Students help make stocking home aquariums more sustainable

            As the rhythm of aquarium pumps echoed through the aquaculture laboratory at the Marine Science Magnet High School of Southeastern Connecticut, senior Hannah Roby reached her hand into a 10-gallon fish tank containing clownfish, corals and other creatures to conduct routine maintenance. It’s an activity she does just about every day as part of her aquatic husbandry course. But it’s also one element of a research project she and her fellow students are engaged in to help make the home aquarium industry more sustainable.

            About 22 million fish of 1,800 species are captured on coral reefs around the world each year to meet the demand from hobbyists who maintain marine aquariums at home, and about half of those fish are sold in the United States.

            “We don’t know if that level of take is sustainable, and we don’t know the conservation status of most of those species,” said Paul Anderson, a research scientist at Mystic Aquarium,

who advises the students. “There are destructive fishing practices happening, like poisoning reefs and dynamiting reefs, which are having devastating consequences for the fish and the coral.”

            When Mystic Aquarium sought to help figure out how to improve the sustainability of the home aquarium hobby, it turned to Roby and her fellow students in Groton. The prestigious school’s aquaculture lab, managed by teachers Eric Litvinoff and Michael Guyot, features dozens of tanks from 10 to 600 gallons in size that are used for classroom lessons as well as for research collaborations.

            “The lab was designed to be adaptable to do whatever we wanted to do to give students the opportunity to learn about aquaculture,” said Litvinoff. “Right now it’s set up for coral aquaculture, because that’s what the students are most interested in.”

            While some of the larger tanks are being used to raise barramundi and trout for sale at

local fish markets, the main focus of the lab is on developing improved methods for raising ornamental fish in captivity to reduce the need to capture fish from the wild.

            “If aquaculture can take some of the pressure off the reefs, then everyone will be better off,” Litvinoff said. “As an educator, it allows me to integrate real-world research with my students so they’re given exposure to what’s happening at the highest levels.”

            One recent project involved testing methods for breeding royal grammas, a popular purple and yellow tropical fish that seldom reproduces in captivity. The fish live in harems in the wild, so the students conducted tests to determine the optimal ratio of males and females to get them to produce the most young.

            Now the students are gearing up to test a new aquaculture feed designed for juvenile fish. Cobalt Aquatics, which makes the feed, requested that their product be tested as an alternative to feeding the fish the live food they prefer – tiny marine creatures called zooplankton.

According to Roby, who lives in Griswold, one of the challenges to breeding and raising clownfish is that it necessitates raising large quantities of zooplankton to feed the young clownfish. Large quantities of phytoplankton – microscopic marine plants – must also be raised in adjacent tanks to feed the zooplankton. To reduce this complexity, the students are preparing to try out the new food pellets on the young clownfish in hopes of eliminating the need for the zooplankton and phytoplankton.

            “Larval fish have really bad eyesight,” said Roby, who plans a career in aquaculture research after college, “but the Cobalt pellets are easy for them to see because it floats slowly in front of their face. Hopefully it will do the trick.”

            In another corner of the lab, students grow vegetables using the techniques of aquaponics, whereby waste produced by fish in adjacent tanks supplies nutrients to the plants.

            Guyot, who worked at Mystic Aquarium before becoming an aquaculture teacher at the school three years ago. said that projects like these help his students develop “an appreciation for things that are often overlooked. Things like coral. Most people just think of them as pretty rocks, but when you gain an appreciation for it, you realize how delicate their ecosystem is. If we can get that information to our students and they share it with their families, more and more people will come to care about things they didn’t know they should care about.”

            In addition, the lab also produces an enthusiastic group of future aquarium professionals.

            “The students get hands-on experience in the lab and can later enter the aquarium industry and be part of the skilled workforce that takes proper care of fish at retail or aquaculture facilities,” said Anderson. “We’ve already had students go on to marine science studies in college and enter the workforce.”

            Anthony DiPasquale, a senior from Old Saybrook, said it was the aquaculture lab and the research opportunities it offered that attracted him to the Marine Science Magnet High School. “I got interested in aquaculture because I see it as a really interesting way of combining what I love about the ocean – I’m big into fishing – with a way of helping the environment. From what I’ve learned here, aquaculture might be the future of food production, and it’s also a really cool thing to learn about.”

           

This article first appeared in the 2019 Connecticut Education Guide.

