If you call yourself a marine biologist, people expect you to be able to identify every shell, carapace, carcass, or blob that washes up on the beach. That was no exception this week when I was asked to ID gelatinous blobs that were dotting the beaches in Newport. Made of 95% water, identifying jellies on the beach can be difficult. Fortunately, I recognized them as some common residents.
Moon jellies (Aurelia labiata) and Pacific sea nettles (Chrysaora fuscescens) are large scyphozoans that are familiar to most people as 'true jellies'. These jellies, especially the sea nettles, are seasonally abundant along our coast with their size and abundance peaking during late summer and early fall.
Over the last few years, sea nettles and moon jellies have been scarce. But this year, these jellies have returned with a vengeance along the entire west coast. ODFW researchers have captured some stunning underwater images of sea nettle aggregations this fall and we have encountered similar aggregations at the surface during NH line trips. Some possible reasons for these population fluctuations are attributed to upwelling strength, basin-scale climate patterns such as the PDO, and ocean currents. It would seem that jellies enjoy cold, productive water. Even as charismatic species, much of jellyfish natural history is still a mystery and is an active area of research. Luckily, you can help track jellyfish distributions and movement by visiting JellyWatch.org or download the app to report or monitor sightings.
So next time you see a blob, take a closer look. It could be signaling the return of an old friend.
Last week, we were lucky to travel down from Newport to La Jolla, California to attend the 2017 CalCOFI Conference. The CalCOFI program is a partnership between several agencies with a history of studying the marine ecosystem off California since 1949.
This conference was an opportunity to interact and network with scientists and management to discuss current happenings in the California Current. Talks and posters included discussions of amphipod distributions off Baja California to modeling population fluctuations of forage fish species along the entire California Current. Attending conferences can keep you up-to-date on the latest science in your field, but they are also an opportunity to get out of your scientific 'comfort' zone. Do you know anything about modeling sardine populations? Well, now's your chance to find out.
Looking back on the days of presentations, an important take-home message stood out. As is evidenced by the scientific findings of programs like CalCOFI and the NH Line, long-term time-series are imperative for understanding a dynamic ocean. How do we know if something is anomalous if we aren't out on the water? Most of the talks echoed this statement and made extensive use of long-term survey data. Which reminds me, I need to prepare for our upcoming Elakha trip!
We finally got a break in the stormy seas and sampled offshore to 85 miles off Newport aboard the F/V Timmy Boy earlier this week. While the seas were not as calm as I had wanted, the skies were clear and the air was crisp. We were anxious about what we'd find offshore, since pyrosomes had recently been washing up on Oregon beaches by the millions.
Indeed, at every station from 10 miles off Newport out to 85 miles- we collected pyrosomes in our plankton nets in fairly high densities. The animals were smaller nearshore, on the continental shelf, ranging from 20-60 mm. Once off the continental shelf, the pyrosomes became larger- reaching 140 mm.
With the exception of the pyrosomes, the plankton samples were not very dense with zooplankton. However, this is the normal pattern during winter, increased winds result in a mixed water column and there is reduced phytoplankton and zooplankton production.
A common visitor was collected offshore, the By-the-Wind sailor, Velella velella. We often collect Velella at the surface in our neuston net, but what struck us this trip, was how large the Velella were. Some of the animals we collected were the largest I have ever seen- diameters reaching approximately 100 mm. The other striking characteristic of these large animals was how thick their float was.