SONY cameras that would record in Digital. One can see the patchy skin typical of the moulting stage just behind the head. This seal had probably already gone through the most serious part of the juvenile moult, which may have occurred on one of the sandy beaches over near Metchosin. The barking in the background is from California sealions. 

Diving on the Underwater Turbine Project

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Thia article appeared in The Link, the college newsletter on  May 6, 2005. Link no. 79

Diving for the Underwater Turbine Project at Race Rocks was amazing. Our task wasn’t simple and the time was limited. To implement the project they need to know what is the best location to install the tidal power generator, so I went diving with Chris and Angie to Race Rocks on a beautiful and sunny Wednesday morning and an ADCP (Acoustic Doppler Current Profiler) was deployed there. The ADCP will collect current regime information for a month.

It was so deep and (Angie said) cold down there but a really interesting experience for both of us. I was filming while Angie and Chris would “drag” the heavy weights (25 kg underwater – that’s 40 kg on surface! – each!!) and position them to secure the device on the sea floor.

It was hard work in very strong current but also very satisfying. It’s awesome to go diving but it’s even nicer when you get to do something important underwater. And on our way back we happened to stop by the boat with the EnCana diver (who was extracting samples of sea floor rocks) and have a long chat with him, who explained to Angie and me many things about being a commercial diver and also about the wetsuit he was wearing. For those that saw the movie “Man of Honor” these pictures may be familiar… Angie and I got really amazed by the huge helmet the diver had and he let us try it. It even has a microphone on it (to communicate with the boat)!!! The benefits of diving….

Rita Santos (year 30)

Stratified Tidal Flow over a Bump- Richard Dewey

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doi: 10.1175/JPO2799.1
October, 2005,
Journal of Physical Oceanography: Vol. 35, No. 10, pp. 1911–1927.

Stratified Tidal Flow over a Bump
RICHARD DEWEY
School of Earth and Ocean Sciences, University of Victoria,
Victoria, British Columbia, Canada
DAVID RICHMOND AND CHRIS GARRETT
Department of Physics and Astronomy,
University of Victoria,
Victoria, British Columbia, Canada
(Manuscript received 8 October 2004, in final form 22 April 2005)

 

ABSTRACT: The interaction of a stratified flow with an isolated topographic feature can introduce numerous distur- bances into the flow, including turbulent wakes, internal waves, and eddies. Measurements made near a “bump” east of Race Rocks, Vancouver Island, reveal a wide range of phenomena associated with the variable flow speeds and directions introduced by the local tides. Upstream and downstream flows were observed by placing two acoustic Doppler current profilers (ADCPs) on one flank of the bump. Simulta- neous shipboard ADCP surveys corroborated some of the more striking features. Froude number conditions varied from subcritical to supercritical as the tidal velocities varied from 0.2 to 1.5 m s1. During the strong ebb, when the moored ADCPs were located on the lee side, a persistent full-water-depth lee wave was detected in one of the moored ADCPs and the shipboard ADCP. However, the placement of the moorings would suggest that, by the time it appears in the moored ADCP beams, the lee wave has been swept downstream or has separated from the bump. Raw ADCP beam velocities suggest enhanced turbulence during various phases of the tide. Many of the three-dimensional flow characteristics are in good agreement with laboratory studies, and some characteristics, such as shear in the bottom boundary layer, are not.

Dewey-RG-Bump-JPO2799

See the full version of this paper at:

ftp://canuck.seos.uvic.ca/papers/Dewey-RG-Bump-JPO2799.pdf

Canadian Geographic Kids Program

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The CBC TV crew accompanied us on a dive to Race Rocks in order to video a sequence that later was used on the nationally televised Canadian Geographic Kids program.

Solmissus marshalli –The Race Rocks Taxonomy

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solmissus

Solmissus sp. taken from the video linked below.

Solmissus marshalli lives in the midwater zone of seas. It feeds by swimming slowly with its tentacles stretched out. When animals bump into the tentacles, stinging cells fire and hold on. Depending on the size of the prey, it can take a jellyfish up to two hours to move food from its tentacles to its stomach. The jellyfish feeds on gelatinous animal plankton, other jellies and copepods. It is a secondary consumer.