Missing out on the dawn chorus

Now that I have cruised well past the half century mark in age, I’ve been taking note – unhappily so – of those activities that remind me that I’m getting older.  I typically avoid wearing socks, for instance, so I don’t have to acknowledge the difficulties of bending over to put them on. And reading in dim light, something I used to pride myself on, is a near impossibility these days.

            Sadly, for the last few years, birdwatching during spring migration – my favorite activity of the year – has also been a reminder that I’m not getting any younger. More accurately, it’s the beautiful warblers, the most treasured of our migrating songbirds, that won’t let me forget that my hearing isn’t what it used to be.

            It started several years ago with blackpoll warblers. They spend the winters in northern South America, and some travel through Rhode Island on their way to breed in the boreal

Blackpoll warbler (Glenn Bartley/Vireo)

forests of Canada and in high elevation forests of northern New England.  The male’s formal black-and-white spring plumage includes a distinctive black cap and white cheek that is suggestive of a chickadee. But his black moustache stripe, two white wing bars, and the black streaks down the side of his white chest make him readily identifiable.

            My problem with blackpolls is that their song is among the highest pitched of all the avian songsters, and I can’t hear them anymore. They sing a rapid buzzy song that sounds a bit like an insect trill.  It’s a song that was hard for me to hear even in my younger days, but today I can’t detect them even when they’re just a few yards away. And since they only stop by our area for a few weeks each May and are typically high in the trees, my inability to detect their songs makes it almost impossible for me to find them.

And blackpolls aren’t the only ones. All of the especially high-pitched singers are dropping off my radar – black-throated green warblers, blue-winged warblers, prairie warblers, pine warblers, blackburnian warblers, worm-eating warblers, black-and-white warblers, northern parulas and more. I used to see and hear all of them around my favorite birding haunts every year in May, but while I still see some of them, I no longer hear them. And that has turned my favorite time of year into a somewhat depressing season.

On a typical spring morning when the warblers are high in the trees and a chorus of other birds are making a delightful racket, I wouldn’t know that most of the warblers were even there were it not for the younger birders pointing out from where the songs are coming. And I hate it when the young kids show me up.

Happily, my eyesight is still spot on and I’m well-practiced at finding the tiny movements of birds hiding among the foliage, so I’m often the first to see the birds that aren’t singing. But that hardly makes up for what I’ve lost.

So this year I invested in a device that transposes the high-pitched songs down to a frequency I can hear, and I’m thrilled to be hearing the warblers again. I am now bombarded by the wonderful dawn chorus that motivates me to get out of bed and start the day with a smile on my face.

I’ve even heard a few blackpoll warblers already this spring. And their buzzy little song was as beautiful as a symphony.

This article first appeared in the Independent on May 16, 2019.

Habitat project provides boost to Rhode Island's rarest toad

            Rhode Island’s rarest toad is round and short-legged with bulging eyes and a spade-shaped protrusion on its hind feet that enable them to corkscrew themselves into the ground, where they stay moist and cool and avoid predators.

But there is just one population of spadefoot toads left in the Ocean State – in Richmond – and they haven’t reproduced since 2014. Scott Buchanan, a herpetologist with the Rhode Island Department of Environmental Management, called the toads “the best example of a species that, as far as we know, is on the verge of disappearing from Rhode Island.”

University of Rhode Island herpetologist Nancy Karraker and research associate Bill

Spadefoot toad (Nancy Karraker)

Buffum are trying to forestall that possibility by constructing additional wetland habitat for them in several communities around the state.

The first of these man-made breeding pools were built May 13 to 15 on property owned by the Richmond Rural Preservation Land Trust.

“Spadefoot toads breed in the most ephemeral of vernal pools,” Karraker said. “They use what most would call a puddle in the middle of an agricultural field, with no forest canopy cover, and they’re filled by torrential storms that occur in May and June. Those big storms that produce thunder and lightning and an inch or more of rain in 24 hours brings the toads up to breed.”

When these conditions occur, the toads lay their eggs within a day, the eggs hatch into tadpoles a day or two later, and they complete their metamorphosis into toadlets and hop away into the forest three weeks after that, she said.

Unfortunately, the proper conditions haven’t occurred at the right time to inspire the toads to emerge and breed in the last five years.

