Category Archives: Marine Biology

Night Paddling Ireland’s Rare Saltwater Lake, Lough Hyne, June 2019

June 21st, the summer solstice. Ten thirty. Night descended like an elaborate dimmer on an antique lamp. Dark, looming ledges leaned over the rare, saltwater lake. My eyes adjusted to barely imperceptible shifts of light as I paddled a two-man kayak through ever-darkening water. Warm, syrupy salted air filled my lungs and swirled around the elderberry cough drop I sucked to keep from coughing. Pneumonia gripped my back and I sat erect, strapped and locked into the skirt of my waterproof waders. Still, water drizzled down my back and I tried to ignore it. I wished more than anything I wore my swimsuit, instead of this neoprene—and that I was swimming. But then I whispered to the lake—I am grateful. This is beautiful. I’m alive. I am so lucky.

Bats swooped. Grey herons shrieked and cackled. Their loud, ear-piercing night calls made my paddling partner, an accountant from Chicago, ask nervous questions from the stern of our kayak. She worried. “Will we get pulled out to sea?” I assured her, “the passageway is way over there. We’re not going anywhere near it, and besides, it’s so narrow, it’s only big enough for a seal to swim through.” “Or a kayak,” she quipped. “Don’t worry,” I said, a bit disappointedly, “we’re not going out to sea.” And we weren’t going out to sea. We paddled away from the direction of the Rapids, a narrow opening in the lake that bordered Barloge Creek, which then broadened into a harbor out onto the Wild Atlantic.

Lough Hyne, Co. Cork, Ireland. Stetson photo

Several months in advance, I’d planned my trip to Ireland with the intention of paddling Lough Hyne, located almost five kilometers from Skibbereen on the southwest coast of Ireland. I’d arrived by electric car, having driven from the small village of Durrus, which should have been a 45-minute drive–according to Google maps, GPS and my guidebooks of the Wild Atlantic Way. By that night, I’d already been driving in southwest Ireland for five days, and had gained the confidence to pass a tractor, drive 80 kilometers per hour (barely 50mph) on curvy back roads between Durrus and Skibbereen—where gut instinct battled confusing GPS commands, and swear in Irish. I’d converted.

When I first arrived at the lake’s launch and parking area, my jaw dropped. A deep azure uninterruptible sky splashed like a reflection over the pretty blue lake. It’s roughly sixty hectares in area, or 150 acres, but splendidly rich in surprises, hidden coves and rock caves, strange myths and an island of castle ruins, an ancient home to a shameful king, an Irish version of the Emperor’s New Clothes. A group assembled beside the launch, practiced paddling in the air, introducing ourselves. One woman and her granddaughter traveled from Perle, Australia to experience night-time paddling on Lough Hyne, an item on her “bucket list,” she told me. As we struggled to climb into waterproof gear—several layers of thick neoprene overalls and hip-waders—that doubled as a skirt attached to the kayak—and strapped life vests over large busts—the four of us women lamented how unnecessary all of this waterproof gear felt.  Just minutes before we selected our boats, two local swimming clubs waded into the lake. The Lough Hyne Lappers wore wetsuits. The other group—the one I wanted to join—wore togs, what Americans call swimsuits. These women called themselves the Dippers, an inside joke. They swam in their togs for a good while—long enough for our kayaking guides to run through the safety protocols, and to assist paddlers with their gear. We resembled trainees in Willie the Whale costumes at an amusement park. I’m glad that no one was allowed to take pictures—we were all required to hand over cameras, cell phones, car keys and watches to put in a safety box until after we returned from paddling. We launched the kayaks around ten o’clock at night and returned well after midnight. (We were not allowed to take our cameras or phones while kayaking.)

