Friday, November 27, 2020

Botanist sows seeds of hope for plant conservation

        Thanks to lessons taught by her grandparents, Hope Leeson has always been drawn to plants. Some of her oldest memories are of trees, especially their different shapes.
        “I’ve always had this haunting sense of awareness of their forms,” said Leeson, a botanist, plant conservationist and botanical educator from South Kingstown who has walked much of Rhode Island in search of wetlands and rare plants. “I was always interested by their shapes, and by other little things on the ground that also attracted my attention, like the incredible structure of inch-high plants, sedges and flowers. There are so many different unbelievable shapes and forms that plants take.”
        Through more than 30 years of field experience, Leeson has developed an intimate knowledge of the Ocean State’s plant communities, and she has applied that knowledge to the protection of rare
Hope Leeson

species, the sustainable collection of plant seeds and the propagation of native plants for habitat restoration efforts. This work has given her unique insights into the changes taking place in the state’s natural areas and their impacts on native species.
        “There’s a lot happening in the ground that we don’t see,” she said. “And there’s certainly a lot happening because of deer eating much of what’s on the ground. Both of those are influencing the next generation of plant communities.”
        She notes that Rhode Island’s abundant deer primarily eat native plants, and they are so voracious that in many places few young plants have a chance to mature before they are eaten. And since deer avoid most invasive species, they are providing inroads for invasives to gain a foothold and spread widely.
        “I also worry that we’re not really aware of the far-reaching impact of earthworms,” Leeson said of the eight species found in southern New England, all of which originated in Europe or Asia. “The plant communities we have are adapted to a slow cycling of nutrients, and earthworms really speed that up. They also take a lot of leaf litter and pull it down into the soil, which changes the whole nutrient cycle, in terms of what’s available to plants.
        “So like deer, earthworms are opening up areas for non-native species to come in, because those non-natives come from areas that have earthworms and can take advantage of the opening that’s been created,” she added. “We can’t control where earthworms go, and they’re really changing the chemistry of the soil.”
           It’s not just soil chemistry that’s changing, Leeson said, but its soil temperature, too. And that may be affecting the mycorrhizal relationship between plants and fungi that enables plants to acquire nutrients through their roots. If that relationship is disrupted, many plant communities could be affected.
        “I just see so many places where it appears like the forest is dying, particularly areas that are more urban,” she said. “It smells different, it looks different, it’s a big change, and how that comes out in the end, we don’t know. It may all be fine, but on our human scale it seems like a loss of something – or maybe there will be a gain in another hundred years.”
        Leeson grew up in Providence and South Kingstown and earned an art degree at Brown University while also taking as many environmental courses as she could. After graduating, she spent a few years painting murals in people’s homes and creating decorative stenciling before taking jobs as a naturalist on Prudence Island and Goddard Park. That work led to jobs at the Rhode Island Department of Environmental Management and several environmental consulting firms.
        During one project, when Narragansett Electric Co. proposed a new power line corridor from East Greenwich to Burrillville, she walked the entire 44-mile route to locate any wetlands the route would cross.
        In more recent years, she consulted with the U.S. Fish and Wildlife Service, Save the Bay, The Nature Conservancy and other agencies to document rare plant communities and invasive species, and worked for more than 10 years as the botanist for the Rhode Island Natural History Survey.
        “Not only does Hope like to dig into the academic understanding of plants, she values the study of native plants because they connect to so many of her other interests and areas of accomplishment, including gastronomy, environmental conservation, art, gardening, teaching, and social networking,” said David Gregg, director of the Natural History Survey. “Her multi-level connection to native plants is readily apparent when you spend time with her, and is an important reason, besides the interest inherent in the projects themselves, that volunteers have been so attracted to working with her on the Survey's various Rhody Native activities.”
        Leeson’s establishment of the Rhody Native program to propagate up to 100 species of native plants for habitat restoration helped diversify habitats at wildlife refuges, salt marshes and private and public gardens. Eventually the program became so successful that she was receiving orders for thousands of plants, which was more than she could produce on her own. Without a commercial nursery willing to take it over, the program was discontinued.
        She is now completing a project to grow a rare wildflower called marsh pink, which is limited to two sites in Rhode Island and one in Connecticut. The plants she is growing will be used to bolster the Connecticut population following a restoration of the marsh.
        “We thought we might cross-pollinate plants from Connecticut with the Rhode Island populations to reduce the genetic bottleneck,” Leeson said. “But the Rhode Island populations are really small, and rabbits ate all of the seedpods before they were ripe, so I was unable to collect any seedpods. But the Connecticut seeds are sown, and they’re just resting for the winter.”
        When she’s not working, Leeson enjoys riding horses, which she says can “eat up a couple hours every other day.” But she’s never far from plants, whether in her garden or in nearby forests.
        “I’m drawn to places that are rocky, because that geography and geology is interesting to me,” she said. “And the coastal plain pond shores are endlessly fascinating to me because their geological life cycle is so interesting. When water levels are down, they have this explosion of plant species, many of them rare, and then there will be a decade when everything is underwater and you wait for ten years before they all reveal themselves again.”
        Leeson also enjoys foraging for food, including the tubers of evening primrose, which she roasts with carrots. She even occasionally cooks with invasive species – she makes pie from Japanese knotweed, pesto from garlic mustard, and enjoys the berries from autumn olive.
        As she approaches retirement age, Leeson is teaching botany and plant ecology at the Rhode Island School of Design. She is especially looking forward to teaching a five-week course in January called Winter Treewatching and a spring semester class on the Weeds of Providence.
        “That one will look at all of the areas around Providence that are vegetated by things that come in on their own,” she said. “It’s getting people to think about how we don’t even notice these things, and yet they’re performing pretty important functions, from carbon sequestration and air filtration to providing food for insects and birds.”
        Although she said that teaching online during the pandemic has been “weird,” she has been pleased to see so many people walking at Rhode Island’s parks and nature preserves.
        “It’s really helping people to slow down and look around them more, at least I hope it is,” she said. “They seem to be noticing things they never noticed before, and I think that’s a really good thing.
        “We’ve gotten so distanced from the natural world around us that there’s not an impetus to steward it or take care of it,” she said. “There’s a sense that it will always be there and it doesn’t really matter, but it’s what sustains us all. We won’t exist without it. So by noticing it, I hope people will become better stewards.”

        This article first appeared on EcoRI.org on November 27, 2020. 

