Happy anniversary Plankton Portal 2.0!

Blog post by Jean-Olivier Irisson

A year ago, we announced Plankton Portal 2.0, which featured a more streamlined design, a simpler tagging interface, and most importantly, a whole new dataset. Since then, this new data from the Mediterranean Sea has spurred a lot of interest and plenty of new questions. Participants on the site were surprised by the difference in size of everyone’s favourite jellies, the Solmarisidae (Solmaris rhodoloma in California, Solmissus albescens in the Med), which are much larger! Siphonophores also seem more abundant there. And the Mediterraean data came with brand new categories of organisms to mark: nice and cute medusa ephyrae (i.e. baby jellies), elegant Pteropods and the elusive fish larvae.
In total, as of last Sunday, 368,361 organisms were marked, on 50,519 distinct images. Through time, the classifications were marked by two peaks in activity: a huge one when the new version was announced through a mailing to the Zooniverse community (thanks everyone!) and another one when we pushed for 1,000,000 classifications in total, to celebrate Jessica’s PhD defense. When we zoom in, we see activity fluctuating around 1000 and now 500 classifications per day. This is still great (but coming back to 1000 would be even better! 😉 ).
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The top 11 contributors, all authors of over 5000 classifications each, are displayed below. If you made this top 11, we owe you special thanks (and probably a beer too). We hope you will stay interested and involved in this project. If you did not, you should really not be disappointed because all other volunteers still collectively account for 60% of the classifications; so you matter very much! Hopefully all of you will be happy to see some of the outcome of your work below.
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Time for a bit of science! The most common classification was… nothing, empty, zero, zlich, zip… Well, you get the idea. Indeed, when we film the sea, we most often see nothing (nothing living at least). Even though we pre-selected potentially interesting frames for Plankton Portal (the ones having some kind of large object in them), about a third of your classifications did not contain any organism we were interested in. In real life, the proportion of dead detritus vs. living organisms is more around 95% vs. 5%, so our pre-filtering still avoided you a lot of blank frames! In terms of organisms, the 10 most abundant are shown in the figure below.

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Doliolids, Copepods, and Radiolarian colonies dominate the rest. We immediately noticed, when we shot the images, that Doliolids were particularly abundant. Those organisms are very effective filtering machines and they may therefore have an impact on the density of smaller organisms, in particular unicellular algae. The relative abundance of Copepods and Radiolarian colonies is to be interpreted carefully: Radiolarian colonies can be large and span several frames (therefore increasing the total count) and Copepods are likely under-estimated because we mostly see the larger ones with ISIIS, and they are not the dominant ones in the Mediterranean. Still, it echoes nicely a recent Nature paper by Tristan Biard (a contributor to PlanktonPortal’s talk, under the username Collodaria), which showed that Rhizaria (a large taxonomic group to which Radiolarians belong) can be equivalent in biomass to Copepods, who were previously thought to largely dominate the plankton. These findings were also based on in situ images, because these fragile Rhizaria cannot be collected with nets.

 

Finally, the images in the Mediterranean were collected along transects (i.e. straight lines) perpendicular to the shore. We were interested in how organisms were distributed along a gradient between coastal and open ocean conditions. In the plots below, the coast is on the left, the open ocean on the right and the vertical direction is depth (top: surface; bottom: 100 m depth). So you basically see a “slice” of water along which ISIIS undulated. The size of the dots is proportional to the number of classifications recorded. You can immediately notice that Doliolids (first plot) are concentrated near the surface, and fish larvae (second plot) even more so! This is a surprising finding for fish larvae, which sometimes ended up in concentrations of over 10  individuals per cubic meter, a number much higher than what was previously observed elsewhere, with conventional plankton nets.
distrib_doliolid_w_icondistrib_fish_w_icon
Radiolarian colonies, on the opposite, tend to be concentrated in mid water (see figure below). Within this messy picture, some structure seems to emerge. Indeed, the white lines on top of the plot are contours of the concentration of Chlorophyll A in the water (i.e. of the amount of unicellular algae). If you look carefully, you will see that those lines are moving up, towards the surface, as we travel offshore (from left to right on the plot). This is actually well known in this region. What is interesting is that the radiolarians seem so follow the same pattern, and that higher concentrations of colonies sit on top of this high Chlorophyll region. Something is definitely going on between these two!
distrib_radiolarian_colonies_w_icon
That’s it for now — thanks again to everyone for this wonderful year of activity! We apologise for not being as active as we would like to be on Talk. To that end, we thank the active moderators who take over this important responsibility. And finally, we thank Zooniverse for the great opportunity and community they created. Now, on to next year!
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Fantastic Finds Fridays: Week 2! #FFF

