Sunday, May 21, 2017

Desmostylia––Ancient Sirenians of the North Pacific

May 21, 2017

This area of southwest Washington and northwest Oregon was underwater for many millions of years. Ancient marine mammals lived here along with fishes and a wide range of invertebrates, even though we do not have fossils from every square mile to look at today. So we look around the Pacific Rim to learn about the diversity of former species.

One of the strangest animals from our watery past is Desmostylia. A chunky, stout aquatic mammal of shallow waters and shorelines, it is distantly related to modern manatees, which are Sirenians. 

Formerly much more common in geologic time, Sirenians include three living species of manatees, one dugong, and the recently extinct Steller's sea cow. Their closest living relatives are elephants and hyraxes. Fossil Sirenian species in the Desmostylia group lived from the Oligocene to the late Miocene, about 25 million years, ending about 7 mya (millions of years ago). 

By the Miocene this area was a shallow sea with several river deltas and emerging mountain ranges, and with extensive swamps along the eastern edge, near the position of the modern Cascade Range. Climate was warmer in the Miocene, tropical to subtropical, and sea level was a couple of hundred feet higher.

Desmostylia fossils, including full skeletons and partial bits of bones, teeth and skulls, have been found around the North Pacific, from the south end of Japan, through Siberia, the Aleutian Islands, Pacific Northwest, south to the south tip of Baja California. Teeth make particularly good fossils because they are hard and slow to break down. Desmostylia has interesting large molars, along with more typical mammalian tusks and canine teeth. These teeth have been described as bundles of columns, which gives them their name, from the Greek desmos (bundle) and stylos (pillar).

These mammals were aquatic, and from isotopic analysis of teeth and bones, we know that they were marine. Other marine mammal features include retracted nostrils (tightly closed when underwater), and raised eye sockets (to see better at the surface). Stocky and stout, they weighed up to 440 pounds and were about six feet long, with a heavy shovel-shaped head and large strong teeth, short strong legs, and broad feet. You can see a complete desmostylian skeleton of at the Natural History Museum of Los Angeles County. This individual lived 10 million years ago, towards the end of the Miocene. The museum has also done reconstructions of living animals, to give us an idea of what they were like.

There are no modern analogs to these mammals. For size comparisons, black bears and wild boars (feral pigs) can grow to 400 pounds or more in size. Hippopotamuses weigh up to 3,300 pounds, and live in freshwater, though some populations live in mangrove swamps. Manatees weigh up to 1,300 pounds, and live entirely in water. We could think of Desmostylia as a small hippo, in a sense, though they are not closely related.

With broad grinding molars, Desmostylians were herbivores. In marine and estuarine waters, what did they eat? Sea grasses and seaweeds, including kelps, are the mostly likely food plants. These plants live in shallow saltwater in large, dense stands. There was another powerful reason to stay in shallow water: Megalodon cruised the open waters of the world's warm oceans and seas. Desmostylia were about the right size to this huge shark to be like chicken nuggets to us.

Imagine if today 400-pound, six-feet-long marine herbivores grazed eelgrass beds in Willapa Bay. They'd jostle with the seals for haul out space, or sprawl in the marshes around the edges, and graze down the eelgrass stands at mid to high tide. Water quality might be an issue. Herbivores tend to produce a lot of poop, about five to seven times the volume, based on body size, that carnivores do. Today, hippos are one of the most dangerous animals we live around. Desmostylia might be similarly dangerous––placid until someone gets too close, and then those large teeth come into action, and oops, there's another ex-kayaker or ex-hiker. It would definitely make boating on the bay lively!

For more information, and good reconstructions of a Desmostylia, see
http://a-fragi.blogspot.com/2011/07/desmostylus-2010.html  where a Japanese sculptor, Hirokazu Tokugawa, has done very nice reconstructions of this fascinating paleo marine mammal. 

Sunday, November 13, 2016

Water Greets Land And Brings a Gift

November 14, 2016

As a child I was fascinated by seasonal floods in Amazonia, where rainforest over millions of acres is flooded by many feet of water. Fish swimming among trees in the forest seemed totally bizarre to that child. 

