Monday, December 17, 2018

Researcher: Oyster aquaculture limits disease in wild oyster populations

                A fisheries researcher at the University of Rhode Island has found that oyster aquaculture operations can limit the spread of disease among wild populations of oysters. The findings are contrary to long-held beliefs that diseases are often spread from farmed populations to wild populations.
                “The very act of aquaculture has positive effects on wild populations of oysters,” said Tal Ben-Horin, a postdoctoral fellow at the URI Department of Fisheries, Animal and Veterinary Sciences in the College of the Environment and Life Sciences. “The established way of thinking is that disease spreads from aquaculture, but in fact aquaculture may limit disease in nearby wild populations.”
                Working with colleagues at the University of Maryland Baltimore County, Rutgers
Oyster farm in Delaware Bay (Tal Ben-Horin)
University, the U.S. Department of Agriculture, and the Virginia Institute of Marine Science, Ben-Horin integrated data from previous studies into mathematical models to examine the interactions between farmed oysters, wild oysters and the common oyster disease Dermo.
Their research, part of a synthesis project at the National Center for Ecological Analysis and Synthesis, was published this week in the journal Aquaculture Environment Interactions.
                According to Ben-Horin, diseases are among the primary limiting factors in wild oyster populations. There are few wild populations of oysters in New England because of Dermo and other diseases, and in the Chesapeake Bay and Delaware Bay, wild oysters are managed with the understanding that most will die from disease.
                Dermo is caused by a single-celled parasite that occurs naturally in the environment and proliferates in the tissue of host oysters, which spread the parasite to other oysters when they die and their parasite-infected tissues decay in the water column. But it takes two to three years for the parasite to kill the oysters. As long as the oysters are held on farms long enough to filter disease-causing parasites from the water, but not so long that parasites develop and proliferate and spread to wild oysters nearby, aquaculture operations can reduce disease in wild populaitons.
                The disease does not cause illness in humans.
                “As long as aquaculture farmers harvest their product before the disease peaks, then they have a positive effect on wild populations,” Ben-Horin said. “But if they’re left in the water too long, the positive effect turns negative.”
                He said that several factors can confound the positive effect of oyster aquaculture. Oyster farms that grow their product on the bottom instead of in raised cages or bags, for instance, are unlikely to recover all of their oysters, resulting in some oysters remaining on the bottom longer. This would increase rather than reduce the spread of the disease.
                “But when it’s done right, aquaculture can be a good thing for wild oyster populations,” Ben-Horin said. “Intensive oyster aquaculture – where oysters are grown in cages and growers can account for their product and remove it on schedule – is not a bad thing for wild populations.”
                The study’s findings have several implications for the management of wild and farmed oysters. Ben-Horin recommends establishing best management practices for the amount of time oysters remain on farms before harvest. He also suggests that aquaculture managers consider the type of gear – whether farmers hold oysters in cages and bags or directly on the seabed – when siting new oyster aquaculture operations near wild oyster populations.     
The next step in Ben-Horin’s research is to gain a better understanding of how far the Dermo parasite can spread by linking disease models with ocean circulation models.
                “Everything that happens in the water is connected. There’s a close relationship between the wild and farmed oyster populations and their shared parasites,” he said. “Sometimes ecosystem level effects are overlooked, but in this case they’re front and center.”

Sunday, December 9, 2018

Outlook dismal for rebuilding region's winter flounder stocks

            Winter flounder is one of the most popular fish among recreational anglers and commercial fishermen, due in part to their thick fillets and great taste. Once abundant in Rhode Island waters, their numbers have declined significantly in recent decades, and new research suggests that the warming climate will likely make it impossible to rebuild their stocks to targeted levels.
            The study, led by a former research associate at the NOAA Northeast Fisheries Science Center in Narragansett, concluded that even if fishing were to be curtailed entirely, winter flounder populations are unlikely to rebound.
            According to Rich Bell, who now works as a fisheries scientist for The Nature Conservancy, winter flounder is a cold-water, coastal species that spawns in estuaries like
Winter flounder (Jerry Prezioso/NOAA)
Narragansett Bay and Buzzards Bay during the fall and winter when most other flounders migrate south or offshore. Their eggs and larvae develop in the estuaries during the coldest months of the year.
            “During the 1980s and 90s they were overfished, and it seems that they never really recovered,” said Bell. “We believe that they come into the bays to spawn in winter where they have a thermal refuge from predation. When it’s cold, there are no predators around, giving them time to grow big enough before it warms up and the predators arrive.”
            The concern is that as the climate has warmed and spring arrives earlier and earlier, the predators are now arriving before the larvae have a chance to grow big enough to escape. Common predators on larval winter flounder include sea robins, summer flounder, sculpins and crangon shrimp.
            By combining winter flounder population models with climate models, Bell and his NOAA colleagues projected future population numbers as the climate continues to heat up. They factored in three fishing scenarios into their models: no fishing, moderate fishing representing a small fishery or incidental catch, and fishing at the expected long-term sustainable level assuming the stock was rebuilt to historic levels.
            “We found that as temperature increases, it’s going to be more challenging for the population to recover. And more importantly, even if there is no fishing and the temperature goes up as expected, they may be unable to reach the targeted recovery level,” said Bell.
            A large part of the problem is that winter flounder produce fewer young in warm waters. The species is now rarely caught in southern estuaries like Chesapeake Bay, and numbers are way down in Delaware Bay and Long Island Sound.
            “There might be so few in Long Island that there are subtle signs of inbreeding occurring,” he said.
            Bell notes that winter flounder are not headed toward extinction. Populations are healthy in colder water regions like the Gulf of Maine, Georges Bank and the Canadian Maritimes. But the continuing declines in southern New England raise challenging questions for their management.
            “It becomes a larger issue of what do we as a society want to do,” Bell said. “Do we want to stop fishing them entirely? Do we want to fish them all now before they’re gone?”
            While Bell wasn’t willing to weigh in on those questions, he said the phenomenon of cold-water fish species experiencing a decrease in productivity and an increase in mortality is not exclusive to winter flounder. Other researchers are documenting similar results in other species as ocean temperatures rise.
            Whether the target levels for rebuilding winter flounder stocks are even plausible is another question. Bell said that those targets are based in part on data collected in the 1960s and 70s before significant warming had occurred and when the species was reproducing at high levels.
            “Rebuilding plans developed assuming constant rates for demographic variables such as growth, reproduction and mortality may not be realistic for stocks like winter flounder,” he said.
The research was published in September in the Canadian Journal of Fisheries and Aquatic Sciences. 