Thursday, November 19, 2020

Saving the planet, one turtle at a time

        Callie Veelenturf was nearing the end of a five-month sea turtle research project in Panama when the nation’s borders were closed due to the pandemic, forcing her to remain in the country for three months longer than planned. She had just completed her first project as a National Geographic Explorer, documenting nests of endangered sea turtles, investigating human interactions with the turtles, and educating residents about the threats turtles face.
        The founder of The Leatherback Project, a sea turtle conservation organization, Veelenturf spent her unexpected additional time in Panama launching an international campaign for a universal
Callie Veelenturf excavates a leatherback turtle nest.

declaration of the rights of nature, a concept similar to human rights but which states that every species of wildlife has the right to exist and persist without fear of extinction from human causes. Just two countries, Ecuador and Bolivia, recognize these rights in their constitutions, and Veelenturf aimed to encourage other countries to support the idea as well.
        “It’s a concept that really resonated with me, and I think it needs to be the basis of the global change we need to see for the planet,” she says. “We must consider the planet and nature when planning future development.”
        Within weeks, she connected with several lawyers, conservationists, and other advocates in Africa, Australia, and South America; met with the first lady of Panama; and worked with a Panamanian senator to draft legislation that is now before the country’s National Assembly. She also made a virtual presentation to the United Nations—her third time speaking to the global intergovernmental organization—to make her case on World Oceans Day.
        It was a whirlwind of activity, but that’s nothing new for Veelenturf. She has already had a lifetime of experiences in just the last few years. She studied sea turtles in Costa Rica, Equatorial Guinea, and Saint Kitts; traveled in a deep-sea vehicle 700 feet below the ocean surface as part of a shark research expedition; won a photography contest sponsored by the journal Nature; was named a fellow of The Explorers Club; tagged hammerhead sharks with conservationists in Colombia; and launched a project to reduce fisheries bycatch of sharks and sea turtles in Ecuador, where she will return for six months beginning in January. And last summer she was selected for the National Geographic Society’s prestigious Early Career Leadership Program.
        “I can’t believe all this is happening,” she says. “It’s like my dreams are coming true.” 

This article first appeared in fall 2020 issue of URI Magazine.

Wednesday, November 18, 2020

An invasion of finches

        Every once in a while, Rhode Islanders who pay close attention to the birds at their feeders have a particularly exciting winter season. That’s when birds that typically spend the whole winter in Canada and northern New England don’t have enough of their favorite foods available, and they head south in large numbers to feast on the seeds we provide.
        This year is already turning out to be one of those years. Birders call it an irruption – different from an eruption, which happens to volcanoes – or an invasion, and it typically occurs with a group of a half dozen species of finch, though a few others are sometimes included in the mix.
        It started in October when nearly every birdwatcher I know reported seeing large numbers of pine siskins at their feeders during the third week of the month. These small birds look somewhat like
Pine siskin (Simon Pierre Barrett)

streaky versions of our common American goldfinch, and we usually only see them during irruption years. They typically feed on spruce cones in the boreal forest of Canada, but apparently this hasn’t been a good year for spruce cones up there, and sunflower and thistle seeds appear to be a satisfactory substitute.
        One morning last month I noticed one siskin scavenging the spilled seed beneath my feeder, and 20 minutes later there were nine. By the end of the day there were more than 50. I spent the next several days repeatedly counting and watching this mass of dainty birds far outnumbering my usual feathered visitors. And I couldn’t have been happier – though I immediately knew my bird feeding budget was going to skyrocket this winter.
        Around the same time, a red-breasted nuthatch made its first appearance in my yard in several years. These little sprites are closely related to the white-breasted nuthatches that are common residents in Rhode Island, but with a pale rusty chest and belly and black-and-white stripes on the side of its face. Although they aren’t a finch and a few are seen in Rhode Island every year, they only appear widely across the region during irruption years.
        A few other invading finches are staying home this winter. Common redpolls, which feed on the catkins of birch trees, apparently have enough to eat in Canada, so they aren’t expected in Rhode Island this year. The same is true of red crossbills, with their oddly crossed beaks, who feed on the cones of white pines. They occasionally invade the Ocean State, but not this year.
        The most anticipated of this year’s invaders is the evening grosbeak. Dressed in gold and black and cream with an oversized seed-crunching beak, they look somewhat like a gigantic goldfinch. They used to be regular winter visitors 40 or 50 years ago, but not any longer. So birders are forced to wait for irruption years to get a look at them. And while there are usually enough pine siskins around during a big year for almost everyone to see one at their feeders, evening grosbeaks seldom turn up in huge numbers, so birders often have to scout out their neighbors’ feeders to find one.
        I still haven’t come across an evening grosbeak yet this season, but I know they’re around. It’s one of the species that makes winter birding in Rhode Island exciting. For while most events in the natural world can be counted on to occur at the same time every year, the cycle of the irruption of winter finches into our area is difficult to predict. And I’m determined not to miss it.
        
This article first appeared in The Independent on Nov. 14, 2020.

Sunday, October 25, 2020

Fungal disease plagues porcupines

        Porcupines are quite common across the northern tier of the United States, but scientists at the New Hampshire Veterinary Diagnostic Laboratory have discovered a crippling fungal disease that is often fatal, and it could have implications for the long-term health of porcupine populations in the region.
        As part of a study of porcupine mortality in Maine, New Hampshire, and Massachusetts, pathologists at the lab examined 44 dead porcupines during a 7-year period and found 12 had died from a disease caused by a fungus known to cause ringworm in wild and domestic animals.
        “The fungus usually causes localized, often minor skin infections in animals and people,” said
Porcupine with fungal disease (NH Veterinary Diagnostic Lab) 

veterinary pathologist David Needle. “In porcupines, however, the skin lesion becomes severe and spreads to the whole body, resulting in debilitation and death if not treated. The pattern of disease caused by this fungus has never been reported in porcupines.”
        The porcupine’s response to the fungus is to try to slough it off by growing a large quantity of keratin, which Needle describes as “a self-adhesive sheet of dried-out cells.” But because the fungus thrives in keratin, and because no inflammation blocks the fungus, the fungus eventually grows over the animal’s entire body, including its eyes and ears in some cases.
        Because the disease has only been diagnosed in the three states – plus a new case in Connecticut – Needle believes that a regional subpopulation of porcupines may be susceptible to the pathogen. Additional cases have been identified by wildlife-rehabilitation clinics in the region, and a newly developed treatment protocol is having modest success at healing the animals.
        The fungus is zoonotic, which means it can be transmitted from animals to humans, although there are no reported cases of humans becoming infected by porcupines. But it is emerging at the same time that several other fungal diseases are affecting other wildlife populations around the world, from bats and frogs to snakes and salamanders.
        How the disease found its way into porcupines is unknown, but Needle speculates that it probably emerged in the last decade and may be spreading. Because porcupines are not commonly rehabilitated and not studied extensively, it is unknown how common the disease is at this time.
        “Porcupines are quite populous in some areas and are sometimes viewed as a pest, so concern for their population numbers isn’t a high priority,” Needle said. “There isn’t a groundswell of financial backing to investigate the disease further. But in areas where fishers had been extirpated and have been recently reintroduced, there has been a plummet in porcupine populations. Added pressure from this fungus is not helping them. They are still common enough in New England that we are not aware of a significant population decline, but studies to assess this may be lacking.”
        To get a better idea of how widespread the disease is, Needle is now assimilating data from 400 dead porcupines studied at diagnostic labs across the country during the last 20 years. “We just started, but this new disease might be the most common diagnosis,” he said.

This article first appeared in the autumn 2020 issue of Northern Woodlands.