Today I walked the road at Greenhead Slough, where Willapa National Wildlife Refuge, working with local and state partners, recently replaced a tide gate with a bridge, restoring tidal hydrology to several streams and associated floodplains. 

Three Chum salmon in the stream, two to the left, one to the right. All have begun to lose skin, hence the whitish appearance on their sides. 

Tides are very high and low now—a spring tide cycle, which occurs twice each month when the moon is full or new. I saw a near-full moon two days ago. On this full moon cycle, the local floodplains, marshes, and in some cases associated forests, are flooded at each higher high tide every 24 hours. 

Chum salmon came back to their natal streams this season in large numbers. Commercial fishermen caught their quota, and still the salmon kept coming. Last year, refuge stream walkers did not see any chum or coho salmon. This year, chum have returned to all the streams they monitor. Today I saw two streams with chum in them, splashing as they mated and dug out redds to lay eggs. There were dead fish too; I could smell the dead fish as I approached. 

Banana slug and fungi:  which one to eat first?


For the next generation of salmon this is good news:  the bodies of their parents fertilize the streams, tree roots pick up and share nutrients, and animals drag dead salmon off to eat and spread them up slope into the forests. For other salmon species, there is better news:  chum salmon smolt (return to salt water) when they are very small, so they are good food for other salmon species that smolt when larger in size. Seeing many adult chum salmon breeding this fall is a strong indication that other runs of other species will be plentiful four years hence, and their adults will be numerous, large, healthy, and strong. 

Forest underwater:  nutrients, fish, organics surge in with the water across the forest floor.


There was also water among the trees in several areas, taking me back decades in memory to that child, seeing photos of fish swimming among Amazonian trees. Marine anadromous fish not only give us pleasure in fishing for them, livelihood for commercial fishermen, and food for bald eagles, bears, and other animals, they give the forests important nutrients, including calcium, nitrogen, phosphorous, and other minerals. It’s a magnificent sight to see the fish, but the implications that carry forward for future health of both forest and fish runs are also important. When we see a healthy run like this, we see the future of both forest and fish in their presence. 

Rough Skinned Newt walking on a floodplain surface, among deep elk footprints.


The weather was wet, a mild day with light rain, though the wind rose as the hours passed and another storm approached. Rough Skinned Newts and Pacific Banana Slugs were out moving around, well sheltered from the sun by the clouds and rain. Thinking about the movement of nutrients from fish to soil to fungi to trees, I realized that these nutrients reach the slugs too, and any insects that feed on plants or fungi, and also newts. There's a bit of ocean in all of those species in a fish-healthy forest. 

Looking over the highway and across Bear River, salt water floods the marshes and streams from forest edge to forest edge. 



At high tide, there is a large sheet of water from the highway west across Bear River and its associated marshes to the Porter Point peninsula. With dikes gone, with hydrology restored, the winter high tides sweep across the entire landscape, just as they did more than one hundred years ago. Water greets land again, and brings a gift of fish. 

Saturday, September 17, 2016

Autumnal Slug Rain––another kind of rain

September 17, 2016

Friends of Willapa Refuge held a ‘Wonders of Willapa’ event at Tarlatt Unit today. The weather was wet, with steady rain during the morning and longer and longer breaks between rainy periods as the afternoon went on. We stopped by the site around 2 p.m., and walked out to the Tarlatt Slough viewpoint, where you can look north in clear weather to the Olympic Mountains. Not one peak was in sight today, low clouds obscured even the north bay. 

The view north along Tarlatt Slough:  Water and sky merge in the rain.

The highlight of the walk was multiple slug sightings. In some areas, there were slugs every three to five feet. Occasionally, there were three or more slugs within a couple of feet. 

Two Pacific Bananaslugs (lower left and upper center) and a Chocolate Slug (upper right).

