I’m excited to announce that I’ve started a new post-doc research position at Florida International University with Dr. Alastair Harborne in the Tropical Fish Ecology Lab! I’m working on a project in collaboration with The Nature Conservancy to map and model fishing impact in the Florida Keys. The research brings together data from NOAA’s coral reef fish visual surveys, commercial and recreational fisheries, as well as a variety of publicly-available fisheries-related data from South Florida. My first challenge is coming up with a fishery-independent metric that works as a proxy for fishing impact over time. Check back for updates and results.
I took my last fieldwork trip to Morro Bay several months ago. As much as I’d love to go back today, I completed my last interview and now need to focus on analyzing data. For those of you who haven’t visited, Morro Bay is an incredibly charming coastal town just south of the Big Sur coast (west of San Luis Obispo). Fishing and ocean culture are strong in Morro Bay. On one side of the harbor is a memorial recognizing all of the fishermen present and past that risk dangerous marine conditions every day. The entire main drag of town is a working waterfront – boats coming and going, gear being fixed, fish changing hands. Hidden in plain sight among fish businesses is a bronze statue remembering a well-loved boat mechanic who passed away several years ago. When I ask for directions in Morro Bay, locals without exception use landmarks in the ocean or at the port as guidance. The number of pickups with buoys, traps, and other boat equipment hint at the town’s reliance on fishing and other ocean-related industries.
If it’s not clear from the paragraph above, I love Morro Bay. I’ve enjoyed every visit, and have learned an incredible amount from fishermen who have talked with me over the past year. And Morro Bay is just one of the vibrant, coastal fishing communities that we still have in California. My work on the nearshore fishery focuses on the connections among aspects of the kelp forest fish assemblage and nearshore marine ecosystem, the people and communities who make up the fishery, and the institutions governing the system. I use the Ostrom social-ecological systems framework (a way to think about connections between human and non-human aspects of a common pool natural resource system) to better understand these connections among fishermen, fishing operations, markets, and nearshore fishes. I use a mixed methods approach, combining information from interviews with fishermen and fish buyers, fishery-dependent landings data (i.e. the type, location and number of fish landed by fishermen each day), and long-term ecological monitoring data (i.e. the number and species of fish in the kelp forest, counted by SCUBA divers) to shed light on relationships and feedbacks in the nearshore fishery system.
This has been academically challenging research as I grapple with ways to combine quantitative and qualitative methods, directly compare social and ecological data collected at vastly different scales and with different approaches, and make meaningful conclusions about the ways that kelp forests influence people and vice versa. It is also incredibly exciting research in that I have gotten the chance to work with a wide range of people (academics from both natural and social sciences, fishery managers, fishermen, fish buyers), integrate different ways of knowing into my research, and generate a product that is directly relevant to the management of the nearshore fishery, in Morro Bay and across the central coast.
The research thus far has likely generated more questions than answers about the nearshore fishery, and I am sincerely excited to continue my study of the small-scale nearshore fishery and its role and relevance in the coastal fishing communities of California that I value so much.
This is a guest blog post I wrote for Kristy Kroeker’s Coastal Sustainability Blog.
I’ve done many dives since moving to central California in 2012, but two stand out in my mind. The first was a dive in the summer of 2012, a banner year for juvenile rockfish. That day, the kelp forest was thick with baby fish that had just arrived from their time as larvae in the pelagic ocean (open ocean). The baby fish were schooling from the top of the kelp canopy to the rocky interface between the reef and the sand, and were so numerous, that one could only describe the schools as rockfish swarms. The second dive was in the fall of 2015. Central California was in the thick of “the Warm Blob” oceanographic conditions, with unseasonably warm water in Monterey Bay. I was trying to count kelp blades just below the surface of the water, but instead I spent the entire dive dodging birds diving down from above and fish darting up from below, all to feed on an enormous group of pelagic red crabs which normally live far away in the pelagic ocean off Baja. Aside from being beautiful and impressive in the sheer abundance of life I witnessed, these dives offered me a window into kelp forest food webs, and a spark of inspiration from the natural world that now motivates the first chapter of my dissertation.
