WDFW Forage Fish
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Presentation to Nisqually River Council on 2/16/18
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WDFW Forage Fish
- 1. Presented to the Nisqually River Council: February 16, 2018
- 2. Forage fish PEW Forage fish are: An ecological, not genetic, group Generally small, highly fecund, schooling fish at the middle of food webs A vital conduit between primary producers and higher level consumers A valuable indicator species of ecosystem health Commercially, recreationally, and culturally important Currently account for over 1/3 of overall marine harvest by weight A valuable indicator of ecosystem health
- 3. PacificWild.org What are forage fish & why are they important? SwitterSB.wordpress.com Forage fish are: An ecological, not genetic, group Generally small, highly fecund, schooling fish at the middle of food webs A vital conduit between primary producers and higher level consumers A valuable indicator species of ecosystem health Commercially, recreationally, and culturally important Currently account for over 1/3 of overall marine harvest by weight Birdnote.org
- 4. What are forage fish & why are they important? Qmakie.wordpress.com Forage fish are: An ecological, not genetic, group Generally small, highly fecund, schooling fish at the middle of food webs A vital conduit between primary producers and higher level consumers A valuable indicator species of ecosystem health Commercially, recreationally, and culturally important Currently account for over 1/3 of overall marine harvest by weight
- 5. Despite their importance, many questions remain…
- 6. -Birds that dive and forage for fish in the Salish Sea, including this western grebe, are 11 times more likely to experience population declines than other birds in the area. (Joe Gaydos, journal of Conservation Biology) Warning signs: Bird declines in WA State Plumas Audubon Society
- 7. Challenges Facing Forage Fish www.deviantart.com/art/Water-Pollution-49872113 Forage fish are susceptible to: Over fishing/Bycatch Poor water quality Habitat Loss Climate change
- 8. Pelagic AnadromousNearshore Common Marine Forage Fish of WA State
- 9. Surf Smelt & Sand Lance spawn on the beach
- 10. Beach Surveys
- 11. Smelt Egg Extraction Techniques 0 10 20 30 40 50 60 70 80 90 100 Vortex Winnow %EggsRecovered Method 90% 59% Winnow Vortex
- 12. Survey nearly all of Puget Sound in 6-7 months.
- 13. Herring Egg Surveys Surveys use a rake to collect this vegetation Egg densities on vegetation and the area covered by spawn are used to estimate the annual spawning population Primary tool for status assessment since 2010
- 14. Herring Spawning Stocks 22 stocks spawn at discrete times and locations Usually spawn January -April, but some stocks spawn into June. Three genetic groups in Puget Sound Cherry Point stock Squaxin Pass stock All other Puget Sound herring stocks
- 15. Herring Stock Trends Once the most abundant stock, Cherry Point herring have declined by over 90% since the 1970s Abundance of Squaxin Pass and “Other Stocks” complex has been relatively stable 8,796 tons 372 tons 299 tons
- 17. Anadromous Spawners: -Longfin smelt (Spirinchus thaleichthys) -Eulachon (Thaleichthys pacificus)
- 18. Eulachon Smelt Eulachon smelt Landings plummeted in 1994 ESA listed and fishery closed* in 2010
- 19. Eulachon: Larvae Sampling Larvae Sampling Began on Columbia River in 1996 prior to fishery closure Expanded to additional rivers in 2011 Estimates larvae density from larvae counts and flow meter readings.
