wildmanyeah
Crew Member
Yeah you got it!!! pinks are my nemeses. Pictures taken from the expedition website.
Was there a dead giveaway that helped you identify them. ?
The secret lives of Salmon.
- Thread starter OldBlackDog
- Start date
Yeah you got it!!! pinks are my nemeses. Pictures taken from the expedition website.
Was there a dead giveaway that helped you identify them. ?
donnie d
Well-Known Member
Couldn’t make out any spots on tails. Do they develop those later into their 2nd year?
wildmanyeah
Crew Member
It's amazing how little we know. This expedition is incredibly important. Just the information they are finding about coho shows just how much little scientists know.
"Coho have been the second-most abundant in the test fisheries, despite being one of the least abundant of the Pacific species.
“What is puzzling about coho salmon is they’re considered to be a coastal species that remain near shore throughout their marine life,” said Neville."
"On-board genetic analysis confirmed that the coho hail from rivers stretching from northern British Columbia to Puget Sound."
https://vancouversun.com/news/local-news/the-secret-lives-of-salmon-where-are-all-the-pinks
The Secret Lives of Salmon: Where are all the pinks?
"Coho have been the second-most abundant in the test fisheries, despite being one of the least abundant of the Pacific species.
“What is puzzling about coho salmon is they’re considered to be a coastal species that remain near shore throughout their marine life,” said Neville."
"On-board genetic analysis confirmed that the coho hail from rivers stretching from northern British Columbia to Puget Sound."
https://vancouversun.com/news/local-news/the-secret-lives-of-salmon-where-are-all-the-pinks
The Secret Lives of Salmon: Where are all the pinks?
wildmanyeah
Crew Member
ITs a shame they had bad weather and were not able to fish all the locations, On their way back now expected in port this monday.
OldBlackDog
Well-Known Member
On-board genetic analysis confirmed that the coho hail from rivers stretching from northern British Columbia to Puget Sound.
So, have the Thompson cohos been decimated by other groups than ours?
So, have the Thompson cohos been decimated by other groups than ours?
wildmanyeah
Crew Member
I think we will have to wait and see what the data says, I have a feeling tho we are in for a good coho return like last year.
My hopes for a decent pink return are not very high unless they were completely missed.
Hopefully that continue to do this assessment for years to come. Seems to me they are learning a lot, kinda hard surprised to know they have little to no knowledge of what salmon eat at see.
wildmanyeah
Crew Member
Emerging patterns
We have now completed 55 sets and covered both southern and northern areas of our study area. We are starting to see patterns emerge that are proving to be extremely interesting. In some cases our observations match our expectations, but in other cases we are surprised by the picture that is slowly materializing. The expected and surprising observations run across all aspects of the ecosystem we are studying, from water chemistry to plankton to fish. Here are a few of the highlights:
The over-arching objective of this study is to examine Pacific salmon immediately after the winter period, when the expectation was that prey availability would be low and only fish that had high energy reserves last fall would survive. We expected to possibly even see visual signs of this with more thin or “skinny” fish than would be typically seen in a summer survey. While there appears to be signs that this may be the case for some species of salmon, it is not, at least directly, clear for other species of salmon.
Chum salmon have been our most abundant salmon species to date, representing about half the catch of all salmon, and are widely distributed across the study area. They have the largest body size range, from small 25-cm-long fish that have just completed their first winter in marine waters, to large 55 cm-long individuals that have spent at least 3 winters in marine waters and—based on the size of the gonads—will likely spawn this coming fall.
While chum abundance is high their condition appears to be is lowest of the salmon captured. Many of the chum salmon are visually thin or what we expected to see at this time of year. Additionally, many of their stomachs are empty. We expected that prey availability in winter would be low resulting in skinny fish, and the condition of these chum certainly seem to indicate this has been the case. With the spring bloom starting, these fish should now start to increase their feeding and should grow and fatten up quickly over the coming months.
However, in stark contrast to Chum salmon, the coho and sockeye salmon which represent about 40% of our catch, appear to be in better condition. Specifically the large sockeye over 450 mm are large and fat, have full stomachs, bright red flesh and eggs and a visible layer of fat just under their skin and coating their internal organs. These larger fish are primarily found in the northern portions of our study area. Along with a different distribution than the majority of the chum salmon we have caught, the sockeye salmon eat different prey. Their diet has largely been zooplankton (copepods and krill) compared to the chum salmon that, when eating, are feeding on gelatinous prey including jellyfish, salps and comb jellies). It remains puzzling as to why their condition would be so different from the chum salmon. The discussion amongst the scientists on the ship on this topic is continuous and it is clear that further analysis from the biological samples we have collected are going to be important in providing the clues needed to untangle this puzzle.
The coho salmon and smaller sockeye salmon are more middle of the road in appearance. What is puzzling about coho salmon is they’re considered to be a coastal species that remain near shore throughout their marine life. Instead, we are catching relatively large numbers of coho (our 2nd most abundant salmon) over 1000 km from land. The on-board genetic analysis of the first 30
coho we caught showed they were from a variety of rivers stretching from Puget Sound to
northern British Columbia. Is the distribution of coho salmon we are observing a new
phenomenon or have coho always used this part of the ocean and we simply have not been out
here sampling sufficiently to know this?