Swimmers and paddlers at Lough Hyne, Co. Cork, Ireland in June 2019. Stetson photo

As we paddled away from the launch in the remaining daylight, I noticed a dreamy rose-colored house that sat nestled in the trees along the shore. Once home to a lord, the 1830 Regency-style Lough Ine House rents for €500 a night in June, complete with a private beach and a small cottage on a 15-acre estate. I spotted an overturned canoe resting beside a little dock but I didn’t see anyone. Immediately, I imagined characters from Daphne du Maurier’s Rebecca: a shy heroine bending to cut roses in the patio garden for a vase in the library; a brooding anti-hero sulking irresistibly in one of the upstairs windows overlooking the lake and the sea beyond. This was one of the many moments I told myself, “One day, I shall live here, and write a book.” (Or, write something, I thought!)

Stetson photo

In pitch black darkness, we could only see the red glowing flashing light on the back of the guides’ headlamps, and the fireworks of bioluminescence streamed like comets from a dozen boats. Like silent firecrackers exploding underwater, microscopic organisms called dinoflagellates, a group of microalgae that act like animals, swim vertically in the water column to feed. Dinoflagellates feed at night. Pulling my paddle through invisible water, I excited these strange little plant creatures. Minature Swampthings. I remembered collecting some of the same dinoflagellates at Kettle Cove State Park in southern Maine. After collecting specimens in a “plankton tow” with a marine net, I inspected a few of the same species abundant in Casco Bay, Maine that marine scientists study in Lough Hyne. Ceratium furca and Ceratium fusus were two such armored species, both characterized by long horn-like bodies—which fascinated my classmates under a microscope—but truly awed and inspired everyone paddling in Lough Hyne with red and blue flashes of bioluminescence. If you’d like to know more about microalgae, see my previous post.

Lough Hyne, in the early evening before dark. Stetson photo

Since the lake is tidally-fed, the Lough is entirely populated by marine species. It was Europe’s first marine reserve. Now it’s a destination for night-time kayakers, marine biologists who study abundant communities of microalgae, the fabled (and very real) five-foot-long lobsters and giant sea stars, and the blue carbon potential of an eelgrass bed in the creek. One of the kayaking guides, Ryan, told me about his master’s degree project on the local eelgrass, and we chatted about the latest carbon sequestration science on salt marshes and eelgrass—called “blue carbon.” Eelgrass is a submerged aquatic flowering plant, a true sea grass with inconspicuous flowers. It spends most of its life submerged, swaying in the ebb and flow of tidal inlets and estuaries in the intertidal zone; its meadows, or beds, capture carbon, and hold onto it, just as salt marshes do. They are quiet climate avengers, in a way.

As we paddled around the perimeter of the lake, circumnavigating the island of castle ruins, we explored rock caves and listened to one of the guides, a graduate student at UCC, tell us about the holy well, Tobarín Súl, situated just beyond our reach. The Lough Hyne holy well draws believers who leave behind their white canes and old glasses—since they’d no longer need them after “doing the rounds,” walking twelve times clockwise around the holy well. Each of the holy wells in Ireland is known for curing (or causing) health issues related to a specific body part. If a believer wanted to curse another person, she or he need only to “do the rounds” counter-clockwise twelve times to cause the ailment, and in the case of the Lough Hyne holy well, might inflict conjunctivitis or blindness, or stink eye.

Once back at the launch, our paddling party stripped out of the neoprene gear as a bearded man announced, “It’s officially my birthday. I’m seventy! Which of you ladies wants to go skinny dipping?” A few laughed. I got scientific. “That would be quite psychedelic! Our bodies would sparkle and glow with the bioluminescence of dinoflagellates! You know—“ No one was interested in the science. Someone liked the idea of glowing bodies and “seeing sparks” but I bantered on, a little ditzy from cold and flu medicine, and antibiotics: “Well, they do reproduce sexually in adverse conditions—that’s why they’re shooting off the light. We interrupted. They were feeding—and…” Only the accountant from Chicago remarked, “Wow, you’re so passionate about this nature-y stuff.” We helped each other out of the gear while the bearded birthday man watched, a little more than disappointed no one was going to go skinny-dipping. I said, “This explains a lot…” and he said, “The Irish invented voyeurism!”

