Part Two:
Observed conditions and some sources of habitat impact
As a result of conducting numerous dives in Cultus Lake during the Cultus Lake Project, I have had the opportunity to observe the sub aquatic shoreline, in differing seasons, and to witness a variety of fish species interacting within their habitats. During this time I have considered the effects that various forces have brought to bear upon those environs. In some cases the effects are self-evident, while with others I can only surmise as to what impact may be occurring. Below is a short list of some of these sources of change:
The road along the eastern shoreline:
While it might not be immediately considered because of its seeming omnipresence, the building of the Columbia Valley road in 1916, and it’s improvement in the mid 1950’s, has greatly impacted, and continues to impact, lake habitat in several ways.
First, it allows relatively easy access to the lake proper and the water shed above, which in turn increases the overall human impact upon the lake. Access and the development of town sites at the southern and northern ends of the lake, as well as day use and overnight camping areas along the eastern perimeter, provides many sources of both broad based and localized human impact. This can be seen broadly in water quality and invasive species issues as they develop, and locally in the deposits of manmade debris at various points within the lake.
Second, construction of the roadbed has altered the natural shoreline, both in shape and by pushing back the treeline from the water’s edge. Though there are an abundance of older trees submerged along the eastern shoreline now, future tree falls of substantive size are now less likely to occur. Looking forward, this may impact the ability of the lake to naturally replace large habitat structures as they decay or are covered over by sediment.
Third, the roadway provides a continued avenue for potential gross negative impact should vehicular accidents occur, causing a hazardous materials release into the lake. This could be in the form of gasoline, oil and other fluids or from cargo such as bulk fuel, fertilizer or chemicals.
Maple Bay South; Stagnation:
An area of question that arises from observation is the region to the south of Maple Bay, stretching towards the Lutheran Church camp site. Diving along this shoreline I have noticed large patches of anaerobic cyanobacteria covering the bottom with a slime coat in a manner sometimes referred to as Bio matting. As well as impacting the substrate, this bacterial film also appears to be coating much of the littoral zone plants, which may have an impact upon present or future fish habitat.
While I have seen bio mats of this nature in other eutrophic lower mainland lakes, this is the largest example of it I have observed in Cultus (to date). Why bio matting is occurring in this location, or what impact it may have on habitat, I do not know but it raises many questions. Is this due to poor water movement in the zone as the result of back eddying from Frosst Creek, or is it an early sign of increasing eutrophication? Are there other locales within the lake undergoing this same process? Is this a permanent or transitory condition and does it mean the loss of natural habitat or will certain species of flora and fauna successfully colonize this area?
The effect of milfoil:
Eurasian Milfoil (Myriophyllum spicatum) is a fast growing, invasive aquatic plant that has spread to many lower mainland lakes, including Cultus. Once established, as it is, it successfully out-competes native species by means of its rapid vertical growth, which reduces the amount of available sunlight to slower growing species. It also rapidly colonizes sites by means of detached segments that travel and take root easily.
Milfoil effects habitat is three ways. First, it replaces native species. While milfoil does create large expanses of cover for small schooling fish during the summer months, it does so at the expense of longer lasting plants such as Egeria (Elodea canadensis) which persist to provide shelter from predation for an extended period of time. In the fall, milfoil “melts” or dies off down to the root crown, until the following early summer, when it re-emerges with rapid growth. This milfoil shortened habitat cycle may favour some fish species more than others if that species can mature quickly to the stage where it transitions to protection from open water schooling behavior. A slower maturing species may need a longer period of shelter than milfoil will allow and, as a result, may succumb more easily to predation.
Second, the annual milfoil die off adds directly to the amount of detritus that accumulates within the lake. This affects benthic den site availability. It also adds indirectly by accelerating eutrophication. Wherein naturally occurring benthic sites may have lasted for many years, decades or even centuries, this time line is dramatically altered by the increase of accumulating detritus deposits.