- 20. Trends in Forage Fish Stocks Eulachon smelt Spawning production monitoring Larger runs observed in 2014 and 2015 allowed for limited fisheries Runs still below historical levels Declining again
- 21. Environmental DNA: Eulachon Presence
- 22. Quantitative Environmental DNA More Fish = More DNA
- 23. 0 0.5 1 1.5 2 2.5 3 3.5 4 0 100 200 300 400 500 600 EggandLarvae/m^3H2O Copies/20uL Date Chehalis River Eulachon Eulachon eDNA Longfin eDNA Larvae Eggs 4 weeks
- 25. Northern Anchovy: Northern Sub-population 0 0.05 0.1 0.15 0.2 0.25 0.3 0.35 0.4 0.45 2010 2011 2012 2013 2014 2015 2016 2017 ProportionofSetswithAnchovy S. Puget Sound Beach Seine
- 26. Resources Forage Fish mapping to tool Interactive map of documented surf smelt and sand lance beaches wdfw.wa.gov/conservation/research /projects/marine_beach_spawning/ Web-based info available Approved biologist list is at: http://wdfw.wa.gov/licensing/hpa/t echnical_assistance.html, then click the “WDFW Trained Biologists” link under the “Forage Fish Beach Spawning Surveys” bullet. For training or consulting contact Phillip Dionne, WDFW Phillip.Dionne@dfw.wa.gov; 360-902-2641
- 27. Puget Sound Mid-Water Trawl
- 28. Puget Sound Mid-Water Trawl
- 31. Study Questions + ? 1.) Can we mark Surf Smelt without killing them? - Holding Trial
- 32. Tag Selection + ? • Selected Visible Implant Elastomer (VIE) tags • Low cost • Minimally invasive • Easy to use • Non-toxic Visible Implant Elastomer (VIE) Tag
- 33. Holding Trial Captured smelt with beach seine 119 marked smelt held for 3 weeks Results: Tag Retention: 100% Survival: 92%
- 34. Study Questions + ? 1.) Can we mark Surf Smelt without killing them? - Holding Trial 2.) Can we mark and recapture Surf Smelt in the wild? - Field Trial
- 35. Capture Sites 1 2 Field Trial
- 36. Field Trial Step 1: Catch Smelt
- 37. 4 Tag locations Field Trial Step 2: Tag with site & date specific marks
- 38. Step 3: Record biological data Field Trial
- 39. Field Trial Step 4: Release marked smelt… alive
- 40. Field Trial Step 5: Repeat monthly 1. 2. 3. 4.
- 41. 0 2000 4000 6000 8000 10000 12000 TaggedSmeltatLarge Unknown Female Male Average Male to Female Ratio 4:1 Results: Tagged Smelt at Large Smelt Tagged Site 1: 4,641 Site 2: 5,356 Total: 9,997
- 42. Results: Recaptures 0 5 10 15 20 25 30 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 NumberofSmeltRecaptured Months After Tagging Female Male
- 43. Study Questions + ? 1.) Can we mark Surf Smelt without killing them? - Holding Trial 2.) Can we mark and recapture Surf Smelt in the wild? - Field Trial 3.)What can we learn about their movements and biology using these methods?
- 44. What did we learn? 0 5 10 15 20 25 30 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 NumberofSmeltRecaptured Months After Tagging Female Male Ø
- 45. What we learned Surf Smelt are hardy enough to mark with VIE tags Adult Surf Smelt retain VIE tags up to 9 months Individual Surf Smelt will spawn multiple times on multiple beaches in the same region Differential spawning frequency may explain the male biased sex ratios observed
- 46. What’s next?: What happened to the other 9,927 smelt? If they left the region, where did they go? Can we enhance smelt creel surveys by combining with tagging efforts? Can we learn more about other Puget Sound species using similar methods? January FebruaryMarch April August 17, 2015 More Questions!
- 47. Questions?
- 48. Partners:
Editor's Notes
- Hello, my name is…
- Forage fish are also sometimes called “bait fish”, but either term can be broadly applied to a diverse assemblage of species that are, in many cases, only related through ecology. Sometimes called “forage species,” to include a greater range of animals such as krill, and squid. Forage fish are generally planktivores, and provide a conduit from primary producers to higher level consumers.
- And, because of their place in the food web, forage fish can be an indicator of ecosystem health. For example, forage fish abundance has been linked to the success or failure of shore bird nesting colonies, salmon runs, and marine mammal survival; and when forage fish abundance drops, other fish, like salmon smolt may be the next item on the menu for many of these predators, like harbor seals.
