People call them air rats or trash birds, but I really like gulls. Especially the western gull (Larus occidentalis), known colloquially among birders as the WEGU. Yes, gulls eat garbage, but that's only because humans are so good at making garbage and leaving it all over the place. Other gulls may travel quite far inland--in fact, the state bird of Utah is the California gull (Larus californicus)--but the WEGU is a California Current endemic species. This means that its natural food sources are the fishes and invertebrates of the California Current, which flows southwards along the west coast of North America. As a result, it lives in only a very narrow strip of coastline, nesting on cliffs and restaurant roofs.
Case in point. Yesterday afternoon I was at Moss Landing with my marine biology students. We had hiked along the road, over the dune to the beach, down the beach a ways, and returned over the dune to circle back to our starting point. The last item of note that we all watched was a western gull hunting along the shoreline of the Moss Landing harbor.
It had grabbed a crab. It looked like a rock crab, but I couldn't tell what species.
The crab wasn't dead, and was thrashing around enough to make it difficult for the gull to get a good grip on it.
The crab gets a reprieve!
But the gull didn't give up. It reached down, came back with the crab in its beak, and then flew off.
Last Wednesday, 23 October 2019, my marine biology students and I visited the Monterey Bay Aquarium Research Institute (MBARI) in Moss Landing. We were led through the facilities by Kim Fulton-Bennett, the PR officer. MBARI isn't generally open to the public, so this was a rare opportunity to peek behind the scenes at what goes on at this work-class institution.
We got to see whatever equipment the engineers and technicians had lying around. Outside we saw the top part of an instrument that had been removed from its buoy for routine maintenance.
One of the few personal items we saw was a certain mooring buoy. It was covered with messages and signatures to a man named Roman Marin. I knew him when he was a graduate student, and had taken a marine plankton course for which I was the TA. I ran into him a few years ago on a previous field trip to MBARI, and we chatted for a few minutes. Anyway, Roman died suddenly about a month ago. I remember hearing of his death and thinking how nice a guy he had been.
Here's Kim Fulton-Bennett showing us a sort of mini-rover called a MesoBot. Its job is to dive down to about 1500 meters, explore the mesopelagic, and relay information through a tethering cable back to the mother ship. It's a brand new robot, having been on a only one test dive so far.
And here are some top-down views of the MesoBot:
The MesoBot was being prepped for either additional test dives or the real thing. When it's time to go out to sea it will be loaded into a half-sized shipping container. The other half of the shipping container holds the control room, from which the MesoBot is driven, and a whole bunch of spare parts. When you're two-weeks out to sea and need to replace something, you can't just nip into the nearest Home Depot. Besides, many of the parts that make up these robots are special-built of materials like titanium and can be built only by MBARI engineers.
When it's time to head out to sea, both shipping containers are loaded by crane onto the deck of the research ship. Then off they go!
This is another robot. Nice to see that amidst all this high-tech stuff, they still use ordinary Kim-Wipes at MBARI. Now that's a technology I understand!
Unlike ROVs, which are tethered to a ship and operated remotely by technicians on the ship, autonomous underwater vehicles (AUVs) are programmed before they are deployed. At sea, they roam around according to their program. They may be collecting data for mapping the seafloor, measuring water parameters, or detecting and following a phytoplankton bloom. Kim tells a story of an AUV working off the coast of Oregon, I think. Its job was to map the sea floor. It got itself stuck inside an old lava tube. Since they can only move forward, it couldn't get out. So it sent up an SOS ping and had to be located and then pulled out of the lava tube by an ROV.
This is the lab where AUVs are built:
Kim always takes us inside to see the big testing pool, and it always feels a little creepy to me. The pool is filled with filtered seawater, and engineers use it to test their devices before sending them out into the ocean.
These grids at the bottom of the pool are used to test a robot's cameras:
MBARI is located in Moss Landing, right in the middle of the backwards letter 'C' that is Monterey Bay. Its location is especially strategic because one arm of the Monterey Canyon begins about 100 yards off the jetty at the Moss Landing harbor. This means that the deep sea is relatively easy to get to from this location. One of MBARI's ships, the R/V Rachel Carson, makes day trips into Monterey Bay. Her ship operators, technicians, and scientists can explore the deep sea and come home every night to sleep in their own beds.