Third, milfoil can directly colonize open expanses of gravel that may be valuable as spawning sites for fish such as the endangered Cultus Lake Sockeye; forcing this population to use less area for reproduction or creating a competition between species for viable spawning space.
Eutrophication and the acceleration of organic deposits:
Much has been written about the effects of eutrophication by those who understand the science far better than I, so I will limit my remarks to the effects on habitat I have observed while diving a number of sites within the lake.
The main “visible” effect that eutrophication appears to be having on habitat within Cultus Lake is to accelerate the covering of den and spawning sites with detritus from decaying plants and phytoplankton. While this might have occurred to some degree regardless, the accelerated pace of lakebed covering that occurs with eutrophication may critically impact these sites by overwhelming nature’s means of compensation.
While diving the Jade Bay spawning site I have observed Salmon and Large Scale Suckers (Catostomus macrocheilus) clearing portions of the gravel bottom to remove built up detritus, but these open spawning areas are surrounded by vast expanses of detritus that continues to re-encroach upon them. I do not know if this is a naturally occurring action, or a developing trend, and it remains to be seen if with increasing eutrophication, these fish will be able to maintain enough viable open space for reproduction.
Sites for benthic dwellers also suffer the same fate, as dens are buried under the relentless depositing of detritus. Large trees and erratic boulders still provide macro structures that will take many years to overwhelm but smaller den sites, like those found among alluvial fans, could become uninhabitable far sooner. With little known about the breeding habits of such sensitive species as the Cultus Pygmy Sculpin, this may become a factor with far reaching implications.
Eutrophication may also alter the water quality in a way that increases the production of anaerobic bacteria or slime molds, which in term could cover fish habitat as well. This habitat could include lakebed den and breeding structures, or it could be the littoral plants that juvenile species need for initial protection from predation.
The altering of habitat due to pond staging:
Spring Bay presents an excellent example of lake maturation as it slowly transitions from lake towards pond stage development. Unlike most of the lakes shoreline, Spring Bay does not immediately slope downwards to the aphotic zone. Rather, it forms a bowl within the bay with a current depth of between 25 to 40 feet. Across a large portion of the bay littoral plants now grow, providing excellent habitat for many juvenile fish species. However, a large percentage of these plants are unfortunately milfoil and this rapidly growing and decaying species is accelerating the accumulation of sediment within the bowl of the bay. Here, staging has advanced faster than in other areas of the lake as detritus cannot easily migrate away, by current and gravity, flowing deeper into the lake. Soon, in geologic terms, marginal plants will begin to develop in parts of the bay as the bottom rises and it will move from lake, though pond and eventually into marsh staging. When this occurs, a new habitat biotope will develop which could alter the composition of fish species now inhabiting the site and surrounding area.
Another area where this transition is occurring is at the northern end of the lake, near Main Beach. Here the lake bed rises on a shallow gradient towards the outflow of Sweltzer Creek and the flow of the lake continues to deposit detritus there. Already much of the lake bed in this region is part of a broad littoral zone and without human intercession, it will begin to host the emergent plants of marsh staging.
Cultus Lake and Lindell Beach town sites:
There can be no doubt that both town sites, as well as the campsites along the eastern shoreline, have impacted the habitat for many of the fish species within the lake. Visible debris is more common in the sub aquatic area that fronts the town sites but, from my observations so far, this appears to have a somewhat minimal impact upon fish.
Far greater is the unseen impact of sewage, chemical runoffs and petroleum contamination which can have far reaching implications. To what degree these actors have impacted the lakes ability to create and maintain habitat is hard to determine from taking a visual “snapshot” of current conditions and that form of study is more suited to traditional sampling and testing methodology.
Fortunately, these town site issues may be some of the easiest to address because resident stakeholders would appear to have a vested interest in positively managing their environment and local special interest groups are able to focus their efforts meaningfully within this target area.