This article first appeared on EcoRI.org on December 7, 2018.

Friday, November 23, 2018

New testing system provides early warning of toxic algae blooms

            When a large bloom of harmful algae appeared in lower Narragansett Bay in October 2016 – and again in early 2017 -- the state’s testing methods were not refined enough to detect it before the toxins produced by the algae had contaminated local shellfish. That scenario is not likely to happen in the future, now that the Rhode Island Department of Health’s laboratories have acquired new instrumentation and analytical tests to detect the toxins early and to determine when they have dissipated enough so shellfish harvesting may resume.
            “It’s an improved early warning system so we don’t have to worry about future problems with harmful algae blooms,” said Henry Leibovitz, the chief environmental laboratory scientist at the Department of Health. “We’re trying to safeguard public health, safeguard our shellfish economy, and safeguard the state’s shellfish reputation.”
            The new testing system was approved in September by the Food and Drug Administration’s National Shellfish Sanitation Program, which regulates the interstate sale of shellfish.
            The 2016 and 2017 blooms, which Leibovitz said were the first harmful algae blooms to occur in Narragansett Bay, forced the closure of parts of the bay to shellfishing and required that some previously-harvested shellfish be removed from the market. It was caused by the
Pseudo-nitzschia (Rozalind Jester)
phytoplankton Pseudo-nitzschia, which, when concentrated in large numbers, can produce enough of the biotoxin domoic acid to contaminate shellfish and cause those who eat the shellfish to contract amnesic shellfish poisoning.
            Another kind of plankton, Alexandrium, produces a biotoxin that can cause paralytic shellfish poisoning. Both Pseudo-nitzschia and Alexandrium occur in Rhode Island waters year-round, but they are only harmful when concentrations are high and the toxins they produce reach 20 parts per million.
            According to Leibovitz, the state’s previous testing system was “a primitive screening test” somewhat like a pregnancy test – it could determine whether the toxins had reached the limit, but not how far over or below that threshold they were. And it was not sensitive enough to detect the lower concentrations of the toxins that would signal that the bloom had dissipated and shellfish harvesting could begin again. To reopen shellfish beds to harvest, the state had to send water and shellfish samples to a private laboratory in Maine, the only lab in the country capable of conducting the test at the time.
            Now that Rhode Island has an FDA-approved lab, it is offering its services to nearby states.
            The state's Harmful Algae Bloom and Shellfish Biotoxin Monitoring and Contingency Plan directs the Rhode Island Department of Environmental Management to collect weekly water samples from areas of the bay where shellfish are harvested. The samples are tested in the Department of Health lab. If large numbers of harmful algae species are found, the plankton are tested to determine the concentration of toxins they are producing. If toxin concentrations are high, shellfish are then tested and a decision is made whether to close particular areas to harvesting.
            The problem of harmful algae blooms has been an annual concern along the coast of Maine for many years, and scientists speculate that it could be a more frequent problem in southern New England in coming years, too.
            “We think the problem is knocking on our door,” said Leibovitz, “and we need to be prepared for it, not only for public health but to protect our strong shellfish economy. Imagine the damage that would occur to our reputation if contaminated shellfish was identified as coming from Rhode Island. People have a long memory for something like that.”
            Public awareness of the risk from harmful algae blooms was raised this year as a result of the months-long red tide in Florida, which killed fish and marine mammals and sickened many people. It was the result of a bloom of a plankton species that produces a toxin called brevetoxin, causing neurotoxic shellfish poisoning in people who eat infected shellfish.
            What triggers the algae to bloom is what Leibovitz calls “the $60,000 question. A lot of people are studying it, including some at the University of Rhode Island, and there are a lot of theories behind it, but there’s nothing conclusive. There’s speculation that the cleaner bay means that the harmful species don’t have the competition that they used to have, but that hasn’t been proven,” he said.
            The bloom of harmful algae in Narragansett Bay in 2016 and 2017 led Rhode Island Sea Grant to fund research to try to answer some of the questions raised by the bloom. Researchers from URI and elsewhere are investigating whether bacteria that accompany the plankton may influence the amount of domoic acid produced; whether nitrogen from the sediments may fuel the blooms; and whether nutrients from outside the bay played a role.
            “The fact that we had our first harmful algae bloom doesn’t mean we’ve had our last,” concluded Leibovitz, “not with it happening every year in Maine. But now we’ll be way ahead of the curve in recognizing when there’s a problem developing.”

This article first appeared on EcoRI.org at November 23, 2018.