Although pink salmon are the most abundant species across the North Pacific by far, less than
10% of our catch has been pink salmon. Pink salmon are also known for their strong even-odd
year abundance pattern, with much larger returns to Asia, British Columbia, and Washington in
odd years than even years. Since this is an odd year we expected that pink salmon would
dominate our catch. So where are they? The pink salmon we have caught have all been in the
southern-most part of our study each, where ocean temperatures are warmer. Reports on
temperature preference of pink salmon has been varied. Published literature indicate that they
possibly have a greater tolerance for higher temperatures than other salmon but they are still
considered to inhabit waters to 3C. In our expedition, we have not caught pink salmon in areas
with surface water lower than 6C.
A key part of the winter habitat experienced by salmon in the Gulf of Alaska is the quantity and
type of zooplankton available for consumption and to support other components of the food web
observed in the salmon diet, e.g., squid and small pelagic fish. To provide this information, Brian
Hunt and Evgeny Pakhomov of Canada (UBC) and Alexander Slabinskii of Russia have been
conducting routine zooplankton net tows at each sampling station. A part of the zooplankton
catch is processed onboard while further, more detailed analyses, will be conducted when we
return to land. Preliminary observations, however, are sufficient to identify substantial shifts in
the zooplankton community across the survey area, and a rapid seasonal advancement with the
approaching spring.
Zooplankton catches have ranged from modest to relatively large for the later winter period. The
greatest difference in composition has been observed latitudinally, form south to north. The
zooplankton catches in the southern part of the have been dominated by very small copepods,
mainly in the size fraction <0.5 mm. However, moving north, the community shifted to being
dominated by large copepods, about 7-8 mm in length, mostly Neocalanus cristatus. There has
also been an increase in the occurrence of euphausiids (shrimp-like crustaceans), mainly
Euphausia pacifica and Thysanoessa spinifera, and pelagic decapods of genera Sergestes from
the mid-survey northward. Both of these groups are strong vertical migrators and are usually
only caught in abundance during the nighttime tows when they are near the surface to feed,
residing deeper than 200 m during daytime. Both large copepods and euphausiids are a valuable
food for growing salmon.
Gelatinous plankton have been extremely abundant in most parts of the survey area. In the south
western corner of the survey grid, the pelagic tunicate Salpa aspera has been highly abundant.
These tunicates disappear from the catches north of 50oN and are replaced by various jellyfish
species. By far the most abundant of these jellyfish is Chrysaora melanaster, the star jellyfish. In
the northern part of the survey grid this species is ever present at the ocean surface during the
night, clearly observable in the ship lights during trawls. Five minute surface counts in a 20
meter window adjacent to the ship have ranged from 200 to over 3000 individuals. The
differences in the species present in the north and south of the survey area also mean differences
for the food web. Salps are little open ocean “vacuum cleaners” feeding on microscopic plants
(phytoplankton), while jellyfish are voracious predators feeding on small zooplankton and
possibly compete with salmon for food.
Our survey is occurring during the transition from winter to spring conditions. A persistent high
pressure system centered over the Gulf of Alaska has not only brought us good weather for much
of our expedition, but has also provided the necessary sunlight to kick start the spring
phytoplankton bloom. As our survey has progressed we have observed a steady increase in the
phytoplankton biomass.
Understanding what is driving the trends we are able to readily detect is what many of the
scientists on the expedition and other colleagues at home will spend time over the coming
months discussing and analyzing. The patterns we’ve described here are just observations we’re
making from looking at what we’re catching in our nets, our emerging sense of the “big picture.”
We’ll have a much deeper understanding of emergent patterns once we’ve processed the 1000s
of samples we’re collecting and start putting it all together. Stay tuned!
We have now completed 55 sets and covered both southern and northern areas of our study area. We are starting to see patterns emerge that are proving to be extremely interesting. In some cases our observations match our expectations, but in other cases we are surprised by the picture that is slowly materializing. The expected and surprising observations run across all aspects of the ecosystem we are studying, from water chemistry to plankton to fish. Here are a few of the highlights:
The over-arching objective of this study is to examine Pacific salmon immediately after the winter period, when the expectation was that prey availability would be low and only fish that had high energy reserves last fall would survive. We expected to possibly even see visual signs of this with more thin or “skinny” fish than would be typically seen in a summer survey. While there appears to be signs that this may be the case for some species of salmon, it is not, at least directly, clear for other species of salmon.
Chum salmon have been our most abundant salmon species to date, representing about half the catch of all salmon, and are widely distributed across the study area. They have the largest body size range, from small 25-cm-long fish that have just completed their first winter in marine waters, to large 55 cm-long individuals that have spent at least 3 winters in marine waters and—based on the size of the gonads—will likely spawn this coming fall.
While chum abundance is high their condition appears to be is lowest of the salmon captured. Many of the chum salmon are visually thin or what we expected to see at this time of year. Additionally, many of their stomachs are empty. We expected that prey availability in winter would be low resulting in skinny fish, and the condition of these chum certainly seem to indicate this has been the case. With the spring bloom starting, these fish should now start to increase their feeding and should grow and fatten up quickly over the coming months.
