These pools are located 0n the West side of Great Race Rocks. They are located at slightly different elevations resulting in different abiotic factors in the pools and different life forms in the pools as well. Our students brave the elements to get some measurements in this video
| Tidepool 1 | |
| Tidepool 2 |  |
| Tidepool 3 |  |
| Tidepool 4 |  |
| Tidepool 5 |  |
| Tidepool 6 |  |
| Tidepool 7 |  |
| Tidepool 8 |  |
| Tidepool 9 |
not available |
| Tidepool 10 |  |
| Tidepool 11 | not available |
| Tidepool 12 |  |
| Peg 5: Tidepool 13 artificial |
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BACKGROUND: As you encounter different ecosystems representing a wide range of ecological niches in different parts of the world, you will begin to notice that there are many examples of organisms which may not even be related which play the same role in the ecosystems of widely separated geographic areas. I came across several examples which may be considered “ecological equivalents” while spending a week aboard the vessel “Samba” in the Galapagos Islands in June 2003. Although separated by 47 degrees of latitude and thousands of miles, surprisingly there are several examples of ecological equivalents on the island archipelagos of Race Rocks and the Galapagos. Islands.
DEFINITION.…Ecological equivalents : species that use similar niches in different habitats or locations are called ecological equivalents .The evolution of life has resulted in general types of habitats and certain successful ways of exploiting the resources in those habitats. Parallel evolution has resulted in unrelated species that have similar niches in different environments.
ECOLOGICAL EQUIVALENTS : GALAPAGOS ISLANDS VS. RACE ROCKS
We frequently find abundant populations of Harpacticoids in the high tidepools number 10, 7 and 2 at Race Rocks
Populations can fluctuate widely through the seasons.. Since pool 7 is at the highest elevation, it may not receive new inputs of seawater unless there is a wind from the West. In the summer, with no rain, and with elevated temperatures, this shallow pool will develop salt crystals. At that time, the only population of Tigriopus californicus is in pool 2 which is deeper and shaded, and in pool 10 which is small but shaded. Later on, in October, pool 7 may have an abundant population concentrated along the vertical walls of the pool. In this photo, The photo above was taken on a compound microscope at 10 power, but it has been enlarged considerably by photomicrography
In this photo Gerald has scooped up a sample from pool 10,where they are visible to the naked eye as small moving reddish dots.
Research done on this organism by the student T.C. Merchant at the Hopkins Marine Station of Stanford University in 1977, refers to this unique osmoregulatory adaptation for this Euryhaline environment.
“Abstract: Tigriopus californicus exhibit a unique osmoregulatory behavior which is highly adaptive in the high splash pool habitat. They conform osmotically in intermediate salinities and regulate hypo and hyper osmotically in high and low salinities respectively. Gut fluid appears to remain isosmotic with the environment. Evidence is presented to suggest the gut may be a regulatory surface in Tigriopus. The range of osmoconformance depends on the length of acclimation to a given salinity. O2 consumption in Tigriopus is high in low salinities decreasing as salinity rises. Metabolism appears not to change significantly over the conforming range 35 to 60 0/00″
Other interesting research on this organism has been on its Phylogeny. Research done in southern latitudes on Tigriopus revealed one of the highest levels of mitochondrial DNA differentiation ever reported among conspecific populations. S.Edmands ( Molecular Ecology,Volume 10 Page 1743 – July 2001) showed that populations from Puget Sound northward had significantly reduced levels of within-population variation based on cytochrome oxidase I sequences. These patterns are hypothesized to result from the contraction and expansion of populations driven by recent ice ages.
The Pesticide Action Network North America.lists extensive results of toxicity studies with Pesticides using Tigriopus californicus.
Dr. Maarten Voordouw working with Dr.Brad Anholt of the University of Victoria has researched the evolution of Sex ratios in Tigriopus californicus. He found there to be a variation in offspring sex ratio larger than the binomial expectation, and that females produce male-biased clutches at higher temperatures. The trait is heritable and is transmitted primarily through the paternal line. http://web.uvic.ca/~banholt/anhlabsite/tigs.html
Other Members of the Phylum Arthropoda at Race Rocks.
 Return to the Race Rocks Taxonomyand Image File |
 The 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. G.Fletcher |
Giant PacificOctopus frequently appear at Race Rocks in the subtidal waters. They are also seen occasionally washed up in the intertidal zone where they contribute to the energy flow of the gulls and eagles. This individual which had died recentlyin June 2002, became the subject of a webcast and an impromptu dissection on the shore.
The most difficult transects to do at Race Rocks Ecological reserve are those underwater. Through the years we have done a number of these, mostly in training sessions with the Pearson College Divers. We experimented with various types of spools for laying out a line, types of weighted line, measuring tape, quadrat sizes, types of underwater paper on clipboards, types of pencils or writing devices etc. The best arrangement was using a 30- 50 metre long tape which could be attached to the peg on shore and then taken out by the diver in a predetermined compass direction. The biggest problem other than the narrow window to get the work done was always the kelp cover, making the process very difficult in the later part of the year when the Nereocystis, (bull kelp) cover would make it impossible to access some areas. The divers working in pairs would then proceed along one side of the line producing a record of the belt transect.
