Farallon Institute Newsletter - Spring 2020

Around The [Home] Office

Farallon Institute is thrilled to welcome Dr. Caitlin Kroeger, our new Postdoctoral Research Associate, to the Farallon Institute team! Caitlin's most recent work has focused on understanding how seabirds adjust behaviorally and physiologically to environmental challenges at sea while searching for food.  At Farallon Institute, Caitlin will be working to understand how variation in ocean currents and eddies of the North Pacific affect zooplankton communities.  She will be modeling how forecasted environmental changes might affect their composition and distribution.  As the co-founder of a science communication organization during her grad work at UCSC, we are also really excited to see what kinds of ideas Caitlin might bring to FI for making our science more accessible to all of you! Read more about Caitlin's background here.

The Farallon Institute team is working from home during the COVID-19 stay-at-home orders and we are adjusting to this different way of working together.  We are mastering the Zoom meeting and have frequent check-ins to make sure we’re all doing as well as we can during this interesting and stressful time.  At this point we’re all healthy and relatively productive at work, and we’re thankful to be able to adapt to this situation.  We hope all of you are healthy and doing all right as well. 

State of the Ocean

This February brought more than the COVID-19 pandemic to California.  January and March registered normal winter conditions in our coastal ocean but February saw record levels of coastal upwelling in the ocean (Figure 1, left).  Coastal upwelling is the result of winds blowing south along the U.S. west coast; these winds bring cold water from depth to the surface by means of dragging surface water away from the coast with the help of our rotating planet (the Coriolis force).  Take a look at Figure 2 to get an idea of how strong and extended these winds were on February 20th.  This record upwelling cooled the otherwise normal sea surface temperature, though still within a normal range (Figure 1, right).  These windy conditions might be good news for the upcoming year; in the past, early upwelling has been associated with a productive marine ecosystem in the California Current.

Figure 1. Left: Upwelling index along the California coast at 39°N.  Right: Sea surface temperature at a buoy off Bodega Bay (38.25°N).  For both, the seasonal cycle is represented by the crossed black line, and a normal range (one standard deviation) is the gray shade.  2019 and 2020 monthly values are represented in color.  Upwelling index data were calculated by NOAA and sea surface data were collected by NOAA/NDBC, buoy 46013.

Figure 2.  Modeled surfaced wind field for February 20, 2020.  Bright trajectories indicate wind direction and speed.  http://earth.nullschool.net.

2020 summer research field seasons affected by the pandemic

With much of the U.S. on some sort of stay-home order, field research programs around the country are being curtailed this year, and in some cases canceled, due to the pandemic.  Farallon Institute’s seabird monitoring program at Alcatraz Island, which typically begins in late March, has been heavily impacted since it has been over six weeks since Alcatraz Island was closed to visitors and researchers.  This past week, however, a small group of researchers, including FI’s Zoe Burr, excitedly (and safely) set foot on the island to check on things.  Hearing the chorus of chirps from the recently hatched cormorant chicks on Alcatraz Island was music to their ears.

We have been trying to find alternative ways to learn about how the birds’ nesting season is going while we’re not on the island (even turning to satellite imagery to spy on birds from space!), but nothing compares to actually being on the island to collect real-time data.  In a normal year, Zoe visits the island twice a week to collect seabird data through the stages of the breeding season, seamlessly flowing from birds dancing their mating displays, nest building, incubating eggs for almost a month, and finally, rearing chicks.  Having not been able to monitor recently, the visit this week felt like: BOOM! Chicks everywhere!

The cormorants seem to be off to a strong, early start on Alcatraz this year, which is a good sign, indicating there is likely enough forage fish nearby to sustain their breeding efforts.  We have yet to finish analyzing the data we collected while out on the island, but the cormorants may be on track to break the record for the highest number of nesting pairs ever recorded on Alcatraz!

Overall, the island without boatloads of visitors is a very different scene.  Gulls were nesting along walkways that are normally frequented by scores of visitors from all over the world.  We hope the break from constant island visitation will provide a nice reprieve for the birds that call Alcatraz home.

Good news about microplastics in oysters

Microplastics, 1 μm (micrometer) to 5 mm in size, reach the ocean by wastewater treatment runoff, terrestrial drainage, or by the breakdown of larger plastic debris.  Some microplastics are manufactured at that small size while others are fragments of larger pieces.  One of the most common types of microplastics in the ocean is microfibers from clothing.  Microplastics are ingested by marine organisms, and those particles can be transferred up trophic chains if those animals are eaten by others, including humans.  For example, a large fish may contain microplastics in its body that were previously in the body of the smaller fish that they consumed. 

As filter feeders, Pacific oysters filter ocean water and remove both organic (food, like diatoms) and inorganic particles (such as sediment) from it.  Washington State is the top producer of farmed bivalves in the U.S. and Pacific oysters are the largest aquaculture industry.  To what degree are Pacific oysters vulnerable to microplastic contaminants?  A study by researchers at the University of Washington sought to determine the abundance and type of microplastics in naturally-occurring Pacific oyster populations in Washington.   

The researchers collected 213 oysters and microparticles (not necessarily made of plastic) were extracted from their tissues in the lab.  63% of the oysters had at least one microparticle, and 96% of these microparticles were specifically identified as microfibers.  To identify what a microparticle is made of, these microparticles were analyzed by an instrument that uses light to determine its chemical structure.  Only 2% of the microparticles were made of plastic materials including polystyrene (plastic utensils and food containers), polypropylene (rope, bottle caps, netting), polyethylene (milk jugs, plastic bags, drinking straws), and polyester (fleece, clothing).  The remaining microparticles were cellulose derivatives (cigarette filters, clothing), resins, and naturally-occurring materials like shell fragments and minerals.  Importantly, the composition of 41% of the analyzed microparticles was inconclusive due to interference with the light instrument, so there were likely more microplastics that were not identified.  It’s encouraging, however, that there were low numbers of microplastics in the oysters given that marine plastic pollution is a very serious issue that is expected to worsen in the future.  This study provides a baseline measurement for microplastics in shellfish in this area that future studies will be able to compare to.

This study, “Low incidence of microplastic contaminants in Pacific oysters (Crassostrea gigas Thunberg) from the Salish Sea, USA”, was published by Martinelli et al. (2020) in the journal Science of the Total Environment.