Monday, November 19, 2018

Bird feeders attract bird eaters

            As much as I love wildlife documentaries on television, I always get queasy when they focus on predators like lions and hyenas.  I love learning about the life cycle and behavior of these amazing creatures, but I have a difficult time watching as one beautiful animal catches and tears apart another beautiful animal.
            Yet it’s not just on TV that I watch this happen. It happens all the time around my bird feeders in my backyard, too.
            We often think of bird feeding as a hobby that benefits the birds. And it is.  But some of the birds that it benefits are hawks that feed on other birds. That’s because some hawks have discovered that active bird feeders – with their unnatural abundance of wildlife – are an easy place to find a snack. 
            Occasionally when I glance out the window at my feeders to see who is about, there is an
Cooper's hawk at a bird feeder (H. Gilbert Miller)
unusual scarcity of birds. And the birds that are visible often look like miniature statues, frozen in place for long minutes at a time.  It’s during these tense moments that I know a hawk is nearby.
            It’s usually a Cooper’s hawk, whose narrow wings and long tail enable it to maneuver quickly through the forest and capture fast-moving prey like songbirds. And their affinity for small birds is why they appear at bird feeders so often.
            Glancing out my back window last week, I saw a burst of motion out of the corner of my eye. Appearing as if out of nowhere, a Cooper’s hawk swooped over the roof and dove at my feeders like a stealth bomber.  In that brief moment, the congregating songbirds were forced to make a life or death decision – should I fly away and hope to outrun the intruder, or should I freeze in place and hope it doesn’t see me.
            Those that froze made the better decision.  A male nuthatch stopped in its tracks on the trunk of a maple tree, head pointed downward like he was about to tumble to the ground. A like-minded downy woodpecker was perfectly positioned on the underside of a branch and out of view of the marauding hawk.  And a tufted titmouse appeared to me to be in full view but was ignored or unnoticed by the hawk.
            The rest of the birds that had been at the feeders took off in a storm of feathers and alarm calls, probably hoping that the hawk was homing in on one of the others.  A flock of goldfinches at the thistle feeder flew away en masse to confuse the hawk in a tornado of yellow and black bodies. But one goldfinch reacted just a little slower than the others. That’s the bird the hawk targeted, and that’s the bird the hawk ate for breakfast.
            I know that many people are uneasy when a hawk is seen around their feeders, and they want to discourage the predators from visiting. But hawks have to eat too, and they play an important role in the food chain by consuming the ill and injured. So it’s better if we simply appreciate the opportunity to get a close-up look at wildlife doing what wildlife does. Like when we watch those public television documentaries.
            It was about ten minutes before the nuthatch and the woodpecker and the titmouse felt safe enough to move again.  And soon after, the goldfinch flock returned to the thistle feeder. To them, it was just another day.

This article first appeared in the Independent on November 15, 2018.

Saturday, November 3, 2018

Upper bay fish survey yields surprising results

            Due to the historically degraded water quality in upper Narragansett Bay, the fish that spend all or part of their lives there have seldom been studied. But as improvements have been made to the wastewater treatment plants in the area and the water quality has improved in recent years, more and more recreational fishermen have been observed reeling in a variety of fish species.
So The Nature Conservancy teamed with the Rhode Island Department of Environmental Management to conduct a baseline study of fish found from Conimicut Point in Warwick to the Pawtucket boat ramp on the Seekonk River. And the results have been somewhat surprising.
William Helt, a coastal restoration scientist at the Rhode Island office of The Nature
Conservancy who is leading the project, said the survey is an effort “to learn what fish are using that area and what the residence times are for those species. We want to get a gauge for how these sites compare to other areas in Narragansett Bay that are considered the healthy parts of the bay.”
Once a month from May to October, Helt and a team of scientists and volunteers visit 12 coastal sites, including Gaspee Point in Warwick, Sabin Point in East Providence, and Stillhouse Cove in Cranston, to survey for fish.
Using a beach seine net – a 130-foot long net with weights at the bottom and floats on top – one member of the research team holds an end of the net on shore while a boat deploys the rest of the net and drags it in a semi-circle back to shore. Any fish collected are counted, identified and released.
“We’re looking at the estuary as a nursery habitat for juvenile fish, so most of the fish we’re catching are about the length of your finger,” Helt said.
The researchers also used fish pots – similar in size and design to a lobster trap – to target larger fish like black sea bass.
While the data has yet to be analyzed or compared with the results from similar surveys in the lower bay and South County’s salt ponds, Helt said they have captured large numbers of bait fish like silversides, mummichogs and killifish. One day at Sabin Point they captured about 140,000 menhaden at one time.
“That means there’s a lot more fish utilizing the upper bay than we thought,” he said.
The net catches juvenile fish popular among local anglers as well, like tautog, winter flounder and scup. And at the mouth of the Seekonk River it collected freshwater species, including white perch and bluegill. It even caught some unexpected southern species like pufferfish and pipefish.
“We haven’t caught as many scup as we thought we would,” Helt said. “They might tend not to favor the close-to-shore habitat that we’re sampling. But we see so many people fishing for scup that we thought we’d catch more.”
Helt would have preferred that the study had started several years earlier to detect how fish populations changed as water quality improved, though he anticipates continuing the project for many years in order to assess changes to fish populations due to warming waters and further improvements to water quality.
The project may also get extended beyond the May-to-October time frame of the first two years.
“That’s when juvenile fish activity is highest; most migrate out of the estuary by October or November,” Helt said. “But we’re seeing plenty of fish in May and October, so we’ve thought about extending it for a couple extra months.”
The data the scientists have collected so far has already got them thinking about habitat improvements that could be made in the upper bay to accommodate even larger numbers of young fish.
Assuming that permits can be secured from the Rhode Island Coastal Resources Management Council and other agencies, Helt said that The Nature Conservancy and DEM anticipate deploying 80 to 100 “reef balls” – four-foot diameter concrete structures with holes in them – just beyond the Sabin Point fishing pier.
“The reef balls tend to aggregate fish,” he explained. “They eventually get fouled with colonizing organisms that provide a food base for juvenile fish, and they provide structure for small fish to hide in. We hope they’ll improve that critical life stage of juvenile fish and attract sport fish that people like to catch.”
The reef balls will likely be deployed in 8 to 10 feet of water just beyond the casting range of recreational fishermen.
The fish survey results may also lead to efforts to improve salt marsh habitat, which also plays an important role in nurturing juvenile fish.
“And in the salt ponds we’ve been studying the use of oyster shell reefs to improve fish habitat. We might do a similar project in the upper bay,” Helt said. “But we’ve got a lot of hurdles to overcome between now and then. That’s a long-term goal.”
The fish survey and subsequent habitat restoration projects are being funded by the U.S. Fish and Wildlife Service’s Sport Fish Restoration Program.

This article first appeared on EcoRI.org on November 2, 2018.