However, in stark contrast to Chum salmon, the coho and sockeye salmon which represent about 40% of our catch, appear to be in better condition. Specifically the large sockeye over 450 mm are large and fat, have full stomachs, bright red flesh and eggs and a visible layer of fat just under their skin and coating their internal organs. These larger fish are primarily found in the northern portions of our study area. Along with a different distribution than the majority of the chum salmon we have caught, the sockeye salmon eat different prey. Their diet has largely been zooplankton (copepods and krill) compared to the chum salmon that, when eating, are feeding on gelatinous prey including jellyfish, salps and comb jellies). It remains puzzling as to why their condition would be so different from the chum salmon. The discussion amongst the scientists on the ship on this topic is continuous and it is clear that further analysis from the biological samples we have collected are going to be important in providing the clues needed to untangle this puzzle.
The coho salmon and smaller sockeye salmon are more middle of the road in appearance. What is puzzling about coho salmon is they’re considered to be a coastal species that remain near shore throughout their marine life. Instead, we are catching relatively large numbers of coho (our 2nd most abundant salmon) over 1000 km from land. The on-board genetic analysis of the first 30
coho we caught showed they were from a variety of rivers stretching from Puget Sound to
northern British Columbia. Is the distribution of coho salmon we are observing a new
phenomenon or have coho always used this part of the ocean and we simply have not been out
here sampling sufficiently to know this?
Although pink salmon are the most abundant species across the North Pacific by far, less than
10% of our catch has been pink salmon. Pink salmon are also known for their strong even-odd
year abundance pattern, with much larger returns to Asia, British Columbia, and Washington in
odd years than even years. Since this is an odd year we expected that pink salmon would
dominate our catch. So where are they? The pink salmon we have caught have all been in the
southern-most part of our study each, where ocean temperatures are warmer. Reports on
temperature preference of pink salmon has been varied. Published literature indicate that they
possibly have a greater tolerance for higher temperatures than other salmon but they are still
considered to inhabit waters to 3C. In our expedition, we have not caught pink salmon in areas
with surface water lower than 6C.
A key part of the winter habitat experienced by salmon in the Gulf of Alaska is the quantity and
type of zooplankton available for consumption and to support other components of the food web
observed in the salmon diet, e.g., squid and small pelagic fish. To provide this information, Brian
Hunt and Evgeny Pakhomov of Canada (UBC) and Alexander Slabinskii of Russia have been
conducting routine zooplankton net tows at each sampling station. A part of the zooplankton
catch is processed onboard while further, more detailed analyses, will be conducted when we
return to land. Preliminary observations, however, are sufficient to identify substantial shifts in
the zooplankton community across the survey area, and a rapid seasonal advancement with the
approaching spring.
Zooplankton catches have ranged from modest to relatively large for the later winter period. The
greatest difference in composition has been observed latitudinally, form south to north. The
zooplankton catches in the southern part of the have been dominated by very small copepods,
mainly in the size fraction <0.5 mm. However, moving north, the community shifted to being
dominated by large copepods, about 7-8 mm in length, mostly Neocalanus cristatus. There has
also been an increase in the occurrence of euphausiids (shrimp-like crustaceans), mainly
Euphausia pacifica and Thysanoessa spinifera, and pelagic decapods of genera Sergestes from
the mid-survey northward. Both of these groups are strong vertical migrators and are usually
only caught in abundance during the nighttime tows when they are near the surface to feed,
residing deeper than 200 m during daytime. Both large copepods and euphausiids are a valuable
food for growing salmon.
Gelatinous plankton have been extremely abundant in most parts of the survey area. In the south
western corner of the survey grid, the pelagic tunicate Salpa aspera has been highly abundant.
These tunicates disappear from the catches north of 50oN and are replaced by various jellyfish
species. By far the most abundant of these jellyfish is Chrysaora melanaster, the star jellyfish. In
the northern part of the survey grid this species is ever present at the ocean surface during the
night, clearly observable in the ship lights during trawls. Five minute surface counts in a 20
meter window adjacent to the ship have ranged from 200 to over 3000 individuals. The
differences in the species present in the north and south of the survey area also mean differences
for the food web. Salps are little open ocean “vacuum cleaners” feeding on microscopic plants
(phytoplankton), while jellyfish are voracious predators feeding on small zooplankton and
possibly compete with salmon for food.
Our survey is occurring during the transition from winter to spring conditions. A persistent high
pressure system centered over the Gulf of Alaska has not only brought us good weather for much
of our expedition, but has also provided the necessary sunlight to kick start the spring
phytoplankton bloom. As our survey has progressed we have observed a steady increase in the
phytoplankton biomass.
Understanding what is driving the trends we are able to readily detect is what many of the
scientists on the expedition and other colleagues at home will spend time over the coming
months discussing and analyzing. The patterns we’ve described here are just observations we’re
making from looking at what we’re catching in our nets, our emerging sense of the “big picture.”