In this video you can see two different species of jellyfish, Solimissus marshalli and Mitrocoma cellularia. These invertebrates are part of the phylum Cnidaria which include hydroids, scyphozoan jellyfishes, sea anemones, sea pens and corals. They are constructed of 2 layers of cells-the outer covering and the inner covering of the digestive cavity. Between is a jellylike layer (mesoglea). Some cells are specialized for digesting or stinging. The jellyfish is the sexual ‘medusa stage’ of a hydroid. The hydroid medusa has a membrane (velum) that grows inward from margin of the bell. Most of the 60 or so local jellyfishes are medusaes of hydrozoans; surprisingly very attractive, but usually very small and they often go unnoticed. These specimens were videoed by Jean-Olivier Dalphond and Damien Guihen on a sunny day of June 2001. Identification was by Dr. Anita Brinckmann-Voss. Anita regularly samples the waters of Race Rocks as well as nearby Eemdyck passage, Beecher Bay , Pedder Bay and Sooke harbour where the upwelling water from the Strait of Juan de Fuca often brings numerous medusae.

Species recognized by World Register of Marine Species (WoRMS) Biota Animalia

Cnidaria

Hydrozoa , Owen

Narcomedusae Haeckel 1879

Cuninidae Bigelow 1913

Solmissus

Solmissus marshalli Agassiz & Mayer, 1902

See this link for other hydroids:  https://www.racerocks.ca/tag/hydroid/
Other Members of the Phylum Cnidaria 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. 

Lester B. Pearson College:
2005 Debra Quek PC Yr 31

 

 

Mitrocoma cellularia : jellyfish – Race Rocks Taxonomy

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mitrocoma

Mitrocoma cellularia


In this video you can see two different species of jellyfish, Solimissus marshalli and Mitrocoma cellularia. These invertebrates are part of the phylum Cnidaria which include hydroids, scyphozoan jellyfishes, sea anemones, sea pens and corals. They are constructed of 2 layers of cells-the outer covering and the inner covering of the digestive cavity. Between is a jellylike layer (mesoglea). Some cells are specialized for digesting or stinging. The jellyfish is the sexual ‘medusa stage’ of a hydroid. The hydroid medusa has a membrane (velum) that grows inward from the margin of the bell. Most of the 60 or so local jellyfishes are medusaes of hydrozoans; surprisingly very attractive, but usually very small and they often go unnoticed. These specimens were videoed by Jean-Olivier Dalphond and Damien Guihen on a sunny day of June 2001. Identification was by Dr. Anita Brinckmann-Voss. Anita regularly samples the waters of Race Rocks as well as nearby Eemdyck passage, Beecher Bay , Pedder Bay and Sooke harbour where the upwelling water from the Strait of Juan de Fuca often brings numerous hydroid medusae. 

From NCBI taxonomy

See this link for other hydroids:  https://www.racerocks.ca/tag/hydroid/ Link to the Race Rocks Taxonomy index

This file is provided as part of a collaborative effort by the students, faculty, staff and volunteers  of 
 Date:
2005		 Garry Fletcher

Installation of Succession plates for the Tidal Energy project

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This video shows the installation process for the tidal energy generator research project. This was carried out by Chris Blondeau and the Pearson College Divers in order to determine which surfaces discouraged growth in the waters at Race Rocks. As a result, Titanium was used in the construction of some parts of the generator as it was one of the metals most resistant to fouling.

See other archived video with Pearson College Divers

Link to the Integrated Energy Project

Caprella laeviuscula: Caprellid shrimp– The Race Rocks Taxonomy

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We found these Caprellids at a depth of 20 metres attached to hydroids on a Balanus nubilus. They frequently dwell amongst hydroids. The size of this individual was 3mm. These individuals were photographed using a Motic Digital Microscope at 10X magnification. Note the response to stimulation by a dull probe.

In the picture below , the current meter float which was in the water for a year, came up covered with Caprellids. See this file on the Current meter:

Look closely to see these tiny skeleton shrimp clinging to bryozoans, hydroids or algae. Their body shape and color help the shrimp to blend into their background. Their bodies are long, cylindrical and range from pale brown and green to rose. Some species can quickly change color to blend into their backgrounds.

Skeleton shrimp look like, and sometimes are called, “praying mantises of the sea.” They have two pairs of legs attached to the front end of their bodies, with three pairs of legs at the back end. The front legs form powerful “claws” for defense, grooming and capturing food. The rear legs have strong claws that grasp and hold on to algae or other surfaces. They use their antennae for filter feeding and swimming.

