Monthly Archives: June 2003

Tidepool #2 at Race Rocks

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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. A characteristic of the pool that is significant is that it is deeper than most of the other pools and it provides good variations in stratification of temperature and salinity.

Some ideas to consider:
The stratification of Salinity and Temperature in this pool is quite distinct. More work could be done in gathering seasonal records of this. Also, the main organisms, harpacticoids are abundant in the late spring and summer. It may be interesting to identify their source of food, probably diatoms that form a thin layer on the walls. Since the pool only receives new salt water occasionally, temperatures can fluctuate. The pool is however usually shaded by the rock cliff to the South.

Tidepool # 1 – Near Peg 6

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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 is located beside Peg #6 and is one of the highest elevated tidepools of the set.

Tidepool Index

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USE THIS INDEX INSTEAD

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

Ecological Equivalents Galapagos Islands vs. Race Rocks

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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

 

 

Tigriopus californicus: Harpacticoid–The Race Rocks Taxonomy

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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.

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.   G.Fletcher

 

The Giant Pacific Octopus

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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.