//
you're reading...

Coastal Management

Ports, Pups, Policy, and Low Sardine Stocks

Paper: Kaplan, I. C., et al., 2016. Cloudy with a chance of sardines: forecasting sardine distributions using regional climate models. Fisheries Oceanography, v. 25(1): 15–27

Pacific sardines live in a sensitive coastal ecosystem. Recently warm winter waters on the US west coast have caused many sardines to seek more northern, colder waters. Credit: NOAA’s National Ocean Service.

Pacific sardines live in a sensitive coastal ecosystem. Recently warm winter waters on the US west coast have caused many sardines to seek more northern, colder waters. Credit: NOAA’s National Ocean Service.

Last month, I began work in ocean policy for the US representative of the Monterey district in California. Since then, watching the coastal marine issues that cross my desk, my attention has been drawn to some upsetting trends happening on the US west coast. Commercial ports, that house normally-thriving fisheries you depend on for your seafood, are seeing disastrous closures year after year. And, along the beaches, starving sea lion moms and pups have been washing up in alarming numbers. Why? There are a multitude of reasons, but to single out a key problem: the sardines are disappearing.

Both the fishery closures and the sea lion strandings – especially pups – have made national headlines. The California Governor has formally requested the Secretary of the US Department of Commerce to declare a fisheries disaster along the west coast, which would provide federal relief funding for the fishermen. Sea lions have been turning up too far inland from coastal beaches, alone confused, and searching for food. One little pup even somehow got into a restaurant on a beach in southern California.

“What’s your fish special?” A stranded and hungry sea lion pup finds its way into an upscale Sani Diego restaurant this winter. Photo credit: CBS news.

“What’s your fish special?” A stranded and hungry sea lion pup finds its way into an upscale San Diego restaurant this winter. Photo credit: CBS news.

As a species, the Pacific sardine is known to have “boom and bust” population cycles: fish numbers rapidly rise and fall over multiple years depending on a variety of environmental conditions. Their population along the west coast has recently seen a “bust” and collapsed due to a number of reasons, including changing ocean conditions and allegations of overfishing.

Pacific sardines are a key forage food for sea lions and many other species, as well as a huge source of income for local and commercial fishermen. Unfortunately, with pupping season well underway and the west coast sardine fishery facing a second year of season closure, sardine stocks are seeing a drastic low. By this summer, sardine populations are forecast to be 33% lower than they were in April 2015, when fishery managers closed the sardine fishery for the season on the grounds that there were too few fish to catch (Figure 1).

The most recent population boom came in 2007, when over 1 million metric tons of fish were estimated to be swimming off the U.S. coast. This was fantastic news for west coast fishermen, especially commercial fishermen who in some years brought in about $20 million annually. However, the population soon became depleted, which led to the managing fishery bodies such as the Pacific Fishery Management Council shutting down the fishery in an attempt to allow the stocks to rebound. Of course, this move drastically hurt employment in coastal towns.

Figure 1: Collapse of Pacific Sardine population. This data was published last year, with stocks down 93% since 2007. For 2016, a draft projection by NOAA puts the stocks down a total of 97% since 2007. Credit: NOAA Fisheries Service.

Figure 1: Collapse of Pacific Sardine population. This data was published last year, with stocks down 93% since 2007. For 2016, a draft projection by NOAA puts the stocks down a total of 97% since 2007. Credit: NOAA Fisheries Service.

In light of recently drafted projections from NOAA showing this summer’s sardine stock numbers down 97% from 2007, the Pacific Fishery Management Council is expected to elect to keep the fishery closed for another year. This is how the policy side can protect the sardine populations: by making sure there are enough fish left to hopefully replenish the stock. But how do they make these projections, and are they accurate enough?

Improving Fishy Forecasting

The science of ecological forecasting is constantly evolving as a tool for anticipating environmental changes. These forecasts help decision-makers and managers plan for the future, make informed decisions, and take appropriate actions to better manage natural resources. Scientists are now trying to improve the accuracy of these forecasts for species such as sardines.

Sardine spawning habitats and migration patterns have been associated with specific temperature, salinity, phytoplankton concentrations, and nutrients. Using these variables, a group of researchers from west coast fishery research institutions tested short-term modeling forecasting for accuracy in predicting sardine populations.

Figure 2: The study compared real survey data of sardine abundance to forecasted abundance based on the model, and organized by a ROMS grid. Credit: Kaplan, I.C., et al.

Figure 2: The study compared real survey data of sardine abundance to forecasted abundance based on the model, and organized by a ROMS grid. Credit: Kaplan, I.C., et al.

Dr. Isaac Kaplan and colleagues tested a forecasting tool called J-SCOPE: the Joint Institute for the Study of the Atmosphere and Ocean (JISAO)’s Seasonal Coastal Ocean Prediction of the Ecosystem. J-SCOPE has been developed for the northern west coast to provide projections of physical, chemical, and biological ocean properties on 6- to 9-month time scales. The forecasts are derived using the output from a Climate Forecast System (CFS) model, and a Regional Ocean Modeling System (ROMS). ROMS has been used for other coastal prediction capabilities such as aquaculture and nutrient mapping.

The study tested their forecasting model’s ability to create an accurate forecast of the distribution of Pacific sardines based on comparing the model with real population distributions. They used 2009 as a test year, estimating relationships between forecasted ocean conditions and real sardine population distributions (Figure 2).

Results were encouraging, suggesting that relatively simple models using predictions of temperature and salinity from the J-SCOPE system can be used to forecast the distribution of sardines. This would mean that they have the ability to forecast, with moderate accuracy, sardine distributions 4– 8 months in advance. The method could serve as an early warning signal for fishery managers who make decisions on a monthly or quarterly basis, for instance to adjust harvest or to change areas open to fishing vessels.