Laura Verhegge and students of Pearson College doing an underwater transect off peg #1 at Race Rocks.
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Return to the Contents page for Environmental modelling with Transects..
In May 2004 the biology class measured features of several pools, including this one, pool 10.
This file has been started to present some of the information we have accumulated on the pool in order to stimulate students to raise further questions and devise problems that can be investigated at the pool. It is also intended to be part of a cumulative digital legacy that those examining the pool can pass on to future students.
This pool has a diameter of less than half a meter .This pool is characterized by having a base of white crystalline quartz. It is also shaded for much of the day, and is usually filled with harpacticoids.
white quartz with harpactacoids visible
SEE THIS REFERENCE in the Race Rocks Taxonomy on Harpacticoids
A large amphipod and the small red harpacticoids in pool 10
Short -Billed Dowitchers, photo by Riley Strother, April 20 2017
This juvenile short-billed Dowitcher was seen up near the tower in August 18 2009. It was very tame and quite unconcerned with the local humans. Image by Ian Perry.
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| The same juvenile, (Aug 18/ 09) , | shown above. Images by G.Fletcher |
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| Dowitcher probing for invertebrates | Note the Halosaccion band of the intertidal zone where it is feeding | rear view- note buff colored underparts | side view- note dark eye. |
| Eukarya | |
| Kingdom | Animalia |
| Phylum | Chordata |
| Subphylum | Vertebrata |
| Class | Aves |
| Order | Charadriiformes |
| Family | Scolopacidae |
| Genus | Limnodromus |
| Species | griseus |
| Common Name: | Short Billed Dowitcher |
The Short-billed Dowitcher breeds in Northern Canada. It winters in South America.
It occurs rarely and solitary at Race Rocks where it stops on migration. Short-billed Dowitchers normally are birds of mudflats along the Pacific Coast. One individual bird was filmed on May 1 2003 (above)as it probed for food among the barnacles and algae of the Halosaccion zone at Race Rocks.
In the photo to the right from September 2005, another dowitcher roamed through the area near the base of the rock on the East side. So presumably we have pictures of the stopover going North and South!
This video shows the Short-billed Dowitcher (Limnodromus griseus) in the intertidal zone to the East of the docks at Race Rocks. Note the “sewing machine ” action as it probes for food. The biology class watched this bird on May1/03 before starting on an intertidal transect in the same area. The coloration was noticeably buff-colored when compared to other shore birds. This individual was very fearless, even returning to feed briefly nearby after we had laid down our transect. This is normally a bird of the Pacific Coast mudflats.
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Other Members of the Class Aves at Race Rocks.
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| Return to the Race Rocks Taxonomy and Image File |
| The 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. May 2003– Garry Fletcher/strong> |
Our thanks to The Royal British Columbia Museum for providing this photo taken by Brent Cooke.
Domain Eukarya
Kingdom Animalia
Phylum Echinodermata
Class Asteroidea
Family Goniasteridae
Genus Ceremaster
Species arcticus (Verrill 1909)
Common Name:
Ceramaster arcticus (Verrill 1909) (Goniasteridae)
From the information Phil Lambert submitted to Syesis, 11:61–64 (1978)
Ceramaster arcticus (Verrill 1909) (Goniasteridae)
British Columbia: Race Rocks, Victoria, 9 m, one specimen (BCPM 973-251-34);
Winter Inlet, Pearse Island, 23 rn, one specimen (BCPM 974-224-43);
Work Channel, 31 m, two specimens (BCPM 974391-6);
northwest of Queen Charlotte Islands, 119 m, one specimen (NMC 1733).
Previously known from Bering Sea to St. Paul Harbour, Kodiak Island, Alaska (57*461N, 152*27W) (Fisher 1911), littoral zone to 186 rn (D’yakonov 1950). The specimen from Race Rocks (48*18’N, 123,36’W) extends the known range 2180 km southward.
References :
Philip Lambert, New geographic and bathymetric records for some northeast Pacific asteroids (Echinodermata: Asteroidea) Syesis, 11:61–64 (1978)
Royal British Columbia Museum Collection data.
| Catalogue Number: | 973-00251-034 |
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| Collector’s Field Number: | |
| Scientific Name: | Ceramaster arcticus |
| Collection Date(YYYY-MM-DD): | 1973-09-18 |
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| Location Name: | Victoria; Race Rocks |
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| Location Description: | passage between lighthouse and small islets in the lee of the rock |
| Province/State: | British Columbia |
| Other Members of the Phylum Echinodermata at Race Rocks |
| Return to the Race Rocks Taxonomy and Image File |
| The 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.