We’ll have a much deeper understanding of emergent patterns once we’ve processed the 1000s
of samples we’re collecting and start putting it all together. Stay tuned!
wildmanyeah
Crew Member
Chinook migrations across the North Pacific Ocean
One species of Pacific salmon that has been in the news a lot lately are Chinook salmon, the “King” of salmon. As the largest Pacific salmon, Chinook are prized as a recreational fish, are important to First Nations in the U.S. and Canada, and get the highest price on a per weight basis of any salmon for commercial fishermen. Management of Chinook salmon is extremely complex because of the large number of ocean fisheries that target Chinook from Alaska to California and because many Chinook populations are subjected to multiple fisheries in both countries. Chinook salmon are also the preferred prey of Resident Killer whales. The Southern Resident Killer Whales reside from southern BC to California. They are the group that feeds on Chinook salmon during summer in the Strait of Juan de Fuca, Strait of Georgia, and San Juan Islands. Recent declines in this population of killer whales have been tied to declines in Chinook salmon abundance. At the same time, many Chinook salmon populations in Washington, Oregon, Idaho, and California receive protection under the U.S. Endangered Species Act because of concerns that rapidly declining populations may go extinct in the near future.
Because of both management and conservation concerns, Chinook salmon are the focus of substantial research to understand where and when they go in the ocean and the factors that determine their survival. Most of this marine research focused on Chinook salmon as they return home as adults with more recent research focused on the early marine period as they enter the ocean as juveniles. Both focal periods occur when Chinook salmon are close to shore and concentrated, and therefore relatively easy to catch by both fisheries as adults or with research nets as juveniles.
One fascinating outcome of this research is the realization that Chinook salmon appear to follow “ancestral feeding routes” during their time in marine waters. Every generation of fish migrate to the same areas at the same time in their life cycle, regardless of whether that area will provide abundant prey, and each stock has its own unique migration pattern. These patterns likely developed over thousands of generations because they were successful at producing returning adults. This fixed migration pathway has been observed by researchers working with juvenile salmon in both U.S. and Canadian waters, and with adults caught by ocean fisheries in both countries.
While we are learning where Chinook salmon stocks are during their early and late ocean migrations, where they go during the 1-4 years in between is poorly understood. Tagging studies conducted since the 1950s by high seas programs have shown that Chinook salmon originating from North America are caught in the Gulf of Alaska, central North Pacific and Bering Sea. However, there isn’t enough data to determine if Chinook salmon maintain these ancestral feeding routes on the high seas, or let prey abundance determine their pathway: they move when prey is low and stay when prey is high. Even less is known about the location and migratory patterns of Chinook salmon on the high seas during winter, when we suspect that prey resources are low and abundant prey simply are not available anywhere. Additionally, we suspect that the conditions the juveniles encounter during their early marine period in the nearshore area can impact their subsequent success, especially during their first marine winter in the high seas. The intent of this expedition was to shed light on this winter period, examine the
distribution, abundance, and condition of salmon in the Gulf of Alaska, and to determine if our expectations were correct.
While our catches of Chinook salmon on this expedition are too low to say much about stock-specific distributions, we can say something about the condition of the salmon we caught and what they’re eating. Our initial impressions are that all Chinook salmon looked very healthy without obvious signs of disease, injury, or starvation. All fish also had very full stomachs filled with deep sea squid and fish, both of which should be high quality prey. This suggests that these fish have encountered good feeding conditions, at least during this February and March, in the Gulf of Alaska. The fish were of mixed age classes and scales will be used to verify age and determine if any, especially the smallest individuals, were experiencing their first winter at sea. We will have a better sense of how healthy the Chinook were at a cellular level once back on shore when we can examine and analyze the numerous tissues we collected. We think all Chinook we caught originated from Washington and British Columbia, which will be confirmed with analyses on shore.
Because of their fixed migration pathway, there are concerns that Chinook salmon will not deviate from their feeding routes, even when conditions are poor and survival is low. Laurie Weitkamp, a salmon biologist with NOAA Fisheries who is on this expedition, has examined the recovery locations of millions of Chinook salmon caught in ocean fisheries over 1 ½ decades. She found that even when conditions were extremely poor, due to El Nin͂o or other climate events, Chinook salmon still went to the same places, even when it wasn’t a good place to be.
Clearly, for salmon to have survived for millions of years--experiencing ice ages, warming events, and everything in between--they have been flexible enough to adapt to changing conditions over time. Chrys Neville a biologist with Fisheries and Oceans Canada and another participant on the expedition, notes that various stocks have differing strategies including the time of year they enter the ocean. In BC, the Chinook salmon from the South Thompson region of the Fraser River, mostly enter the ocean in mid-summer rather than the spring with other Chinook salmon entering the Strait of Georgia. Over the last decade this group of fish have had improving escapements in contrast to most other stocks. This variability may be the strength of Chinook salmon. However, it may also mean that as managers we need to recognize that the Chinook and other salmon stocks that have been dominant in the last 20-40 years, may not be the same ones that are successful in the future.
Laurie and Chrys both note that this is further complicated by climate change which is increasing the rate of change in our oceans and extreme events such as “the blob” occur suddenly and without warning. How well Chinook and other Pacific salmon can adapt to such rapid changes is not known. However, by understanding the factors that regulate the survival we will be better informed to be able to successfully manage and sustain this species for years to come
One species of Pacific salmon that has been in the news a lot lately are Chinook salmon, the “King” of salmon. As the largest Pacific salmon, Chinook are prized as a recreational fish, are important to First Nations in the U.S. and Canada, and get the highest price on a per weight basis of any salmon for commercial fishermen. Management of Chinook salmon is extremely complex because of the large number of ocean fisheries that target Chinook from Alaska to California and because many Chinook populations are subjected to multiple fisheries in both countries. Chinook salmon are also the preferred prey of Resident Killer whales. The Southern Resident Killer Whales reside from southern BC to California. They are the group that feeds on Chinook salmon during summer in the Strait of Juan de Fuca, Strait of Georgia, and San Juan Islands. Recent declines in this population of killer whales have been tied to declines in Chinook salmon abundance. At the same time, many Chinook salmon populations in Washington, Oregon, Idaho, and California receive protection under the U.S. Endangered Species Act because of concerns that rapidly declining populations may go extinct in the near future.