- Forage fish have supported commercial and recreational fisheries, currently accounting for about 37% of marine harvest (by weight) and have been important to Native Americans and 1st Nations in North America. These photos are of…
- Despite how clearly important forage fish are, there is still a great deal of uncertainty surrounding them, and for some species we’re still seeking answers even basic questions about life history and abundance. For many species we don’t even have enough data to guess if their populations growing, declining or stable, but we do have reason to be concerned …Segue: One of the challenges of studying forage fish is that they are a diverse group of species with a variety of life histories and occupy a variety of habitats…
- …Segue: Another challenge of monitoring forage fish is understanding how human activities might impact abundance… Forage fish stocks fluctuate dramatically in response to ocean conditions. In this example I’ve highlight how the colder years of the PDO (top figure) favor Peruvian Anchovy (bottom figure) while the warmer years favor Sardine. Scientists need to be able to separate these effects from human induced effects, and recent studies have shown that fishing pressure can make these declines more dramatic and prolonged. …Segue: Here in Puget Sound there is a lot of concern over forage fish abundance because even though we have very little direct estimate of abundance, the indicators we do have are not promising…
- …Segue: Here in Puget Sound there is a lot of concern over forage fish abundance because even though we have very little direct estimate of abundance, the indicators we do have are not promising… This study from 2014 showed that… …Segue: So what are some of the factors that could contribute to declines of forage fish in WA waters?...
- …Segue: So what are some of the factors that could contribute to declines of forage fish in WA waters?... We think of these as our usual suspect… Climate change: The rise and fall of forage fish populations are often correlated with ocean conditions as I showed earlier. Changes in the frequency, severity and duration of these events may result in shifts in the distribution or abundance of some forage fish species, and over time these species may become less abundant. Over fishing and bycatch: Schooling makes forage fish vulnerable to overfishing; they are easy to find and easy to catch in large numbers. Some are also caught in large numbers when they are not being targeted. Poor water quality has been shown to negatively impact many fish species including forage fish, especially early life stages, and the nearshore species we’ll talk about today are often exposed more frequently to contaminated water because of their proximity to human development. Habitat loss may be surprising because the ocean is such a huge area, but some species in Puget Sound rely specifically on the narrow band of beach at the edge of the water to lay their eggs and now these species must compete with human interests for space on the beach.
- So know that we know why forage fish are so important and some of the challenges facing them, I’d like to introduce to you a few of the more common forage fish in WA State. For simplicity, I’ve divided these species based on where they spawn.
- …Segue: One of the challenges of studying forage fish is that they are a diverse group of species with a variety of life histories and occupy a variety of habitats… For example, the spawning habits for the species I will discuss in more detail today can be divided into 3 general types, but the each species is unique in its specific location and timing, and as we’ll see, we even see differences within the same species. …Segue: Another challenge of monitoring forage fish is understanding how human activities might impact abundance…
- …Segue: One of the challenges of studying forage fish is that they are a diverse group of species with a variety of life histories and occupy a variety of habitats… For example, the spawning habits for the species I will discuss in more detail today can be divided into 3 general types, but the each species is unique in its specific location and timing, and as we’ll see, we even see differences within the same species. …Segue: Another challenge of monitoring forage fish is understanding how human activities might impact abundance…
- The 3 common nearshore spawning forage fish we study are Herring , Surf Smelt, and Sand Lance. There is overlap between the spawning habitat for each species, but generally Herring spawn in the lower intertidal to subtidal zone on aquatic vegetation, Sand Lance spawn in the mid to upper intertidal zone on fine sandy substrate, and Surf Smelt spawn in the upper intertidal zone on substrate composed of sand and gravel. Surf Smelt and Sand Lance are intertidal spawners, meaning that their eggs are deposited on the beach above low tide, while Herring are subtidal spawners, so we need to use different methods to study their spawning habitat. Now I’ll pass the mic to Dayv and Kira so that they can tell you about some of the work we do with these nearshore species.
