Tag Archives: Pedder Bay

The Hooded nudibranch: Melibe leonina

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Laura Verhegge has posted this note about Melibe leonina, seen today in Pedder Bay  on the Pearson College Marine Science website

A multitude of Melibe drift to the Pearson College dock

melibe

Melibe the hooded nudibranch photo by Laura Verhegge

melibe3

Melibe leonina photos on Race Rocks Taxonomy by Ryan Murphy

 

(see other images and a video of the movement on her website)

 

 

 

 

Ryan Murphy got these images for the  Race Rocks Taxonomy.

 

 

 

 

 

Domain: Eukarya
Kingdom: Animalia
Phylum: Mollusca
Class: Gastropoda
Subclass: Opisthobranchia
Order: Nudibranchia
Superfamily: Tritoniodea
Family: Tethydidae
Genus: Melibe
Species: leonina Gould, 1852
Common Name: Hooded Nudibranch

Sector 4 PEDDER BAY

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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.
Pedder Bay, British Columbia Wave Climate Study and Wave Protection Considerations
March 1991 Fisheries and Oceans report

PEARSON COLLEGE SHOREFRONT

Lester 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 marine science 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.

 

 EDUCATIONAL EXPERIENCES in PEDDER BAY of Marine Science Education at Pearson College

 

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  • Mudflats and RockyIntertidal 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.
Often 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.The  file in the list of exercises. below provides a lab assignment on quantification of plankton biodiversity .

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THE BIRDS of PEDDER BAY

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Starting on the outer South Shore of Pedder Bay at Cape Calver , this review will take you into the bay and around the shores and out to the North side and William Head

MANOR and FOSSIL POINT TO CAPE CALVER :
ROCKY COASTLINE..

This section is notable mainly for its 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.

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DND RESIDENCES TO JETTY SHORELINE

 

 

 

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PEARSON COLLEGE DOCKS AND SHORELINE

 

 

 

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Pedder Bay Marina to estuary , waterfall and Matheson Lake
Aerial Map Courtesy of the CRD Natural Areas Atlas 

 

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South arm of the Pedder Bay Estuary

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MATHESON LAKE -connected by a stream from the South  arm (above) of the Estuary

 

 

 

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NORTH SIDE INNER PEDDER BAY

 

 

 

 

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WEIR POINT and beach to North Outer Shore

 

 

Weir point from south side of Pedder Bay

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ANTHROPOGENIC HABITAT MODIFICATION in PEDDER BAY

Sewage Outfalls in Pedder Bay

 

 

 

Pearson College fronts on the bay on the north side. Modifications to the shoreline have changed the habitat of the bay. The floating docks provide a large substrate for additional growth of biomass. Boats, diesel and gasoline, provide additional hydrocarbon discharge into the bay. Introduction of efficient four stroke engines in recent years have helped to mitigate boat engine pollution. No Inorganic fertilizers or pesticides are used on the campus, so surface runoff is not an issue.

Pedder Bay marina docks have a great number of boats which provide a large potential input of hydrocarbons. Chronic oil pollution from bilge systems of boats in marinas such as this provide a continual hazard to marine life.

Location of Sewage outfall is not known, although it is believed that it runs at least part way out of the bay.

The trailer court at Pedder Bay sits on the bank of the estuary . Sewage from this location is pumped seaward and terminates in middle Pedder Bay. Primary sewage treatment only is available.

 

 

The Rocky Point DND sewage outfall runs down the shore in a buried pipe, and terminates over 100 meters seaward in the bay. It is presumed that secondary treatment has been done on this effluent. runs down the shore in a buried pipe, and terminates over 100 meters seaward in the bay. It is presumed that secondary treatment has been done on this effluent.

 

The small DND floating dock on the south side of inner Pedder Bay, now no longer used.

 

 

 

The bottom of the ocean at the DND Jetty has been dredged to deepen it for ocean going vessels. This is a fixed concrete pier.

 

 

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This site has been created to represent the contiguous ecosystems of the Race Rocks Ecological Reserve/Marine Protected Area and for the use of the Green Blue Spaces sub committee of the Metchosin Environmental Advisory Select Committee ( MEASC

SECTOR 4: PEDDER BAY

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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 reportPEARSON 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

 

 

 

what

 

 

 

 

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

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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.

 

Pedder Bay, British Columbia Wave Climate Study and Wave Protection Considerations

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Pedder Bay, British Columbia-Wave Climate Study and Wave Protection Considerations

Final Report
( THE FIRST FEW PAGES ONLY ARE PRINTED. The COMPLETE VERSION IS AVAILABLE FROM FISHERIES AND OCEANS )

Prepared for: Government of Canada, Fisheries and Oceans

Prepared by: W.F. Baird & Associates Coastal Engineering Ltd.