To explain my research, I want to start with food webs. We all learned about them in high school. These are the connections between all of the organisms that eat or get eaten in an ecosystem. Needless to say, in a species-rich ecosystem like a kelp forest, the food web is quite complicated. To deal with this complexity, kelp forest ecologists often think about food webs with only the set of organisms that live full-time in the kelp beds. However, my dives illustrated that there is other food available that only lives part-time in the kelp forest, and sometimes, in huge amounts! This is what scientists call a subsidy – a resource that comes into an ecosystem from another ecosystem, or from the outside. My research focuses on what these subsidies mean for kelp forest ecosystems and the animals that live within them.
My major question is simple, are these subsidies important? Or do they merely represent a “drop in the bucket” relative to all of the food produced in the kelp forest (an ecosystem more productive than trophic rainforests!)? I want to share three examples of especially visible and interesting subsidies in the Monterey Bay area to show how “ordering in” food from the outside could be extremely important for kelp forest inhabitants.
Pelagic Red Crabs
These creatures typically live in the mid-water and the bottom of the deep ocean off Baja, but during El Niño years, they show up in Monterey Bay en masse! The crabs are protein-rich and often exist in extremely high densities for short periods of time. I hypothesize that this subsidy might offset the loss of other prey items in the kelp forest during warm water, El Niño years where productivity is lower.
Pelagic red crabs washed-up on a beach (after moving through the kelp forest) in Monterey Bay (photos: Chad King, Monterey Bay National Marine Sanctuary).
First, why are rockfish considered a subsidy when they live in the kelp forest? As larvae they spend time in the open ocean, eating and growing, before bringing all of that newly gained energy from the open ocean back to the nearshore kelp beds. In some years we see very high numbers of juvenile fish, in other years, almost none. What does this major variation mean for juvenile rockfish predators such as adult rockfish (yes, they eat their babies!)? Maybe adult rockfish grow more and survive better in years when more juvenile rockfish are available as prey.
Juvenile rockfish in Carmel Bay (photo: Chad King, Monterey Bay National Marine Sanctuary).
These animals are ubiquitous across ecosystems, are food for everything from turtles to fishes, frequently occur in large blooms, and are vastly understudied. In Monterey Bay, currents and waves transport jellies (science name: Cnidarians), comb jellies (science name: Ctenophores) and tunicates (gelatinous organisms more closely related to humans than jellyfish!) into the kelp forest. Though these are not the most nutrient and protein-rich food items (think watermelon instead of an avocado), fish can capture and digest them using almost no energy. Perhaps gelatinous creatures make up an important, but rarely noticed component of the diverse diets of kelp forest fishes.
Next time you’re on the beach or in the water, keep an eye out for ecological subsidies. You might see algae washed up on the shore (a subsidy from the kelp forest to the sandy beach) or see jellies in the kelp forest from the water’s surface (a subsidy from the open ocean to the kelp forest). Subsidies like these are the norm, not the exception in our oceans, and as climate change continues to impact marine systems, the timing and magnitude of subsidies will change as well. Understanding how important (or unimportant!) these subsidies are for the ocean species we care most about will give us insight into ecosystems and food webs of the future.
I’m writing my first review paper, and though it’s a lot of work, there are some perks. There’s the obvious perk of not having to worry that there is a 19 foot swell on the ocean today (seriously) and there’s no chance that divers will be out collecting data. The data for this paper has already been collected (mostly) by other people! And the less obvious perks – namely, that I got to spend time with actual books in the actual library last week. Sometimes it’s the small things that get me through a week of dissertation writing :)
The review is on pelagic-based trophic subsidies to kelp forest ecosystems. Think juvenile rockfish fresh from the pelagic ocean and recruiting to their adult kelp forest habitat only to be promptly eaten by adults, pelagic red crabs being dive-bombed by nearshore birds from above, and gelatinous zooplankton stranded in the kelp forest and getting sucked up by surfperches at every opportunity. Stay tuned for the paper to come out!
And for those interested in fish and fisheries in California, be sure not to discount information found in California Fish and Game Department bulletins going back to the early 1900s (images below) just because it hasn’t yet been digitized and put online. I found some incredible natural history information in these tomes.
I’m back out at sea on the NOAA Southwest Fisheries Science Center’s annual rockfish recruitment cruise. I’m on a slightly longer leg this year (June 1st-13th), but I’ve got a great route along the entire California coast – Eureka to San Diego. We’re also on a much swankier boat this year than in years past (the newly-commissioned NOAA R/V Reuben Lasker). The Lasker is a ship outfitted for science on the West Coast of the US, and provides a great platform for the trawl surveys that are the basis of the rockfish cruise each year.