Tuesday, October 30, 2018

Cutting bacteria's cell service

            Scott Ulrich is working to create a drug that disrupts the communication system that bacteria use to coordinate disease-causing behaviors, and he was just awarded a major grant from the National Institutes of Health to help him do it.
            The Ithaca College associate professor of chemistry will use the three-year $360,000 grant to design complex molecules that will block the communication system known as quorum sensing.
            “Bacteria communicate with each other using chemical signals,” explained Ulrich. “When their signaling is engaged, the population undertakes a new behavior. Sometimes that behavior causes diseases in people. If we can block that signaling, then the behaviors the signaling controls would also be suppressed. I want to accomplish that by creating a drug-like inhibitor.”
            Ulrich has been studying quorum sensing for more than a decade. In his previous work, he and two students – in collaboration with scientists from Princeton University – created a drug that blocked the bacterial signal detector, essentially making the bacteria deaf so they did not know that other bacteria were trying to communicate. Now he is attempting to render the bacteria mute by preventing their ability to generate a communication signal in the first place.
            “This is a very hard thing to do. Few other chemists have found such drugs,” he said. “Several IC students and I have worked without much success since 2010 to set up the biochemical system needed to find such compounds. I was ready to give up.”
            Then came Erin Higgins, a biochemistry student who insisted on working on the project last year despite Ulrich’s repeated advice not to.
            “She re-created the signal generation system in a test tube using purified bacterial proteins, and it actually makes the signaling molecule,” he said. “Now we can add candidate drugs to the system to see if they block the process of making the signal. It’s the most impressive work I’ve ever seen an undergraduate do. Her results led directly to the grant and serve as the foundation for the work my students and I will do for many years.”
            There is still plenty of difficult work ahead. Ulrich said that the enzyme that produces the communication signal provides clues to the kind of organic structures that might block the system from working. And he already has some designs in mind. So his students will spend the next three years building as many different kinds of molecules as they can and testing to see which ones are most successful at disrupting the bacteria from communicating.
            “The ideal outcome would be to find a molecule that blocks the quorum sensing signal production without requiring a large dosage,” Ulrich said. “Generally, more potent compounds work better against the intended target and are safer.”
            Assuming he succeeds at building an effective molecule, his next step would be to work with his Princeton collaborators to test the molecule to see if it inhibits the disease-causing behavior.
            “That’s the outcome we’re looking for,” he said.

This article first appeared on the Ithaca College News website on October 30, 2018.

Tuesday, October 23, 2018

Award-winning carver brings wooden birds to life

            When Ray Tameo was a young boy and his friends invited him to play baseball, he usually turned them down in favor of going birdwatching. The retired highway bridge designer from Attleboro later combined his passion for birds with his interest in duck hunting and began experimenting with carving duck decoys.
            Today, Tameo is an award-winning bird carver whose carvings are in numerous private collections and exhibited around the region. He will be one of a dozen carvers who will display their work at the Audubon Society of Rhode Island’s annual Bird and Wildlife Carving Exposition in Bristol on November 3 and 4 from 10 a.m. to 4 p.m.
            “I’m entirely self-taught, and the longer you’re at it, the better you get,” said Tameo. “The more you put into it, the more you get out of it.”
            Tameo’s carving evolved from duck decoys to small songbirds, which typically take him about 125- to 150-hours to complete. Working in his basement workshop or garage, depending
on the weather, he carves highly detailed birds perched in lifelike settings. His carvings are made almost exclusively from tupelo wood from Louisiana because of its light weight, absence of grain, whitish color and ease of carving.
            “It also takes paint beautifully,” he said.
            The first step, he said, is to draw the bird’s profile on the wood, then cut it out using a small band saw.
“From that, I put a centerline down the middle and start shaping the bird and cutting off excess wood. Then I use Dremel tools – a rotary tool – to start shaping it finer and finer. Once that’s done, I do relief carving.”
            For the final details, he uses an Exacto knife to give texture to the feathers and finishes with a burning tool. Painting the birds involves two coats of acrylic sealer and seven or eight layers of paint.
            “I’m very meticulous; I’m a perfectionist,” he said. “Down the road, I’m going to be long
gone, and my carvings are going to be in somebody’s house, so I don’t want to produce a mediocre bird. I want a bird that will last. It will speak for me when I’m gone.”
            Most of Tameo’s carvings are commissioned by clients and collectors he meets at exhibits like the Audubon show. One man in Bristol has purchased 17 of his shorebird carvings over the last five years.
            While he occasionally enters carving competitions or gives lessons to beginning carvers, Tameo said he’s too busy to focus on anything but the work his clients commission him to produce. He just finished painting carvings of an eastern bluebird perched next to an abandoned woodpecker hole and a Baltimore oriole on a maple tree branch. He even carved each maple leaf on the branch. Now he is in the early stages of work on a three-quarter size common loon and a life-sized black-capped chickadee and northern cardinal.
His most visible work, however, was done for Greg Esmay, the owner of the popular Old Grist Mill Tavern in Seekonk, which burned down in 2012 after a tractor trailer rolled over, slid into the building, and ruptured a gas line. Prior to the fire, the restaurant displayed Esmay’s extensive collection of antique duck decoys, most of which were damaged in the fire and subsequent demolition of the structure. Tameo restored 35 of them.
            “I put new heads on some, made other repairs on others, and I made them all look antique-ish again,” he said proudly. “Then he asked me to carve three Canada geese flying that I mounted on a piece of wood from the original restaurant.”
            The geese are now hanging over the rebuilt restaurant’s fireplace. Esmay purchased several original Tameo carvings as well, including a puffin and kingfisher.
            Out of all of his carvings, Tameo is most proud of his rendering of an eastern meadowlark perched on a barbed wire-wrapped fencepost, the bird’s head tilted back and its beak open wide as if in full song.
            “That’s my favorite,” he said. “I won’t part with that one.”
            The Bird and Wildlife Carving Exposition takes place at the Audubon Nature Center and Aquarium, 1401 Hope St., Bristol. In addition to the exhibition of finished carvings, some of the participants will demonstrate their carving techniques. For more information, visit www.asri.org or call 401-949-5454. Admission is $5.