Friday, October 23, 2020

Search for rare salamander takes place in the dark

        After dark at a well-hidden vernal pool in Richmond, Peter Paton shined his flashlight back and forth at the moss-covered ground around the nearly-dry pond basin. He was searching for marbled salamanders, the only autumn-breeding salamander in New England, and one that is seldom seen except on rainy fall evenings. It didn’t take him long to spot one.
        “I got one,” he called out. “Over here.”
        Marbled salamanders are the second largest salamander in the region – after only the spotted salamander -- and their attractive black-and-white patterning makes them unmistakable. The one Paton found, a male, was on his way out of the pond basin, indicating that the animal had completed his
mating duties and was headed to the forest to spend the winter underground.
        Female salamanders were likely hidden in the sphagnum moss around the pond, where they remain for a month or more to guard their eggs until rain fills the pond and the eggs are protected from predators and the elements. The eggs hatch within days after being covered in water, and the larvae overwinter in the pond.
        Paton, a professor of natural resources science at the University of Rhode Island, was confident of finding
Marbled salamander (Todd McLeish)
marbled salamanders at the Richmond site, since it was a place he studied and monitored in 2000 and 2001, when he and colleagues conducted an amphibian survey of 137 vernal pools around the state. Marbled salamanders were found in just four of the pools, however, making it one of the rarest pond-breeding amphibians in the region.
        Previous efforts in the 1980s and 1990s by Chris Raithel, a wildlife biologist at the Rhode Island Department of Environmental Management, documented as many as 50 marbled salamander breeding sites in the state, mostly in Kent and Washington counties. There are no records from Bristol county or from areas adjacent to Narragansett Bay and few from the Blackstone Valley.
        “The present localized distribution of marbled salamanders in Rhode Island may be related to habitat fragmentation and patch isolation,” Raithel wrote in his 2019 book, Amphibians of Rhode Island. “If this effect is real, the species is secure only in the larger contiguous habitats of southern and western Rhode Island, and additional range retraction should be evident to future generations.”
        Marbled salamanders require a very specific habitat for breeding – ponds that are surrounded by sphagnum moss and dry up in the summer, keeping fish and large dragonfly larvae from inhabiting the pond and preying on the salamander larvae.
        “They tend to like relatively small ponds, and there aren’t many sites available that fill their habitat requirements,” Paton said.
        In addition to habitat fragmentation, road mortality is also a significant concern for the species, because they are often crushed by vehicles as the adults cross roads to reach their breeding ponds or as juveniles disperse to find territories.
        On the other hand, Paton said it’s possible that the changing environmental conditions associated with the warming climate may make southern New England more favorable to marbled salamanders in the future. Their current range extends as far south as northern Florida and eastern Texas, and populations in warmer climates tend to be considerably larger than those in Rhode Island.
        “They aren’t very tolerant of the cold, so we’re at the northern limits of their range,” Paton said. “The larvae don’t grow much in the winter because it’s too cold, but once wood frogs arrive to breed in early spring, the salamander larvae feed on the frog tadpoles as their main fuel source to undergo metamorphosis.”
        After metamorphosis, the salamanders leave their ponds and spend the rest of their lives in the forest, except for brief breeding periods each fall.
        Despite how few marbled salamander breeding sites were found during the last amphibian survey, a recent graduate student at the University of Massachusetts at Boston thinks a new survey method may detect the salamanders more effectively than traditional sampling methods.
        Jack He, who graduated in May, used eDNA – environmental DNA collected from water or soil – to detect the presence of marbled salamanders even when the animals could not be seen.
        “Everything sheds DNA in one form or another, like from skin cells or blood, and they release it into the environment,” He said. “Ideally we can collect water or soil samples containing those cells and extract that DNA and sequence it to determine what species are present.”
        He detected marbled salamander DNA in a number of water and soil samples from vernal pools in western Massachusetts. He calls it a less labor-intensive method of determining if the salamanders are present at a site than using dipnets to capture larvae in the spring, which is how Paton conducted his survey.
        “I’ve done dipnet studies and compared them to eDNA, and I found that eDNA was a bit more effective,” he said.
        Paton, however, isn’t convinced.
        “My impression is that larvae are relatively easy to find, but I could be biased,” he said. “Maybe they’re in there and I missed them a lot. But however you do it, I suspect that marbled salamanders are still fairly rare in Rhode Island.”

This article first appeared on EcoRI.org on October 22, 2020.

Tuesday, October 20, 2020

Some bats are migratory contrarians

        October is one of the busiest months of the year for migration.
        Millions of songbirds that spent the summer breeding in the Northeast – warblers and flycatchers and orioles, for instance – are winging their way southward to Central America, South America or the Caribbean to enjoy the warm climate and to feed on the abundance of insects that are mostly absent during our northern winters. They’re joined by an equal number of their offspring, all of whom are making the dangerous journey for the first time.
        At the same time, geese and ducks and finches and many sparrows are heading southward from the north, destined to spend the winter eating from our bird feeders or carousing in our ponds or along our
Little Brown Bat (Kentucky Fish and Wildlife)
 coastlines. For them, the New England winter is their version of the Tropics. They’re accustomed to chilly winters and adapted to eating seeds or mussels or whatever else we have available in winter.
        Our few migratory butterflies and dragonflies have departed by now, too, in their search for warmer temperatures to the south. Reptiles and amphibians are also on the move, just not nearly as far – mostly to nearby underground lairs or to the muddy bottoms of ponds and streams.
        But strangely enough, one group of animals is going in the opposite direction. Most of our bats are migratory contrarians. October is the time when they are moving northward instead of south, toward caves and mines in Vermont, New Hampshire and the Adirondacks.
        They’re seeking out a very precise environmental condition – high humidity and a temperature that will remain stable a bit above freezing for the next five months. That’s where they’ll hang together from the ceiling, sometimes in large numbers, in a state of inactivity and slow their metabolism so they don’t have to eat or drink for the entire winter. Rhode Island doesn’t have any suitable caves or mines in which bats can hibernate, so most of our bats head to those closest to us, all of which are to the north and northwest.
        These bat caves – officially called hibernacula – are the perfect location for their long winter naps. But because the bulk of the region’s bat populations are all gathered together in a very few sites, it made it easy for an unexpected disease to rapidly spread among them. Bunched together wing to wing, a deadly disease called white nose syndrome was quickly passed from one bat to another – sort of like Covid-19 among party-goers – and over a few short years close to 90 percent of our bats died.
        That’s why we’re seeing far fewer bats now than we did 20 years ago. The one exception is a species called the big brown bat – as opposed to the little brown bat, which used to be the most abundant species in the Northeast. A few big browns have found enough old buildings, underground bunkers and earthen crevices in Rhode Island with adequate enough conditions to keep them home for the winter. Which may be one factor – along with good genes and naturally occurring probiotics – that has allowed them to survive the disease in greater numbers. Their populations only crashed by about 50 percent.
        I wouldn’t want to suggest that the bats that migrated in the opposite direction of all the other wildlife on our continent are like the clumsy Gang That Couldn’t Shoot Straight, but there’s something to be said for the bat that simply chose to stay home. Maybe, by not migrating at all, the big brown bat is the true migratory contrarian. 

This article first appeared in The Independent on Oct. 11, 2020.