I’ve walked in ancient forests in late February, in the rain, and stepped over a frog or salamander with ever step. We call these Salamander Rains, when the coldest temperatures of winter are easing into spring, the soil is thoroughly wet, the air is wet, and amphibians can easily move around from winter hideouts to spring mating streams and ponds. 

In late summer, after months of dry weather, the first soaking rains wet the ground, promote decay of drying vegetation, and voila! The slugs come out of their summer hideouts and frolic in the broad light of day, or so it seemed today. 

Low light, ample food (decaying leaves and fungi for Pacific Bananaslugs, introduced vegetation for Chocolate Slugs), and plenty of atmospheric moisture made this an ideal day for gliding and browsing by slugs, and while the calendar is not quite to Fall, it seems appropriate to name this an Autumnal Slug Rain––not a rain of slugs, but a rain that brings out the slugs. 

A buckskin Pacific Bananaslug, pale yellow and gliding over grasses on the dike.

Pacific Bananaslug, Ariolimax columbianus, is the largest native slug on the coast, commonly seen in forested areas. On the dike these slugs were many yards from the coastal forest, which is their usual habitat. Bananaslugs eat decaying vegetation, mosses and fungi.  The damp day and ample food lured more than one hundred bananaslugs out into the open for the first good noshing they’d had in wet daylight weather for many months. Coloration varied from pale yellow to ochre yellow, some with black spots (small to large), and others plain, or in local lingo, pinto, appaloosa and buckskin slugs. 

Another color form of Pacific Bananaslug, with black spots on an ochre brown body. 

Chocolate Slug, Arion rufus, is one of the larger introduced slugs in the Pacific Northwest. Colors vary from medium brown to very dark brown to black. Today we saw medium brown and very dark brown colorations. This slug is common in gardens, and rarely found in native forest. The dike is largely covered in introduced grasses and flowers, so it too was right at home, feeding in the open on a suitably wet afternoon. As with the bananaslugs, there were more than one hundred Chocolate Slugs in the short walk from the edge of the forest to the overlook area. 


Chocolate Slug, with a medium brown, milk-chocolate-colored body.
I did not see any native or introduced snails today. Shells provide them with some cover during dry seasons, allowing them to move a bit more freely than slugs can. 

Another Chocolate Slug, this one is more of a dark bitter chocolate brown color.



To read more about terrestrial mollusks, see the recent book, Land Snails and Slugs of the Pacific Northwest, by Thomas Burke, with photographs by William Leonard, OSU Press, 2013. There are dozens of native and introduced species in the coastal Pacific Northwest. As for rain terms, at last count, my rain words list has more than one hundred twenty terms. 

Wednesday, August 24, 2016

Ancient Trees, Young Trees, the Forest Abides

Kathleen Sayce, August 22, 2016

Last Saturday I walked in the ancient red cedar grove on Long Island. I first saw this grove in the 1970s while timber cruising on the island for the refuge. Forty-one years later, these trees are as magnificent as they were then. Their habitat is as complex and multilayered. This stand is a climax forest, and it richly expresses the diversity of a climax forest in a coastal temperate rainforest biome.  

What has changed most is the forest around the cedar grove. 

This stand along the trail from the beach at Smokey Hollow was too dense with young western hemlock to see into 40 years ago. Today, you can see sky among the canopies, and there are mosses and ferns on the ground, with young shrubs starting to grow in some spots. 

In the 1970s, most of the island had been logged and was regrowing as naturally sprouted western hemlock trees in dense 'dog hair' stands. These were young, many less than forty years old, and they lined the roads like green walls. No sunlight reached the forest floor. One could not see into the stands from the roads. I cored a few of those hemlocks four decades ago, and their growth rings were tiny, a few millimeters per year or less. 

Forty-one years later, natural loss has thinned the hemlock stands by more than seventy-five percent, leaving behind more widely spaced living trees that are three times as tall with trunks correspondingly bigger. Ferns and shrubs are scattered on the ground. Mosses now carpet the ground. Another two hundred years, and these young stands will be approaching solid middle age. Western hemlock trees live around four hundred years. 