Garry Fletcher |
On a field trip to Race Rocks with the Biology class in the spring 2003, we took some time to observe and video the surge channel out on the south-west tip of Great Race Rock. It was a calm day which had been preceded by a few days with storms out in the Pacific Ocean. The energy imparted to the water column was just now reaching Great Race and the water was breaking on the west shore. The effect of “Surge” as an abiotic factor is not often considered in affecting the intertidal zonation of organisms on rocky coastlines in marine biological research. See this file on this abiotic factor.
It is our firm belief that here, the level up the shoreline in the intertidal zone where many invertebrates and algae can survive is elevated. These intertidal organisms are able to keep moistened longer, ambient temperatures are depressed from evaporation and and they even have longer availability to food resources being carried in the surging water. This is most obvious with the Goose Neck barnacle population and the intertidal anemone distribution along this shore. Additionally the tidepools up the channel are flooded more frequently, resulting in lower temperatures and more stabilized salinity conditions. It should be emphasized that this is not directly “wind-driven” water movement. As one can see in the video, the surrounding sea is calm, with little wind that day.
 A general view of the pool.It is perched on a shelf which easily gets flooded when there is a slight swell in the ocean. |
 Polymorphism in the Snails of Pool # 4, Extended essay in Environmental Systems, |
 A student examines the life of pool 4 |
 A mphipods collected with a suction bottle from pool#4. |
 A microscopic picture of the diatoms that grow as a fuzz in the pool in the early spring. They remain a few months until they are grazed off. |
 Roberto and the Biology Class measure salinity in pool 4.. May 2004 |
 Enteromorpha growing in the pool. May 2004. |
 Bay mussels, Mytilus trossulus in the brackish water of Pool#4 |
 In May 2004,it is clear where the grazers, Littorina snails and amphipods) have trimmed off the diatoms on the bottom. |
 Arunas measures the depth of pool 4 while watching for swells |
 In February, 2007, the diatoms cover almost the entire bottom of the pool. This is the winter pattern. Grazing as shown above gradually removes the covering of diatoms.
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 January, 2007. The tide is at its peak today, showing pool 4 being entirely submerged. |
 On February 11, 2008 a beast is photographed in the tidepool. |
 Close up of the Filamentous golden algae filling the tidepools in early spring. |
 Weird form shades a covering of diatom fuzz! |
Some ideas to consider:
Invitations to Inquiry:
This pool is unique in a number of ways. The white substrate in the bottom of the pool is the result of a quartz intrusion that has flooded while molten, through the cracks of the basalt.
What is the effect of this white reflective surface on the temperature of the pool and the organisms that live in the pool?In 1997 while doing a detailed analysis of the organisms in the pool, we noticed for the first time that there were white periwinkles. At that time 26 were counted by Nadia and Catherine. Speculate on the evolutionary implications here.
The mussels in pool #4 are Mytilus trossulus, the bay mussel. Mussels that you can see on the surrounding intertidal areas are the Mytilus californianis. Why the species difference?
The pattern of diatom distribution changes in the bottom of the pool. In the winter, it covers the pool with a thick felt-like appearance, as spring approaches, the cover of diatoms starts to disappear, starting along the cracks where the mussels are anchored.. could one measure the rate of grazing from the amphipods in the cracks?
Temperature and Salinity in the pool fluctuate widely and at times form stratified layers. How does this affect organism distribution.?
The biotic and abiotic features of this pool vary considerably from other pools in the near vicinity. Quantify and explain the differences or similarities.
The only other pool that resembles this one is found over on the north-east corner of the island, at location peg15-pool #14. Compare the biotic and abiotic factors of these two pools, and explain the differences.
The following lab on tidepool abiotic factor measurement was done by Chiara Ravetti in September,2005.
Biology Laboratory
Analysis of the Abiotic Factors in Race Rocks Tidepools
The measurements of salinity, ph, and temperatures of different tidepools at Race Rocks was done September19, after 11.30 a.m., with high tide. For this reason the pools selected were only five, two (pool 7 and 8) several meters away from the sea at that time of the day, the other three (pool 1, 2 and 4) closer to the water and larger.
Data analysis and further note
| pool 1 | pool 2 | pool 4 | pool 7 | pool 8 | Ocean water | |
| Salinity | 62.1 | 32.8 | 21.9 | 45.3 | 45 | 30 |
| Temperature | 14.4 C | 14.4 | 14.2 | 15.4 | 15.2 | 10 |
| ph | 8 | 6.8 | 6.9 | 7 | 8 | — |
The measurement of salinity is expressed in parts per thousand; the instrument utilizes electricity, that passing through salt ions determines its quantity.
The pools were contaminated by sealions excrement, which reduced the visibility inside the pool and probably altered the pH of the water.
Other factors which might affect these values in a tidepool are: evaporation, precipitation, and in general pollution, scarce precipitation at that time of the year, the presence of the estuary, (The Strait of Juan de Fuca) with the influence of fresh water. The salinity in a tidepool is higher than the sea, for the evaporation and the little exchange of water, therefore the organisms living in it must tolerate high salinity, as well as variations in temperature. The smaller tidepools further from the sea present even more significant changes.