Thursday, October 15, 2020

Survey of knowledge, beliefs about coyotes seeks to inform management

        A University of Rhode Island graduate student is seeking to inform coyote management in Rhode Island by conducting a survey of Ocean State residents to gain insights into their knowledge, beliefs and feelings about the controversial carnivore.
        Kimberly Rivera, of Westchester County, New York, is examining the relationship between what people know and believe about coyotes and their first-hand experience with the animals. She will also factor in their personal environmental beliefs and demographics.
        “Coyotes aren’t going anywhere, so the better we understand where we stand with them, the better we’ll be able to coexist with them,” said Rivera.
        She is seeking at least 500 Rhode Islanders from throughout the state to take the survey before the end of November. It takes about 10 minutes to complete and can be found here.
           According to Rivera, about half of all nuisance wildlife calls received by state wildlife officials are about coyotes, which may have more to do with people’s beliefs about coyotes than it does about the actual threat the animals pose.
        Rivera plans to combine the results of her survey with data from a statewide camera trap study of
Eastern coyote (Todd McLeish)

coyotes to see if people’s opinions about coyotes are more or less positive in areas where the animals are most abundant.
        “We’re going to take what we learn from these surveys and disseminate it to wildlife managers so they can incorporate the data into their management practices,” she said. “If there are areas with greater conflict or where people are especially antagonistic toward coyotes, then maybe we can manage them better for both the coyotes and the people.
        “I’m especially interested in learning about interactions between pets and coyotes,” Rivera added. “There are lots of stories about missing pets suspected of, or witnessed, being taken by coyotes, and I’d like to learn how often it really happens and how often people think it happens.”
        The survey also aims to gauge opinions about current management practices, such as trapping coyotes with foothold traps, which is illegal in the state. Results of the survey may be used to inform future management decisions related to the harvesting of coyotes.
            Rivera’s coyote survey is the result of a survey she had planned to conduct with farmers in Madagascar about conflicts between carnivores and livestock. The pandemic cancelled her travel plans to the island nation off the east coast of Africa, so she sought to focus on a related issue closer to home.
            “I fell in love with spotted hyenas while doing an internship in South Africa while I was an undergrad,” Rivera said. “They’re considered vermin there because they are presumed to depredate livestock. It got me thinking about how perceived interactions can change how people think about a species. Those opinions are important. If people don’t care about animals, we’re not going to be able to conserve or coexist with them.”

Tuesday, October 13, 2020

Scientists investigate effects of marine heat wave off southern New England

        A team of scientists from the University of Rhode Island and partner institutions depart today aboard the research vessel Endeavor for a five-day cruise to investigate the implications of a marine heat wave in the offshore waters of New England.
        The waters on the continental shelf – extending from the coast to about 100 miles offshore – have been 2 to 5 degrees Fahrenheit warmer than usual since July, according to URI oceanographer Tatiana Rynearson, one of the leaders of the expedition. And that warmth could have significant impacts for local fisheries and the marine ecosystem.
           “The water is very warm compared to the average of the last 40 years,” said Rynearson, a professor at the URI Graduate School of Oceanography who studies plankton. “The question we’re
URI ship Endeavor

asking is, how is it affecting the ecosystem and the productivity of the continental shelf waters.”
        The Northeast Pacific Ocean experienced a similar marine heat wave in 2014 and 2015, when what was described as a “blob” of warm water spread offshore from Alaska to California, resulting in major die-offs of fish and seabirds and closures of fisheries.
        “The impacts went all the way up the food chain from that warm blob of water,” Rynearson said. “Similar dramatic impacts haven’t been documented for New England waters, but we’re going to try to understand what’s going on out there.”
        Rynearson hopes the expedition will provide a clearer understanding of how the marine ecosystem responds to short-term heat waves and how it may react to the long-term temperature increases that are expected in the ocean due to the changing climate.
        “We think these heat waves will happen more frequently in the future, so it’s important to understand how the ecosystem responds to them,” she said. “We’re also interested in whether the response to this heat wave will give us insight into the general warming trend.”
        The expedition – which includes scientists from the Woods Hole Oceanographic Institute, Wellesley College, University of Massachusetts at Dartmouth, and the National Oceanic and Atmospheric Administration – is part of a long-term ecological research project funded by the National Science Foundation. Its aim is to compare how variability in the environment affects the ecosystem, from microscopic plankton to fish.
        “From our ongoing study we’ve learned that there are two different kinds of water out there – cold, nutrient-rich water that supports a lot of fisheries production, and warm, less-productive water,” Rynearson said. “We’re interested in the balance between how long the waters are warm and nutrient-poor versus cold and nutrient-rich.”
        The researchers will collect data along a transect from Narragansett to Martha’s Vineyard and then southward about 100 miles to an area at the edge of the continental shelf where the water is about 5,000 feet deep. Along the way they will take water samples at various depths to evaluate how much plankton is in the water, the rate of photosynthesis, and the rate that tiny marine animals called zooplankton are feeding upon tiny marine plants called phytoplankton.
        “We’ll also be looking at what species of phytoplankton and zooplankton are out there, because there seem to be differences in the community when you have cold, nutrient-rich waters versus warm, nutrient-poor waters,” said Rynearson. “We’ll ask, are we still seeing a summer community of marine life out there or is it too late in the year for that.”
        The research team also aims to gain a better understanding of the marine food web by studying the links between the tiniest creatures and the forage fish that are fed upon by the top predators in the ocean and captured in local fisheries.
        “We’re probing a part of the food web that’s not well understood in terms of the transfer of energy or the response to climate change,” Rynearson said. “That part of the food web is a bit of a black hole, and we want to shine some light in there.”

Thursday, October 8, 2020

Volunteers find Rhode Island's rarest turtle at new sites

        A pilot project using volunteers to scout for new populations of Rhode Island’s rarest turtle, the diamondback terrapin, turned up 15 new sites where the turtles have been confirmed. But despite the new populations, the biologist who led the project said the state’s terrapins are no less threatened than they were before the new populations were discovered.
        Herpetologist Scott Buchanan, a wildlife biologist at the Rhode Island Department of Environmental Management, said that prior to 1990, when a population of terrapins was discovered in Barrington, “no one had seen a terrapin in Rhode Island in many years.” Additional populations were
Diamondback terrapin (Todd McLeish)