We are at the end of week 2 and we pulled out some of the best finds from this past week. As a reminder, every Friday we will post a selection of Fantastic Finds. If you think you have found something really great on Plankton Portal then tag #FFF and we will check it out for use on the blog. Thanks for tagging your favorites this week!

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Larval fish
http://talk.planktonportal.org/#/subjects/APK00015nq

Larval fish are actually considered part of the plankton, as fish in their early life stages will drift along in the oceanic environment. Because larval fish are relatively poor swimmers, they are under high predation pressure and more than 99% of baby fish that hatch from eggs will not make it! It’s a tough life. You might not know it from this site, but studying larval fish is a major component of our lab. Dr. Cowen has spent his career studying larval fish, their distributions, dispersal and population connectivity. In this particular study, we did not sample very many larval fish so we did not include it as one of the categories. However, we are incredibly interested whenever we see one so definitely tag the fish in the forum when you see any! #Larval #fish

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Liriope tetraphylla (#Medusae #4tentacles) with Arrow worm
http://talk.planktonportal.org/#/subjects/APK0000q5x

This is one of my favorite pictures from this week because what you see Liriope tetraphylla actually eating the arrow worm! Here one of his tentacles has brought up the arrow worm into the gastric peduncle (that’s the long thin appendage in the middle of the umbrella that looks like a handle). He appears to be holding the arrow worm in place while he eats his dinner. As far as I know, the only scientific study of what Liriope eats is from a paper by Larry Madin in 1988, published in the Bulletin of Marine Science, where he found that Liriope eats larvaceans, crustacean larvae, heteropods and juvenile fish. No one has reported that Liriope also eats arrow worms … until now.

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Sphaeronectes koellikeri – #rocketship #thimble
http://talk.planktonportal.org/#/subjects/APK00002cl

This beautiful creature falls within the broad group of jellyfish-relatives called the Siphonophores. Here you see this animal in a stunning feeding display. Though these guys are small and relatively inconspicuous, other siphonophores can get up to hundreds of feet long, and as a group are considered the deadliest predators in the ocean.  One fun fact: these rocketship siphonophores grow from the base of the stem towards the tail end. So the tail end of the stem is one of the oldest parts of the body. Sometimes you’ll even see small rocketships budding from the tail!

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Radiolarian colony – #radiolarian #colony
http://talk.planktonportal.org/#/subjects/APK00003kq

We know that you’ve been frustrated by those small fuzzy round objects that invite classification but really aren’t supposed to be classified. Those are protists, a diverse group of eukaryotic microorganisms. One type of protist is the radiolarian, which are known for their glass-like exoskeleton, or “tests.” They are incredibly important in marine science because their tests are made of silica, which are preserved in marine sediments after they die and sink to the bottom of the ocean, and provide a record for paleo-oceanographic conditions, such as temperature, water circulation, and overall climate.

Radiolarians also form colonies. Colonial radiolarians are interesting because first, little is known about them, despite their abundance in the open ocean, and secondly, they are hosts to symbiotic algae that are modest but significant primary producers in the ocean. It has also been suggested that we are vastly underestimating the abundance of radiolarian colonies. Since primary production (photosynthesis, the conversion of sun energy into carbon) is the basis upon which all ocean life can exist, it’s incredibly important to understand who all the different primary producers are and how many of them are out there!

 

That’s all, folks. Thanks for reading, thanks for classifying, and remember: mark your favorites with #FFF for next week’s Fantastic Finds Friday!