on laguna creek
I had a wonderful day today hiking and running through the redwoods of the Santa Cruz mountains with my best friend of 22 years, David Spencer, who is a paramedic in the San Francisco Fire Department, and a real-life hero.
Dave recently became steward to a swath of the Laguna Creek Watershed in Santa Cruz County. This land features towering granite spires, amazing cave complexes, native Ohlone dwelling/tool-making/ritual sites, majestic waterfalls, and an incredibly diverse habitat to thousands of species.
Here Dave explains how the local Coho Salmon run ends at the waterfall we hiked to.
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Salmon is the common name for several species of fish of the family Salmonidae. Several other fish in the family are called trout; the difference is often said to be that salmon migrate and trout are resident, a distinction that holds true for the Salmo genus. Salmon live in both the Atlantic (one migratory species Salmo salar) and Pacific Oceans, as well as the Great Lakes (approximately a dozen species of the genus Oncorhynchus).
Typically, salmon are anadromous: they are born in fresh water, migrate to the ocean, then return to fresh water to reproduce. However, there are rare species that can only survive in fresh water. Folklore has it that the fish return to the exact spot where they were born to spawn; tracking studies have shown this to be true but the nature of how this memory works has long been debated.
To lay her roe, the female salmon uses her tail (caudal fin), to create a low-pressure zone, lifting gravel to be swept downstream, excavating a shallow depression, called a redd. The redd may sometimes contain 5,000 eggs covering 30 square feet (2.8 m2). The eggs usually range from orange to red. One or more males will approach the female in her redd, depositing his sperm, or milt, over the roe. The female then covers the eggs by disturbing the gravel at the upstream edge of the depression before moving on to make another redd. The female will make as many as 7 redds before her supply of eggs is exhausted. The salmon will then die within a few days of spawning.
The eggs will hatch into alevin or sac fry. The fry quickly develop into parr with camouflaging vertical stripes. The parr stay for one to three years in their natal stream before becoming smolts, which are distinguished by their bright silvery colour with scales that are easily rubbed off. It is estimated that only 10% of all salmon eggs survive to this stage. The smolt body chemistry changes, allowing them to live in salt water. Smolts spend a portion of their out-migration time in brackish water, where their body chemistry becomes accustomed to osmoregulation in the ocean.
The salmon spend about one to five years (depending on the species) in the open ocean where they become sexually mature. The adult salmon returns primarily to its natal stream to spawn... Prior to spawning, depending on the species, salmon undergo changes. They may grow a hump, develop canine teeth, develop a kype (a pronounced curvature of the jaws in male salmon). All will change from the silvery blue of a fresh run fish from the sea to a darker color. Salmon can make amazing journeys, sometimes moving hundreds of miles upstream against strong currents and rapids to reproduce. Chinook and sockeye salmon from central Idaho, for example, travel over 900 miles (1,400 km) and climb nearly 7,000 feet (2,100 m) from the Pacific ocean as they return to spawn.
Condition tends to deteriorate the longer the fish remain in fresh water, and they then deteriorate further after they spawn, when they known as kelts. Between 2% and 4% of Atlantic salmon kelts survive to spawn again, all females.
Each year, the fish experiences a period of rapid growth, often in summer, and one of slower growth, normally in winter. This results in rings (annuli) analogous to the growth rings visible in a tree trunk. Freshwater growth shows as densely crowded rings, sea growth as widely spaced rings; spawning is marked by significant erosion as body mass is converted into eggs and milt.
Freshwater streams and estuaries provide important habitat for many salmon species. They feed on terrestrial and aquatic insects, amphipods, and other crustaceans while young, and primarily on other fish when older. Eggs are laid in deeper water with larger gravel, and need cool water and good water flow (to supply oxygen) to the developing embryos. Mortality of salmon in the early life stages is usually high due to natural predation and human-induced changes in habitat, such as siltation, high water temperatures, low oxygen concentration, loss of stream cover, and reductions in river flow. Estuaries and their associations wetlands provide vital nursery areas for the salmon prior to their departure to the open ocean. Wetlands not only help buffer the estuary from silt and pollutants, but also provide important feeding and hiding areas.
The salmon has long been at the heart of the culture and livelihood of coastal dwellers. Many people of the Northern Pacific shore had a ceremony to honor the first return of the year....