Because of both management and conservation concerns, Chinook salmon are the focus of substantial research to understand where and when they go in the ocean and the factors that determine their survival. Most of this marine research focused on Chinook salmon as they return home as adults with more recent research focused on the early marine period as they enter the ocean as juveniles. Both focal periods occur when Chinook salmon are close to shore and concentrated, and therefore relatively easy to catch by both fisheries as adults or with research nets as juveniles.
One fascinating outcome of this research is the realization that Chinook salmon appear to follow “ancestral feeding routes” during their time in marine waters. Every generation of fish migrate to the same areas at the same time in their life cycle, regardless of whether that area will provide abundant prey, and each stock has its own unique migration pattern. These patterns likely developed over thousands of generations because they were successful at producing returning adults. This fixed migration pathway has been observed by researchers working with juvenile salmon in both U.S. and Canadian waters, and with adults caught by ocean fisheries in both countries.
While we are learning where Chinook salmon stocks are during their early and late ocean migrations, where they go during the 1-4 years in between is poorly understood. Tagging studies conducted since the 1950s by high seas programs have shown that Chinook salmon originating from North America are caught in the Gulf of Alaska, central North Pacific and Bering Sea. However, there isn’t enough data to determine if Chinook salmon maintain these ancestral feeding routes on the high seas, or let prey abundance determine their pathway: they move when prey is low and stay when prey is high. Even less is known about the location and migratory patterns of Chinook salmon on the high seas during winter, when we suspect that prey resources are low and abundant prey simply are not available anywhere. Additionally, we suspect that the conditions the juveniles encounter during their early marine period in the nearshore area can impact their subsequent success, especially during their first marine winter in the high seas. The intent of this expedition was to shed light on this winter period, examine the
distribution, abundance, and condition of salmon in the Gulf of Alaska, and to determine if our expectations were correct.
While our catches of Chinook salmon on this expedition are too low to say much about stock-specific distributions, we can say something about the condition of the salmon we caught and what they’re eating. Our initial impressions are that all Chinook salmon looked very healthy without obvious signs of disease, injury, or starvation. All fish also had very full stomachs filled with deep sea squid and fish, both of which should be high quality prey. This suggests that these fish have encountered good feeding conditions, at least during this February and March, in the Gulf of Alaska. The fish were of mixed age classes and scales will be used to verify age and determine if any, especially the smallest individuals, were experiencing their first winter at sea. We will have a better sense of how healthy the Chinook were at a cellular level once back on shore when we can examine and analyze the numerous tissues we collected. We think all Chinook we caught originated from Washington and British Columbia, which will be confirmed with analyses on shore.
Because of their fixed migration pathway, there are concerns that Chinook salmon will not deviate from their feeding routes, even when conditions are poor and survival is low. Laurie Weitkamp, a salmon biologist with NOAA Fisheries who is on this expedition, has examined the recovery locations of millions of Chinook salmon caught in ocean fisheries over 1 ½ decades. She found that even when conditions were extremely poor, due to El Nin͂o or other climate events, Chinook salmon still went to the same places, even when it wasn’t a good place to be.
Clearly, for salmon to have survived for millions of years--experiencing ice ages, warming events, and everything in between--they have been flexible enough to adapt to changing conditions over time. Chrys Neville a biologist with Fisheries and Oceans Canada and another participant on the expedition, notes that various stocks have differing strategies including the time of year they enter the ocean. In BC, the Chinook salmon from the South Thompson region of the Fraser River, mostly enter the ocean in mid-summer rather than the spring with other Chinook salmon entering the Strait of Georgia. Over the last decade this group of fish have had improving escapements in contrast to most other stocks. This variability may be the strength of Chinook salmon. However, it may also mean that as managers we need to recognize that the Chinook and other salmon stocks that have been dominant in the last 20-40 years, may not be the same ones that are successful in the future.
Laurie and Chrys both note that this is further complicated by climate change which is increasing the rate of change in our oceans and extreme events such as “the blob” occur suddenly and without warning. How well Chinook and other Pacific salmon can adapt to such rapid changes is not known. However, by understanding the factors that regulate the survival we will be better informed to be able to successfully manage and sustain this species for years to come
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wildmanyeah
Crew Member
Sampling the WHOLE salmon!
The primary objective of the expedition is to document the abundance, ecology, and health of salmon across the northeast Pacific during the winter, a potentially critical period of the salmon life cycle that we know little about. To achieve our objective, in addition to counting the salmon, we take a wide range of tissue samples from outside and inside each fish. Some of these samples are processed on board the Professor Kaganovskiy within hours, while others require large (and often expensive) equipment and instead will be analyzed in laboratories around the Pacific Rim. By the time we’re done processing each fish in each haul, there isn’t much left except the head, skeleton, and a few bits of flesh.
