Pyrosomes Invade Northwest Waters

An unprecedented number of unusual, tube-like organisms have begun to appear along the Oregon Coast. Called pyrosomes, these small invertebrates are usually found in tropical areas but are now invading Pacific Northwest waters. Such an unexpected shift in an animal population in the area has scientists worried about what changes may have occurred in our environment to allow a mass influx of non-native species and how these foreign creatures will effect other animals already living in Northwest waters.

Until recently, little was known about pyrosomes, whose name was inspired by their ability to glow in the dark. An Oregonian report describes what scientists have discovered about these gelatinous, nondescript blobs — which are actually made up of myriad tiny multicellular organisms — and why they think these rare animals have arrived in the first place.

According to the report, scientists working both OSU and the National Oceanic & Atmospheric Administration believe the pyrosomes may have showed up because of the warm “blob” that has developed in Pacific waters over the past few years. But what worries biologists the most isn’t the fact that they’ve been presented with more proof of the impact of global warming in the area. It’s the risks of how a massive influx of new organisms may impact the delicate food chain.

In particular, these researchers described a change they had observed in an animal that plays an important part in the ocean ecosystem: the rockfish. Normally, rockfish live off of krill and shrimp — both important to survival due to being great sources of fat — but now, rockfish are choosing to consume pyrosomes instead of sticking to their regular diet, since pyrosomes are so easy to find. Unfortunately, pyrosomes aren’t nutritious and could harm the entire population of fish that eat them. As NOAA research fisheries biologist Laurie Weitkamp described, “They’re thinking they’re eating hamburgers and instead they’re eating celery — even worse than celery.” 

The Oregonian reported that these scientists from OSU and NOAA will continue to observe the gelatinous pests in the hopes of working to mitigate the harm they may end up causing to the complex ecosystem.

By Kiki Genoa