We entered on Estero Way, and worked our way out to the mouth of the marsh. Then we retraced our steps, and wrapped around next to the railroad tracks until we could walk out along the dike on the west side of the Santa Monica Creek channel. Toward the southern end of the dike there is a large patch of an invasive non-native with tall spindly stalks; Andrea tentatively ID’d it as black mustard (Brassica nigra). Here’s a shot looking past one of those stalks back toward the northwest:

I took that photo because Andrea had notice something interesting in the plant. Here’s a closer view:

It’s a collection of six spherical objects suspended in a loose web; Andrea’s guess was that they were spider egg sacs. Here’s a close-up:

There was one more interesting thing we noticed: Where the stem holding the spheres met the main stalk of the plant, there was a triangular structure that appeared to be made from the same silk as the web. You can see it on the left side of this picture:

Here’s a close-up:

We couldn’t find any spider to go with the putative egg cases, but after I got home I posted photos on bugguide.net, and within 15 minutes Charley Eiseman, co-author of the upcoming book Tracks & Sign of Insects & Other Invertebrates (which I can’t wait to buy) had ID’d the spheres for me. They are indeed the egg cases of a spider, specifically the Bolas spider Mastophora cornigera.

The spider is nocturnal; it hides in plain site during the day by looking exactly like a rounded bird dropping. (When I mentioned that to Andrea, she replied that she actually had noticed what she thought was a bird dropping on the plant not far from the egg sacs. I didn’t notice it at the time, and I can’t find it in any of my photos, unfortunately.)

The spider also has an interesting way of hunting: It dangles a strand of silk with a sticky ball on the end, and swings it with one of its legs to capture flying insects. The ball gives off a scent that mimics moth pheromones, and researchers have found that the spider can vary the scent over the course of an evening to appeal to different moth species that are active at different times of night.

Here’s a segment from David Attenborough’s Life in the Undergrowth showing M. cornigera hunting:

One mystery I still haven’t solved: What was that triangular silk structure at the base of the stem? I tried sending an email to Peter Bryant, a biologist at UC Irvine who has posted some neat photos of Bolas spiders on the web. I wrote him as follows:

I came across what I believe are some Mastophora cornigera egg cases yesterday at the Carpinteria Salt Marsh. I’m curious about one thing, though: There was an odd triangular structure, apparently built out of spider silk, at the point where the stem from which the egg sacs are suspended meets the main stalk of the plant. You can view a photo of the structure in relation to the egg sacs here:

http://bugguide.net/node/view/356752/bgimage

…and a closeup of the triangular structure here:

http://bugguide.net/node/view/356754/bgimage

At first I was thinking the structure might be a hiding place for the spider, but now that I’ve had some help identifying the species, and have looked at the wonderful photos you’ve posted of the adult female, I don’t think that structure would be large enough to hide one (and it doesn’t sound like they go in for that sort of thing, anyway, given their impressive bird-dropping mimicry).

I’m trying to figure out what purpose that structure might have. My lay speculation so far consists of:

* The aforementioned hiding place for the adult spider.
* A structural reinforcement, to prevent the weight of the egg sacs from causing the stem to break off the plant.
* A barrier to help prevent egg-sac predators from traveling from the stalk to the stem.

I’m curious if you know the answer, or would be willing to speculate. Thanks!

Dr. Bryant wrote me back, but unfortunately he didn’t have any ideas about that triangular silk structure. He suggested visiting the location again to see if the spider is nearby, which I’d love to do, but so far I haven’t had a chance (and I’d need to go with Peter, or someone else with official permission to enter that part of the marsh).

More Bolas spider links:

• Wikipedia article on Bolas spiders
• Bolas spider, Mastrophora cornigera – Interesting photos and captions by Peter J. Bryant.
• Science Spider Friday: The Bolas Spider! – by DailyKos user hekebolos

The chaparral mallows (Malacothamnus fasciculatus) were really in bloom at the salt marsh a month or so ago, when I snapped this photo of a particularly attractive set of flowers. There still are a few mallow flowers here and there at the marsh, but lately it’s the coyote brush (Baccharis pilularis) that has been catching my eye. I think it’s interesting how there are male and female coyote brush plants, with each gender having its own, specific kind of flower. I’ll try to get some photos of those the next time I’m at the bluffs or the marsh.

Linda was the one who taught me to pay attention to the tide. Low tide is her favorite time to check out the rocks at Tar Pits, or walk the beach to the marsh entrance at Sand Point. If the tide is high, she’s not really interested.