Recreational use:
Originally developed as Cultus Lake Park in the 1920’s, and then formalized as a Provincial Park in the 1950’s, much has been written about the impact that recreational use has upon watersheds of all kinds; and while strategies to mitigate its impact on Cultus (like efforts to stop or address the introduction of Milfoil) have met with varying results, these efforts should not be neglected. If anything, efforts should be intensified to target specific activities or behaviors, as it would appear that general recreational users have the most impact on the lakes habitat, next to issues of chemical or nutrient seepage.
In some cases the impact by recreational user groups can be attributed to a lack of understanding, while in other cases it is simply due to a lack of concern for the environment. It would appear to be much harder to effect change in these groups (as compared to resident stake holders) because, as temporary visitors in many cases, they have little invested in the long term health of the lake. Recreational users also interact primarily on the surface of the lake, where little effect of their impact can be seen or felt. These are difficult issues to address while still allowing unrestricted access.
Perhaps, the greatest source of negative impact by recreational users would be from chemical/petroleum contamination via the activity of power boating; the potential of which, for gross destruction, far outweighs that of discarded paper glass or plastic. Such behaviors as refueling on the water, dumping oil containers and even throwing used batteries overboard (I have retrieved two lead acid batteries from Jade Bay this year alone) all have the potential to cause great harm to fish species throughout the lake. More so perhaps, for the endangered Cultus Sockeye, as one of its known spawning sites is directly adjacent the busiest boat launch on the lake (Jade Bay).
Army training sites:
Cultus Lake has a unique distinction among other local lakes as being the only wet gap training site in the west currently operational for the Canadian Army. On the shores and lake proper, Combat Engineers practice various bridging and equipment ferrying techniques.
In 1941, Camp Chilliwack, which would later become CFB Chilliwack, was built near Vedder Crossing with corresponding water training areas situated on today’s Blue Heron Reserve and Entrance/Jade Bay sites. After several years, the training area on the eastern shore was relocated to the western shore where it remained for many decades. Today it is a provincial park group campsite. The DND land is comprised of two adjoining beach areas and at one time had a dock system and boathouse, among other structures. Now, nothing remains on shore except for some half buried pieces of building material, a pump and some foundations.
Below the water line however, there is ample evidence of the army’s past presence in the form of concrete mooring blocks, cables, train rails, pieces of machinery and even a large section of modular dock. Far more would appear to be buried under layers of silt. Most of the debris in this area appears to be stable, in the sense of decomposition, and is made up of either, rubber, iron, steel or wood with various species of fish present in schools and den sites
.
Over on the eastern shore, in the area of Jade Bay, military debris can also be found. Discarded panels from a Bailey bridge, old tires and rims and even the wreckage of two large folding plywood boats with a steel superstructure known as Mk 3 Bridging Equipment, have been located.
The old marina site:
A case study could be made by an enterprising marine ecology student on just this one area of the lake. Site of a boating marina for many years, this small stretch of eastern lake shoreline has been cleared in preparation for future condo development. Under water however, nothing was done to remediate decades of environmental abuse when the notion that “out of sight meant out of mind“ prevailed. Adding to the below water landscape is a major gully wash outflow that has deposited ample tree debris of various size.
Today it would appear most of the damage to water quality has been done and what remains is an amazing assortment of manmade and natural debris that fish species now make use of. A mid 1950’s Austin automobile lies upside down in 30 feet of water. Several dozen oil drums, remnants of a docks flotation system, lay about in varying stages of decay. Many anchors and mooring blocks, many with lines still attached, create aquatic spider webs. Old tires, pipes, a portion of a boiler, and a massive jumble of wooden debris from the gully above decorates the slopes.
Along the littoral zone the remnants of a felt mat, used to suppress plant growth, lies abandoned. Down one section of slope, the fused remains of ancient cans, bottles, china and wooden barrels form a unique conglomeration that marks an old garbage dump site. Although the way in which this debris was deposited is not to be emulated, in various ways, most of these objects now act as habitat for fish species.
