Nightpooling

Hawaii has a relatively small tide range compared to the west coast of the US mainland. For example, the spring tide range is less than a meter at Hanalei Bay on the north shore of Kauai. That is much smaller than I am accustomed to in California or the Pacific Northwest where daily fluctuations of the tide can be several meters. However, even with a reduced range, low tide in Hawaii can help reveal interesting intertidal biota on both more wave swept and calmer shores.

Anahola Bay, Kauai with the moon over the horizon.

At the southeast corner of Anahola Bay on the northeast coastline of Kauai, there was significant shelter from the wind that blew in heavy tropical air over most of this coastal enclave during our visit last November. I was exploring the rocks in this calm near sunset and noticed that I had conveniently stumbled upon low tide. As the sun would soon set, I returned to the beach cabin for lights before heading back out to the intertidal. Thus was born my temporary rediscovery of night tidepooling, which I had done only intermittently over the years.

With low tides creeping later with each passing day, I returned to the same corner of Anahola Bay the next evening with the crew. We ambled along the edge of a relatively narrow intertidal of basalt rock inshore of a wide flat reef that was still under some water. Photography in the dark was a new challenge, but not impossible. I held the waterproof camera in one hand, and worked with a headlamp in the other to illuminate organisms from the side where the light would not reflect off the water surface right into the camera.

Our headlamps and lights had a limited reach in the night sky, so my observing eye necessarily focused on organisms immediately in sight. Night brought a sense of being enveloped, like thick coastal fog, where everything beyond the short distance of what was visible would remain a mystery.

Spiny, striped sea cucumber.

Invertebrates and algae on the dark boulders were easiest to observe. Crabs, and large spiny sea cucumbers (echinoderms of the Class Holothuroidea) were common here. I found creeping mats of the green alga Caulerpa and red seaweeds. Much easier to observe during the day, I did see some fish as well. A few brightly colored species swam in the shallows, and in somewhat deeper water offshore, where little light could reach, I observed a few elusive dark, elongated forms. These lurkers may have been large eels.

The lights illuminated tiny dots among the rocks too – the eyes of little shrimp common in the intertidal, shining electric specks.

Night pooling along much of the California or Oregon coastline would probably be rather hazardous at night, especially where large waves frequently crash into the shoreline. But the calm tropics seem particularly well suited for this adventure, and I’ll have to remember this on my next trip to Hawaii!

Napali coast

The Kalalau trail traverses the famous northwestern coast of Kaua’i in what I presume is one of the most scenic hiking trails anywhere in the United States. The first two miles are open to day hikers and a backpacking permit is required to venture further. Because of recent flooding however, the whole trail was closed during our visit to the island last fall.

That unfortunate news left just a few other options to see this dramatic coastline. We availed ourselves of two of these: ridge-top hiking trails accessible from Kokee State Park, and offshore views of the coast from the sea on a chartered boat tour.

The Napali Coast reminds me of Big Sur in central California where in both cases steep coastal mountains abruptly meet the gorgeous Pacific Ocean. The mountains of the Napali coast are more deeply sculpted and luminous than Big Sur, but both are examples of breathtaking coastal wilderness.

Napali coast cliffs from offshore.

Spinner dolphins astride the boat near the Napali coast.

Our first views of this area were by charter boat that left early in the morning from the port on the southern side of the island. A very long sandy beach in southwestern Kauai suddenly gives way to the deeply incised ridges and valleys that rise to several thousand feet above the Pacific. A large pod of spinner dolphins milled around the tour boat, swimming near the bow and leaping out of the water.

We pulled closer to shore at several locations along the Napali coast and anchored at one for a chance to snorkel offshore. The site was in about 10 m of water though I swam in towards shore with my two older kids to a shallower area. Water clarity was decent, though I enjoy swimming in pretty shallow areas when possible because they offer more opportunity to see the small biota on the reef. I was about the last person to hop back on the boat, hoping to spend as much time as possible in the water.

Fishes at our snorkeling spot along the Napali coast.

Our other views of the Napali coast were from above. One must actually circle all around the island from the Kalalau trail, head up the steep road that traverses the west side of Waimea Canyon, and access one of the trails that descends down the mountain ridges from the state parks.

View from the Awaawapuhi trail.

We descended down onto one of the ridges via the Awaawapuhi trail. The coast wasn’t visible at all for the first two miles or so but then the trail ran along a narrow saddle with ravines to the north and south. After another mile and a half it ended, and opened up to a spectacular view of the Pacific from a high point with views to the north and south. A rainbow graced the coastline to the north for a few minutes.