- Surf Smelt are also special because they lay their eggs on the beach near high tide, which means their habitat is very close to our habitat.
- Risks to nearshore forage fish habitat include but are not limited to both direct and indirect effects of nearshore development: -Direct habitat loss when the beach is built on -Loss of riparian cover -Changes in drainage patterns -Changes in wave energy and sediment transport And -Impoundment of beach nourishing sediment
- We have two crews of WCC members working with us to sample, and process the samples every month. For those of you familiar with surf smelt beach spawn sampling with Puget Sound, most of our methods are based on the revised 2006 “Field Manual for Sampling Forage Fish Spawn in intertidal shore regions,” by Dan Penttila and Lawrence Moulton. When we arrive at a designated set of coordinates, we assess the location for accessibility by the crew, and habitat suitability. For habitat that is unsuitable, for example mud or hardpan, we do not collect samples, but we do collect habitat characteristics. At suitable sites, we collect a sediment sample across a 100’ section of beach That sediment is later sieved through progressively smaller sieves, keeping only the sediment left in the 0.5mm sieve. Any eggs are then extracted from the sample, by running them through a vortexing apparatus called “the blue bowl.” This is where our methods vary from the standard manual. The blue bowl is a new method for egg extraction, that we have spent the last year testing. We have found that the vortexing method is able to extract a much higher percentage of eggs from our samples, and reduces the sediment that must be processed in the lab. We now use to process all of our samples. I’m not going to go into detail about it here, but if you have any questions about it, please feel free to ask myself or Phillip Dionne later. Once the light fraction of the sample has been extracted, it is analyzed in the lab for Surf Smelt egg presence, egg abundance, and egg developmental staging. In the data that I will show you, egg presence indicates two or more eggs found in a sample.
- We have two crews of WCC members working with us to sample, and process the samples every month. For those of you familiar with surf smelt beach spawn sampling with Puget Sound, most of our methods are based on the revised 2006 “Field Manual for Sampling Forage Fish Spawn in intertidal shore regions,” by Dan Penttila and Lawrence Moulton. When we arrive at a designated set of coordinates, we assess the location for accessibility by the crew, and habitat suitability. For habitat that is unsuitable, for example mud or hardpan, we do not collect samples, but we do collect habitat characteristics. At suitable sites, we collect a sediment sample across a 100’ section of beach That sediment is later sieved through progressively smaller sieves, keeping only the sediment left in the 0.5mm sieve. Any eggs are then extracted from the sample, by running them through a vortexing apparatus called “the blue bowl.” This is where our methods vary from the standard manual. The blue bowl is a new method for egg extraction, that we have spent the last year testing. We have found that the vortexing method is able to extract a much higher percentage of eggs from our samples, and reduces the sediment that must be processed in the lab. We now use to process all of our samples. I’m not going to go into detail about it here, but if you have any questions about it, please feel free to ask myself or Phillip Dionne later. Once the light fraction of the sample has been extracted, it is analyzed in the lab for Surf Smelt egg presence, egg abundance, and egg developmental staging. In the data that I will show you, egg presence indicates two or more eggs found in a sample.