The third part of this article can be found here: Part Three
Observed conditions and some sources of habitat impact
As a result of conducting numerous dives in Cultus Lake during the Cultus Lake Project, I have had the opportunity to observe the sub aquatic shoreline, in differing seasons, and to witness a variety of fish species interacting within their habitats. During this time I have considered the effects that various forces have brought to bear upon those environs. In some cases the effects are self-evident, while with others I can only surmise as to what impact may be occurring. Below is a short list of some of these sources of change:
The road along the eastern shoreline:
While it might not be immediately considered because of its seeming omnipresence, the building of the Columbia Valley road in 1916, and it’s improvement in the mid 1950’s, has greatly impacted, and continues to impact, lake habitat in several ways.
First, it allows relatively easy access to the lake proper and the water shed above, which in turn increases the overall human impact upon the lake. Access and the development of town sites at the southern and northern ends of the lake, as well as day use and overnight camping areas along the eastern perimeter, provides many sources of both broad based and localized human impact. This can be seen broadly in water quality and invasive species issues as they develop, and locally in the deposits of manmade debris at various points within the lake.
Second, construction of the roadbed has altered the natural shoreline, both in shape and by pushing back the treeline from the water’s edge. Though there are an abundance of older trees submerged along the eastern shoreline now, future tree falls of substantive size are now less likely to occur. Looking forward, this may impact the ability of the lake to naturally replace large habitat structures as they decay or are covered over by sediment.
Third, the roadway provides a continued avenue for potential gross negative impact should vehicular accidents occur, causing a hazardous materials release into the lake. This could be in the form of gasoline, oil and other fluids or from cargo such as bulk fuel, fertilizer or chemicals.
Maple Bay South; Stagnation:
An area of question that arises from observation is the region to the south of Maple Bay, stretching towards the Lutheran Church camp site. Diving along this shoreline I have noticed large patches of anaerobic cyanobacteria covering the bottom with a slime coat in a manner sometimes referred to as Bio matting. As well as impacting the substrate, this bacterial film also appears to be coating much of the littoral zone plants, which may have an impact upon present or future fish habitat.
While I have seen bio mats of this nature in other eutrophic lower mainland lakes, this is the largest example of it I have observed in Cultus (to date). Why bio matting is occurring in this location, or what impact it may have on habitat, I do not know but it raises many questions. Is this due to poor water movement in the zone as the result of back eddying from Frosst Creek, or is it an early sign of increasing eutrophication? Are there other locales within the lake undergoing this same process? Is this a permanent or transitory condition and does it mean the loss of natural habitat or will certain species of flora and fauna successfully colonize this area?
The effect of milfoil:
Eurasian Milfoil (Myriophyllum spicatum) is a fast growing, invasive aquatic plant that has spread to many lower mainland lakes, including Cultus. Once established, as it is, it successfully out-competes native species by means of its rapid vertical growth, which reduces the amount of available sunlight to slower growing species. It also rapidly colonizes sites by means of detached segments that travel and take root easily.
Milfoil effects habitat is three ways. First, it replaces native species. While milfoil does create large expanses of cover for small schooling fish during the summer months, it does so at the expense of longer lasting plants such as Egeria (Elodea canadensis) which persist to provide shelter from predation for an extended period of time. In the fall, milfoil “melts” or dies off down to the root crown, until the following early summer, when it re-emerges with rapid growth. This milfoil shortened habitat cycle may favour some fish species more than others if that species can mature quickly to the stage where it transitions to protection from open water schooling behavior. A slower maturing species may need a longer period of shelter than milfoil will allow and, as a result, may succumb more easily to predation.
Second, the annual milfoil die off adds directly to the amount of detritus that accumulates within the lake. This affects benthic den site availability. It also adds indirectly by accelerating eutrophication. Wherein naturally occurring benthic sites may have lasted for many years, decades or even centuries, this time line is dramatically altered by the increase of accumulating detritus deposits.