As the stands of hemlock age, other trees will seed in, including Douglas-fir, red alder, Sitka spruce and, of course, western red cedar. When we walked these roads last weekend, it was easy to see more than one hundred feet into the forest all along the road.

The trail into the cedar grove has also opened up in the past 40 years. Sunlight reaches the forest floor. Ferns are lush. Some trees are more than 12 inches dbh (diameter at breast height, 4.5 ft from the ground) now. 


In the cedar grove, meanwhile, a few trees have died, one or two snags have fallen, and otherwise, the grove looks very much as it did then. There are abundant mosses on the ground, on logs and in the trees. There are layers of ferns and shrubs. Some of the shrubs are more than ten feet tall. There are young trees, many are hemlocks, with a few others. There are dozens of mature cedars, 850 to 900 years old. The oldest living trees are around 1200 years old. Study these trees, and you can see the signs of old nurse logs, where living trees now seem to be on their toes, hollows showing at the ground level where their supporting nurse logs have rotted away. Lightning scars are visible on many trees, signs of historic damage. 

Every tree species has a different feel as an elder, and when in groves. Here in the island cedar grove, the ancient trees are each distinctly different in shape, but all have multiple dead tops, showing the candelabra form that is distinctive to the coast.

More strikingly, these trees live close to the coast, a few miles from the Pacific Ocean, and this proximity shapes their form. They aren’t very tall, around 200 feet in height. Cedars can grow more than 300 feet tall. Winter storms, high winds and salt in the air kill the growing tips. Cedars respond by growing new tips, forming in time a crown of dead and living tops in the shape of a complex candelabra––candelabra cedars. The large trunks, often more than ten feet in diameter, rise in huge columns to these woody crowns. Shrubs, ferns and young trees sprout from pockets of soil and moisture, often one hundred or more feet in the air. 

A refuge manager here in the 70s, Joe Welch once told me that he was worried that there were so few young cedars in the stand. Dr. Jerry Franklin, a forest researcher who visited the grove soon after, told him not to worry. The cedars live such long lives that to them, the hemlocks are just passing through. Sitka spruces live eight hundred years or more, as do Douglas-fir, so the tree species  balance is not skewed to hemlocks over millennia. Cedars have been here for thousands of years, and will remain a major presence in this grove. 

Cedars may stand dead for many centuries before they fall to the ground, and then take more centuries to decompose. Living around one thousand years, the decomposition process also takes around one thousand years. There are logs in the grove that have been on the ground for hundreds of years, and still have bark firmly attached. 

A magnificent western hemlock snag, with pileated woodpecker holes, and polypore fungi fruits.

It is satisfying to know that natural forest processes are dominant here as they have been for at least four thousand, perhaps eight to ten thousand years. These aren’t sequoias or bristlecone pines, to individually live several thousand years, nor are they redwoods, which can resprout from the ground after fire, and live on after major wildfires, growing a new trunk and fresh canopy of leaves on old roots. 

During my own lifetime, I have watched logging trucks on the road, first with old growth, then with old second growth, and then, younger and younger trees. The average age of a conifer log on a logging truck now is less than thirty years. Knowing that this small grove, less than 300 acres, is preserved, intact, functional forest is also comforting. The cedar grove abides.  





Monday, August 15, 2016

Red Tide on the Columbia River

Kathleen Sayce, August 15, 2016

In mid summer on the Columbia River Estuary a color change appears in the water, red to purple, and persists into early fall. It’s a natural red tide, when billions of single celled animals, ciliated protozoans, called Myrionecta rubra (also called Mesodinium rubrum) bloom.  The bloom is particularly striking from the high span over the shipping channel, on the south end of the 101 bridge near Astoria. It is not toxic, but it is very red. 

The band of purplish-red water is a colorful streak of Myrionecta rubra cells, seen from the Astoria-Megler bridge on August 14th, 2016. 