But high tide is a great time to visit the marsh. I took a walk there last weekend, and timed it to coincide with maximum high tide. It was a 6.3; that is, the water’s surface was 6.3 feet above Mean Lower Low Water (MLLW). A 6.3 isn’t as high as it gets; at new moon a couple of days later (a couple of days ago, now, as I write this), the tide got up to 7.2.

At 7.2 pretty much all the low marsh habitat, which is dominated by pickleweed (Salicornia virginica), is underwater. Here’s a shot I got last weekend of some pickleweed taking its saltwater bath:

It’s a neat trick for a plant: being able to live in the open air, while also being able to survive immersed in seawater for hours at a time. The high marsh plants, like saltbush, ragweed, mugwort, and sagebrush, can handle a lot, but immerse them in salt water and they’re history.

Because of the tide, the marsh’s plant communities are vertically stratified, and once you learn to look for it it’s really obvious. Going from lowest to highest, the marsh’s major communities are:

• Eelgrass beds – Below the lowest of low tides, in the bottoms of the channels that wind through the marsh, is eelgrass. These are strictly aquatic plants.
• Mud flats – A little higher, in the intertidal zone, are the mud flats. Not much in the way of visible vegetation lives here, but there’s lots of decaying detritus. There are also microorganisms that feed on it, and lots of invertebrates, and aquatic vertebrates (like fish) and terrestrial vertebrates (like shorebirds) that take turns exploiting the flats as the water rises and falls.
• Low marsh – This is the area where the pickleweed reigns supreme. Most of the time this community is above the waterline, but twice a day the high tide soaks its lower reaches, and twice a month (at the time of new and full moon) the high tide goes all the way to the top, killing any would-be invaders from the high marsh, and maintaining the boundary, as level as if it were layed out by a surveyor, between the two communities.
• High marsh – A wider assortment of plants, tolerant of the high salt levels in the marsh soil, but incapable of actually being immersed.

There’s something else that happens during the highest tides in the marsh: Aquatic predators (like fish) invade the inundated area, picking terrestrial insects off the pickleweed stems. I’d love to see that.

Lately I’ve been seeing a single mute swan, now in the stunning all-white adult plumage, in either the Franklin Creek or Santa Monica Creek channels at the marsh. Whenever I’m there with William and we see the swan he insists on my snapping a photo with my phone, so I have this to share: a shot of William watching the swan in the Franklin Creek Channel last weekend:

This past Friday I was visiting UCSB as part of the incoming-freshmen-and-parents orientation (because Julia will be starting there in the fall), and as we were walking around near the dorms (which I note are in a more beautiful setting than anywhere I’ve ever lived), we spotted two mute swans in the campus lagoon. Here’s the (slightly fuzzy) shot I took:

I wonder if these are the other two of that original trio of siblings.

The first thing we noticed at the marsh, though, was this tire near the northern Ash Avenue entrance. My guess is that someone just dumped it there, but maybe there’s more of a story behind it?

On the midge question, my (very rough) sense of things was that about half of the dozen or so galls I looked at had visible emergence holes. At one point while examining the terminal bud of a coyote brush (a bud that did not have a gall), I saw a small, black, winged insect climbing around, and I wondered if it might be a gall midge. It certainly looked fly-like, and was about the right size, judging by the emergence holes in the galls I’ve looked at. I tried to get a photo, but couldn’t get the focus right, and can’t see the insect in any of the shots I took.

A little more googling for information about the midge turned up an article from the Annals of the Entomological Society of America, titled Portrait of an Ephemeral Adult Stage: Egg Maturation, Oviposition, and Longevity of the Gall Midge Rhopalomyia californica (Diptera: Cecidomyiidae). Quoting from the abstract:

Observational and experimental studies in the field demonstrate that this midge typically completes its entire lifetime reproduction in a single day: females usually emerge at dawn, mate, and after a posteclosion period of resting, they initiate a sustained period of active oviposition during which most eggs are laid over a 4–5-h period. Mean longevity of adult females is very short, consistently <1 d and only 5–6 h on clear and warm days.

I had no idea the adult midges were so short-lived: The females emerge as adults from the gall with their eggs fully formed, mate, deposit their eggs, and die, all within a single day. I guess that means I have my work cut out for me in terms of finding an adult gall fly.

As often happens when I visit the marsh, the thing I went looking for wasn’t the most interesting thing I found. Instead, my big discovery was how clear the water in the Franklin Creek channel was. You could see all the way to the bottom across the whole width of the channel, and William and I had great views of fish swimming under the footbridge.