Third, milfoil can directly colonize open expanses of gravel that may be valuable as spawning sites for fish such as the endangered Cultus Lake Sockeye; forcing this population to use less area for reproduction or creating a competition between species for viable spawning space.
Eutrophication and the acceleration of organic deposits:
Much has been written about the effects of eutrophication by those who understand the science far better than I, so I will limit my remarks to the effects on habitat I have observed while diving a number of sites within the lake.
The main “visible” effect that eutrophication appears to be having on habitat within Cultus Lake is to accelerate the covering of den and spawning sites with detritus from decaying plants and phytoplankton. While this might have occurred to some degree regardless, the accelerated pace of lakebed covering that occurs with eutrophication may critically impact these sites by overwhelming nature’s means of compensation.
While diving the Jade Bay spawning site I have observed Salmon and Large Scale Suckers (Catostomus macrocheilus) clearing portions of the gravel bottom to remove built up detritus, but these open spawning areas are surrounded by vast expanses of detritus that continues to re-encroach upon them. I do not know if this is a naturally occurring action, or a developing trend, and it remains to be seen if with increasing eutrophication, these fish will be able to maintain enough viable open space for reproduction.
Sites for benthic dwellers also suffer the same fate, as dens are buried under the relentless depositing of detritus. Large trees and erratic boulders still provide macro structures that will take many years to overwhelm but smaller den sites, like those found among alluvial fans, could become uninhabitable far sooner. With little known about the breeding habits of such sensitive species as the Cultus Pygmy Sculpin, this may become a factor with far reaching implications.
Eutrophication may also alter the water quality in a way that increases the production of anaerobic bacteria or slime molds, which in term could cover fish habitat as well. This habitat could include lakebed den and breeding structures, or it could be the littoral plants that juvenile species need for initial protection from predation.
The altering of habitat due to pond staging:
Spring Bay presents an excellent example of lake maturation as it slowly transitions from lake towards pond stage development. Unlike most of the lakes shoreline, Spring Bay does not immediately slope downwards to the aphotic zone. Rather, it forms a bowl within the bay with a current depth of between 25 to 40 feet. Across a large portion of the bay littoral plants now grow, providing excellent habitat for many juvenile fish species. However, a large percentage of these plants are unfortunately milfoil and this rapidly growing and decaying species is accelerating the accumulation of sediment within the bowl of the bay. Here, staging has advanced faster than in other areas of the lake as detritus cannot easily migrate away, by current and gravity, flowing deeper into the lake. Soon, in geologic terms, marginal plants will begin to develop in parts of the bay as the bottom rises and it will move from lake, though pond and eventually into marsh staging. When this occurs, a new habitat biotope will develop which could alter the composition of fish species now inhabiting the site and surrounding area.
Another area where this transition is occurring is at the northern end of the lake, near Main Beach. Here the lake bed rises on a shallow gradient towards the outflow of Sweltzer Creek and the flow of the lake continues to deposit detritus there. Already much of the lake bed in this region is part of a broad littoral zone and without human intercession, it will begin to host the emergent plants of marsh staging.
Cultus Lake and Lindell Beach town sites:
There can be no doubt that both town sites, as well as the campsites along the eastern shoreline, have impacted the habitat for many of the fish species within the lake. Visible debris is more common in the sub aquatic area that fronts the town sites but, from my observations so far, this appears to have a somewhat minimal impact upon fish.
Far greater is the unseen impact of sewage, chemical runoffs and petroleum contamination which can have far reaching implications. To what degree these actors have impacted the lakes ability to create and maintain habitat is hard to determine from taking a visual “snapshot” of current conditions and that form of study is more suited to traditional sampling and testing methodology.
Fortunately, these town site issues may be some of the easiest to address because resident stakeholders would appear to have a vested interest in positively managing their environment and local special interest groups are able to focus their efforts meaningfully within this target area.