- We have two crews of WCC members working with us to sample, and process the samples every month. For those of you familiar with surf smelt beach spawn sampling with Puget Sound, most of our methods are based on the revised 2006 “Field Manual for Sampling Forage Fish Spawn in intertidal shore regions,” by Dan Penttila and Lawrence Moulton. When we arrive at a designated set of coordinates, we assess the location for accessibility by the crew, and habitat suitability. For habitat that is unsuitable, for example mud or hardpan, we do not collect samples, but we do collect habitat characteristics. At suitable sites, we collect a sediment sample across a 100’ section of beach That sediment is later sieved through progressively smaller sieves, keeping only the sediment left in the 0.5mm sieve. Any eggs are then extracted from the sample, by running them through a vortexing apparatus called “the blue bowl.” This is where our methods vary from the standard manual. The blue bowl is a new method for egg extraction, that we have spent the last year testing. We have found that the vortexing method is able to extract a much higher percentage of eggs from our samples, and reduces the sediment that must be processed in the lab. We now use to process all of our samples. I’m not going to go into detail about it here, but if you have any questions about it, please feel free to ask myself or Phillip Dionne later. Once the light fraction of the sample has been extracted, it is analyzed in the lab for Surf Smelt egg presence, egg abundance, and egg developmental staging. In the data that I will show you, egg presence indicates two or more eggs found in a sample.
- Herring surveys are conducted by boat and use a special rake that is dragged through the water to collect samples of vegetation. The density of eggs on the vegetation and the area of the seafloor covered by the vegetation are used to estimate the number of eggs in the area and then the number of adults that would have spawned that number of eggs.
- Herring surveys have been conducted since the 1970s. Spawning has been documented in about 20 different areas, and spawning generally occurs from January through April for most stocks, but some stocks spawn into June. Genetic analysis of Herring in Puget Sound indicates that there are 3 genetically distinct groups; the Cherry Pt. Stock, Squaxin Pass Stock, and then all the other areas group together genetically. Commercial harvest of herring in Puget Sound is for bait and averages 300-400 metric tons annually.
- The Cherry Pt. stock was once the most abundant stock in Puget Sound, but since the 1970’s this stock has declined by over 70%. While the abundance of the other stocks has remained relatively stable, the average size and age of Herring in Puget Sound has declined.
- Longfin smelt and Eulachon are both anadromous, and return to rivers and estuaries to spawn in late fall through late spring. -Longfin dipped in Nooksak -Eulachon commercial and recreational Longfin smelt generally return to spawn at 2 to 3 years of age, and eulachon return at 3 to 5 years of age, and after spawning, most adults die. Eggs attach to sand and gravel and generally take 20 to 30 days to hatch. Runs of Eulachon have historically been important to first nations, and until the recent ESA listing, supported both commercial and recreational fisheries.
- Longfin smelt and Eulachon are both anadromous, and return to rivers and estuaries to spawn in late fall through late spring. -Longfin dipped in Nooksak -Eulachon commercial and recreational Longfin smelt generally return to spawn at 2 to 3 years of age, and eulachon return at 3 to 5 years of age, and after spawning, most adults die. Eggs attach to sand and gravel and generally take 20 to 30 days to hatch. Runs of Eulachon have historically been important to first nations, and until the recent ESA listing, supported both commercial and recreational fisheries.
- Longfin smelt and Eulachon are both anadromous, and return to rivers and estuaries to spawn in late fall through late spring. Longfin smelt generally return to spawn at 2 to 3 years of age, and eulachon return at 3 to 5 years of age, and after spawning, most adults die. Eggs attach to sand and gravel and generally take 20 to 30 days to hatch. Runs of Eulachon have historically been important to first nations, and until the recent ESA listing, supported both commercial and recreational fisheries.
- Forage fish stocks are known to fluctuate widely, but the trends of some stocks are declining and some stocks appear to be at lower abundance than we’ve ever seen before.
- The second component of our study focused on the distribution of Eulachon spawning in the Columbia River and its tributaries, and other rivers along the Washington-Oregon coast. Because low numbers of returning adults meant that it would be difficult to document their presence, we relied on collecting eggs and larvae to determine if a river had been used for spawning. Samples were collected using primarily ichthyoplankton nets, but artificial substrates were also used to collect eggs.
- Forage fish stocks are known to fluctuate widely, but the trends of some stocks are declining and some stocks appear to be at lower abundance than we’ve ever seen before.