Karraker studied spadefoot toads for three years in Virginia, where they are quite

Volunteers help construct spadefoot toad breeding pool (Lou Perrotti)

common, and documented their night-time emergence to feed, their travels across the landscape from forests to breeding ponds, and their corkscrew behavior back into the sandy soil.

“But we have no idea what they do here in Rhode Island,” she said.

An endangered species in the state, spadefoot toads are at the northern limits of their range in southern New England, which Karraker said means the conditions are probably not ideal.

“But they’ve been here for millennia, evolving and changing with their environment,” she said. “They just haven’t been able to deal with the fact that we’re destroying their breeding habitat.”

Karraker and Buffum are working to change that with a project they are calling Operation Spadefoot RI. They spent three years gathering funding and a coalition of partners to construct just the right kind of ephemeral pools the toads require for breeding. This week they brought together more than two dozen volunteers to construct the first two pools not far from the state’s historic spadefoot toad population in Richmond.

The partners include URI, DEM, the Natural Resources Conservation Service, the Rhode Island Natural History Survey, The Nature Conservancy, Roger Williams Park Zoo, the Rhode Island Conservation Stewardship Collaborative, the Beech Tree Foundation, and the Richmond Rural Preservation Land Trust.

Kentucky-based wetlands consultant Tom Biebighauser, who constructed 21 spadefoot toad breeding pools in Massachusetts in recent years, as well as pools for other amphibians around the U.S. and Canada, led the project. Eighteen pools were designed last year for sites in Richmond, South Kingstown and Barrington, and if they are successful at hosting breeding populations of the toads, additional pools may be constructed elsewhere.

The process involves using an excavator to dig a hole 12 to 15 inches deep and 40 to 60 feet in diameter, covering it with what Karraker called “geotextile pads” to provide a cushion beneath a specially-made liner, covering the liner with additional geotextile pads, and then spreading soil on it and scattering straw around it for erosion control.

“The reason they need such a specific kind of pool is so they aren’t competing with other tadpoles or dragonfly or beetle larvae. They’re in there by themselves,” Karraker said. “It’s an ingenious ecological strategy.”

Karraker hopes that the toads from the Richmond population will find the newly constructed pools on their own. If they do not, she intends to bring tadpoles from the historic site to the new pools. Tadpoles will have to be relocated to the pools that will be built next year on land owned by the South Kingstown Land Trust and the Barrington Land Conservation Trust.

“Our grand plan over the long term is to perhaps head-start the tadpoles at the zoo – and possibly at the Greene School to get kids interested in the project and raise public awareness of this charismatic creature – before releasing them in the new pools,” Karraker said.

“We’ve been going around the state for years looking for other breeding populations, so the chances are we would have detected them if there were any,” she added. “But maybe with an increase in outreach and public awareness, we’ll learn about other existing populations, which would be a great thing.”

This article first appeared on EcoRI.org on May 15, 2019.

Nest predators, rising waters threaten rare turtle

            Diamondback terrapins are among the rarest turtles in the Northeast, and the only ones that spend most of their lives in salt marshes and other quiet brackish waters. While populations are holding their own in many locations, nest predators are an increasingly serious threat.

            Three researchers speaking at the Northeast Natural History Conference in Springfield, Mass., last month said that in almost every year, the eggs in most of the terrapin nests they monitor are consumed by predators.

            “Raccoons are the most important predator,” said Russell Burke, a Hofstra University

Diamondback terrapin (Rhode Island Natural History Survey)

biology professor who has studied diamondback terrapins at the Jamaica Bay National Wildlife Refuge in New York City for 20 years. “Everyone who works on terrapins has had the experience of watching a terrapin put a nest in the ground, and you come back the next day and find a collapsed nest hole and broken eggs.”

            Danielle Marston, a volunteer terrapin monitor with the New England Coastal Wildlife Alliance, said that raccoons destroy most of the nests she has observed in Buzzard’s Bay, Mass., too. And George Bancroft, who monitors terrapins in the lower Taunton River watershed, also indicated that nest predation rates are very high.

            Burke worried that the tiny survey flags he placed to mark the locations of the nests he monitored could be a roadmap for raccoons to follow to terrapin nests, so he conducted a study to learn what method the raccoons use to find the nests. He placed survey flags of various colors where there were no nests, applied a human scent to other sites, dug artificial nests, and experimented with numerous other factors.