Here’s a shot I took that shows five fish swimming in a line from the bottom of the frame toward the top. They were about 18 inches long; I think they might be striped mullet (Mugil cephalus):

Obviously, when I talk about how clear the water was, I’m talking in relative terms. Normally I can’t see the bottom at all, or see fish that are more than a few inches beneath the surface, so this view qualifies as exceptional in my book.

I also got several shots of what I think was a round stingray (Urolophus halleri). The ray was about the size of a dinner plate:

Here’s another shot I got just as the ray was swimming into my shadow. Unfortunately, I didn’t include the entire ray in the shot, but this gives a pretty good view of its coloration, including the big, pale spots on its body:

I’m not sure why the water in the creek was so clear yesterday. We had some light, unseasonal rain last week; maybe that brought some fresh, relatively clear water into the creek channel? In any event, it was really neat to get a good look at what was going on under the surface.

I’ve also seen them at the Carpinteria bluffs. (Thanks to William in both cases for pointing them out. Even though I was specifically looking for them, it took my perceptive 11-year-old to actually find them.)

The number of adult beetles on the coyote brush is still pretty small; I saw a few bushes that had 4 or 5 beetles climbing around in one area, but if the vast number of larvae I was seeing in the marsh a month or so ago is any indication, we’re due for a lot more beetles to appear in the weeks ahead.

Near El Carro stands a tall sycamore, one of the last big trees along this part of the creek. Here’s a view looking up into its branches.

A little ways south of the sycamore, a footbridge crosses the creek. There are big bottlebrush bushes on each end of the bridge, with tons of bees (and Selasphorus hummingbirds). Here’s a shot looking north from “bottlebrush bridge”:

Here’s a view looking south from the bridge toward Via Real:

Down at Via Real, here’s the view looking back north:

Here’s the view looking south, across Via Real to the 101 freeway:

If you cross the freeway at Santa Ynez Avenue and head west along Carpinteria Avenue, you can rejoin the creek at the Carpinteria Avenue crossing. Here’s William looking north from there, with the 101 freeway in the distance:

Here’s the view looking south from a point along Sandyland Cove Road, toward the railroad crossing and the salt marsh:

Finally, here we are at the point where the concrete creek channel ends, looking back north past the railroad bridge toward the mountains:

Here’s the view from the end of the channelized creek looking south. Santa Monica Creek has now become a dredged channel through the salt marsh, winding toward the marsh entrance and the Pacific Ocean. That’s a young mute swan standing in the channel, just beyond a couple of American coots.

There’s a new sign at the north entrance to the marsh, by the way. Wouldn’t this make a cool photo for Mystery Bird of the Day? Can you recognize the bird? It’s a common species in the marsh and on nearby beaches.

One of the first invertebrates I noticed at the marsh during my walk were these shiny green insect larvae, happily munching away on the leaves of coyote brush (Baccharis pilularis).

These guys were on every coyote brush I looked at; I count six of them in this picture alone. I did a quick estimate, and decided that there were about 500 of them on a single large plant. Multiply that by the amount of coyote brush at the marsh, and that’s a lot of larvae.

At first I thought they were some kind of caterpillar, but after posting my photo at bugguide.net, early speculation has centered on the genus Trirhabda, a kind of leaf beetle. Looking at this image of Trirhabda flavolimbata made me remember that several months ago I’d seen a beetle that looked a lot like that all over the coyote brush. According to this entry at bugguide.net, there are at least three species of Trirhabda in coastal California, with T. flavolimbata being the one that specializes in coyote brush.

Update: I took most of the photos in this blog entry during a walk with William on Sunday, March 29. Based on the discussion at bugguide.net, I went back this morning — Thursday, April 2 — with Julia to get some better photos. Here are three that she took (posted at bugguide.net here, here, and here).

This gives you a good shot of the larva’s head:

This shows the larva’s body, as well as a dark fluid on the plant that I’m assuming is related to the larva in some way, though I’m not sure how. Maybe it’s fluid that is draining from the fresh “frass” (insect poop) on the leaf above it?

In reference to that fluid, Charley Eiseman, author of the upcoming book Invertebrate Tracks & Sign, wrote in response to an email I sent him:

If these were caterpillars or sawfly larvae, I might be a little worried about their health, but more “soupy” excrement isn’t too unusual for leaf beetle larvae.

You know, I never expected when I got out of bed this morning that I’d be learning about the consistency of leaf beetle excrement. But I think it’s cool that the larva’s soupy poop actually helps confirm the ID.