- The 3 common nearshore spawning forage fish we study are Herring , Surf Smelt, and Sand Lance. There is overlap between the spawning habitat for each species, but generally Herring spawn in the lower intertidal to subtidal zone on aquatic vegetation, Sand Lance spawn in the mid to upper intertidal zone on fine sandy substrate, and Surf Smelt spawn in the upper intertidal zone on substrate composed of sand and gravel. Surf Smelt and Sand Lance are intertidal spawners, meaning that their eggs are deposited on the beach above low tide, while Herring are subtidal spawners, so we need to use different methods to study their spawning habitat. Now I’ll pass the mic to Dayv and Kira so that they can tell you about some of the work we do with these nearshore species.
- Both anchovies and sardines are pelagic, or open water spawners. Both species may spawn multiple times within their life time, and their eggs will drift and generally hatch within about 2- 4 days of spawning. Sardines are primarily found on the outer coast. Anchovies occur in Puget Sound and the outer coast. Northern anchovy stocks have not been formally assessed since 1995. Federal scientists estimated the 2015 stock size at 31,427 mt based on acoustic trawl surveys, and have recently presented data showing the stock may have declined over 90 percent since the 1980s.
- Both anchovies and sardines are pelagic, or open water spawners. Both species may spawn multiple times within their life time, and their eggs will drift and generally hatch within about 2- 4 days of spawning. Sardines are primarily found on the outer coast. Anchovies occur in Puget Sound and the outer coast. Northern anchovy stocks have not been formally assessed since 1995. Federal scientists estimated the 2015 stock size at 31,427 mt based on acoustic trawl surveys, and have recently presented data showing the stock may have declined over 90 percent since the 1980s.
- Both anchovies and sardines are pelagic, or open water spawners. Both species may spawn multiple times within their life time, and their eggs will drift and generally hatch within about 2- 4 days of spawning. Sardines are primarily found on the outer coast. Anchovies occur in Puget Sound and the outer coast. Northern anchovy stocks have not been formally assessed since 1995. Federal scientists estimated the 2015 stock size at 31,427 mt based on acoustic trawl surveys, and have recently presented data showing the stock may have declined over 90 percent since the 1980s.
- Both anchovies and sardines are pelagic, or open water spawners. Both species may spawn multiple times within their life time, and their eggs will drift and generally hatch within about 2- 4 days of spawning. Sardines are primarily found on the outer coast. Sardines had a resurgence in the 1990’s, but didn’t approach the abundance observed in the 1940’s and have since declined leading to the subsequent closure of the fishery once again in 2015. Anchovies occur in Puget Sound and the outer coast.
- Both anchovies and sardines are pelagic, or open water spawners. Both species may spawn multiple times within their life time, and their eggs will drift and generally hatch within about 2- 4 days of spawning. Sardines are primarily found on the outer coast. Sardines had a resurgence in the 1990’s, but didn’t approach the abundance observed in the 1940’s and have since declined leading to the subsequent closure of the fishery once again in 2015. Anchovies occur in Puget Sound and the outer coast.
- Northern Anchovy are divided into 3 sub-populations: North (WA & OR), Central (CA), and South (Mexico). Anchovy stocks haven’t been formally assessed since 1995 (oceana: http://usa.oceana.org/responsible-fishing/northern-anchovy), but abundance estimates of the central population have been as high as 2 million tons, and most recent estimates put this population at only 18,000 tons (MacCall et al. 2016).
- Northern Anchovy are divided into 3 sub-populations: North (WA & OR), Central (CA), and South (Mexico). Anchovy stocks haven’t been formally assessed since 1995 (oceana: http://usa.oceana.org/responsible-fishing/northern-anchovy), but abundance estimates of the central population have been as high as 2 million tons, and most recent estimates put this population at only 18,000 tons (MacCall et al. 2016).
- For more information you can use some of the online resources on our web site, or you can contact me directly. You can also utilize SalmonScape which is an online mapping tool that shows documented surf smelt and sand lance beaches through out the state.