This article first appeared in EcoRI.org on Oct. 18, 2018.

Saturday, October 20, 2018

Rhode Island at crossroads of migration express

Plenty of Rhode Islanders have begun making plans to migrate south for the winter. For almost all, the move is entirely about the weather. They’re trying to avoid the cold and snow and ice that invariably comes with winter in the Ocean State.
Lots of different kinds of wildlife are preparing to make a similar move, and while the weather has a lot to do with it, their migration is often driven by the availability of food.
Birds are the animals most frequently associated with migration. Every fall, billions of birds take off from Canada and the northern U.S. and head to South America, Central America, the Caribbean and the southern states in search of a reliable food supply. Most are bug eaters seeking a location where insects are abundant during the winter months.
Seed eating birds don’t usually migrate as far as the bug eaters. Many sparrows, finches
and other seed-eaters end their migration in southern New England, knowing that seeds and berries – and bird feeders – are abundant here during the winter. Those species also have unique physiological adaptations to weather the weather here.
But birds aren’t the only animals for whom migration is a successful strategy. And not all travel in the same southerly direction.
Bats for instance. Those that roost in trees for the winter, like red bats and hoary bats, do so in the southern U.S. after a short fall migration. But those that hibernate in caves, including little brown bats and tricolored bats, migrate north from Rhode Island to caves and mines in New Hampshire, Vermont and upstate New York where the temperatures remain steady at about 40 degrees throughout the season. Many big brown bats don’t migrate at all, choosing instead to spend the winter here with the rest of us.
Some butterflies and dragonflies are in the midst of migration right now. Monarchs are the most famous of them all, traveling to the mountains of central Mexico to winter. But it’s not uncommon to see swarms of dragonflies like green darners or wandering gliders along the coast or even out over the ocean at this time of year as they seek warmer climes.
Reptiles and amphibians in our area are on the move now, too, though their movements are comparatively short. Some frogs just move from local ponds to nearby forested upland areas, while others seek out a comfortable spot in the mud or along a stream. Garter snakes often migrate to communal dens underground to hibernate.
In many mountainous states, especially in the West, migration occurs in a vertical direction. Mammals like elk, mountain goats and bighorn sheep migrate from high elevations down to lowlands to escape winter’s icy conditions to where they can find food more easily.
Migration happens in the ocean environment, as well. Harbor seals are now beginning to arrive in Narragansett Bay after breeding along the coast of Maine and the Canadian Maritimes. Humpback whales are on their way to the Caribbean to breed during the winter months. Bluefish and striped bass are headed south to warmer waters, too, and horseshoe crabs are slowly making their way to deep water after summering along the coast.
So as you make your winter migration – regardless of where your plans take you – don’t be surprised if you’re joined by some of Rhode Island’s wild summer residents.

This article first appeared in the Independent on October 18, 2018.

Thursday, October 4, 2018

Solution to lobster shell disease remains elusive

            Despite more than 20 years of declining lobster populations in southern New England and extensive studies of the shell disease that is a major factor in their decline, scientists are still struggling to provide definitive answers to help restore hope to those working in the local lobster fishery.
            A new study of lobsters along the eastern Connecticut coast has found that the disease is linked to warming water temperatures, while progress is slow in efforts to identify probiotics to counteract the disease and to better understand why so many lobsters are blind.
            “Epizootic shell disease first appeared around 1996 and became quite prevalent around 1999, and it continues to be prevalent,” said Maya Groner, who conducted the Connecticut study
Diseased lobster (Jeff Shields/VIMS)
as a post-doctoral researcher at the Virginia Institute of Marine Science. “It’s been a challenge to figure out what the pathogen associated with the disease is. The best evidence suggests it may be a suite of bacteria that chews away at the carapace, but that suite of bacteria changes over the course of the disease.”
            Her study found that the increased prevalence of the disease stems from warmer water temperatures that induce the lobsters to molt their shells earlier than usual.
            Using data on 200,000 lobsters collected over 37-years in Waterford, Conn., as part of the biological monitoring near the Millstone Nuclear Power Station, Groner found that about 80 percent of male lobsters have the disease during warm years, with females contracting the disease at a slightly lower rate.
            “Molting their shell resets their health,” she said. “If they don’t molt, there’s no way they can recover. But now that they’re molting earlier in the spring, the molt happens before they’re even challenged with the disease.” And the earlier molt allows the disease to progress longer than if the lobsters molted in summer, as they typically do.
            Groner found that for every 1.8 degree increase in the average temperature of the bottom-water in May, lobsters molted about 6 days earlier. In early-molting years, disease prevalence doubled by September.
            “It’s very consistent with trends we’ve seen with other marine diseases,” Groner said. “Organisms at the southern part of their range – like lobsters in Long Island Sound – are limited by temperature. They’re at their thermal tolerance limit. So as temperatures increase, they’re becoming stressed and less able to cope with diseases.”
            University of Rhode Island fisheries researcher Kathy Castro has been studying lobsters for more than two decades, and she decided to look for a solution to help lobsters recover from the disease even though the precise cause of the disease was still uncertain. She is collaborating with URI colleagues who are studying probiotics on oysters.
            “Why can’t we identify good bacteria that normally occur on lobsters, take the bad bacteria off, and repopulate their shells with good bacteria?” she wondered. “In essence, the idea works, but we don’t know what’s the right bacteria, how do we treat the lobsters, how often, and how to do it in a reasonable time frame.”
            In a laboratory setting, Castro’s URI colleagues David Nelson and David Rowley isolated probiotics from healthy lobsters and tested them against what they believe may be the “bad bacteria.” The strategy looked promising. Initial trials on adult lobsters were positive as well. But it may not be practical.
            “Our initial idea was that lobstermen could treat the lobsters on their boat,” she said. “But it’s hard to do; you have to do it in a lab. Maybe we still haven’t identified the right probiotic. And are we even working with the right pathogens?”
            While that work is continuing, Castro is investigating why about half of the lobsters she has tested are functionally blind.
            “That’s a more concerning issue to me than shell disease,” she said. “My question is, is it related to shell disease. The lobster’s endocrine control system is located in their eye stalk, so if a lobster is blind, is it molting incorrectly, and is that contributing to the disease.”
            Castro said a colleague in Virginia thinks the cause of the blindness may be manganese, a neurotoxin that harms optic nerves and is released from sediments under low oxygen conditions. But studies are just now under way.
            “In my mind, it has to be related to shell disease. That’s my gut feeling,” she said.
            One of the challenges to finding the answers has been inadequate research funding, Castro said, so much of the research is being done piecemeal.
“I really wish there was something fundamentally easy that we could do to solve all these problems,” she said. “That would be my greatest dream. But I know it takes time. And as much as we know about lobsters, there’s a lot more we don’t know.”

