Quite a bit, actually! On Earth Day, the Marine Debris Program ran an albatross bolus dissection workshop as part of NOAA’s annual Bring a Child to Work Day. In the workshop, about 60 kids ages 10 – 12 picked apart albatross boluses that were collected on Midway Atoll in the Northwestern Hawaiian Islands. What we found was pretty disturbing! Let’s start with some background…
Adult Laysan Albatrosses forage for food in the surface ocean, feeding mainly on squid, flying fish eggs, and fish larvae. Unfortunately the birds often mistake floating debris for prey and end up consuming man-made material, in particular plastics that are less dense than seawater. After foraging at sea, adult albatrosses feed their chicks by regurgitating the contents of their stomach into the chick’s mouth. Albatross chicks later throw up all of the indigestible material in the form of a bolus, similar to a hairball or owl pellet. The contents of boluses thrown up by the albatross chicks are an indication of what can be found floating in the surface ocean around Midway Atoll.
Overall, squid beaks were the most common items found in the albatross boluses. Squid are a major food source for the Laysan Albatross but their beaks are made of chitin, an indigestible material. There was also a surprising amount of plastic in the boluses, ranging from microplastics to bottle caps to a 10 cm-long fishing lure. The kids also found pieces of canvas, monofilament fishing line, pumice, and wood.
What happens to albatrosses that ingest this plastic? The plastic that isn’t regurgitated can block the birds’ gastrointestinal tract and lead to internal injury. Ingestion of plastic can also starve the birds, as it gives them a false sense of being full. Laysan Albatrosses from Midway Atoll are only one of many types of seabirds that are affected by marine debris.
The bolus dissection workshop gave everyone involved a first-hand example of the impact that marine debris can have on marine life. It was a powerful reminder that debris that makes its way from our rivers, bays, and shorelines out to sea might be out of sight but it should not be out of mind. Marine debris is everyone’s problem!
A special thank-you to the staff and volunteers of the USFWS in the Northwestern Hawaiian Islands.