Here's Kim pointing out to where the Monterey Canyon begins:
All in all, for anyone interested in marine science and technology, MBARI is the place to be. And even if you're not a marine scientist or a technophile, you certainly can't complain about the view!
When we stop to marvel at the wonders of the natural world, we usually forget about all the life that is going on that we don't get to see. But there is a lot happening in places we forget to look. For example, any soil is an entire ecosystem, containing a variety of small and tiny animals, bacteria, and fungi. In fact, if a fungus didn't send up a fruiting body (a.k.a. mushroom) every once in a while, most observers wouldn't realize it was there at all. We humans tend to behave as though something unseen is something that doesn't exist, and I admit to the very same thinking with regards to my own kitchen: anything stored way up in cupboards I can't reach, may as well not be there at all.
But there are places where we can witness the life occurring below our feet, and floating docks in marinas and harbors are some of the best. Of course, the trick is to "get your face down where your feet are", a piece of advice about how to observe life in tidepools that applies just as well to investigating the dock biota. Once you get used to the idea of lying on the docks, which can be more or less disgusting depending on time of year and number of birds hanging around, a whole new world literally blossoms before your eyes.
Some of the flower-looking things are indeed anthozoans ('flower animal') such as this plumose anemone:
and this sunburst anemone:
Other animals look like dahlias would look if they were made of feathers. Maybe that doesn't make sense. But see what I mean?
This is Eudistylia polymorpha, the so-called feather duster worm. These worms live in tough, membranous tubes attached to something hard. They extend their pinnate tentacles for feeding and are exquisitely sensitive to both light and mechanical stimuli. There are tiny ocelli (simple, light-sensing eyes) on the tentacles, and even casting a shadow over the worm causes it to pull in its tentacles very quickly. This behavior resembles an old-fashioned feather duster, hence the common name. These were pretty big individuals, with tentacular crowns measuring about 5 cm in diamter. Orange seems to be the most common color at the Santa Cruz harbor.
One of the students pointed down at something that he said looked like calamari rings just below the surface. Ooh, that sounds intriguing!
And he was right! Don't they look like calamari rings? But they aren't. These are the egg ribbons of a nudibranch. They appeared to have been deposited fairly recently, so I went off on a hunt for the likely parents. And a short distance away I caught the nudibranchs engaging in the behavior that results in these egg masses. Ahem. I don't know if the term 'orgy' applies when there are three individuals involved, but that's what we saw.
To give you some idea of how these animals are oriented, that flower-like apparatus is the branchial (gill) plume, which is located about 2/3 of the way down the animal's dorsum. The anterior end bears a pair of sensory organs called rhinophores; they look kind of like rabbit ears. You can see them best in the animal on the left.
When you see more than one nudibranch in such immediate proximity it's pretty safe to assume that they were mating or will soon be mating. Nudibranchs, like all opisthobranch molluscs, are simultaneous hermaphrodites, meaning that each can mate as both a male and a female. The benefit of such an arrangement is that any conspecific individual encountered is a potential mate. The animals pair up and copulate. I'm not sure if the copulations are reciprocal (i.e., the individuals exchange sperm) or not (i.e., one slug acts as male and transfers sperm to the other, which acts as female). In either case, the slugs separate after mating and lay egg masses on pretty much whatever surface is convenient. Each nudibranch species lays eggs of a particular morphology in a particular pattern. Some, such as P. atra, lay eggs in ribbons; others produce egg masses that look like strings of miniature sausages.
This is the first time I've seen big Polycera like these. The slugs were about 4 cm long. They eat a bryozoan called Bugula, and there is a lot of Bugula growing at the harbor these days. Maybe that's why there were so many Polycera yesterday. Nudibranchs are the rock stars of the invertebrate world--they are flamboyantly and exuberantly colored, have lots of sex, and die young. They can be very abundant, but tend to be patchy. Quite often an egg mass is the only sign that nudibranchs have been present.
The next time you happen to be at a marina poke your head over the edge and take a look at the stuff living on the dock. Even if you don't know what things are, you should see different textures and colors. With any luck, you'll be pleasantly surprised at the variety of life you find under your feet.