Salmon population levels are of concern in the Atlantic and in some parts of the Pacific but in Alaska stocks are still abundant. Fish farming of Pacific salmon is outlawed in the United States Exclusive Economic Zone, however, there is a substantial network of publicly funded hatcheries, and the State of Alaska's fisheries management system is viewed as a leader in the management of wild fish stocks. Some of the most important Alaskan salmon sustainable wild fisheries are located near the Kenai River, Copper River, and in Bristol Bay. In Canada, returning Skeena River wild salmon support commercial, subsistence and recreational fisheries, as well as the area's diverse wildlife on the coast and around communities hundreds of miles inland in the watershed. The status of wild salmon in Washington is mixed.
Out of 435 wild stocks of salmon and steelhead, only 187 of them were classified as healthy; 113 had an unknown status, 1 was extinct, 12 were in critical condition and 122 were experiencing depressed populations. The Columbia River salmon population is now less than 3% of what it was when Lewis and Clark arrived at the river. The commercial salmon fisheries in California have been either severely curtailed or closed completely in recent years, due to critically low returns on the Klamath and or Sacramento Rivers, causing millions of dollars in losses to commercial fishermen.
Salmon is a popular food. Classified as an "oily fish", salmon is considered to be healthy due to the fish's high protein, high Omega-3 fatty acids, and high vitamin D[10] content. Salmon is also a source of cholesterol, ranging 23–214 mg/100g depending on the species. According to reports in the journal Science, however, farmed salmon may contain high levels of dioxins. PCB (polychlorinated biphenyl) levels may be up to eight times higher in farmed salmon than in wild salmon. Omega-3 content may also be lower than in wild caught specimens, and in a different proportion to what is found naturally.... A simple rule of thumb is that the vast majority of Atlantic salmon available on the world market are farmed (greater than 99%), whereas the majority of Pacific salmon are wild-caught (greater than 80%).
The population of wild salmon declined markedly in recent decades, especially north Atlantic populations which spawn in the waters of western Europe and eastern Canada, and wild salmon in the Snake and Columbia River system in northwestern United States. The decline is attributed to the following factors:
Disease transfer from open net cage salmon farming, especially sea lice. The European Commission (2002) concluded “The reduction of wild salmonid abundance is also linked to other factors but there is more and more scientific evidence establishing a direct link between the number of lice-infested wild fish and the presence of cages in the same estuary.” It is reported that wild salmon on the west coast of Canada are being driven to extinction by sea lice from nearby salmon farms....
Ocean and river warming which can delay spawning and accelerate transition to smolting.
Ulcerative dermal necrosis (UDN) infections of the 1970s and 1980s which severely affected adult salmon in freshwater rivers.
Loss of suitable freshwater habitat, especially degradation of stream pools and reduction of suitable material for the excavation of redds. Historically stream pools were, to a large extent, created by beavers (see section below). With the extirpation of the beaver, the nurturing function of these ponds was lost.
Reduction of the retention of the nutrients brought by the returning adult salmon in stream pools. Without stream pools, dead adult salmon tend to be washed straight back down the streams and rivers.
The construction of dams, weirs, barriers and other "flood prevention" measures, which bring severe adverse impacts to river habitat and on the accessibility of those habitats to salmon. This is particularly true in the northwest USA, where large numbers of dams have been built in many river systems, including over 400 in the Columbia River Basin.
Other environmental factors such as light intensity, water flow, or change in temperature dramatically affects salmon during their migration season.
Loss of invertebrate diversity and population density in rivers because of modern farming methods and various sources of pollution, thus reducing food availability.
Reduction in freshwater base flow in rivers and disruption of seasonal flows, because of diversions and extractions, hydroelectric power generation, irrigation schemes, barge transportation, and slackwater reservoirs, which inhibit normal migratory processes and increase predation for salmon.
Loss of suitable low gradient stream habitats due to agricultural practices such as the removal of riparian plants, destabilization of stream banks by livestock and irrigation processes.
There are efforts to relieve this situation. As such, several governments and NGOs are sharing in research and habitat restoration efforts.
Results overall are showing that estuary problems exist for some rivers, but issues involving feeding grounds at sea are impacting populations as well. In 2008 returns were markedly improved for Atlantic salmon on both sides of the Atlantic Ocean, but no one knows if this is a temporary improvement or sign of a trend.
on laguna creek
I had a wonderful day today hiking and running through the redwoods of the Santa Cruz mountains with my best friend of 22 years, David Spencer, who is a paramedic in the San Francisco Fire Department, and a real-life hero.