The cool, dark drive back to Durrus on curvy back roads both exhilarated my nerves and tested my courage. No street lights aided; only my headlights and the GPS—and my inner compass guided my way. I had to turn around twice—once when I came to a four-way intersection with no visible signage, and a second time as I pulled erroneously into the driveway for the Maulinward Burial Ground. I second-guessed myself there—and thought, “Is this a sign—a spiritual sign? Like a dark night of the soul sign?” I turned around, and eventually crept silently in my electric rental car down a dirt road.

Durrus, Co. Cork. Stetson photo

The moment I smelled horses—that wholesome meadow-sweet animal scent, I knew I’d come home. On my first night, I’d walked down that dirt road and came nose-to-nose with a mare on the other side of a fence lined with hot pink foxglove. She had a foal just old enough to walk but young enough that it hid behind its mother’s hind legs, staring at me. I talked to the mare in clicks and cries of joy, and sighs—like we were old friends, exchanging gossip from the field. On my last night in Durrus, there was a storm—a wild, windy torrential rain. Tree branches, leaves and flower blossoms danced chaotically through the garden like creatures out of Oz, or fairy land. I spent that last Sunday inside, watching the storm, sipping lemon tea and listening to the sounds of the Four Mile Water falls rushing over the road.

Four Mile Waters in Durrus, Co. Cork, Ireland. Stetson photo

If you’re interested in sea kayaking in this part of Co. Cork, Ireland, and want to paddle at night on Lough Hyne like I did, you can find out how to do this with Atlantic Sea Kayaking.

For the Love of Eelgrass

Stetson watercolor. I have a jar of eelgrass on my patio table that helped me create this illustration.


Last summer, we were still in the midst of a pandemic, and I was overcome by grief over losing my dog, Sophie-Bea. I am still grieving, but I have been busy in graduate school, studying ecopoetics and marine biology at University of Maine–as a graduate student in the Interdisciplinary PhD program. While I was in the throes of grief last summer, I made my way to the midcoast Maine region, to my mother’s house near the river, and swam as often as I could. The river soaked up my tears, and I felt comforted by that. Swimming through eelgrass has always rejuvenated my spirits. Is it because I came of age in an eelgrass meadow, kicking against the current in the cold, cold waters of the Gulf of Maine? Eelgrass beds provide critical nursery habitat for young marine creatures, baby fish, juvenile lobsters, winter flounder, as well as horseshoe crabs, and other estuarine life in the Gulf of Maine. During the full moon in Pisces, I collected some seawater from the river, as well as a jar-full of eelgrass, so that I could study it, even after I returned to my home in the town known for the “land-locked salmon” near Sebago Lake. I’ve had a ritual of collecting “moon water” (on the full moon in Pisces every year) for over 25 years, but I’m also so fond of eelgrass. I did not pick (or harvest) the eelgrass. It was floating in the river, and snagged in some rockweed.

My “Pisces Full Moon” saltwater, with rockweed. Stetson photo
Eelgrass in a jar on the left; seawater on the right.
Stetson photo