Though the main goal of the cruise is to estimate the number of larval rockfish in the open ocean for management of California’s rockfish fisheries, we do all sorts of other sampling. Marine mammals and seabirds are counted during all hours of daylight, CTD (conductivity to measure salinity, temperature and depth/pressure) measurements are taken at every sampling site and at other sites up and down the coast to help us better understand the relationship between the physical ocean environment and the fish that we catch, zooplankton samples are collected and identified, and all species brought up in the night midwater trawl nets are identified, sometimes measured and recorded. This is everything from larval hake and market squid (two other very important fish species for California’s economy) to pelagic cnidarians (jellyfish!) and myctophid fishes like the California headlightfish.
I’m on this cruise for several reasons. First, folks at NOAA’s Southwest Fisheries Science Center have been extremely helpful to me during my Ph.D. work. They’ve been generous with their time and happy to think about dissertation questions with me. So in turn, I’m happy to fill in on a leg of the cruise where they’re short-handed on scientists. Second, this is a great opportunity to collect some of my own samples.
I’m interested in the connection between ecosystems. In the kelp forests of central Californian, fish rely on energy derived from two distinct food chains – (1) energy from macroalgae (primarily giant kelp) in the forest itself, and (2) energy from phytoplankton in the open ocean (the system we’re sampling on this cruise!). A connection. Phytoplankton dynamics and prey resources in the open ocean impact the kelp forest food web. For example, the recruitment of juvenile crabs to the kelp forest (crabs that have been feeding on phytoplankton in the open ocean) could provide an energy-rich food source for benthic fishes. Or an influx of ctenophores (a jellyfish-like organism) from the California Current could provide easily accessible and abundant food for midwater-feeding blue rockfish. This seems plausible, even likely, but quantitatively showing the food web connection and the importance of the connection is not always straight-forward.
I’m on the cruise taking samples of organisms that I know (or suspect) are occasionally carried to the kelp forest on currents. Size measurements will give me an idea of the size distribution of these organisms in the open ocean environment, and for now, I’ll have to assume that their size distribution in the kelp forest would look similar. Counts of the animals give me estimates of density. I’m still not sure how I can use open ocean density to estimate density in the kelp forest…that’s a work in progress. Finally, frozen samples I keep will be burned in a bomb calorimeter to tell me how much energy a fish would gain from eating one individual salp, jellyfish, pelagic red crab (or any of the other organisms that I’ve sampled). Basically, I’ll get a calorie count for each open ocean prey item that a kelp forest rockfish might eat. Based on my estimates of the density and average size of an open ocean animal in the kelp forest, and how much energy each provides, I can start a more in-depth analysis of the importance of this connection. If the energy provided is significant relative to the energy a fish gets from prey items that live in the kelp forest, I’ll continue to pursue these questions. If not, maybe prey from the open ocean provides a convenient and tasty treat for fish, but doesn’t influence wider population and ecosystem dynamics. Only time, samples, and more science will tell.
We also had a NOAA Teacher-at-Sea aboard the Lasker during this leg! He’s an 8th-grade and high school science teacher creating lessons about West coast fisheries. Check out his blog here.
There are many benefits of being part of a large, diverse lab. One of the most fun (and I think most valuable) of these is the opportunity to help other grad students with their fieldwork. A few weeks ago, I spent the day on the Mokelumne River with Megan Sabal, a Ph.D student in the Palkovacs and RC Labs.
Aside from getting to watch juvenile salmon swim through a staged “migration route” with and without predator cues (the scent and sights of predators), I got a window into the thought process of another scientist. Because I study social-ecological systems and ecosystem food webs, I think that I sometimes overlook dynamics that occur at the level of the individual organism. Megan, on the other hand, is always thinking about how individual differences in behavior or physiology of any given fish might impact the wider environment or the population that it is a part of. In the experiment that Megan just completed, she’s hypothesizing that differences in individual salmon’s behavioral response to predators impact their migration rates, potentially their feeding ecology, and ultimately their survival and whether or not they recruit into the fishery as adults.
In the context of the group of rockfish that call the kelp forest ecosystem home (my study system), individual differences in rockfish feeding ecology almost certainly exist. And though my approach will remain one that brushes over this individual variability to characterize the community or population, a day on the Mokelumne was a good reminder to take time now and again to focus in on the individual fish.