This article first appeared on EcoRI.org on October 3, 2018.

Friday, September 28, 2018

South County's role in monkey conservation

            Down a long unpaved driveway deep in the woods of northern Charlestown is not the place that one would expect to find an international organization dedicated to protecting monkeys and other primates around the world. After all, the only wild primates for more than 1,500 miles are humans.
            Nonetheless, this unexpected location is the headquarters of Primate Conservation Inc., a non-profit foundation that funds research on many of the world’s 511 species of primates. Led by the group’s founder and director Noel Rowe, the organization plays a vital role in studying
Noel Rowe with a Barbary Macaque (photo by Marc Meyers)
rare primate species, protecting their habitats, and defending them from hunters.
            “Generally, primates aren’t doing well in the wild,” Rowe said. “The weed species – the macaques, howlers, capuchins, the generalists that get along with people – they’re doing all right. But a lot of the others are in trouble. The gibbons, for instance, are all in trouble. They need big ranges and big forests. They’re targets because they’re loud and easy to hunt. And a lot of the Asian leaf monkeys are critically endangered.”
            Primate Conservation provides small grants to graduate students and scientists to study primates of all sorts in tropical locations around the world. Since 1993, Rowe has raised more than $1 million and awarded 650 grants for primate studies in 29 countries.
            The key to protecting primates is having researchers in the field as often as possible to discourage hunters and those that might destroy the animals’ habitat, Rowe said. “The science is part of it, but it’s mostly just having people there. They know where the animals are, and they’re hiring local people who start to take pride in them.”
            Retired from a long career as a photographer, Rowe grew up in Cincinnati but spent many summers in Weekapaug. He became interested in primates as a child after visits to the Cincinnati Zoo.
            “I worked at the zoo, I went to a school that had a zoo, and I was always interested in wildlife. But mostly, I always wanted to grow up to be a monkey,” he said with a grin. “They climb, they play, and they always seem like they’re having a good time.”
            In the 1980s, Rowe served as a volunteer on primate research projects in Madagascar, Borneo, Ethiopia and Thailand. While enrolled in a class at Stony Brook University with noted primatologist Patricia Wright – who is now Rowe’s fiancĂ© – he asked if there was a book showing all of the primates in the world. Wright said there wasn’t one, and she suggested that he take on the project himself. It took him four years and the formation of his own publishing company, but his Pictorial Guide to the Living Primates came out in 1996 featuring all 234 species known at that time.
            Since then, more than 100 new primate species have been discovered in the wild, and behavioral and genetic studies have revealed nearly 200 more. So he spent 12 years editing an 800-page volume called All the World’s Primates, which came out last year and includes 505 species. Six more species have been discovered since it was published.
“We just lived through the golden age of primate discovery,” he said. “It’s been a revelation.”
Rowe was responsible for one of those discoveries. The Tonkin snub-nosed monkey of northern Vietnam hadn’t been seen since before the Vietnam War, but in 1992 Rowe was shown a recent photo of an infant Tonkin snub-nosed monkey. So he and a friend traveled to Vietnam – when it was still illegal for Americans to do so – and met with local scientists.
“They were sure we were from the CIA, but they took us to the forest where they’d found the baby, and three days before Christmas we had a glimpse,” he recalled. “I took the first bad picture of the species in the wild. But we proved it was there and saw a whole group of them. I came back and got the Wildlife Conservation Society involved to study them.”
Rowe still travels the globe regularly to photograph primates, attend conservation conferences, raise money for his foundation, and meet with people who study primates.
"Noel is fully heart, soul, and mind dedicated to primate conservation and helping his fellow humans in the cause," said University of Rhode Island anthropologist Holly Dunsworth, who studies the evolution of primates. "He's a fantastic photographer and he writes authoritative, highly respected reference volumes on primates, with his color photos of their wonderful diversity in appearance, behavior and ecology. Anthropologists, primatologists and zoologists around the world rely on Noel's work for their science, scholarship and conservation."
He is also always looking for ways to raise awareness about the threats facing the animals.
“There are a lot more people involved in primate conservation than there used to be, so that’s a very good sign. And some species are recovering, like the golden lion tamarin in Brazil,” he said. “But the human population keeps expanding, so the forest keeps getting smaller. And then you have climate change, which is throwing a monkey wrench into things, because sea level rise is going to flood the low forest and the high elevation species can’t go any higher.”
While Rhode Islanders may think there is little they can do to improve the situation for primates in distant countries, Rowe has a long list of suggestions, starting with writing your Congressional delegation to protect the Endangered Species Act. The landmark legislation, which is constantly under threat of being weakened, has been instrumental in slowing the primate pet trade and the trade in bush meat.
“And if you travel to the tropics, be aware of where your money is going,” he said. “Is it going to an ecotourist operation or a local group protecting the animals you’re going to see, or is it going to some big business that’s taking the money out of the country? Responsible tourism is very important.”

This article first appeared in the Fall 2018 issue of South County Life magazine.