Each tissue type we collect only tells us about a single aspect of the salmon, much like an individual jigsaw puzzle piece shows only a small fraction of the picture. By assembling the many pieces each analysis provides, we create the “big picture,” namely a comprehensive determination of how each fish is doing. Because so little salmon research has been conducted in this area at this time of year, our collective results fill an important gap in our knowledge of the salmon life cycle.
When the fish come on board the ship, the first thing we do is identify them to species: pink, chum, sockeye, coho, and Chinook salmon. We do this using a suite of characteristics, including body size and shape, the size of gill rakers and scales, and the shape and coloration of the tail, back, anal fin, and color inside the mouth. Distinguishing between species requires attention to detail, which can be hard when you’ve left your warm cozy bunk at 3 am to process the catch. Having several people--even sleepy ones--examine each fish ensures we get the species right, a critical first step in processing salmon.
We then examine the outside of the fish, noting whether the adipose fin has been clipped (indicating either a wild fish or the presence of an internal coded wire tag), any obvious scars or wounds, the presence of sea lice, and external signs of disease such as black spots (caused by an internal parasite). We secure a tag containing a unique number around the tail of each fish so we can trace all samples collected during processing back to each individual fish, or find the fish when we realize hours later that we forgot to take some tissue sample. Carefully recording the sample numbers that came from each fish is essential to fully assemble our jigsaw puzzle—if we don’t know which sample came from which fish, we lose a lot of information.
Next, we measure the length and weight of each fish, a deceptively simple procedure that provides extremely useful but rough information about approximate fish age, growth rate, and feeding success (skinny or fat). We also get detailed age and growth information from scales
and otoliths tissues we collect, but they take longer to process and will be analyzed back on shore. For example, we’ve been seeing several sizes of chum salmon (small, medium, and large), which we expect the scale data will show are fish that have spent 1, 2 and 3 winters in the ocean.
We then take several small fin clips that will be used to genetically determine where each fish originated from. Because salmon home to their natal streams, populations are genetically distinct and can be assigned to the geographic region or river of origin. For example, we can genetically distinguish between 24 populations of sockeye salmon in the Fraser River. Using the same methodology popular for human ancestry tests, we do this by comparing the genetic “finger print” of each fish to a baseline composed of genetic characterizations of hundreds of populations from rivers around the Pacific Rim.
We have the equipment and supplies on board the ship to make an initial genetic analysis for coho and Chinook salmon, a process that takes roughly two to three days to complete. The first batch of coho salmon was started yesterday and we eagerly await the results. Some of the questions the genetic data should answer are where each salmon came from, and whether the coho we’ve caught so far represent mixtures of stocks or largely come from a single population. If all goes well, we’ll have answers by dinner!
We can also learn where fish came from two “tags” we’re collecting: internal tags (coded wire and PIT tags) and otolith thermo-marks, or bar coding of the ear bones, which will be processed on shore. Both techniques are largely restricted to hatchery fish and applied while young fish are still in the hatchery. These are also important tools for salmon management, such as estimating harvest rates and catch distributions. However, we take advantage of the information they contain to tell us which specific hatchery each tagged fish comes from.
Once the external examination is complete, we put on the latex gloves and begin the dissections. Stomachs are removed and analyzed within hours of collection to determine both the amount and type of prey in their stomachs. Once the stomach is out of the way, we record whether the fish is male or female, and weigh the eggs or testes to document whether the fish will spawn in the coming year (maturing) or in will wait for future years (immature) before it returns to its home stream.
We also note the presence of large parasitic round worms, called nematodes, which inhabit the stomach, body cavity, and other parts of the body. These nematodes have complex life cycles that involve being passed from host to host, as the first animal they infect is eaten by the next host and the worm hitchhikes along. Most of the worms we’ve see use salmon as a temporary intermediate host; the worm’s ultimate host—where they complete their life cycle--is typically a marine mammal. At low abundances these nematodes probably don’t hurt the fish, but some of the high levels we’ve observed—up to thirty 4 cm-long worms in a single individual--probably have negative health effects.
The primary objective of the expedition is to document the abundance, ecology, and health of salmon across the northeast Pacific during the winter, a potentially critical period of the salmon life cycle that we know little about. To achieve our objective, in addition to counting the salmon, we take a wide range of tissue samples from outside and inside each fish. Some of these samples are processed on board the Professor Kaganovskiy within hours, while others require large (and often expensive) equipment and instead will be analyzed in laboratories around the Pacific Rim. By the time we’re done processing each fish in each haul, there isn’t much left except the head, skeleton, and a few bits of flesh.
Each tissue type we collect only tells us about a single aspect of the salmon, much like an individual jigsaw puzzle piece shows only a small fraction of the picture. By assembling the many pieces each analysis provides, we create the “big picture,” namely a comprehensive determination of how each fish is doing. Because so little salmon research has been conducted in this area at this time of year, our collective results fill an important gap in our knowledge of the salmon life cycle.
When the fish come on board the ship, the first thing we do is identify them to species: pink, chum, sockeye, coho, and Chinook salmon. We do this using a suite of characteristics, including body size and shape, the size of gill rakers and scales, and the shape and coloration of the tail, back, anal fin, and color inside the mouth. Distinguishing between species requires attention to detail, which can be hard when you’ve left your warm cozy bunk at 3 am to process the catch. Having several people--even sleepy ones--examine each fish ensures we get the species right, a critical first step in processing salmon.