Diet
diatoms (microscopic plants), detritus, filtered food particles, amphipods 
Size
to 1.5 inches (4 cm) long 
Range
low intertidal zone and subtidal waters in bays,

Conservation Notes

Skeleton shrimp are abundant and live in many habitats, including the deep sea. They play an important role in the ecosystem by eating up detritus and other food particles. 

Cool Facts

Shrimp, sea anemones and surf perch prey on skeleton shrimp. The females of some skeleton shrimp species kill the male after mating. 

Skeleton shrimp use their front legs for locomotion. To move, they grasp first with those front legs and then with their back legs, in inchworm fashion. They swim by rapidly bending and straightening their bodies. 

To grow, skeleton shrimp shed their old exoskeletons and form new, larger ones. They can mate only when the female is between new, hardened exoskeletons. After mating, the female deposits her eggs in a brood pouch formed from leaflike projections on the middle part of her body. Skeleton shrimp hatch directly into juvenile adults.

Source: Monterey Bay Aquarium:
Online Field Guide http://www.mbayaq.org/efc/living_species/default.asp?hOri=1&inhab=521

Other Members of the Phylum Arthropoda 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. This file was originally started by Kevin Mwenda PC Yr 31

Deploy and Retrieve ADCP Instrument 2005

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In order to predict the best location for the installation of the tidal power generator, an ADCP ( Acoustic Doppler Current Profiler) supplied by ASL Environmental Sciences was deployed. This instrument will collect current regime information for a period of one month. Rita Santos did the video and Angie Karlsen helped Chris Blondeau lift and position the concrete weights used to secure the device on the sea floor..

See other archived video with Pearson College Divers

Anthopleura xanthogrammica: Giant Green Anemone–The Race Rocks Taxonomy

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rmintertidalanem

Anthopleura xanthogrammica : photo by Ryan Murphy

Physical Description: As says its name, the Giant Green Anemone is the largest green anemone. The diameter of its column can easily reach 175 mm and its height, 300 mm. The column is covered with adhesive tentacles that are short and conical. The green color of the anemone changes, from bright green to a dark greenish brown.

Global Distribution: Anthopleura xanthogrammica lives in the tide pools along the Pacific coast. It can be found from Alaska to Panama.

Habitat: The Giant Green Anemone most likely lives on the rocks of tide pools, usually not deeper than 30 m. Also, it can be found in deep channels in exposed rocky shores.

Feeding: It eats with the help of thousands of nematocysts located on its tentacles. These paralyze the prey. Usually, the Giant Green Anemone feeds on detached mussels, crabs, sea urchins and small fishes.

Predators: This anemone can be eaten by crabs and sea stars, but its most common predator is the snail, which feeds on its tentacles or its column, and the sea spider, which feeds on its column.

Reproduction: To reproduce, Anthopleura xanthogrammica releases sperm and brownish eggs. When the larvae is formed, it swims or floats for a period of time and becomes dispersed. The reproduction of the Giant Green Anemone happens in late spring and summer
.
Interesting fact: Bright sunlight makes the green color of the anemone brighter by encouraging the algae that lives in its tissue to grow. But in the shade, the algae grows weak, making the anemone less colourful and more white in color. Also, a compound from Anthopleura xanthogrammica is now used as a heart stimulant.

Domain Eukarya
Kingdom Animalia
Phylum Cnidaria
Class Anthozoa
Subclass Zoantharia
Order Actiniaria
Family Actiniidae
Genus Anthopleura
Species xanthogrammica
Common Name: Giant Green or surf anemone

References:
Gotshall, Daniel W. Guide to marine invertebrates. Monterey : Sea Challengers, 1994.
Abbot, Donald P., Eugene C. Haderlie and Robert H. Morris. Intertidal Invertebrates of California. Stanford : Stanford University Press, 1980.
Giant Green Anemone. 1999. Monterey Bay Aquarium. 8 Nov 2005.

return to the Race Rocks Taxonomy gallery

This file is provided as part of a collaborative effort by the students , faculty, staff and volunteers of
Pearson College UWC
 Date:
2005		 by Caroline Laroche, Québec year 32