Finally, here’s a shot that shows the larva’s prolegs. Some of the commenters at bugguide.net were especially interested in seeing those.

[Back to the original blog entry.]

While looking at the coyote brush, I also noticed this interesting white object:

I wasn’t sure at the time what it was, but I had a vague recollection that led me to google for “scale insect”, and sure enough, this looks a lot like a cottony cushion scale (Icerya purchasi) (and Charley Eiseman, writing at bugguide.net, agrees). Here’s a cropped version of the original image to give you a better look:

My google search led me to gardenbees.com’s Cottony Cushion Scale: The pest that launched a revolution in pest control methods. Among the things I learned there:

• This is a female scale insect.
• The actual insect is the brownish thing at the upper right, covered by white waxy fibers. She’s attached herself to the plant, and is more or less immobile.
• The large, white, grooved part extending to the left is not her abdomen, as I originally thought. It’s an external egg case.
• The cottony cushion scale is not native to North America. It hitchhiked here from Australia in 1868, arriving on a shipment of plants and soon becoming a serious pest in the California orange groves.
• The scale was eventually controlled by introducing one of its natural predators, an Australian lady bug. When I read that, it reminded me that I’d already read another account of that same event, in Sue Hubbell’s excellent book, Broadsides from Other Orders.

Continuing the list of things feeding on the coyote brush, I noticed this swelling at the end of a coyote brush stem. It’s a gall, the work of an insect that lays its egg inside the plant, leading the plant to create an enlarged chamber within which the insect larva grows:

I had no idea what insect might have done this, though Charley Eiseman responded at bugguide.net that he thinks it was made by a species of midge, Rhopalomyia californica. Looking at some of the other photos at bugguide.net, I think he’s probably right. I’ve been unable to find an image of the adult midge, but Flickr user “Eric in SF” opened up one of the galls and took a photo of the larva.

According to an article abstract I found online (Ecology of Rhopalomyia californica Felt at Jasper Ridge), the midge “is under investigation as a possible biological control agent against related species of Baccharis that are rangeland weeds in Texas and Australia.”

Another type of gall can be seen in this photo. These are in a leaf of the arroyo willow (Salix lasiolepis) growing next to the boardwalk that winds through the marsh’s small patch of coastal dune habitat:

Again, I had no idea as to the species of insect involved, but Charley Eiseman wrote at bugguide.net that he thinks it is a sawfly of the genus Pontania.

As I mentioned, the marsh’s patch of coastal dune habitat is small, but it’s very important to at least one species: the globose dune beetle (Coelus globosus), a coastal specialist that has become rare as coastal dunes give way to houses and condos. Andrea Adams-Morden has pointed out the trails in the dunes to me and told me they were produced by globose dune beetles, and I’ve seen a few dead beetles, but so far I’ve never found a live one. In the meantime, I like checking out their trails, which the beetles leave as they burrow just under the surface of the sand. Can you see the beetle trails in this photo?

Here’s a closeup of some beetle trails. It looks to me like maybe there was a single beetle that entered from the upper right, did a counter-clockwise loop, crossed its own earlier trail, and exited at the upper left:

There’s a neat series of photos of a related species, Eusattus dilatatus, at the myrmecos blog: Friday Beetle Blogging: Eusattus Dune Beetle. You can see the beetle burrowing into the sand, a process that takes about 30 seconds.

One of the best-known invertebrates in the Carpinteria salt marsh is the California horn snail (Cerithidea californica). Millions of these marine snails live in the marsh; you can see them crawling over the mudflats at low tide, and after they die their shells get washed out of the marsh entrance and turn up along the beach at Carpinteria, where I’ve picked up dozens of them during a single walk.

One of my favorite lectures during docent training was given by Dr. Kevin Lafferty, a parasitologist who has studied the use of horn snail parasites as a way of measuring ecosystem health in coastal marshes. I didn’t get any photos of horn snails during my walk in the marsh this past weekend, but I did take some photos of the very cool interpretive sign near the Franklin Creek bridge that talks about the complex life cycles of salt marsh parasites. Here’s a close-up of part of the sign:

If you want to learn more, you can see the image of the whole sign that I posted on Flickr, and click through to the largest size, which should be fairly readable.

One other invertebrate at the marsh, one that’s actually kind of similar to the California horn snail in size and shape, is the decollate snail (Rumina decollata). It’s a terrestrial snail, not an aquatic one. I noticed them crawling across the trail near Ash Avenue one morning when I was walking the marsh with William, and I was surprised, because I’d never seen an elongated snail like that on land before. An email to the carpmarshfriends Yahoo group got me some help with the ID, after which I learned more about the snail at the nice Wikipedia article on it.