I actually ended up taking a second excursion to the Napali Coast offered by a different tour company. My main interest in this second tour was the destination of Lehua Rock off the north shore of Nihau where the group would be allowed to snorkel. However, before we even departed we were told this might not be possible due to rough seas, and a short time later on the water, that disappointing news was confirmed. We viewed the Napali coast again, but did not even snorkel there, rather stopping at a small cove near the harbor. I now have two excellent excuses to visit Kaua’i again – the Kalalau trail and Lehua Rock!

Small coastal waterfall.

Spinner dolphins.

Rainbow at the end of the Awaawapuhi trail.

Queen Emma's Bath, Kaua'i

(I am still catching up on blog posts from late 2018 and early 2019…the next couple pertain to a trip to Kaua’i in November 2018.)

Fishes in Queen Emma's Bath.

A few years ago, I went with the family to the Big Island, my first visit to Hawaii in many years. Over the course of a week and a half we circumnavigated the island, snorkeling, hiking, and exploring. Three years later during the same fall season, we decided to do a similar trip to the Garden Island, which like the Big Island in 2015, was a new destination for all of us.

One location on the north shore of Kaua’i that piqued my interest before arriving was Queen Emma’s Bath in the Princeville area. This landmark is a large pool set within black basalt at the end of a short trail on a section of coastline exposed to the north Pacific. The first time visited, we were quickly in the thick of a very muddy trail that descends from the parking area to the shore. I was completely unprepared for this sort of hiking, carrying an unwieldy bag and trying to walk on slippery mud in sandals. Once we made it down the slope of red mud and out onto the ledges of basalt, a gorgeous view of the northern shore of the island opened up with the coastlines of Hanalei and Napali in view to the west.

Large swells were crashing on the rocks and made the pool at least a little unsafe for swimming so we just explored the higher rocks along the shore. Water running off the coastal slope created a sort wetland where sedges and other plants grew where sediment collected in the volcanic rock, black tadpoles rested atop the orange silt, and a few light blue damselflies danced about.

Turtles just offshore of Princeville, Kaua'i.

I returned alone to Queen Emma’s two days later better prepared for the trail with sturdier footware and a backpack. However, it had probably had become even worse by this point. Down at the coast the swells had decreased markedly allowing safer access to the intertidal and snorkeling pools.

At the bottom of the trail I first turned east, away from Queen Emma’s Bath, and explored a large shallow pool that I had to myself for the next hour and a half. A ledge of higher basalt protected the pool from the open ocean where waves still hit, but with much less force than a few days before.

Green sea turtles were hanging out offshore of the pool, at times coming right up next to the edge of the basalt ledge. I counted at least five turtles, in a range of sizes. With my phone in hand to photograph them, suddenly a spotted octopus scampered onto the exposed rocks right in front of me! Perhaps its sudden appearance was due to escaping a predator, or it decided to abandon some hiding place because of the turtles swimming nearby. Since my phone was in hand and ready to go, I had the chance to capture a few photographs during the few seconds this normally shy creature was out in the open.

A surprise visit from an octopus!

Near the mouth of the large pool where it connected with the ocean, there were excellent populations of macroalgae. Tufts of bright green Chaetomorpha with individual cells evident to the naked eye were attached to the exposed rocks, and there were carpets of the red alga Pterocladia with its orderly pinnate branching. Other algae thrived submerged in thes shallow pool including the tropical green seaweeds Caulerpa, Halimeda, and Bryposis. I initially mistook one lightly calcified green seaweed, Neomeris, for a benthic invertebrate. There were several species of fish inhabiting the pool, most skittish.

After my more solitary exploration of the first pool, I walked over to Queen Emma’s bath where there was a rather large crowd of people and many were using the pool not for snorkeling, but to jump off the basalt rocks. I snorkeled briefly in the pool anyway, but it didn’t have the best water quality. I then found two smaller undisturbed pools further to the west in which to snorkel. The second of these two smaller pools had lush cover of Sargassum seaweeds and several species of soft corals/ zooanthids. The pools were just large enough for a snorkeler or two and just deep enough to make a bit of a dive under the surface.

One of my small snorkeling pools.