A rooted, submerged aquatic flowering plant, Zostera marina, commonly known as eelgrass, is a pantemperate seagrass that grows globally along coasts and prefers sandy to muddy sediment in the lower intertidal zone of estuarine and marine environments. By “pantemperate,” I refer to the wide range of temperature (0-30°C) and salinity levels (10-30 ppt) that eelgrass tolerates, taking root in sandy bottoms as well as muddy areas, and it even grows in tide pools. (Tyrrell, 2005)[1] Eelgrass beds, or meadows, make ideal nurseries and Essential Fish Habitat (EFH) for invertebrates, young fish, and other marine life. (Lazzari, 2015) Eelgrass meadows provide EFH as nursery areas for young fish and shellfish species as well as providing refuge from predators, especially those which rely on visual-predation strategies (they see prey), as smaller fish and invertebrates can hide in dense meadows.[2] Marine scientists study Zostera marina for another reason: like other seagrass meadows, eelgrass beds sequester carbon, and that carbon sequestration potential is known as “blue carbon,” with implications for climate change, carbon budgets, and climate mitigation schemes in coastal communities. There are over fifty species of seagrasses worldwide; of those, Zostera marina is the most widespread seagrass species in the temperate northern hemisphere in the Pacific and Atlantic Oceans.[3] (Olsen, Rouze, et al. 2016) Between the ecosystem services that eelgrass meadows provide, including EFH and nutrient retention, and carbon sequestration and erosion control, seagrass meadows are still ranked as “among the most threatened on Earth.” (Waycott, et al. 2009; Olsen, et al. 2016)

In my exploration of eelgrass as a marine biology student, I have been learning more about its fascinating biology, its ecological relationships within estuarine and coastal ecosystems, and how eelgrass is also used in sustainable living design. As a mixed media artist, I have also been returning to a love for making “seaweed art,” something that I used to do (in the 1990s, early 2000s, and in 2018), and marine biology-themed illustrations of eelgrass and some of the marine life that depends on seagrass meadows for survival. Sea turtles depend on seagrasses, for example, and I made this watercolor of a Green sea turtle (Chelonia mydas) foraging in Turtle grass (Thalassia testudinum):

Stetson watercolor. Mixed media (mostly watercolor).

Zostera marina L. as ‘Essential Fish Habitat’ (EFH) for Young Fish            

A marine resource scientist and ichthyologist with the Maine Department of Marine Resources (DMR), Mark Lazzari conducted a study on “Eelgrass (Zostera marina) as ‘Essential Fish Habitat’ for Young-of-the-Year winter flounder (Pseudopleuronectes americanus) in Maine estuaries.” (Lazzari, 2015) Lazzari defined “Essential Fish Habitat” as “the waters and substrate necessary to fish for spawning, breeding, feeding, and growth to maturity.” (Lazzari, 2015) Eelgrass meadows are considered “nursery areas” and provide a refuge to certain species from predators. (Lazzari, 2015) Comparing study data from 2003-2004, Lazzari argues that knowledge of eelgrass meadows is important because “shallow inshore habitats act as nurseries and feeding grounds, are environmentally variable, and subject to anthropogenic impact.” In the case of winter flounder, the “year-of-the-young” fish aged 0- x months, are “estuarine-dependent” in their early life stages. (Lazzari, 2015) “Beds of eelgrass, Zostera marina, represent a valuable habitat for shallow-water fishes including winter flounder and decapods.” (Lazzari, 2015) Moreover, the value of eelgrass as critical fish habitat as eelgrass is a “good predictor” of “winter flounder abundance” in Mid-Atlantic eelgrass meadows, and “small, dense patches of eelgrass may reach a carrying capacity, causing more extensive use of other habitats. (Lazzari, 2015) This leads to implications for future possible research on faunal density and “carrying capacity” in eelgrass meadows in Maine. Midcoast, Maine estuaries are often selected as study sites because of the coastal morphology and deep, narrow, strike-aligned estuaries. (Lazzari, 2015) Lazzari’s work has inspired my curiosity to research eelgrass in midcoast Maine estuaries, especially in the context of EFH for species like winter flounder. While I was reading Lazzari’s studies, and the state’s Wildlife Action Plan for 2015-2025, I felt inspired to make this quick sketch in my art journal.

Winter flounder in an eelgrass meadow. Stetson watercolor, mixed media in my art journal.