The cells are less than 100 micrometers long, and have two rows of cilia between two round body sections, which give this tiny animal the swimming dexterity of a jet fighter. They look like two round balls of different sizes stuck together. The beating rows of cilia allow it to jump ten to twenty body lengths in one movement, which would be like a 6-feet-tall human jumping sixty to one hundred twenty feet. 

Seen under the microscope, they spin, dash and turn with amazing speed. The red color comes from a red alga that lives inside the cell.  The algae cells are not permanent residents; each cell lives around 30 days inside the protozoan. There may be several algae cells in each Myrionecta organism, and carbon fixed through photosynthesis by the algae feeds the protozoan. 

During warm, sunny weather the blooms form in long streaks in the Columbia River Estuary between the jetties to above (east) of the Astoria-Megler bridge. Sometimes they also form in Youngs Bay, and can be seen on that causeway and bridge. In some years, the entire river looks like it’s running with blood instead of water. Most years, the bloom is in streaks surrounded by otherwise normal-colored water, green to gray to blue. 

One spectacular year in the 1990s, the Myrionecta bloom in local waters coincided with a dinoflagellate bloom, of Ceratium species. Dinoflagellates are often golden to warm red in color. That year, the dinoflagellates were golden orange. The combination of strong red-purple and gold  from billions of organisms of different colors in different parts of the river gave the water a very weird red-orange color combination. Ceratium organisms gathered in warmer shallow water, and Myrionecta tended to the deeper waters of the main channels, so the colors were blended together in some areas, and distinctly separate in others. Both blooms stopped as the storm season got underway that fall.  

This species prefers lower salinity water, and warm weather. August and September are the usual months to see the long red to purple streaks. Cool storms disrupt the bloom in fall, and by mid to late October, unless weather has been unusually calm, it’s gone again for the year. Individual cells turn up in plankton samples throughout the year, however, it's only late summer to early fall when their numbers rise into the billions and become visible to us. 

Myrionecta has been seen and collected in the surf zone along the north coast beaches in Oregon and south coast beaches in Washington, on each side of the river. It’s also been found in Willapa Bay, and the Willapa and Palix Rivers. 


In Alaska, residents say that when the fireweed blooms, summer is almost over. Here, when we see the red tide of Myrionecta rubra on the Columbia from the Astoria-Megler Bridge, we know fall is going to arrive in a few weeks. 

Monday, July 11, 2016

Another D*** Yellow Composite

July 11, 2016

There's a joke in wildflower classes that the first yellow-flowered daisy species students learn is ADYC, short for another D*** Yellow Composite. This has some truth to it, because superficially many species look similar in flower. The goal of wildflower classes is to look closer, to see the details that make one species distinct from all others, even DYCs. 

Today I present a primer on four introduced species, Crepis capillaris, Hypochaeris radicata, Leontodon saxatilis and Taraxacum officinale.

All are tap-rooted biennial to perennial species in the Asteraceae, or composites, which have compound flower heads of dozens to hundreds of tiny yellow flowers. All are common on open ground, including pastures, lawns, roadsides, and in the dunes, back from the open west edge. So how to tell them apart? Look closely at the backs of each flower, and seed head, at the leaves, and the differences will appear. 

Crepis capillaris, smooth hawkweed

   



Smooth hawkweed has many small flowers on a tall stem, and like common dandelion has smooth leaves with sharp points and deep scallops. Flower heads are yellow underneath as well as on top. The seed heads are also small, and the seeds are slightly curved and strongly ribbed. There is no long stem between seed and the bristles that carry it aloft; instead the lofting plumes attach directly to the seed at one end.



Hypochaeris radicata, hairy cat's-ear






 


Hairy cat's-ear has hairy leaves in large rosettes, forming large succulent mounds [excellent for sheltering baby slugs and snails]. There are 1 to several large yellow flowers per stem. The backs of the outer flowers are light purplish/brown. Seed heads are large, with a long stem between  seed and lofting bristles. 