Decollate snails are non-native; they originate near the Mediterranean, and are predators who feed on the eggs and young of other snails. They’re used by gardeners as a means of controlling another non-native, the invasive brown garden snail, and presumably that’s how these guys got into the marsh: crawling in from someone’s garden along Ash Avenue.

They’re nocturnal, and so far I’ve only seen them early in the morning after a rain. I couldn’t find any on my recent walk, but I did find this empty shell of one:

Update: When Julia and I returned to the marsh on April 2 to get better photos of the larvae on the coyote brush, we also found a decollate snail climbing in the blue-eyed grass (Sisyrinchium bellum). I really like this shot Julia took of it:

She also got this shot from the other side, showing what looks to me like a thread of some sort emerging from the area of the snail’s mouth. I didn’t notice it at the time, so I can’t tell you anything else about it, but it’s certainly interesting. What’s going on with that?

Thinking about it some more, and staring at the largest version of the image, I find myself thinking a wacky thought: What if the snail actually ate a spider? Could that happen? If it did, could it have left the spider’s dragline extending away from the snail’s mouth? I guess it’s a lot more likely that the snail decided to snack on a stray piece of silk, or just ran into it and got tangled up.

Overall, I had a really fun time rummaging for invertebrates at the marsh. I hope you enjoyed reading about them.

Those are lupines in the foreground, lupines and California poppies in the background, and people with dazed grins on their faces walking the trail. This was right by the road — I snapped the photo with my phone out the passenger window while Linda drove.

I’ve seen lots of interesting plant reproduction closer to home lately, too. The young California sycamores at the Heath Ranch Park had some pretty reddish fruits coming in the other day:

It’s seeding time for the arroyo willows at the Carpinteria salt marsh; here’s a shot that shows seeds embedded in the fluff that will carry them away the next time a good wind blows through:

Finally, I’d never noticed the blue-eyed grass at the marsh before; I’m not sure how I managed to just walk by such beautiful flowers in years past without paying attention. They were starting to fade when I was there today, but a few weeks ago they were really impressive looking:

From: William Abbott
Sent: Wednesday, January 14, 2009 5:04 PM
Subject: Salt Marsh restoration party: Martin Luther King Jr. Day

Hello all Salt Marsh Friends,

We have good news for Martin Luther King Jr. Day! Patagonia and the Land Trust are facilitating a restoration work party, starting at 9AM on Monday. Patagonia is sending 6 volunteers from 9 to NOON; any local Salt Marsh lovers are welcome to join in and stay for as long as they like! Bring waders, if you have any!

By William Abbot’s count, 21 volunteers showed up for the event (counting me); here’s a shot he took of us doing our weeding (that’s me in the middle):

Here are some of us at the end of the event (again, that’s me in the middle):

The best part for me was that I got to pester Andrea Adams-Morden (second from the right in that second picture) with all manner of questions about the plants we were pulling up, and the ones we were putting in. Andrea is the volunteer coordinator for the marsh docents, and knows an awful lot about the plants in the marsh.

Monday’s event was in the part of the marsh that is owned by the Land Trust for Santa Barbara County. That’s the part beyond (that is, west of) the new footbridge spanning Franklin Creek. It’s interesting to compare it to the city-owned section near Ash Avenue, where a lot of restoration work was done in the late 1990s, and where volunteers have been doing monthly weeding sessions ever since. The Land Trust parcel is weedier (in the sense of having more non-native plants), and also has some bare spots where mud gets dumped during flood-control dredging. In both ecological and aesthetic terms it’s arguably more degraded than the area along Ash Avenue. On the other hand, it’s also farther away from day-to-day human activity. It’s quieter, and wilder. It’s the part of the marsh where the (non-native, I realize, but still very cool) red foxes hang out.

On one of my first trips across the footbridge after it was opened last summer, I sat on one of the big, rounded boulders near its western end. There’s a small channel there, with a pool where egrets and herons like to fish. I sat there for a while, enjoying the solitude, and then I noticed an odd sound. It was a sort of whispering, a very low-volume series of pops and clicks, coming from the muddy margin that the low tide had exposed. It took me a second to realize what it was: The sound of hundreds of horn snails crawling through the mud.

The Land Trust parcel at the marsh is a work in progress. But I really like it, and it felt good to be able to help it out with some weeding.