discovered elsewhere in the state in the past decade, and when Buchanan was hired in 2018 and began asking around, he heard a number of unconfirmed reports of terrapins being observed elsewhere in Rhode Island.
        "That led me to think that they’re probably more widespread in the state than the narrative would lead us to believe,” he said.
        So he examined maps to identify “reasonable places” where he could send volunteers on a regular basis to see if they could spot the terrapins, the only turtle in the region that lives in salt marshes and brackish waters. Four volunteers each visited two to four sites twice a week from late May through mid-July, and an additional volunteer surveyed a dozen sites. During each visit they scanned the water with binoculars for three 5-minute periods and counted any turtle heads they observed.
        The discovery of 15 new sites was a revelation to Buchanan.
        “What it means is that they are much more widespread than we had thought,” he said. “It’s encouraging from a conservation standpoint, but at many of these sites, we have little or no information about how many turtles may be there, whether they are successfully breeding, or whether they are established populations. We don’t want to be overconfident or get too comfortable with the fact that there are multiple sites containing the species.”
        Most of the newly discovered terrapin sites are in coves along mid and upper Narragansett Bay. They’re still mostly absent from the lower bay, according to Buchanan.
        “What we’re seeing now is probably a shadow of their former distribution and abundance,” he said. “They’re out there, that’s excellent, but we know there’s lots of places they don’t occur. All the evidence suggests that they’re still absent from many places where they were historically present. And the types of abundances that we’re documenting are probably far less than historic abundances.”
        Buchanan speculated that the newly discovered populations in the upper bay may be the result of dispersal from the Barrington population, which has grown to number in the hundreds because of extensive conservation efforts.
        Despite the success of the survey project, Buchanan is still concerned for the state’s diamondback terrapins. Most terrapin eggs are consumed by what he calls “human-subsidized predators,” including coyotes, raccoons, skunks, and dogs. Terrapins are also at risk of being illegally collected for the pet trade, which is why he prefers not to reveal the location of the newly discovered sites. They also face drowning in crab traps, injury from being struck by boats, and automobile strikes as females cross roads on their way to their nesting territories.
        “The big threat, though, is sea-level rise and salt marsh decline,” he said. “They’re an obligate salt marsh species; if sea level rises and marshes disappear, they don’t have a chance. That’s something I’m especially worried about over the next 10, 20, 30 years along the Rhode Island coast. Salt marshes are critical as a source of food and a place where they overwinter and take shelter, especially the juveniles and hatchlings.
        “This new information we have is very encouraging, but it doesn’t mean we should let our guard down. They’re still a species that warrants conservation, even without sea-level rise. We must remain vigilant.”
        Having identified the location of additional terrapin populations, Buchanan hopes to prioritize those sites for future conservation efforts, modeled after the successful nest-protection and monitoring efforts in Barrington.
        “Knowing where they are, there are lots of small steps you can do to improve their conservation,” he said. “Things like small-scale habitat management, create barriers to keep them off busy roads, public outreach to ensure boaters use caution, adapt local pot fishery management.”
        The success of the pilot project to identify new diamondback terrapin populations has inspired Buchanan to double or triple the effort next summer at numerous additional locations. He also hopes to continue the project for many years to eventually be able to identify population trends at each site. He will be seeking additional volunteers this spring to survey coastal sites around the state in June and July. Those interested in volunteering should contact Buchanan at scott.buchanan@dem.ri.gov.

The story first appeared in EcoRI.org on October 5, 2020.

Wednesday, September 23, 2020

URI grad student finds chemical contaminants in seabirds

        Evidence continues to accumulate about human and wildlife exposure to chemical compounds called per- and polyfluoroalkyl substances, collectively referred to as PFAS, and their deleterious effects on the environment. The latest study, by a University of Rhode Island graduate student, found high levels of the compounds in seabirds from offshore Massachusetts and coastal Rhode Island and North Carolina.
        Chief among the findings was the discovery that one type of PFAS, perfluorooctanesulfonic acid or PFOS, which has not been produced since the early 2000s, is the most dominant PFAS compound in the birds from all three sites, further illustrating how these chemicals do not breakdown in the environment and can remain in animal tissues for many years.
        “Wildlife is being inundated with PFAS,” said Anna Robuck, a doctoral student at the URI
Anna Robuck dissecting seabirds

Graduate School of Oceanography, who has been studying PFAS with Professor Rainer Lohmann since 2016. “We don’t really understand what that means for wildlife health overall, since scientists are just catching up with what PFAS means for human health. What we do know is that we’re seeing significant concentrations that laboratory studies tell us are concerning.”
        Her research was published this month in the journal Environmental Science and Technology.
        The concentrations of PFAS Robuck found in seabird livers are comparable to levels found in other bird studies that suggested that the compounds may be causing negative reproductive health outcomes.
        “This speaks to the incredible persistence of these compounds,” she said. “Once in the environment, it’s there in perpetuity for it to be accumulated by wildlife. And even though we no longer produce PFOS, we still produce a series of related compounds that, once in the environment, readily transform into PFOS.”
        Robuck, a native of Chadds Ford, Pennsylvania, measured the levels of PFAS in the livers of herring gulls from Narragansett Bay, Rhode Island, great shearwaters in the offshore waters of Massachusetts Bay, and royal and sandwich terns from Cape Fear, North Carolina. All of the birds were juveniles found dead near their breeding or feeding grounds. The three sites were chosen to represent birds from an urban area where PFAS exposure is common (Narragansett Bay), an offshore area of birds that seldom approach land (Massachusetts Bay), and an area downstream of a major PFAS producer (Cape Fear).
        “We studied their livers because there is a specific protein in the liver that PFAS love to bind to,” Robuck said. “We also know that in humans, PFAS exposure leads to liver damage and impairment of function.”
        Among her other findings, Robuck discovered that the North Carolina birds that hatched downstream from a PFAS production site contained several novel PFAS compounds that have been created in recent years to replace those that have been phased out.
        “The nesting colonies where we got the Cape Fear birds from are 90 miles from the production facility,” she said. “This is the first detection of these compounds in liver tissue and the furthest distance from the known industrial source.
        “Surprisingly, we also found those same novel PFAS in birds that have no connection to Cape Fear – in one gull from Narragansett Bay and two shearwaters in Massachusetts Bay,” she added. “It suggests that these replacement compounds are highly persistent and capable of migrating further in the environment than we were aware of. There also may be more sources of the compounds than we know about.”
        Of particular note, Robuck also found that as PFAS levels increased in the birds, the phospholipid levels in their liver decreased, a finding that is especially concerning.
        “That’s a really big deal because fats are important for reproductive health, migration, raising their young successfully, and other elements of their life cycle,” Robuck said. “The fact that there is an observable relationship between PFAS and fats deserves a lot more investigation to see what it could be doing to wildlife populations.”
        In addition, Robuck detected the same PFAS levels in the offshore birds as those from inshore Rhode Island.
        “They didn’t have the same kind of PFAS, but they had the same total level,” she said. “I expected offshore birds to be a lot lower, since those birds never come to land. It suggests that even our most remote and most pristine habitats are facing exposure to these compounds.”
        Robuck’s next study will analyze the PFAS concentrations in other tissues from the same birds. She hopes the resulting data will be included in future government assessments of the impact of PFAS in wildlife and the environment.

Thursday, September 17, 2020

Deadly rabbit disease threatens rare cottontail

        It hasn’t yet reached Rhode Island, but local scientists are on the lookout for a disease that rapidly kills wild and domestic rabbits before it wipes out the rarest rabbit in the Northeast, the New England cottontail.
        Rabbit hemorrhagic disease causes what Roger Williams Park Zoo veterinarian Kimberlee Wojick called “very sudden death” in rabbits by attacking internal tissues and causing acute bleeding. The animals seldom show symptoms of the virus and instead are simply found dead with blood coming from their noses.
        The disease can be traced to Europe and Asia, but outbreaks have been reported this year in nine states, resulting in the death of several species of wild cottontails, hares and jackrabbits, mostly in the Southwest.
        “We don’t know how it got to the U.S., but it’s having widespread effects on wildlife,” Wojick said. “The virus can survive for a long time in the environment outside of the rabbit — it’s shed through
New England cottontail (iStock)