Recreational use:
Originally developed as Cultus Lake Park in the 1920’s, and then formalized as a Provincial Park in the 1950’s, much has been written about the impact that recreational use has upon watersheds of all kinds; and while strategies to mitigate its impact on Cultus (like efforts to stop or address the introduction of Milfoil) have met with varying results, these efforts should not be neglected. If anything, efforts should be intensified to target specific activities or behaviors, as it would appear that general recreational users have the most impact on the lakes habitat, next to issues of chemical or nutrient seepage.
In some cases the impact by recreational user groups can be attributed to a lack of understanding, while in other cases it is simply due to a lack of concern for the environment. It would appear to be much harder to effect change in these groups (as compared to resident stake holders) because, as temporary visitors in many cases, they have little invested in the long term health of the lake. Recreational users also interact primarily on the surface of the lake, where little effect of their impact can be seen or felt. These are difficult issues to address while still allowing unrestricted access.
Perhaps, the greatest source of negative impact by recreational users would be from chemical/petroleum contamination via the activity of power boating; the potential of which, for gross destruction, far outweighs that of discarded paper glass or plastic. Such behaviors as refueling on the water, dumping oil containers and even throwing used batteries overboard (I have retrieved two lead acid batteries from Jade Bay this year alone) all have the potential to cause great harm to fish species throughout the lake. More so perhaps, for the endangered Cultus Sockeye, as one of its known spawning sites is directly adjacent the busiest boat launch on the lake (Jade Bay).
Army training sites:
Cultus Lake has a unique distinction among other local lakes as being the only wet gap training site in the west currently operational for the Canadian Army. On the shores and lake proper, Combat Engineers practice various bridging and equipment ferrying techniques.
In 1941, Camp Chilliwack, which would later become CFB Chilliwack, was built near Vedder Crossing with corresponding water training areas situated on today’s Blue Heron Reserve and Entrance/Jade Bay sites. After several years, the training area on the eastern shore was relocated to the western shore where it remained for many decades. Today it is a provincial park group campsite. The DND land is comprised of two adjoining beach areas and at one time had a dock system and boathouse, among other structures. Now, nothing remains on shore except for some half buried pieces of building material, a pump and some foundations.
Below the water line however, there is ample evidence of the army’s past presence in the form of concrete mooring blocks, cables, train rails, pieces of machinery and even a large section of modular dock. Far more would appear to be buried under layers of silt. Most of the debris in this area appears to be stable, in the sense of decomposition, and is made up of either, rubber, iron, steel or wood with various species of fish present in schools and den sites
.
Over on the eastern shore, in the area of Jade Bay, military debris can also be found. Discarded panels from a Bailey bridge, old tires and rims and even the wreckage of two large folding plywood boats with a steel superstructure known as Mk 3 Bridging Equipment, have been located.
The old marina site:
A case study could be made by an enterprising marine ecology student on just this one area of the lake. Site of a boating marina for many years, this small stretch of eastern lake shoreline has been cleared in preparation for future condo development. Under water however, nothing was done to remediate decades of environmental abuse when the notion that “out of sight meant out of mind“ prevailed. Adding to the below water landscape is a major gully wash outflow that has deposited ample tree debris of various size.
Today it would appear most of the damage to water quality has been done and what remains is an amazing assortment of manmade and natural debris that fish species now make use of. A mid 1950’s Austin automobile lies upside down in 30 feet of water. Several dozen oil drums, remnants of a docks flotation system, lay about in varying stages of decay. Many anchors and mooring blocks, many with lines still attached, create aquatic spider webs. Old tires, pipes, a portion of a boiler, and a massive jumble of wooden debris from the gully above decorates the slopes.
Along the littoral zone the remnants of a felt mat, used to suppress plant growth, lies abandoned. Down one section of slope, the fused remains of ancient cans, bottles, china and wooden barrels form a unique conglomeration that marks an old garbage dump site. Although the way in which this debris was deposited is not to be emulated, in various ways, most of these objects now act as habitat for fish species.
The third part of this article can be found here: Part Three