Thursday, September 27, 2018

Tracking the changing populations of migratory birds

            In a tiny plywood shed deep in the woods of South Kingstown, migrating songbirds of numerous sizes and colors twitched in the darkness of small cloth bags hanging on hooks. The birds, some of which began their journey in the boreal forests of Canada and were headed for South America, stopped off in South County to rest and refuel, but they became entangled in fine nets set up at the Kingston Wildlife Research Station.
            Julie Shieldcastle disentangled the birds and placed them in the bags as she prepared to process them. She weighed and measured each one, then secured an aluminum band around their legs before releasing them to continue their long migration. It’s a project that has taken
place nearly every day from mid-August through early November for more than 60 years on this 82-acre property just off Route 138. The data collected about the birds has revealed dramatic insights about changing bird populations, expanding ranges, and the effect of climate change on the birds that travel through the region.
            “It’s a great place for documenting the long-term trends in bird populations in a typical southern New England landscape,” said ornithologist Peter Paton, the University of Rhode Island professor who has managed the site with Professor Scott McWilliams since 1998. “And the fact that it’s near the coast means that it’s used by a large number of migratory birds.”
            The research station is the former home of Douglas Kraus, a URI chemistry professor and avid birdwatcher who began banding birds on his property in the late 1950s. When he died in 2000, he left his house and land and all of his records to the Audubon Society of Rhode Island, along with an endowment to continue operating the site as a bird research facility.
“It’s one of the longest continuously-running bird banding stations in North America, so it really gives you insights into what’s happening to the avian community over time,” Paton said.
For instance, the nets at the site captured about 133 birds for every 100 hours of operation in the 1960s, whereas the capture rate in recent years is just 24 birds per 100 hours. The diversity of species captured has changed little through the years, but the number of individuals is way down.
“It’s quantifying what Rhode Island’s older birdwatchers have observed,” Paton said. “There are a lot fewer birds around than there used to be.”
The data also documents how southern species have expanded their ranges northward in recent decades. Birds like the tufted titmouse and Carolina wren were seldom captured when Kraus began banding birds, but now the titmouse is one of the most commonly captured species each year.
“We’ve also documented changes in the chronology of fall bird migration,” added Paton. “As the climate warms, birds are migrating an average of two days later per decade.”
            It’s not just URI researchers that have access to the data, however. Scientists around the country regularly contact Paton to gather information about particular species or about regional migratory trends for national and international studies. Last year, for example, a scientist from Ithaca College used data collected at the site for an analysis of whether two species – the blue-winged warbler and golden-winged warbler – should be lumped together and considered a single species. The Kingston data indicated that the golden-winged warbler migrates earlier than its blue-winged cousin and its wings are slightly longer, which helped the researcher argue that the birds should remain separate species.
            In addition to its value as a bird research facility, the Kingston Wildlife Research Station is also prized as a site for hands-on education. Students in URI ornithology classes visit regularly to get close-up views of the species they are learning about and to try their hand at banding the birds.
            On a recent class visit, Paton and a group of 21 students checked each of the 15 nets on the property every 30 minutes to disentangle the birds. Among the species they captured were blackpoll warblers, white-throated sparrows, gray catbirds, a northern waterthrush and a rarity – a Kentucky warbler. Prior to releasing each of the birds, Paton pointed out key features of each species, demonstrated how to determine their age and gender, blew on their belly feathers to reveal how much fat they had stored, and discussed their migration routes by showing a map of each bird’s range on his cell phone.
            The next time the students checked the nets, they returned to the banding shed with more blackpoll warblers and white-throated sparrows, along with a swamp sparrow that had already been caught once that day.
            “This has not been a good day for that bird,” Shieldcastle announced as she released the sparrow for the second time.
            What’s next for the Kingston Wildlife Research Station? Paton said there is funding available to continue the bird banding operation for many years to come. And a recent restoration of some of the property’s habitat is leading to new research to evaluate how various bird species respond to those changes.
            The biggest question, however, is whether the downward trend in the number of birds captured each year will continue.
            “The numbers are dwindling pretty low for a lot of species,” Paton said. “Hopefully we’re not documenting the demise of a lot of these birds, though it looks like that’s sort of what we’re doing.”

This article first appeared in the Fall 2018 issue of South County Life magazine.

Wednesday, September 26, 2018

Keep an eye out for Rhode Island's cutest animal

            Otters have been on my mind a great deal lately. That’s partly because I spent the last four years writing a book about sea otters, the adorably cute, hand-holding, tool-using marine creatures found exclusively on the West Coast. But it’s also because I’ve enjoyed several recent encounters with river otters here in Rhode Island, and I’m captivated by their playful behaviors.
            Members of the weasel family with long, streamlined bodies and a flattened head, river otters are somewhat common in the Ocean State anywhere there is fresh water. Charlie Brown, a wildlife biologist for the Rhode Island Department of Environmental Management, has found
more than 450 locations – spread throughout every community in the state except Block Island – where otters haul themselves out at the edge of ponds, lakes and rivers.
            Not that the animals are easy to see. River otters are shy and secretive. Most of my sightings have been near dusk or dawn and are typically quite brief. But your chances of seeing one are pretty good if you pay attention when passing by local waterways almost anywhere you go.
            If you catch a glimpse of one, take a moment to enjoy it, because it will surely leave you smiling.
            At the Great Swamp Management Area in Kingston, I watched as an otter darted across a dike and dragged itself through a muddy area on its way to a pond where it proceeded to give itself a bath. Near the Scituate Reservoir last winter, an otter reclined on a frozen pond while it chewed on a freshly-caught fish. And somewhere along the North South Trail in the western part of the state, two otters appeared to be doing what looked like synchronized swimming – side-by-side loop-de-loops just below the surface of the water. Whether they were chasing fish, rinsing off, or just having fun is something I’ll never know.
            My favorite river otter observation occurred in Washington, where I was looking for sea otters but instead came across a mother river otter taking her four pups on a hunting expedition. None of the young ones seemed to have much success during the 10 minutes I watched, but a pair of noisy ravens was perched on a rock nearby, looking like they were planning to steal whatever the little guys caught.
            If you want to go looking for a river otter, now is a good time, because some of the pups born last spring are beginning to venture out on their own, searching for available territories and practicing their hunting skills. And they’re at the age when they’re most playful – wrestling in the water, chasing each other around and around, sliding down hills, and practicing their fighting skills.
            It’s hard to say, but I think river otters in Rhode Island may be a little less skittish than those found in other regions. That may be because the Ocean State is the only place east of the Mississippi that does not have a trapping season. Trapping of river otters was banned by law in Rhode Island in 1970.
            That’s not to say that otters don’t have a reason to fear people – or at least their vehicles. Charlie Brown has documented nearly 100 river otters struck and killed by cars in the state in recent years, and he’s sure it happens far more often than that.
            So drive slowly near your local pond or stream, and watch for the telltale signs of what may be Rhode Island’s cutest animal.