their urine and blood, it’s in carcasses and can contaminate food sources — so even though an infected rabbit may have died and been removed from the land, the virus could still be there when a new rabbit moves through.”
        Both species of wild rabbit in Rhode Island, the eastern cottontail and New England cottontail, are highly susceptible to the disease.
        “The eastern cottontail population is large and thriving, so while they may take an overall hit, they won’t be decimated because their population is so high,” Wojick said. “What we are really worried about is the New England cottontail.”
        New England cottontails are the only rabbit native to New England, and they have declined precipitously in recent decades because of habitat loss and competition with eastern cottontails. Efforts are underway to breed the species in captivity at Roger Williams Park Zoo, maintain a breeding colony on Patience Island in Narragansett Bay, and release them into the wild at targeted locations throughout the region.
        “If the disease gets here fast and furious, we could lose the entire remaining New England cottontail population,” said Lou Perrotti, director of conservation at Roger Williams Park Zoo, who is responsible for the captive breeding effort. “It’s that contagious, that ruthless. We could stand to lose a few eastern cottontails, but we don’t have enough New Englands.”
        Conservationists in the region are making plans for how to respond if the disease approaches the area. Much of the planning involves the development of biosecurity protocols so the biologists working with New England cottontails don’t inadvertently move the disease around.
        “There’s a lot of on-the-ground conservation of the species going on, lots of field monitoring of existing populations, biologists trapping rabbits and collecting fecal samples,” Perrotti said. “We’re going to have to do things like disinfect the tires on our trucks, change our clothes, disinfect our traps and bags and anything that holds rabbits. Whenever moving from population to population, we have to be conscious of what we’re bringing and be diligent about proper disinfection methods.”
        The New England cottontail conservation team is in close contact with counterparts in California who are similarly trying to protect the endangered riparian brush rabbit.
        “They’re freaking out about the disease, and their first reaction was to contact us about how to hold a safe, captive population in a bio-secure location,” Perrotti said. “We’re also getting information from them about how they’re dealing with the disease, because that’s a state where it’s already reared its ugly head.”
        The potential saving grace is that a vaccine is available in Europe, though it’s not yet licensed for use in the United States. To get it, conservationists must apply through the U.S. Department of Agriculture (USDA), work through an import broker, and ensure it gets through U.S. Customs while remaining refrigerated. The USDA will not approve applications for the vaccine from states not already affected by the disease, however.
        “We need a positive case in the area before they’d even think about giving us the vaccine,” Perrotti said. “But in an area as small as Rhode Island, if we find a case it’s going to be too late.”
        Assuming the vaccine can be acquired, Perrotti and the cottontail conservation team are developing a plan for how best to administer it. Captive animals will likely be vaccinated first, followed by as many in the Patience Island breeding colony as can possibly be captured.
        “And then we’d opportunistically vaccinate any other rabbit we get our hands on,” he said. “Can we get them all? No. Can we target all populations? No. But we’d prioritize the vital populations that are especially important.”
        According to Wojick, the vaccine only provides immunity to the disease for about one year, and immunity is not transmitted to their offspring. But since the rabbits typically only live for one or two years, a one-year immunity may be sufficient.
        While the arrival of the disease in southern New England isn’t necessarily imminent, it could easily make the leap from the Southwest to Rhode Island by someone transporting an infected domestic rabbit to the area.
        “What we’re most afraid of is some dude that moves East with his domestic rabbits. If they’re infected and he puts them in a hutch outside, wild rabbits will be drawn to the smell of the hay and food and there will be an interaction,” Perrotti said. “That’s all it’s going to take.”
        He noted that Rhode Island doesn’t have large-scale breeding of domestic rabbits for game dinners or laboratory use, as some other states do. And domestic rabbit shows are also not big business in the state.
        “The pet industry is quite large, though, so the risk of getting the disease here is not low,” said Dylan Ferreira, a wildlife biologist at the Rhode Island Department of Environmental Management (DEM). “That being said, COVID has canceled a lot of rabbit shows, and that has helped us mitigate the potential spread.”
        DEM has a fact sheet with detailed recommendations for rabbit breeders and wildlife rehabilitators on biosecurity practices to prevent the spread of the disease. Those who observe unusual rabbit mortalities or other suspicious cases should report them to Ferreira at 401-789-0281 or Scott Marshall, the state veterinarian, at 401-222-2781.

        This article first appeared on EcoRI.org on September 16, 2020.

Wednesday, September 16, 2020

Scientists fight invasive beetle with beetle-killing wasp

        When the invasive emerald ash borer, a beetle native to the Far East, was found in Rhode Island in 2018, it was a sign that most of the state’s mature ash trees were likely to die soon. Now a team of entomologists from the University of Rhode Island is fighting the invader with a predatory wasp from its native land in hopes that the region’s next generation of ash trees will survive.
        Lisa Tewksbury, director of the URI Biocontrol Laboratory, and her students have been on the lookout for the emerald ash borer for more than a decade, soon after it was first discovered in the United States in Michigan. Now that they know it’s here, they are deploying three species of parasitic
Emerald ash borer (USDA)

wasp from Asia that lay their eggs in the beetle’s eggs or larvae. When the wasp eggs hatch, the wasp larvae consume the beetle eggs and larvae from the inside.
        “The beetle doesn’t have any natural enemies in the U.S., so we’re reuniting it with its natural enemies from back where it came from,” said Tewksbury. “We’re using one organism to control another.”
        The parasitic wasps have been extensively tested to ensure that they will only prey upon emerald ash borers. They are being raised at a federal laboratory in Michigan and shipped to Rhode Island as pupae that are about to become adult wasps inside blocks of ash wood, which the URI team delivers to areas where the beetle has previously been found. Once there, the wasps will emerge and lay eggs in beetle larvae the ash trees nearby.
        Tewksbury has a permit from the U.S. Department of Agriculture to release the wasps in targeted locations to attack the beetle.
        Ash trees make up just two percent of forests in Rhode Island, but they are found extensively in parks and along streets throughout the state.
        “The emerald ash borer isn’t a huge concern for our forests,” Tewksbury said. “But it will be a concern to people who have ash trees in their yards and on their streets. There are a lot of them in Newport and Providence.”
        Last year, Tewksbury released the three parasitic wasps in Hopkinton, near where the beetles were first discovered, and this year they are being released in five additional locations in Burrillville and Cumberland. The last round of releases for this year are taking place this month, and ongoing statewide surveillance for the beetle will indicate where additional wasp releases may take place next year.
        Next year will also be the beginning of an effort to determine if the wasps have become established and are doing their job. Tewksbury will peel back the bark of dead and dying ash trees to see if she can find evidence of dead beetle larvae.
        “We are resigned to that fact that we’re going to lose most of our larger ash trees, but by doing this biological control effort we’re hoping the wasps can protect the smaller trees so we’ll have some ash left in the future,” Tewksbury said.
        Targeted biocontrol efforts such as this are often the most cost-effective and least damaging way of fighting invasive insects. Tewksbury’s lab is involved in testing another predatory wasp for possible future deployment against what she expects will be the state’s next harmful pest, the spotted lanternfly, another tree-killing invasive species from Asia that is expected to arrive in Rhode Island in two or three years.