Ottawa, Ontario

March 1991

TABLE OF CONTENTS

1.0 INTRODUCTION 1
2.0 SITE BATHYMETRY 2
3.0 WATER LEVELS 3
4.0 CURRENT DATA 5
5.0 WIND DATA 6
6.0 WIND-WAVE HINDCAST 11
7.0 PACIFIC OCEAN SWELL 17
8.0 RECORDED WAVE DATA 19
9.0 WAVE CONDITIONS AT THE PROPOSED SITE 20
10.0 SAMPLE BREAKWATER CROSS-SECTIONS 22
11.0 CONCLUSIONS AND RECOMMENDATION 24
REFERENCES

APPENDIX A – WIND DATA SUMMARIES

APPENDIX B – DEEP WATER WAVE HINDCAST SCATTER DIAGRAMS

APPENDIX C – WAVE HINDCAST SCATTER DIAGRAMS FOR THE LOCAL CLIMATE AT THE SITE

APPENDIX D – WAVE DIFFRACTION DIAGRAMS

APPENDIX E – RECORDED WAVE DATA

 

1.0 INTRODUCTION

The Department of National Defence (D.N.D.) is considering the expansion of the existing facilities and the construction of a new jetty at Canadian Forces Ammunition Depot (CFAD) Rocky Point located on Pedder Bay. British Columbia. Pedder Bay is situated at the southern end of Vancouver Island and is open to the southeast to Juan de Fuca Strait, as shown in Figure 1. 1. Figure 1. 2 shows a closer view of the existing bathymetry and facilities at the site.

The site is directly exposed to waves generated locally within Juan de Fuca Strait, particularly by winds from the east and southeast directions. In addition, the site is also partially subjected to long period swells that propagate through the Juan de Fuca Strait from the Pacific Ocean and diffract around the Rocky Point headlands into Pedder Bay.

The overall objectives of this investigation were to define the wave climate at the proposed site and to complete an initial assessment of wave protection requirements. Specific tasks that were undertaken included:

Assessment of possible wave protection requirements for the proposed harbour.

The results of this investigation are presented in the following sections of this report.

2.0 SITE BATHYMETRY

The water depths within Pedder Bay and the nearby portions of Juan de Fuca Strait is described on a series of charts produced by the Canadian Hydrographic: Service , Fisheries and Oceans Canada,

The underwater topography (bathymetry) within Pedder Bay, as shown in Figure 1.2, is fairly regular with water depths in excess of 20 m at the entrance to the bay. Much of the bay. east of Watt Point, has water depths of approximately 5 to 10 m. Depths along the existing DND jetty range from 6.5 m to 9.5 m according to a 1982 survey by CHS. A small series of shoals and emergent rocks are located on the north side of Pedder Bay directly opposite the jetty. The navigable water is indicated by buoys maintained by the DND.

The bathymetry within Juan de Fuca Strait in the vicinity of Pedder Bay is relatively deep, dropping off to 80 m or greater in a distance of 1000 m from the entrance to the bay. A prominent topographic feature to the south of the bay is an extensive series of shoals called the Race Rocks. These rocks have a direct effect on waves generated from the south and on long period swells propagating down Juan de Fuca Strait.

A hydrographic survey has been carried out in the area east and north of Fossil Point by Klohn Leonoff Ltd. (1990) for DND. An initial comparison of the results of this survey with previous surveys shows little change to the bathymetry in this area.

 

3.0 WATER LEVELS

Water level recorders near Pedder Bay have been located at Victoria and at Sooke Harbors. The Victoria gauge has been operating since 1909 and the Sooke gauge has been partially operational since 1973. Tides In the waters between Vancouver Island and the mainland vary considerably due to the presence of numerous islands and the complex bathymetry of this region. The tides at Sooke are mixed. mainly semi-diurnal (two high and two low waters in one day) while at Victoria the tides are mixed, mainly diurnal (one high and one low water in a day).

The mean water level at Pedder Bay Is estimated by Fisheries and Oceans Canada at 1.8 m above Chart Datum. Table 3.1 represents the tidal heights and extremes for Pedder Bay, Sooke and Victoria.

 

Table 3.1

Tidal Heights and Extremes

Height Above Chart Datum (metres)RECORDED

HHW LLW Mean LLW Mean HHW Mean Highest Lowest
Pedder Bay 3.3 0.2 2.5 0.6 1.8 N.A. N.A.
Sooke 3.6 0.3 2.8 0.8 1.9 3.8 0.2
Victoria 3.3 0.2 2.5 0.7 1.9 3.7 -0.5

Note: HHW = Higher High Water

LLW = Lower Low Water

Based on the above values, it is recommended that a maximum water level of +3.8 m be utilized for the design of any harbour structures. The mean water level of +1.8 m was utilized for all refraction and diffraction analyses.

Conversations with representatives of CHS have indicated that Geodetic Datum has not been extended to the Pedder Bay area: however, the recent survey by Klohn Leonoff Ltd.

(1990) shows a conversion between Geodetic and Chart Datum. This conversion is given

as: Elevation (Geodetic) = Elevation (Chart Datum) -1.878 m

4.0??CURRENT DATA

The tides flowing into and out of Juan de Fuca Strait create significant currents within the Strait. The magnitude of these currents depends on the size of the tide and may be considerably altered by the meteorological conditions.

Currents were measured four miles south of the Race Rocks in the centre of Juan de Fuca Strait, as shown in Figure 1. 1. On a typical large tide. the maximum tidal currents are approximately 1.5 m/s and 2.0 m/s for the flood (rising) and ebb (falling) tides, respectively.

The peak tidal currents within Pedder Bay Itself are not expected to be large enough. to significantly affect the piloting of vessels into a new facility due to the limited tidal volume contained within the Bay. Currents will, however, have some effect on the refraction of waves into Pedder Bay at certain times, as discussed in Section 6.2.

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