Leontodon saxatilis, hairy hawkbit




















Hairy hawkbit has low rosettes of hairy leaves, slightly scalloped, making small mounds in a lawn. Flowers are single, one per stem, and light purple on the underside of the head. Seed heads are small, and seeds are slim, slightly curved, with bristles attaching to one end without a stem. 


Taraxacum officinale, common dandelion




 

Dandelions form rosettes of leaves, with thin leaves, deeply scalloped, single flowers per stem, and with green bracts under the outer flowers that persist on the seed head. There are two sets of green bracts, one large set under the flower, and a second smaller set that points down towards the ground. Even on seed heads, these 2 sets persist. There are long stems between seed and lofting filaments. 

*****

Mid to late summer is the time to look at all DYCs, because leaves, flowers, seed heads and ripe seeds are all present. We have other species here, both native and introduced, but these are the common species in most yards, called by most people "dandelions". 

Monday, June 27, 2016

Saltwater and Spruce Trees

June 17, 2016

A rumor came my way last week that is so off base I am writing about it today. 


On Highway 101 in south Pacific County, there is a straight stretch of road from Bear River to Greenhead Slough. Last year, a bridge replaced a very undersized culvert near the north end of the straights. That summer, trees began dying along the highway, upriver from the new bridge. 

June 2016:  Sitka spruce and Pacific crabapple trees are dead and dying along the road south of the new bridge; which is immediately to the left of this image. The road in the foreground is Highway 101; Bear River is to the right, looking south east along the highway.  

The rumor is that this area was sprayed with herbicide as part of industrial forest management. 

Marshes are not industrial forests; this low forest and marsh area is part of the Willapa National Wildlife Refuge. Corporate timber growers do not waste money spraying non-logging areas, especially on land they do not own. 

So if this area wasn't sprayed, what happened?

When the drainage was opened with a bridge in 2015, the upper reaches of the marsh east of the highway returned to the old hydrology pattern––fully tidal––which means that tide waters are higher at high tide than they have been for six or seven decades. Water levels are also lower at low tide. 

Fish, including salmon, can now easily enter the ditch along the highway, and from there, five or six streams that drain from the hills to the east. Floods no longer surge up to the road edge on the east side, held back by a small culvert and tide gate. Given that we have experienced more flash floods in recent years than in decades before, this is good. 

Trees, especially conifers, that grew behind the tide gate were abruptly exposed to saltwater on very high tides, and their roots began to die as soon as this salt exposure started. Sitka spruce, Picea sitchensis, is the dominant large conifer tree along the edge of Willapa Bay. A small hardwood tree, Pacific crabapple, Malus fusca, is also common in the marsh [the small gray bubbles in the background of the photo are crabapples].  Both trees grow on slightly higher ground than the main salt marsh level. 

Summer 2016 is the second growing season with full tidal cycling, and the trees are now dead or dying along almost a mile of road. A few spruces are still green; these are trees that are slightly higher in growing position than those that are dead. 

Both species tolerate some salt exposure. The new hydrology brought too much salt to their roots, however. Six months of dry weather last summer probably accelerated the impact. The result was that several dozen conifers and even more crabapples abruptly died. 

If you look east across the marsh into the hills, you will see that trees on the slopes and at the base or toe of slope above the marsh are alive, still green and in active growth. Only the trees that were too low have died. 

There is another place to see the same sort of response to a change in hydrology, also on Highway 101 in south Pacific County, on Chinook River. Here the tide gate is closed only on extreme high tides, and the rest of the time, the gates are open so that fish can move more easily in and out of the river. 

Just east of the highway, there was a stand of alder; now it's a stand of snags with salt marsh sedges and other species covering the ground. This transition took just a few years with new gate management methods. The spruces behind the alders were high enough in position to keep living.  

Better management of water through changes in tide gates, or replacing gates with bridges means that fish can access their natal streams more easily. It also means that during periods of high rainfall more water drains off more quickly. These are good outcomes. But for trees that began growing in locations that were not quite high enough, it means that they can no longer live in those locations, and it's that abrupt change from alive to dead that catches our eyes as we drive Highway 101.