Monday, September 14, 2020

New disease is killing beech trees

        A University of Rhode Island scientist said that a disease that can kill beech trees was discovered in southwest Rhode Island in June, and both American and European beech trees throughout the region are at risk.
        According to Heather Faubert, who coordinates the URI Plant Protection Clinic, beech leaf disease was first identified in Ohio in 2012, and it spread to Pennsylvania, New York and Connecticut before arriving in Rhode Island. The disease damages a tree’s leaves, causing them to fall off. The energy
Beech tree leaves with beech leaf disease
required to regrow leaves stresses the trees, and if it happens several years in a row, the trees could die.
           “It’s really sad that it’s arrived here because beeches make such beautiful forest trees,” Faubert said. “Beech forests are stunning, their bark is gorgeous, and in fall their leaves turn a beautiful coppery color.”
        She said the disease is caused by a nematode, a microscopic worm that feeds inside the leaves.
        “It’s very easy to see if a tree is infected,” Faubert said. “If you hold a leaf up to the sun and you can see dark bands running parallel to the veins of the leaves, that’s the sign of an infected tree.”
        No treatment for the disease is available, as nematodes are difficult to control in the forest environment, but research is underway to identify treatments for individual landscape trees.
        “That’s the worst part; we don’t know what to do about it yet,” said Faubert, who observed diseased trees in an extensive area of beeches in Ashaway but did not find it in beech forests in Portsmouth or Middletown. “We also don’t know how it’s being transmitted from tree to tree, so if people walk around in the area of diseased trees, they should probably wash the bottom of their shoes before going into another forest.”
        She also advises that residents avoid digging up beech tree saplings from one forest and transplanting them elsewhere so as not to move potentially diseased trees to uninfected areas.
        Those who believe they have beech trees infected with beech leaf disease should take a photo and report it on the Rhode Island Department of Environmental Management’s invasive species pest report form.

Saturday, September 12, 2020

Identifying some wildlife is now a snap

        If you’re at all like me, whenever you see an animal or plant you’ve never seen before – be it a bug, bird, bat or begonia – you want to know what kind of living thing it is. You want to put a name to it. You want to know what to call it so you can tell your friends and family what you saw.
        That’s my immediate reaction every time, and it’s not unusual. Everybody does it, though not necessarily always with wildlife. For some people, they react the same way when seeing a car they’ve never seen. They need to know what make and model it is. While I can’t tell the difference between most cars these days, I’m always impressed by those who can distinguish them by tiny characteristics like taillights or bumpers.
        Where do you turn when you want to identify wildlife you’ve never seen before? Most of my friends turn to me. I get text messages and email messages almost daily from people who want me to help them identify something they got a brief glance at. If they send me a picture, I can usually help them. But often, the characteristics they claim to have seen don’t match up with anything that lives around here. Or they don’t notice the key distinguishing features of the specimen. With many species, you have to know what to look for to identify it correctly.
        But now that’s less of an issue, thanks to some extremely helpful free smartphone applications and websites that have turned identifying wildlife into a relatively simple experience. Most of the time.
        The Seek app is my favorite. Wave your phone over a plant or insect or turtle, for instance, and it quickly identifies it for you. That’s been a huge help whenever I see an interesting plant that I know I should know or a strange bug perched on my deck. It’s not so good for creatures that won’t sit still long enough for you to wave your phone in front of them, like birds and butterflies, or for animals you can’t get close to, like mammals. But for those that cooperate, it quickly solves the identification puzzle.
        When I wrote in July about identifying more than 250 species of wildlife in my backyard in 24 hours, it was mostly due to the Seek app that I was able to do so. I can confidently identify birds and mammals and amphibians, but insects and plants have always been a challenge for me, and close to 200 of the species I identified that day were plants and insects. It wouldn’t have been possible without Seek.
        For wildlife that you can photograph from a distance but can’t get close enough to use Seek, including birds, dragonflies, butterflies, bees and mammals, post your images to iNaturalist – either the website or app – and it will identify it for you. The Google photos app does something similar by comparing your photo to other online images (it will even identify cars).
        You can also get identification help for certain categories of wildlife at eBird, BugNET, eButterfly, Odonate Central (dragonflies) and similar online sources.
        Since I’ve started telling people about Seek and these other apps, I don’t get nearly as many texts and emails asking for my help identifying things as I used to. Now I seldom hear from anybody at all.
        As one so-called friend jokingly said, “Now that I’ve got Seek, what do I need you for?”

This article first appeared in the Independent on Sept. 3, 2020.

Friday, September 11, 2020

Dragonfly predation on eastern newts

Eastern newt (Elise Tillinghast)
        Common green darners are among the largest dragonflies in the Northeast, and they are voracious predators, capturing large flying insects – including other dragonflies – while in flight. During their long larval stage in freshwater ponds, they are equally predatory, feeding on aquatic insects, minnows, tadpoles, and even developing froglets.
        But whether they also feed on the larvae of eastern newts was unknown. Although newt larvae are similar in size to other green darner prey, newts also contain a neurotoxin that may make them unpalatable. So Brian Gall, a biology professor at Hanover College in Indiana, conducted a series of laboratory experiments to determine whether darner larvae will eat newt larvae and whether the newts employ any behavioral strategies to avoid being eaten.
         The palatability question is particularly complex, as it is unknown how much neurotoxin the newts contain in larval form. Adult newts have only low levels of the toxin, and Gall said they are known to deposit some of their toxin in their eggs, but is it enough to repel green darner larvae? Juvenile newts – called efts – contain high levels of the toxin, even though it is believed that they are unable to produce it themselves.
        In the first experiment, green darner larvae were provided newt larvae in all three developmental stages to determine which was preferred. “They ate them all,” Gall said. “Young ones were eaten, old ones were eaten, and metamorphs were eaten. That was a surprise.”
        Next he assessed the survival rate of newt larva when exposed to dragonfly larva in environmental chambers. In two experiments, the dragonfly larvae ate 19 of 20 newt larvae. Because newt larvae rely on their sense of smell to detect predators, Gall then placed newt larvae in water previously containing green darner larvae, and it became clear that the newts could smell the dragonflies. They immediately slowed down their movements.
        “Even though they don’t have enough toxin to protect themselves, the newt larvae have behavioral mechanisms to help keep them safe,” Gall explained. “When they smell a dragonfly, they reduce their activity and hide by sitting at the bottom of a pond until they don’t smell that dragonfly anymore.”
        Given how voraciously common green darner larvae prey on newt larvae in controlled experiments, one might think that the newts may struggle to survive in the wild. But Gall isn’t worried about them. “I’m sure the dragonflies are eating a lot of newt larvae, but every fall we find thousands of developing efts, so the dragonflies aren’t getting close to eating all of them. The newts have evolved mechanisms to survive.”
        Still, he’s curious how the relationship plays out in the wild. “Newts aren’t confined in a little dish with nothing to hide them,” he said. “I’d like to look at mortality rates in the field and understand how successful dragonfly larvae are in the wild when they have other things to eat. How likely are newt larvae to survive in those conditions?”

This article first appeared in the fall 2020 issue of Northern Woodlands magazine.