After briefly snorkeling, I explored the exposed intertidal too in this area. It did not disappoint either. There were helmet urchins, Colobocentrotus atratus, pressed to the more wave swept rocks, and underneath a ledge, a small population of tiny red sea grapes, which turned out to be a small species of Botryocladia, one of my favorite genera of red algae!

Botryocladia skotsbergii. 

Blue soft coral Sarcothelia and zoanthid Protopalythoa.

A blenny at the bottom of Queen Emma's Bath.

Cascade Canyon

4 Sept 2018. During my week-long trip to Wyoming last summer, I actually spent more time in Grand Teton National Park than Yellowstone. Prior to visiting, I had heard many positive things about Grant Teton, Yellowstone’s companion to the south. It is smaller, and less crowded than the more iconic park, but certainly had its share of visitors over Labor Day weekend.

Glaciers on the Teton Range.

The Park encompasses a small granitic mountain range with high vertical relief, and is part of the greater Yellowstone ecosystem. The short range runs from south to north and is adjacent to a wide flat valley situated to the east. The dramatic vertical difference between the valley (which lies at about 7000 ft) and the higher of the Teton peaks (which rise to about 14,000 ft) owes it origin to north-south fault activity. Repeated occurrences of large earthquakes led to the uplift of a large block of granite that became the Teton Range.

Deep valleys among the mountains offer some beautiful scenery and opportunity for exploration. Glacial activity has played at least some role in carving out this topography, and there are some small glaciers that are still visible on the eastern side of the range. Glaciers have also presumably contributed to the presence of many of the lakes at the base of the higher mountains. A range of small to large lakes occur at a modest elevation above the valley floor, their water corralled by sills of rock that I assume were pushed out by glacial activity when glaciers were much larger than they are today.

Just south of Grand Teton, there is a deep east-west running valley named Cascade Canyon. Starting near String Lake one morning in early September, MWS and I ventured into the canyon for a 17-20 mile hike that is probably the longest day hike I have ever done.

To ascend up into the canyon there is some elevation gain from String Lake, but once the valley begins to narrow the hike is relatively flat for several miles. The trail on the canyon floor runs along an alpine creek that fans out in some areas, supporting small alpine meadows of Carex sedges or other wetland plants. On the north side of the valley the vegetation becomes more sparse, grading into fields of granitic scree that then slope up even more abruptly into steep granitic walls.

The head of Cascade Canyon near Solitude Lake.

Cascade Canyon is not unlike Yosemite Valley in some days, though the latter has a wider flat valley and more impressive waterfalls. But both present an impressive geologic backdrop to wild nature. After several miles the trail bifurcated to the southwest and northwest and we continued in the latter direction into the head of the canyon. Gaining some additional elevation, trees became sparser and the intense afternoon sun had more of a presence. In the open areas there were more flowers including patches of pink Penstemom blooms. Finally the trail reached 9000 ft to take us to the eastern side of Solitude Lake.

Solitude Lake, Grand Teton National Park.

We returned back through Cascade Canyon because time didn’t really permit the additional climb up into Paintbrush Canyon which would have made a wonderful loop hike. I think I very briefly spotted a fox on our return in the canyon, and an osprey perched on a tall dead tree on the last stretch of our hike back to the trailhead.

Yellowstone's hydrothermals

I haven’t posted on this blog for a year (!) and I have a number of trips to get caught up on, starting with a fun week in Wyoming at Yellowstone and Grand Tetons during late summer of last year.

Hydrothermal feature called "The Fisher"
at the edge of Yellowstone Lake. 

Yellowstone is the oldest national park in the world and I’m sure visitors arrive in this northwest corner of Wyoming for many reasons. For me, the hydrothermal features were the most exciting part of my first visit to this iconic park last summer.

The park’s hydrothermal features owe their existence to a geologic hotspot that lies under Yellowstone. Like the hotspots under the Hawaiian Islands, Iceland, and other locations across the planet, geologic hotspots are places where hot magma rises closer to the Earth’s surface than elsewhere. The volcanic intrusions into the crust heat groundwater that then rises to the land surface in a variety of forms.

One geologic signature of hotspots that I find fascinating is the volcanic traces they leave over the surface of the Earth over geologic time. As the tectonic plates comprising the crust move over the mantle (in the case of Yellowstone it is movement of the North American Plate), the hotspot remains relatively fixed below the moving plates and a “trail” of volcanic activity develops at the land surface over millions of years. This phenomenon is very easily observed with the island chain of Hawaii that formed as the Pacific Plate has gradually moved to the northwest over the Hawaiian hotspot. The trail of evidence is the string of Hawaiian Islands and Emperor seamounts across the north Pacific. In the case of Yellowstone, the history of volcanic activity in that region over the last 15 million years or so can be seen as a series of surface volcanic features that stretches from northwest Wyomingto southeast Oregon.