For the many fishermen already out of sardine work for this year, and for the scores of sea lion pups who are not getting enough food, this model doesn’t help them much. However, with each improvement to ecological and fishery forecasting, fishery managers may begin to adjust their practices and policies in the future to protect stocks like sardines from becoming depleted in the first place.

Discussion

No comments yet.

Post a Comment

Instagram

  • by oceanbites 9 hours ago
    This week for  #WriterWednesday  on  #oceanbites  we are featuring Hannah Collins  @hannahh_irene  Hannah works with marine suspension feeding bivalves and microplastics, investigating whether ingesting microplastics causes changes to the gut microbial community or gut tissues. She hopes to keep working
  • by oceanbites 1 week ago
    Leveling up - did you know that crabs have a larval phase? These are both porcelain crabs, but the one on the right is the earlier stage. It’s massive spine makes it both difficult to eat and quite conspicuous in
  • by oceanbites 2 weeks ago
    This week for  #WriterWednesday  on  #Oceanbites  we are featuring Cierra Braga. Cierra works ultraviolet c (UVC) to discover how this light can be used to combat biofouling, or the growth of living things, on the hulls of ships. Here, you
  • by oceanbites 3 weeks ago
    This week for  #WriterWednesday  at  #Oceanbites  we are featuring Elena Gadoutsis  @haysailor  These photos feature her “favorite marine research so far: From surveying tropical coral reefs, photographing dolphins and whales, and growing my own algae to expose it to different
  • by oceanbites 1 month ago
    This week for  #WriterWednesday  on Oceanbites we are featuring Eliza Oldach. According to Ellie, “I study coastal communities, and try to understand the policies and decisions and interactions and adaptations that communities use to navigate an ever-changing world. Most of
  • by oceanbites 2 months ago
    This week for  #WriterWednesday  at  #Oceanbites  we are featuring Jiwoon Park with a little photographic help from Ryan Tabata at the University of Hawaii. When asked about her research, Jiwoon wrote “Just like we need vitamins and minerals to stay
  • by oceanbites 2 months ago
    This week for  #WriterWednesday  on  #Oceanbites  we are featuring  @riley_henning  According to Riley, ”I am interested in studying small things that make a big impact in the ocean. Right now for my master's research at the University of San Diego,
  • by oceanbites 2 months ago
    This week for  #WriterWednesday  at  #Oceanbites  we are featuring Gabby Stedman. Gabby is interested in interested in understanding how many species of small-bodied animals there are in the deep-sea and where they live so we can better protect them from
  • by oceanbites 2 months ago
    This week for  #WriterWednesday  at  #Oceanbites  we are featuring Shawn Wang! Shawn is “an oceanographer that studies ocean conditions of the past. I use everything from microfossils to complex computer models to understand how climate has changed in the past
  • by oceanbites 3 months ago
    Today we are highlighting some of our awesome new authors for  #WriterWednesday  Today we have Daniel Speer! He says, “I am driven to investigate the interface of biology, chemistry, and physics, asking questions about how organisms or biological systems respond
  • by oceanbites 3 months ago
    Here at Oceanbites we love long-term datasets. So much happens in the ocean that sometimes it can be hard to tell if a trend is a part of a natural cycle or actually an anomaly, but as we gather more
  • by oceanbites 4 months ago
    Have you ever seen a lobster molt? Because lobsters have exoskeletons, every time they grow they have to climb out of their old shell, leaving them soft and vulnerable for a few days until their new shell hardens. Young, small
  • by oceanbites 4 months ago
    A lot of zooplankton are translucent, making it much easier to hide from predators. This juvenile mantis shrimp was almost impossible to spot floating in the water, but under a dissecting scope it’s features really come into view. See the
  • by oceanbites 5 months ago
    This is a clump of Dead Man’s Fingers, scientific name Codium fragile. It’s native to the Pacific Ocean and is invasive where I found it on the east coast of the US. It’s a bit velvety, and the coolest thing
  • by oceanbites 5 months ago
    You’ve probably heard of jellyfish, but have you heard of salps? These gelatinous sea creatures band together to form long chains, but they can also fall apart and will wash up onshore like tiny gemstones that squish. Have you seen
  • by oceanbites 6 months ago
    Check out what’s happening on a cool summer research cruise! On the  #neslter  summer transect cruise, we deployed a tow sled called the In Situ Icthyoplankton Imaging System. This can take pictures of gelatinous zooplankton (like jellyfish) that would be
  • by oceanbites 6 months ago
    Did you know horseshoe crabs have more than just two eyes? In these juveniles you can see another set in the middle of the shell. Check out our website to learn about some awesome horseshoe crab research.  #oceanbites   #plankton   #horseshoecrabs 
  • by oceanbites 7 months ago
    Feeling a bit flattened by the week? So are these summer flounder larvae. Fun fact: flounder larvae start out with their eyes set like normal fish, but as they grow one of their eyes migrates to meet the other and
  • by oceanbites 7 months ago
    Have you seen a remote working setup like this? This is a photo from one of our Oceanbites team members Anne Hartwell. “A view from inside the control can of an underwater robot we used to explore the deep parts
  • by oceanbites 8 months ago
    Today is the day of  #shutdownacademia  and  #shutdownstem  and many of us at the Oceanbites team are taking the day to plan solid actions for how we can make our organization and the institutions we work at a better place
WP2Social Auto Publish Powered By : XYZScripts.com