We then examine the outside of the fish, noting whether the adipose fin has been clipped (indicating either a wild fish or the presence of an internal coded wire tag), any obvious scars or wounds, the presence of sea lice, and external signs of disease such as black spots (caused by an internal parasite). We secure a tag containing a unique number around the tail of each fish so we can trace all samples collected during processing back to each individual fish, or find the fish when we realize hours later that we forgot to take some tissue sample. Carefully recording the sample numbers that came from each fish is essential to fully assemble our jigsaw puzzle—if we don’t know which sample came from which fish, we lose a lot of information.
Next, we measure the length and weight of each fish, a deceptively simple procedure that provides extremely useful but rough information about approximate fish age, growth rate, and feeding success (skinny or fat). We also get detailed age and growth information from scales
and otoliths tissues we collect, but they take longer to process and will be analyzed back on shore. For example, we’ve been seeing several sizes of chum salmon (small, medium, and large), which we expect the scale data will show are fish that have spent 1, 2 and 3 winters in the ocean.
We then take several small fin clips that will be used to genetically determine where each fish originated from. Because salmon home to their natal streams, populations are genetically distinct and can be assigned to the geographic region or river of origin. For example, we can genetically distinguish between 24 populations of sockeye salmon in the Fraser River. Using the same methodology popular for human ancestry tests, we do this by comparing the genetic “finger print” of each fish to a baseline composed of genetic characterizations of hundreds of populations from rivers around the Pacific Rim.
We have the equipment and supplies on board the ship to make an initial genetic analysis for coho and Chinook salmon, a process that takes roughly two to three days to complete. The first batch of coho salmon was started yesterday and we eagerly await the results. Some of the questions the genetic data should answer are where each salmon came from, and whether the coho we’ve caught so far represent mixtures of stocks or largely come from a single population. If all goes well, we’ll have answers by dinner!
We can also learn where fish came from two “tags” we’re collecting: internal tags (coded wire and PIT tags) and otolith thermo-marks, or bar coding of the ear bones, which will be processed on shore. Both techniques are largely restricted to hatchery fish and applied while young fish are still in the hatchery. These are also important tools for salmon management, such as estimating harvest rates and catch distributions. However, we take advantage of the information they contain to tell us which specific hatchery each tagged fish comes from.
Once the external examination is complete, we put on the latex gloves and begin the dissections. Stomachs are removed and analyzed within hours of collection to determine both the amount and type of prey in their stomachs. Once the stomach is out of the way, we record whether the fish is male or female, and weigh the eggs or testes to document whether the fish will spawn in the coming year (maturing) or in will wait for future years (immature) before it returns to its home stream.
We also note the presence of large parasitic round worms, called nematodes, which inhabit the stomach, body cavity, and other parts of the body. These nematodes have complex life cycles that involve being passed from host to host, as the first animal they infect is eaten by the next host and the worm hitchhikes along. Most of the worms we’ve see use salmon as a temporary intermediate host; the worm’s ultimate host—where they complete their life cycle--is typically a marine mammal. At low abundances these nematodes probably don’t hurt the fish, but some of the high levels we’ve observed—up to thirty 4 cm-long worms in a single individual--probably have negative health effects.
wildmanyeah
Crew Member
We then sample the various internal organs for several different purposes. The most extensive collection of tissues are used to assess how healthy each fish is and the presence of any diseases the fish might carry, whether or not it looks sick. Small pieces of heart, liver, spleen, muscle, brain, blood, and kidney are carefully removed, preserved on board, and will be analyzed back in the lab both microscopically and genetically for the presence of viruses and other diseases. We will also determine overall fish health, as shown by the up- or down-regulation of specific genes. This technique will allow us to determine if, for example, large nematode infestations are affecting the health of the fish. Some diseases that fish acquire in freshwater as juveniles go into remission while in saltwater but can then flare up again when the fish return to freshwater to spawn. Our samples help us understand this process.
We’re also collecting tissue samples to construct an energy budget for salmon overall: how much energy they consume in their food, how much they use for metabolism, how much they store as muscle or fat, and how much they devote to reproduction. To do this, we collect tissue samples from the muscle, liver, eggs, and stomach contents from each salmon, all of which are frozen on board. Back on shore, each tissue type will be analyzed for total energy and fat content. This information is entered into a bioenergetics model, which accounts for temperature-based metabolic rates. Once the energy budget is complete, we can estimate the energy demand of salmon across the Northeast Pacific, and how it varies by species or location. We can also use this framework to explore how energy budgets vary under different scenarios, such as the effects of elevated ocean temperatures (since salmon metabolism increases with water temperature) or changes to the abundance of particularly high or low energy prey.