This article first appeared in The Independent on September 20, 2018.

Friday, September 21, 2018

Rare beaked whales may not be so rare after all

            A month-long survey of the deep waters from George’s Bank to the continental shelf south of Rhode Island has turned up an unexpectedly large number of a little-known whale, and scientists are excited that they were able to tag one of the animals for the first time.
            True’s beaked whales were first identified in 1913 and have seldom been observed anywhere in the world since then. Yet researchers from the Northeast Fisheries Science Center in Woods Hole, Mass., saw and heard several of the elusive animals almost every day during their expedition from July 20 to August 19.
            “Deep-diving cetaceans such as beaked whales are difficult to study due to their cryptic nature and their offshore distribution. But they are an important part of the deep-water marine
True's beaked whale (NOAA Fisheries under MMPA permit 21371)
ecosystem,” said Danielle Cholewiak, the chief scientist on the project. “Beaked whales are an extraordinary group of species, adapted for an extreme lifestyle. They dive to incredible depths to forage and spend long periods of time deep underwater.”
            Portsmouth native Annamaria Izzi, one of the biologists participating in the expedition, jokingly described True’s beaked whales as looking “like ugly upside-down dolphins” with no teeth inside their mouth but two teeth sticking outside their mouth that males use to fight with each other.
            Every day during the research cruise, Izzi and her colleagues deployed an array of hydrophones – underwater microphones – that were dragged behind the ship to listen for whales.
            “We went from knowing nothing about them to having interesting clicks on the hydrophone and a couple visual approaches that cued us in to what they look like and sound like,” Izzi said. The clicking sounds were created by the whales using their echolocation abilities to navigate in the darkness of the deep water. “Beaked whales are similar to bats in their use of echolocation,” she added.
            This year’s expedition was a follow-up to similar efforts in 2016 and 2017 that resulted in the discovery of what Izzi called “hotspots of acoustic detection of beaked whales,” mostly near the Northeast Canyons and Seamounts Marine National Monument south of Cape Cod.
            “The noise they make is supersonic; you can’t hear it, so you have to see it,” explained Izzi. “A computer program takes in the sounds detected by the hydrophone and gives a visual representation of it.”
            One of the main accomplishments of the expedition was the tagging of one True’s beaked whale using what scientists call a digital acoustic recording tag attached to the whale with a suction-cup. The device recorded the movements and acoustic behavior of the whale for about 12 hours before it came off and was recovered.
            “The data from this tag gives us the first detailed glimpse into the underwater behavior of True’s baked whales,” said Cholewiak. “We are excited about the new insights we can glean about this species.”
            The scientists will soon compare the diving behavior they recorded of the True’s beaked whales to the behavior of other species of beaked whales.
            Izzi said the expedition raised a lot of new questions.
            “I’m focused on the acoustic aspect of these whales, so I’m really interested in learning more about what we’re recording with the towed array,” she said. “The hydrophones are at the surface while the whales are diving deep, and they’re only clicking when they’re down deep. I know I’m not getting all the clicks they’re emitting, so I wonder what part of the diving sequence I’m picking up. What am I hearing and how is that different from what they’re actually producing?”
            The scientists also collected water samples in the immediate vicinity of where the beaked whales swam in an effort to collect bits of whale DNA.
            “Environmental DNA, or eDNA, is DNA left in the environment when an animal passes through it,” said Cholewiak. “It’s an exciting tool that may provide a better understanding of species identity and population structure, just from sampling water.”
            A dozen eDNA samples were collected by the scientists and paired with biopsy samples and whale photographs to match the DNA samples to specific animals.
            Why are True’s beaked whales being found in good numbers in the waters off southern New England? Izzi said it’s because the whales prefer the habitat around small island chains or underwater mountains, and the edge of the continental shelf and the seamounts in the new marine monument provide that unusual habitat.
            “A lot of previous studies have been around the Canary Islands, the Bahamas, or around San Clemente Island off Southern California,” she said. “We don’t have any deep-sea islands around here, but we do have deep-sea seamounts, which are a good place for upwelling and primary productivity, where there’s more prey availability that can support large populations of whales.”
            Izzi said the next step in studying True’s beaked whales in the region is to place more tags on the animals.
            “We have information that gives us a first look at the species, but it’s only based on one tag for 12 hours. Every whale is different,” she said. “We really need to get more tags on more whales. Our chief scientist is interested in looking at group structure and creating a photo ID catalog of individual whales based on their unique scar patterns. And we want to keep working with this eDNA approach to see if it works for beaked whales.”
            The research is being conducted as part of the Atlantic Marine Assessment Program for Protected Species, an annual survey sponsored by the National Oceanic and Atmospheric Administration to assess the populations of marine mammals in area waters. The program focuses on the collection of seasonal data on the abundance, distribution and behavior of marine mammals, sea turtles and seabirds in the U.S. Atlantic Exclusive Economic Zone.

This article first appeared on EcoRI.org on September 20, 2018.