Phylogeny of Eelgrass (Zostera marina)

Based on the entry in the AlgaeBase, Carl Linnaeus included classification of Zostera marina Linnaeus (often written as Zostera marina L.)  in his 1753 publication, Species Plantarum (May 1753). The taxonomic classification is listed here, below (credit to AlgaeBase and Carl Linnaeus):

Empire/Domain: Eukaryota
      Kingdom Plantae
            Phylum Tracheophyta
                 Subphylum Euphyllophytina
                      Infraphylum Spermatophytae
                             Superclass Angiospermae
                                     Class Monocots
                                           Subclass Alismatidae
                                                 Order Alismatales
                                                        Family Zosteraceae
                                                              Genus Zostera
                                                                    Species marina

Eelgrass I found in a tidal pool on the coast of St. Andrews, Scotland, 2018
Stetson photo

In recent years, phycologists have traced the phylogeny of Zostera marina in relation to other seagrasses and the “Tree of Life” and discovered that the genome shows indications that it adapted to living in a marine environment, and this is a special achievement for a flowering plant—an angiosperm. In their study, Dr. Jeanine Olsen, who specializes in marine benthic ecology, and colleagues, found that as the seagrasses evolved, through convergent and reversal evolution, Zostera marina and another grass, a freshwater species called freshwater duckweek (Spirodela polyrhiza) must have “diverged between 135 and 107 million years ago (Mya) and phylogenomic dating of the Z. marina suggests WGS (Whole genome shotgun approach) that it occurred 72-64 Mya.” (Olsen, Rouze, et al. 2016) Olsen and her team mapped the signatures of gene families onto a phylogenetic tree showing where Zostera marina enters the picture. To put this into context with related seagrasses, one of the oldest known plants is a clone of a Mediterranean seagrass, Posidonia oceanica commonly known as Neptune grass, which is about 200,000 years old, dating back to the Ice Age of the late Pleistocene.[1] (See Smithsonian)

Based on the genomic sequencing research that Dr. Olsen and her colleagues published in 2016, however, the first of its kind in sequencing the genomic phylogeny of any seagrass, their findings suggest that perhaps Zostera marina L. is one of the oldest seagrasses. (This remains an uncertainty, however, as there is an opportunity for genomic sequencing of other seagrasses for comparison.) Among their findings, Zostera marina “lost its ultraviolet resistance genes” adapting it to live comfortably in a marine environment, where it receives fluctuating and “shifted spectral composition,” unlike terrestrial flowering plants. (Olsen, Rouze, et al. 2016) Zostera marina also displays signatures of salt-tolerant genes, and “re-evolved new combinations of structural traits related to the cell wall,” (Olsen, Rouze, et al. 2016) creating a “cell wall matrix” that includes zosterin and “macroalgal-like sulfated polysaccharides.” (Olsen, et al. 2016) This is a key adaptation for a terrestrial plant. Zostera marina also “possesses an unusual complement of metallothioneins,” (Olsen, et al. 2016) chelators, or compounds that form complexes with metal ions, aid the plant in stress resistance. I find this so fascinating!! References are below.

While I am completing my graduate coursework, I will do my best to add fresh content to this blog. I am sorry I have been away from blogging–which I love to do–but it’s really been due to a combination of mourning my dog, and my focus on grad school.


[1] Details on Neptune grass found on the Smithsonian webpage for Seagrasses: https://ocean.si.edu/ocean-life/plants-algae/seagrass-and-seagrass-beds


[1] Tyrrell, Megan C. NOAA Coastal Services Center Fellow. “Gulf of Maine Marine Habitat Primer.” Ed. Peter H. Taylor. Gulf of Maine Council on the Marine Environment. 2005 www.gulfofmaine.org

[2] Lazzari, Mark A. “Eelgrass, Zostera marina, as essential fish habitat for young-of-the-year winter flounder, Pseudopleuronectes americanus (Walbaum, 1792) in Maine estuaries.” Journal of Applied Ichthyology. Vol. 31. 2015. Pg. 459-465

[3] Olsen, Jeanine L., Pierre Rouze, et al. “The genome of the seagrass Zostera marina reveals angiosperm adaptation to the sea.” NATURE. Vol. 530. February 18, 2016. Pg. 331-347