- The Cherry Pt. stock was once the most abundant stock in Puget Sound, but since the 1970’s this stock has declined by over 70%. While the abundance of the other stocks has remained relatively stable, the average size and age of Herring in Puget Sound has declined.
- Each species has requirements and preferences for selecting a spawning beach. These may overlap among species and co-occurrence on a given beach is not uncommon. (Read Slide) In northern Puget Sound, surf smelt spawn year round but primarily in the summer, and in southern Puget Sound they spawn primarily in the winter.
- Example of Surf Smelt beach
- Stick to rocks
- Since the 1970’s when we began beach surveys, over 1077 miles of coast have been surveyed and 266 miles of Surf Smelt spawning beach have been documented. Most Beaches have only been surveyed on a couple of occasions, so with the exception of a few areas, we know little about how frequently a given beach is spawned on but it appears that spawning may be patchy in some areas with eggs documented in some years but not others, while other areas appear to have eggs present every year, year round. We’ve learned that while Surf Smelt spawn year round, in northern Puget Sound the peak of spawning occurs in the summer while in the southern Puget Sound the peak occurs in the winter. Preliminary result of a genetics study indicates that there is no genetic differentiation, but we have another more detailed genetic study underway that we are still awaiting the results of. Unlike Herring, we have no estimate of abundance, but number of bird species that feed on forage fish in Puget Sound have declined, and anecdotal reports suggest Surf Smelt have declined.
- Though both surf smelt and sand lance eggs can be found on the same beaches and in the same samples, sand lance eggs are generally found lower on the beach in finer sediment. (Read Slide)
- Note the finer sediment.
- This is an example of a spawning pit which you might observe if you happen upon a beach immediately after spawning. Note rough material in pit is actually eggs with sand grains.
- While we’ve been conducting beach surveys since the 1970’s, it wasn’t until the 1980’s that it was recognized that Sand Lance were intertidal spawners and we began counting their eggs. Since then we’ve documented 118 miles of Sand Lance spawning beach. Besides documenting Sand Lance in both nearshore and deep water sand, little else is known about their life history, and we have no estimate of abundance.
- Forage Fish are generally not considered great candidates for this kind of study because there are pretty good odds that something is going to eat them before you ever have a chance to see them again, But we were inspired when we were collecting fin clips from surf smelt from a genetics study and on one occasion we returned to a site and were surprised when we recaptured one of the same fish we had clipped several days earlier. So we decided to undertake this pilot study just to find out whether batch marking could be a useful tool for us.
- The first thing we learned was that smelt will move between local spawning beaches
- The first thing we learned was that smelt will move between local spawning beaches
- We have two crews of WCC members working with us to sample, and process the samples every month. For those of you familiar with surf smelt beach spawn sampling with Puget Sound, most of our methods are based on the revised 2006 “Field Manual for Sampling Forage Fish Spawn in intertidal shore regions,” by Dan Penttila and Lawrence Moulton. When we arrive at a designated set of coordinates, we assess the location for accessibility by the crew, and habitat suitability. For habitat that is unsuitable, for example mud or hardpan, we do not collect samples, but we do collect habitat characteristics. At suitable sites, we collect a sediment sample across a 100’ section of beach That sediment is later sieved through progressively smaller sieves, keeping only the sediment left in the 0.5mm sieve. Any eggs are then extracted from the sample, by running them through a vortexing apparatus called “the blue bowl.” This is where our methods vary from the standard manual. The blue bowl is a new method for egg extraction, that we have spent the last year testing. We have found that the vortexing method is able to extract a much higher percentage of eggs from our samples, and reduces the sediment that must be processed in the lab. We now use to process all of our samples. I’m not going to go into detail about it here, but if you have any questions about it, please feel free to ask myself or Phillip Dionne later. Once the light fraction of the sample has been extracted, it is analyzed in the lab for Surf Smelt egg presence, egg abundance, and egg developmental staging. In the data that I will show you, egg presence indicates two or more eggs found in a sample.