Tuesday, September 8, 2020

Bay warming causes seasonal shift in jellyfish-like creatures

        Nearly 50 years of weekly surveys in Narragansett Bay have revealed changes in the seasonal activities of ctenophores – small, non-stinging, jellyfish-like creatures – that have implications for the health of fish populations in the bay.
        Scientists at the University of Rhode Island and Rutgers University report in the Journal of Plankton Research this month that while numbers of the ctenophore Mnemiopsis leidyi have not increased, as had been speculated, higher temperatures in the bay have led them to be more prevalent earlier in the spring and later in the fall than previously observed.
        And because they feed voraciously on copepods – zooplankton near the bottom of the food chain, upon which many young fish feed – they are likely limiting the amount of food available to larval fish
Ctenophore by Michael Salerno

. Ctenophores also eat fish eggs and some larval fish, which also could affect fish populations.
        Barbara Sullivan-Watts, emerita marine research scientist at URI’s Graduate School of Oceanography and an adjunct professor of biology at Providence College, who manages the survey data, calls ctenophores “big bags of water that aren’t terribly nutritious, so very few predators will eat them.” Rather than using venom to capture prey, they use sticky cells like flypaper to subdue potential victims. They propel themselves by waving tiny comb-like cilia – hence their nickname, comb jellies – and they are bioluminescent, which makes them glow in warm temperatures.
        The animals have been collected from the same location in Narragansett Bay nearly every week since 1972 using a cone-shaped net that is pulled by hand from the bottom of the seafloor to the surface. The work was started by the late Ted Smayda, an international expert on plankton at the Graduate School of Oceanography, and continued by Sullivan-Watts. It is one of the longest-running quantitative plankton studies in coastal waters around the globe.
        Ctenophores do not feed or reproduce until water temperatures approach 50 degrees Fahrenheit, and their activity levels and reproduction rates increase as temperatures rise through mid-summer. In the first decades of the survey, that meant the peak of their reproduction – or what scientists call a bloom – was in July. But now, after years of increasing temperatures, their blooms occur many weeks earlier. In recent years, they have also had a second bloom in early fall.
        “They’re dormant and slow and lazy in winter, but once conditions get favorable and the ecosystem begins ramping up with phytoplankton blooms and copepods increasing, that’s when ctenophore abundance increases and they’re rapidly feeding. That’s when they start to reproduce,” said Emily Slesinger, a doctoral student at Rutgers who analyzed the data. She participated in the data collection in 2014 while, as an undergraduate at the University of California at Santa Cruz, spending the summer at URI.
        “In winter, they just hang around until they starve to death or disintegrate and disappear,” added Sullivan-Watts. “They stop reproducing in winter and spend that time in shallow embayments most years.”
        If ctenophores are active and reproducing for a longer period of time than they used to be, then why haven’t their numbers increased? The researchers aren’t certain.
        Sullivan-Watts said that it could be because of the 50 percent reduction in nutrients being discharged into the bay from wastewater treatment plants since 2005. That may have affected the abundance of phytoplankton, limiting food available to zooplankton like copepods, and ultimately decreasing the availability of food to ctenophores. The scientists have detected a slight decrease in the abundance of ctenophores in the bay in the last few years, which may be the result of this cascade of events.
        While that cascade has not yet been proven, what is known is that some species of copepods that used to be abundant in Narragansett Bay are now less common because so many are eaten by ctenophores.
        “It appeared that the copepods might suffer a permanent decline,” Sullivan-Watts said. “More data is needed to determine if the copepods are also changing their seasonality to escape predation by the ctenophores.”
        Yet despite the changes in the timing of ctenophore activity and their impact on copepods and fish, Sullivan-Watts said she isn’t sure there will be a long-term impact on the bay ecosystem.
        “It’s not a catastrophe; it’s just a change,” she said. “We don’t really know how this change perpetrates itself on other elements of the food web.”
        The introduction of the ctenophore to European waters has not been as benign, however. Beginning in the Baltic Sea in the 1980s and spreading elsewhere, they reproduced explosively and contributed to the collapse of fisheries throughout the region.
        To get a clearer picture of their impact in Narragansett Bay will require the continuation of the long-term data collection on which the new research is based.
        “Time-series studies like this are tremendously important to tracking our environment,” said Sullivan-Watts. “If you don’t have people continuously taking data the same way year after year, you don’t know what has changed.”

        This article first appeared on EcoRI.org on Septemnber 8, 2020.

Wednesday, September 2, 2020

Researchers track groundwater discharges into salt ponds

        The movement of groundwater in aquifers deep beneath the surface often carries with it a variety of contaminants that can be traced to leaking septic systems, damaged underground infrastructure, excessive fertilizer use and other land uses. But where that groundwater and those contaminants end up is often unknown.
        Using a drone with an infrared thermal imaging camera, a team of University of Rhode Island researchers led by doctoral student Kyle Young has tracked some of it to the Ocean State’s coastal ponds.
        “We’re looking to quantify the amount of nutrients being brought into our estuaries and what’s happening to those nutrients,” said Young, a Coast Guard helicopter pilot and physics teacher at the
Coast Guard Academy on leave to earn his doctorate. “The key nutrient is nitrate. In small amounts, nitrate is a good thing, but in larger amounts it can be degrading to the ecosystem.”
        Young and his advisor, URI Associate Professor Soni Pradhanang, seek to quantify the discharge of groundwater into the salt ponds as part of an analysis of what they call a “water budget” or an accounting of all of the water that flows into and out of the area.
        “We know the amount of precipitation that comes down, we can quantify how much runoff goes into stream water, but one thing that’s not easy to directly quantify is groundwater flow,” said Pradhanang. “We don’t know how much water is going from the aquifers into other water bodies.”
        Since the temperature of groundwater is cooler than the salt ponds in late summer, a drone equipped with an infrared thermal imaging camera can detect a plume of cool water in the ponds that is likely a discharge of groundwater. And that’s exactly what Young and Pradhanang Lab graduate student Jeeban Panthi and undergraduate Janelle Kmetz have found at Green Hill and Ninigret ponds.
        They flew their $10,000 drone at 400 feet over miles of salt pond coastline and captured several infrared images showing significant cool zones suggesting that groundwater is entering the pond from the bottom. Because groundwater is freshwater and less dense than the saltwater in the ponds, it rises to the surface, delivering a clear signal to the infrared camera.
        “Just because we don’t see plumes in some areas doesn’t mean there isn’t groundwater discharge there, too,” noted Young. “There could be too small of a freshwater component for it to show up in the thermal signature, or it might not be cool enough compared to the surrounding water. But one thing we can say about the plumes we found is that they have ample freshwater, signifying waters that came from the terrestrial zone.”
        What that means for the health of the coastal ponds is uncertain. Discharges such as those the researchers found have likely been going on for many years, and groundwater doesn’t always contain contaminants. But identifying their locations may be useful in tracking the movement of terrestrial pollutants into the ponds in the future.
        The discovery also has implications in the context of climate change. According to Pradhanang, the groundwater affects the salinity and pH of the pond water, which is critical to many water activities like aquaculture, as well as to the plants and animals that live in the ponds.
        If storm surges happen more frequently, as is predicted with climate change, they might affect the amount of groundwater entering the water bodies, changing the environmental conditions and negatively affecting the wildlife that lives there. “It could have implications at an ecosystem level,” Pradhanang said.
        Now that the plume locations have been identified, Young is continuing his drone flights to see how the weather and tides affect the plumes.
        “Flying highly sensitive equipment on an aircraft is high stakes research,” he said. “Quantifying how the discharge changes over time is the next step. But so far it’s nice that we’ve been able to identify the sites of possible pollution contribution to the ponds.”
        Once Young returns to the Coast Guard Academy next year, Pradhanang hopes future students will take up the project to identify groundwater discharge locations and quantities into other salt ponds, coastal and freshwater bodies, Narragansett Bay, and elsewhere around the region.