The Yellowstone caldera and hydrothermal features inside the national park boundaries. Base map from NPS.

Yellowstone has experienced volcanic eruptions a few times over the last several million years, but today volcanic activity in the park is just manifest as earthquakes and numerous hydrothermal features. Four types of hydrothermal phenomena are present in the park. Each is fueled by heat from below the surface, but all involve water at different temperatures and in different quantities. Mud pots consist of little basins of heated mud of different consistencies at the ground surface. The mud inside the pot is formed when acids dissolve rocks. As steam rises through the mud, it gurgles or bubbles at the ground surface. In Yellowstone, I was able to view mud pots at the Artist’s mud pots area southeast of the Grand Canyon of the Yellowstone.

Four types of hydrothermal features at Yellowstone. By CNJ, after NPS display.

Mud plots.

Steam vents, or fumaroles, are a second type of hydrothermal feature. They release super heated water vapor through sub-surface vents. Fumaroles can be small, just quietly releasing a steady stream of steam.

A fumarole near the Artists' Paintpots.

Castle Geyser erupting.

Geysers have subsurface reservoirs that fill with heated water which is periodically ejected violently through an opening in the ground. Geysers can erupt with predictable periodicity or can have irregular timing. Yellowstone has the greatest concentration of geysers anywhere in the world. They are diverse in terms of eruption height and periodicity.

Old Faithful is among the class of regularly-erupting geysers, though it is not the tallest geyser in Yellowstone. It erupts approximately every 70 minutes, and I saw several eruptions during the few days we were in the park. For me, a more impressive geyser was Castle Geyser which only erupts about every 12 hours, but for an impressive 20-30 minutes at a time. I was fortunate to catch one of its episodes. Both Old Faithful and Castle Geyser are in the Upper Geyser Basin where there are a wide variety of interesting hydrothermal features.

Hot springs are the final type of hydrothermal feature. At hot springs, heated water forms pools at the ground surface. They can be rather quiescent or quite active like the Beach Spring which periodically alternates between calm conditions and a vigorous flush of bubbles that rise to the surface of the pool that lasts for a minute or two. 

Examples of hot springs in Biscuit Basin. Shell Spring (left) and Mustard Spring (right).

Hot springs are often lined with precipitated minerals and microbial assemblages, lending them a variety of colors. Blue hues are due to the reflection of other colors of light from the pool. Yellow colors are due to precipitated sulfur compounds. Photosynthetic cyanobacteria and other algae may lend green colors to the water. Bacterial mats at the edges of pools may be white, black, or reddish in color.

Many of the more attractive hot spring pools have two or three colors, but the chromatic display at Yellowstone is most brilliant at Grand Prismatic Spring. This spring is so large it looks like a small lake. Lying across a large flat muddy treeless expanse, steam billows from the superheated spring. When the steam clears, the Grand Prismatic has a beautiful spectrum of blue, green, yellow, and orange.

Grand Prismatic Spring as seen from a trail on the west side of the lake (left) and from up close (right).

Boardwalks facilitate an up-close view of the Grand Prismatic Spring from the east side at ground level, but a short trail that climbs a nearby hillside also leads to a view from above. Since we were backcountry camping for two nights in a forest just a short distance from Grand Prismatic Spring, we viewed it on several occasions and from different angles. In the cool mornings, the brilliant colors of the pool were generally obscured by a large cloud of steam perpetually rising from the spring. However, later in the day as air temperatures warmed, there was less steam to block the rainbow of colors.

Our last of several visits to Grand Prismatic also held an unusual surprise. While we were out on the farthest boardwalk near the edge of the spring, a bison crossed over the boardwalk behind us and into the mudflat to the east of the spring. It seemed unfazed by either the runoff from the spring (which I presume was rather warm), or the eager tourists eyeing the huge animal. In no rush, it seemed unsure of where to go next. We left before learning of the resolution of that event. Curiously I had earlier seen some animal prints in the soil close to the spring, and this surprise visit confirmed that bison do wander quite close to the hydrothermal features from time to time. 

Several examples of smaller springs in Upper Geyser Basin.

The Sapphire Pool in Biscuit Basin.