SECTOR 4: PEDDER BAY

 

Aerial Map Courtesy of the CRD NATURAL AREAS ATLAS
Helicopter Images from GEOBC

 

The geography of Pedder Bay and the exposure of its shores to the marine environment results in a number of contrasting ecosystems on the upland part of the shores. It also contributes significant materials to the marine environment and through four or five months of the year contributes a large volume of freshwater, acting more like an estuary than a regular bay. Click on the sectors of the bay above to jump to the sector pages.
Pedder Bay, British Columbia Wave Climate Study and Wave Protection Considerations
March 1991 Fisheries and Oceans report
PEARSON COLLEGE SHOREFRONTLester B. Pearson College opened in 1974 on the north side of Pedder Bay on land formerly owned by the Department of National Defence . At high tide, most of the shoreline of the campus is rocky intertidal, however at low tide, mudflats appear along much of the shore.

The following is excerpted from the College reference guide ” The Road Ends at Our Place: The Ecosystems of Pearson College.

One of the first projects the students faced when the college was founded was to build the floating docks as their outlet to the sea. This provided for a rich marine environment program which has expanded since that time. College boats provide for field trips in the biology and environmental systems classes, and the afternoon activities in sailing, SCUBA diving and kayaking lead to an active seafront.

In 2003, the addition of the floating lab provided room for three more classrooms as well as a diving equipment room, workshop, office and storage space for the sea activities. The immediate access to the ecosystems of Pedder Bay make it an ideal facility for the life sciences.

Only on rare occasions (once in ten years) do we get a week of cold weather and snow which causes the inner part of the bay up to the college docks to freeze over. The campus for a few brief days takes on a unique beauty when this happens. It also is a time when we can take advantage of the learning opportunity by having the students experience the unique aspects of “snow ecology”. For students from tropical countries who may never have experienced such conditions, there is a realization that snow has insulating features, can be breathed through, is variable in weight and density, and plants from temperate climates adapt to it in unique ways. Meanwhile down at the waterfront, unique patterns of salinity and fresh water can be discovered with ice formation.

The academic building viewed from the docks after one of those rare snowfalls that we get in Pedder Bay.

 

 

 

 

 

  • Plankton, Diatoms, of Pedder Bay

    Mudflats and rocky intertidal ecosystems of Pedder Bay

The shores of Pedder Bay provide more fascinating variety to our campus, and the profile of the bay changes considerably from low to high tide, a range of 3 meters. The water of the bay varies in temperature from 8 degrees Celsius in the winter to 13 degrees in the summer.

The mudflat in front of the sea front commons building is typical of the small inlets along the bay. It provides a rich habitat to mud-dwelling organisms and red-rock and dungeness crabs. Overhanging trees and trees which have fallen into the water provide the substrate for the bay mussel , Mytilus trossulus, and several barnacle species. Several species of limpet and littorine snails graze rocks in the intertidal zone and the large white anemone , Metridium farcimen, can be seen on the bottom of the bay, anchored to submerged branches or exposed rocks. All the invertebrates contribute their larva to the rich planktonic mix in the waters of the bay. The main producers in the bay are the large round centric diatoms, Coscinodiscus sp. but on different occasions under the microscopes of the biology students, a wide array of geometric shapes of other phytoplankton species will appear. Copepods and the nauplius larvae of barnacles make up the main zooplankton of the bay.
Mesodinium rubrumOften in the spring when the sunlight levels are adequate, the nutrient laden water from winter run-off may support a non-poisonous red tide. A deep reddish bloom caused by the organism Mesodinium rubrum will cover parts of the bay. This is a unique marine photosynthetic ciliate which can fix energy because it has a cryptophyte endosymbiontic red algae inside it. A good example of a mutualistic relationship occurring on a massive scale within the bay.

The Floating lab and docks provide a great amount of substrate on which a variety of organisms attach. These areas have also been useful for the science classes in providing areas for hanging baskets for aquaculture experiments. Within easy access there is a rich fouling community which provides many specimens used in classes. Almost every invertebrate phylum is represented on the underside of these docks. The plankton of Pedder Bay form the nutritional and energy base of the ecosystem.This file provides a lab assignment on quantification of plankton biodiversity .

The Seabirds of Pedder Bay

 

 

 

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MANOR and FOSSIL POINT TO CAPE CALVER :
ROCKY COASTLINE
This section is notable mainly for it’s geological features. Here there is evidence of the most recent glaciation of 10,000 years ago: a massive conglomerate boulder on the shore and the glacial striae or grooves on the rock of the coastline. In other parts of the bay, granite boulders add to the collection of bits of glacial evidence

. Shore pine, Pinus contorta , penetrates along the shore into Pedder Bay from the outer parts of Rocky Point. In this outer section, salt spray is received above the intertidal zone in winter storms from the north east. The fetch, or distance across the ocean upon which the wind can impart energy in a storm is well over 50 kilometers for this outer section if a line is drawn from Cape Calver to a point in the open ocean beyond Victoria. Further into the bay from Fossil Point where there are more protected shores, the predominant tree cover is Douglas fir, and trees can grow closer to the water.

The Plankton of Pedder Bay Lab

Triceratops

BACKGROUND: Microscopic plankton can be can be collected in a way that allows us to determine densities of the organisms, and therefore compare different pelagic environments. We have already seen how plankton populations can vary from part of the ocean to another. In order to quantify plankton, the following method is suggested. You are urged to come up with your own research problem concerning plankton populations and then proceed to use the following techniques to investigate. Although this lab refers to Pedder Bay on Vancouver Island,, It could be modified to suit any location.PROCEDURE:In order to determine densities of organisms, we first have to know the volume of the water from which the sample is taken.
1. Calibrating the log:

    • You will use a plankton net with a small propellor driven counting log to measure distance travelled in the water that is sampled. To calibrate the log, measure off a distance on the docks, read the dial at the beginning of the trial, drag it through the water the length of the measured section, and the difference in the reading at the end of your tow will be the length of your cylinder of water.
    • Now calculate how many counts on the dial there are per meter.
    • Divide the number of counts per meter into the number of counts through the distance you drag the net for your sample. This gives you a number of meters in length for the sample cylinder.
    • Measure the diameter of the net opening and now calculate the volume of sample taken from the open ocean. The formula for volume of a cylinder is V=(pi X radius squared) X h(meters)

3. What is in The sample?

      • Note the total volume of the sample traken. Then remove a representative subsample of 1 ml.
      • Place the 1ml sample in a slide with a measured viewing chamber. Count numbers of individual species in representative quadrats. Obtain the average, and multiply this number by the total number of quadrats available.

4. Density determination.

      • .Now calculate the density of the individual species in the sample . i.e. number per cubic cm. then per cubic meter.

5. Option :

    • Calculate the number for a larger area e.g. Pedder Bay ! Hint treat it as a segment of a cone for volume determinations, use a chart to determine the measurements of the bay..

Pedder Bay frequently has booms of Mesodinium rubrum. This organism turns the bay a deep wine color . It is not a poisonous red tide , but we have noticed that when it is pumped up into seawater tanks, it will easily smother some of the filter feeders such as sponges. Blooms often coincide with nutrient loading followed by a period of sunny weather.