I attended the 2017 Society for Applied Anthropology meeting in Sante Fe from 28 March – 1 April with my mentor, Carrie Pomeroy. The highlight was presenting a paper in the session titled “Interdisciplinary Perspectives for Managing Marinescapes” along with talented folks from University of Alaska Fairbanks, U Saskatchewan and the U of Maryland.
For my talk, “Social-ecological coupling in the central California nearshore, commercial fishery”, I focused on fisheries landings data from 1995-2015 and interpreted trends in this data using qualitative data collected from interviews with nearshore fishermen. Despite the fact that I got many suggestions to significantly expanding this project (something I’m not currently looking to do at the end of the 5th year of my PhD work), I gained so much just being able to interact for a week with professionals doing fisheries anthropology, oral history work, resilience theory work, and generally social science that is directly relevant to fisheries policy.
Oh, and Sante Fe was beautiful. EVERYTHING was blooming and the art was incredible.
Check out a new publication from the UCSC Raimondi-Carr Lab and the Lubchenco-Menge Lab at OSU!
and the press release to go along with it:
The RC Lab’s famous kelp forest made another appearance! This time at Mar Vista Elementary School. The kelp forest (which we pair with underwater video of actual monitoring transects) gives the students an idea of what marine surveys actually entail. In the lesson we’ve developed over the last several years, students learn the ID of several common species, think about habitat associations, make hypotheses, survey the “kelp forest”, and graph their data. We also let students try on and model our SCUBA gear which ends up being pretty entertaining (and hopefully sparking interest in marine research).
If anyone knows elementary (or middle school) teachers in the area that might be interested in our traveling kelp forest show, shoot me an email!
Ecology is one of the natural sciences, and for many people, that means that ecologists are left-brain dominated folks. We use the scientific method, apply ecological theory, and work to understand patterns in the natural world. What people don’t always see is that ecology requires an enormous amount of creativity. In fact, this is one of the things that draws many of us to the field.
As fishery ecologists begin to think more about our changing climate, creativity is essential. One of the major goals in the field is to understand how our fish stocks will respond to future ocean conditions. Often the best place to start is looking at how fish stocks responded to climate shifts in the past. Easy, right?
Fish stock responses in the Past + Climate predictions for the Future = Predicted fish stocks in the Future
But wait. Where do we look to understand how fish responded to climate shifts in the past? NOAA wasn’t around 100 years ago monitoring fish stocks and measuring oceanographic information. And though we have anecdotal evidence from fisheries, this isn’t always sufficient to truly know what a fish stock was doing.
[Enter creative problem solving.]
Tree ring scientists have been hind-casting climate (predicting what climate was doing in the past) using tree rings for a very long time. The basic method is simple.
- Core tree to expose tree rings
- Count the tree rings (assigning the latest ring to the current year) and assign a year of formation to each ring
- Measure the width of each ring assuming that a wider ring means that the tree grew more in that year
- Based on an understanding of the factors that make trees grow faster (i.e. rain, certain temperature ranges), use tree ring widths to predict rainfall and temperatures in the past.
But, what does this have to do with fisheries and fish responses to climate change? Take a look at the photos below. The first is the rings of a hardwood tree, the second, analogous rings in the ear bone of a fish! Fish produce rings – very similar to tree rings – in their otoliths (ear bones) as they grow. Borrowing methods from tree ring science, we can use the width of these rings to make predictions about ocean conditions in the year that each ring was formed.
My collaborators and I used this method in a new paper out in Climate Research about Pacific Ocean Perch (Sebastes alutus) and past climate conditions in the Bering Sea. Since Pacific Ocean Perch can live to ~100 years old we were able to make climate predictions (using otolith ring width data) back to 1919! The chronology shows that shifts in the Pacific Decadal Oscillation (a shift from relatively warm to relatively cool Pacific Ocean temperatures) have critical and long-lasting impacts on the growth of this rockfish. Read the paper here for more detailed results:
One of my favorite things about working with this group of collaborators has been the strong focus on making this work available and applicable to management of Pacific Ocean Perch, a high volume and economically important fishery in Alaska. Two authors on the paper are staff at the Alaska Fisheries Science Center, tasked with managing the fishery. This collaboration ensured that our work was relevant and that it is now in the hands of those making decisions for the sustainability of this culturally and economically important fish stock.
Photo credits: Live fish in ROV image: Washington Department of Fish and Wildlife; Pacific Ocean Perch haul: Alaska Fisheries Science Center.