Dave recently became steward to a swath of the Laguna Creek Watershed in Santa Cruz County. This land features towering granite spires, amazing cave complexes, native Ohlone dwelling/tool-making/ritual sites, majestic waterfalls, and an incredibly diverse habitat to thousands of species.
Here Dave explains how the local Coho Salmon run ends at the waterfall we hiked to.
^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^
Salmon is the common name for several species of fish of the family Salmonidae. Several other fish in the family are called trout; the difference is often said to be that salmon migrate and trout are resident, a distinction that holds true for the Salmo genus. Salmon live in both the Atlantic (one migratory species Salmo salar) and Pacific Oceans, as well as the Great Lakes (approximately a dozen species of the genus Oncorhynchus).
Typically, salmon are anadromous: they are born in fresh water, migrate to the ocean, then return to fresh water to reproduce. However, there are rare species that can only survive in fresh water. Folklore has it that the fish return to the exact spot where they were born to spawn; tracking studies have shown this to be true but the nature of how this memory works has long been debated.
To lay her roe, the female salmon uses her tail (caudal fin), to create a low-pressure zone, lifting gravel to be swept downstream, excavating a shallow depression, called a redd. The redd may sometimes contain 5,000 eggs covering 30 square feet (2.8 m2). The eggs usually range from orange to red. One or more males will approach the female in her redd, depositing his sperm, or milt, over the roe. The female then covers the eggs by disturbing the gravel at the upstream edge of the depression before moving on to make another redd. The female will make as many as 7 redds before her supply of eggs is exhausted. The salmon will then die within a few days of spawning.
The eggs will hatch into alevin or sac fry. The fry quickly develop into parr with camouflaging vertical stripes. The parr stay for one to three years in their natal stream before becoming smolts, which are distinguished by their bright silvery colour with scales that are easily rubbed off. It is estimated that only 10% of all salmon eggs survive to this stage. The smolt body chemistry changes, allowing them to live in salt water. Smolts spend a portion of their out-migration time in brackish water, where their body chemistry becomes accustomed to osmoregulation in the ocean.
The salmon spend about one to five years (depending on the species) in the open ocean where they become sexually mature. The adult salmon returns primarily to its natal stream to spawn... Prior to spawning, depending on the species, salmon undergo changes. They may grow a hump, develop canine teeth, develop a kype (a pronounced curvature of the jaws in male salmon). All will change from the silvery blue of a fresh run fish from the sea to a darker color. Salmon can make amazing journeys, sometimes moving hundreds of miles upstream against strong currents and rapids to reproduce. Chinook and sockeye salmon from central Idaho, for example, travel over 900 miles (1,400 km) and climb nearly 7,000 feet (2,100 m) from the Pacific ocean as they return to spawn.
Condition tends to deteriorate the longer the fish remain in fresh water, and they then deteriorate further after they spawn, when they known as kelts. Between 2% and 4% of Atlantic salmon kelts survive to spawn again, all females.
Each year, the fish experiences a period of rapid growth, often in summer, and one of slower growth, normally in winter. This results in rings (annuli) analogous to the growth rings visible in a tree trunk. Freshwater growth shows as densely crowded rings, sea growth as widely spaced rings; spawning is marked by significant erosion as body mass is converted into eggs and milt.
Freshwater streams and estuaries provide important habitat for many salmon species. They feed on terrestrial and aquatic insects, amphipods, and other crustaceans while young, and primarily on other fish when older. Eggs are laid in deeper water with larger gravel, and need cool water and good water flow (to supply oxygen) to the developing embryos. Mortality of salmon in the early life stages is usually high due to natural predation and human-induced changes in habitat, such as siltation, high water temperatures, low oxygen concentration, loss of stream cover, and reductions in river flow. Estuaries and their associations wetlands provide vital nursery areas for the salmon prior to their departure to the open ocean. Wetlands not only help buffer the estuary from silt and pollutants, but also provide important feeding and hiding areas.
The salmon has long been at the heart of the culture and livelihood of coastal dwellers. Many people of the Northern Pacific shore had a ceremony to honor the first return of the year....