In a parallel study, we’re using naturally occurring stable isotopes of carbon and nitrogen, and fatty acids (think Omega 3 fatty acids), to trace the flow of energy throughout the food web. These trophic biomarkers get passed from prey to predator more or less intact, allowing us to study the flow of energy at time scales of weeks to months. To assemble this energy flow diagram, we’re collecting muscle tissue from each salmon, as well as tissue samples of potential salmon prey items ranging from zooplankton and jelly fish to small fishes, and also muscle from salmon predators (so far just sharks). Like the energy analysis, all the lab work for this study will be conducted back on shore. And like the energy analysis, it allows us to trace the flow of energy across the entire food web, from photosynthetic phytoplankton to salmon prey to salmon themselves and then their predators. We can then use the model to explore how energy flow will likely change under different scenarios.
Finally, we’re left with a carcass that consists of the head, backbone, a few bits of muscle, and the intestines. Each carcass goes into a labeled plastic bag and gets frozen in case we need to take additional types of samples (e.g. kidney tissues) or realize we missed something in the frenzy of fish processing. We are slowly filling the ship’s freezers with hundreds if not thousands of carefully numbered tissue samples in labeled vials, bags, and boxes, and an equal number that are chemically preserved. Although they don’t look particularly impressive at this point, they are invaluable for what they will tell us about the salmon we catch.
When we reach Vancouver in three weeks, we will get off the Professor Kaganovskiy with many completed analyses in hand, namely detailed information about the abundance, distribution, size, and diets for the five species of Pacific salmon across our study area. In the coming weeks and months, the thousands of tissue samples collected at sea will be analyzed at laboratories across the Pacific Rim. If all goes as planned, in a year or two many of the puzzle pieces should be complete and we will begin to assemble this jigsaw puzzle that tells the story of salmon marine ecology. We expect the scientific contribution of this expedition will be huge, and shape our thinking about salmon in the ocean for decades to come.
We’re also collecting tissue samples to construct an energy budget for salmon overall: how much energy they consume in their food, how much they use for metabolism, how much they store as muscle or fat, and how much they devote to reproduction. To do this, we collect tissue samples from the muscle, liver, eggs, and stomach contents from each salmon, all of which are frozen on board. Back on shore, each tissue type will be analyzed for total energy and fat content. This information is entered into a bioenergetics model, which accounts for temperature-based metabolic rates. Once the energy budget is complete, we can estimate the energy demand of salmon across the Northeast Pacific, and how it varies by species or location. We can also use this framework to explore how energy budgets vary under different scenarios, such as the effects of elevated ocean temperatures (since salmon metabolism increases with water temperature) or changes to the abundance of particularly high or low energy prey.
In a parallel study, we’re using naturally occurring stable isotopes of carbon and nitrogen, and fatty acids (think Omega 3 fatty acids), to trace the flow of energy throughout the food web. These trophic biomarkers get passed from prey to predator more or less intact, allowing us to study the flow of energy at time scales of weeks to months. To assemble this energy flow diagram, we’re collecting muscle tissue from each salmon, as well as tissue samples of potential salmon prey items ranging from zooplankton and jelly fish to small fishes, and also muscle from salmon predators (so far just sharks). Like the energy analysis, all the lab work for this study will be conducted back on shore. And like the energy analysis, it allows us to trace the flow of energy across the entire food web, from photosynthetic phytoplankton to salmon prey to salmon themselves and then their predators. We can then use the model to explore how energy flow will likely change under different scenarios.
Finally, we’re left with a carcass that consists of the head, backbone, a few bits of muscle, and the intestines. Each carcass goes into a labeled plastic bag and gets frozen in case we need to take additional types of samples (e.g. kidney tissues) or realize we missed something in the frenzy of fish processing. We are slowly filling the ship’s freezers with hundreds if not thousands of carefully numbered tissue samples in labeled vials, bags, and boxes, and an equal number that are chemically preserved. Although they don’t look particularly impressive at this point, they are invaluable for what they will tell us about the salmon we catch.
When we reach Vancouver in three weeks, we will get off the Professor Kaganovskiy with many completed analyses in hand, namely detailed information about the abundance, distribution, size, and diets for the five species of Pacific salmon across our study area. In the coming weeks and months, the thousands of tissue samples collected at sea will be analyzed at laboratories across the Pacific Rim. If all goes as planned, in a year or two many of the puzzle pieces should be complete and we will begin to assemble this jigsaw puzzle that tells the story of salmon marine ecology. We expect the scientific contribution of this expedition will be huge, and shape our thinking about salmon in the ocean for decades to come.
wildmanyeah
Crew Member
https://vancouversun.com/news/local...international-expedition-returns-to-vancouver
The Secret Lives of Salmon: International expedition returns to Vancouver
The Secret Lives of Salmon: International expedition returns to Vancouver
wildmanyeah
Crew Member
wildmanyeah
Crew Member
A couple of my fav slides
wildmanyeah
Crew Member
Expedition to probe Pacific salmon survival
https://www.timescolonist.com/news/local/expedition-to-probe-pacific-salmon-survival-1.24077551
https://www.timescolonist.com/news/local/expedition-to-probe-pacific-salmon-survival-1.24077551
Texadafisher
New Member
This is great. I only wish this research would have taken place years ago.
Not so sure about that, Dave. If you look close - one can see some residual parr marks on the 4 bottom ones & they have slender peduncles. I'd say sockeye (or maybe chum) w 1 pink on top. The larger-looking eyes would lead one to think they might be sockeye. To bad one can't see the gill rakers.
wildmanyeah
Crew Member
I believe in the caption of the picture it says their pinks
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