Salmon population levels are of concern in the Atlantic and in some parts of the Pacific but in Alaska stocks are still abundant. Fish farming of Pacific salmon is outlawed in the United States Exclusive Economic Zone, however, there is a substantial network of publicly funded hatcheries, and the State of Alaska's fisheries management system is viewed as a leader in the management of wild fish stocks. Some of the most important Alaskan salmon sustainable wild fisheries are located near the Kenai River, Copper River, and in Bristol Bay. In Canada, returning Skeena River wild salmon support commercial, subsistence and recreational fisheries, as well as the area's diverse wildlife on the coast and around communities hundreds of miles inland in the watershed. The status of wild salmon in Washington is mixed.
Out of 435 wild stocks of salmon and steelhead, only 187 of them were classified as healthy; 113 had an unknown status, 1 was extinct, 12 were in critical condition and 122 were experiencing depressed populations. The Columbia River salmon population is now less than 3% of what it was when Lewis and Clark arrived at the river. The commercial salmon fisheries in California have been either severely curtailed or closed completely in recent years, due to critically low returns on the Klamath and or Sacramento Rivers, causing millions of dollars in losses to commercial fishermen.
Salmon is a popular food. Classified as an "oily fish", salmon is considered to be healthy due to the fish's high protein, high Omega-3 fatty acids, and high vitamin D[10] content. Salmon is also a source of cholesterol, ranging 23–214 mg/100g depending on the species. According to reports in the journal Science, however, farmed salmon may contain high levels of dioxins. PCB (polychlorinated biphenyl) levels may be up to eight times higher in farmed salmon than in wild salmon. Omega-3 content may also be lower than in wild caught specimens, and in a different proportion to what is found naturally.... A simple rule of thumb is that the vast majority of Atlantic salmon available on the world market are farmed (greater than 99%), whereas the majority of Pacific salmon are wild-caught (greater than 80%).
The population of wild salmon declined markedly in recent decades, especially north Atlantic populations which spawn in the waters of western Europe and eastern Canada, and wild salmon in the Snake and Columbia River system in northwestern United States. The decline is attributed to the following factors:
Disease transfer from open net cage salmon farming, especially sea lice. The European Commission (2002) concluded “The reduction of wild salmonid abundance is also linked to other factors but there is more and more scientific evidence establishing a direct link between the number of lice-infested wild fish and the presence of cages in the same estuary.” It is reported that wild salmon on the west coast of Canada are being driven to extinction by sea lice from nearby salmon farms....
Ocean and river warming which can delay spawning and accelerate transition to smolting.
Ulcerative dermal necrosis (UDN) infections of the 1970s and 1980s which severely affected adult salmon in freshwater rivers.
Loss of suitable freshwater habitat, especially degradation of stream pools and reduction of suitable material for the excavation of redds. Historically stream pools were, to a large extent, created by beavers (see section below). With the extirpation of the beaver, the nurturing function of these ponds was lost.
Reduction of the retention of the nutrients brought by the returning adult salmon in stream pools. Without stream pools, dead adult salmon tend to be washed straight back down the streams and rivers.
The construction of dams, weirs, barriers and other "flood prevention" measures, which bring severe adverse impacts to river habitat and on the accessibility of those habitats to salmon. This is particularly true in the northwest USA, where large numbers of dams have been built in many river systems, including over 400 in the Columbia River Basin.
Other environmental factors such as light intensity, water flow, or change in temperature dramatically affects salmon during their migration season.
Loss of invertebrate diversity and population density in rivers because of modern farming methods and various sources of pollution, thus reducing food availability.
Reduction in freshwater base flow in rivers and disruption of seasonal flows, because of diversions and extractions, hydroelectric power generation, irrigation schemes, barge transportation, and slackwater reservoirs, which inhibit normal migratory processes and increase predation for salmon.
Loss of suitable low gradient stream habitats due to agricultural practices such as the removal of riparian plants, destabilization of stream banks by livestock and irrigation processes.
There are efforts to relieve this situation. As such, several governments and NGOs are sharing in research and habitat restoration efforts.
Results overall are showing that estuary problems exist for some rivers, but issues involving feeding grounds at sea are impacting populations as well. In 2008 returns were markedly improved for Atlantic salmon on both sides of the Atlantic Ocean, but no one knows if this is a temporary improvement or sign of a trend.