The raccoons ignored most of the sites. “They seemed to be cued more into a disturbance of the sand than the flags,” he said. “Wherever we dug a hole, the raccoons were interested. If you dig any kind of hole in the nesting area, the raccoons were likely to dig it up.”

Burke believes that microbes in the sand become active and release a detectable odor when the sand becomes aerated by digging a hole. But the smell dissipates within about a day or two.

“We get essentially no predation after the second day after nesting,” he said. “If the nests make it through 48 hours, they make it all the way to hatching, and that’s probably due to olfaction.”

He noted that there is often increased nesting activity and decreased nest predation when it rains, perhaps because the rain hides the microbe odor. “It seems to be one of the strategies that terrapins have evolved to minimize raccoon predation,” Burke said.

Those who monitor diamondback terrapin nests in Rhode Island have also found high rates of nest predation, but some are succeeding in combatting it.

At Hundred Acre Cove in Barrington, where Charlotte Sornborger has been monitoring the terrapins for nearly 30 years, between 200 and 300 nests were destroyed by predators each year during the first 15 years of her studies. In addition to raccoons, Sornborger confirmed that foxes, skunks and coyotes also predated the nests. But when she began using wire mesh “excluders,” which prohibit scavengers from digging below the surface to reach the eggs, predation rates declined significantly.

Predation at a recently discovered terrapin nesting site at the mouth of the Hunt River in Warwick was very high during the first year of monitoring in 2015 – just three of 87 nests survived to hatch – with dogs being among the chief culprits. But recent surveys have indicated that predation may not be as high as originally thought, according to University of Rhode Island Professor Laura Meyerson.

Two surprising new predators have been added to the list of threats to diamondback terrapins – bald eagles and osprey. Neither disturbs the terrapin nests, but the birds have been found to prey on juvenile terrapins in Buzzard’s Bay and in the Palmer River near the Barrington population. According to Sornborger, a hunter reported empty terrapin shells under an osprey platform used by bald eagles along the Palmer River, and two nearby homeowners also observed empty terrapin shells on their lawns.

Another new threat to diamondback terrapin populations is also emerging – rising sea levels.

“For Rhode Island’s terrapins, sea level rise is really worrisome,” said Scott Buchanan, a herpetologist for the Rhode Island Department of Environmental Management. “They live right at the margins of the coastal zone, and their habitat type is going to experience dramatic alterations and impacts from sea level rise. We don’t know what that’s going to mean for terrapins.”

            “The biggest issue for us in Buzzard’s Bay,” added Marston, “is that we’re losing ground to the big surge in tidal action at our nesting locations. The nesting area is going to disappear with the projected sea level rise. Already we’re seeing that the nests that don’t fail from predation fail from an intrusion of water into the nests. The terrapins keep trying to nest where they used to, and the nests keep getting flooded.”

            With little nesting habitat available inland of the present nesting sites, the combination of predators and rising seas makes the long-term outlook for the species uncertain.

This article first appeared on EcoRI.org on May 13, 2019.

The first to grow pearls in quahogs

            When Brendan Breen learned in a University of Rhode Island aquaculture class how oysters make pearls – and more importantly, how to artificially trigger that process – he was energized. As a teenager he had worked as a commercial fisherman, owned his own fishing boat, and put in time at a Massachusetts aquaculture business, and he was looking for an entrepreneurial opportunity in the fishing industry. With that lesson in pearl culturing, he found what he was looking for.

            The Newport resident sought to become the first person to culture pearls in the Ocean State’s official state mollusk, the quahog. “I’m surprised that no one had even tried it before,

A quahog pearl cultured by Brendan Breen

because the anatomy of the quahog is similar to the oyster,” he said. “I figured there was no reason why I couldn’t do it myself.”

            It wasn’t easy. With funding from an undergraduate research grant from URI, he spent every available hour of his junior year studying mollusk biology and pearl culture and then working in a lab to devise a method to induce the quahogs to make pearls.

            “I had to be creative and figure it out for myself,” said Breen. “I had some mortalities in the beginning, but then I got to a point where I felt my method was pretty good. So I let the clams grow, and when I came back for my senior year, I continued minding them and taking notes. Just before winter break, I harvested some of them, and I was overjoyed to find that they had produced quahog pearls down to a T.”

            A year later, he has a patent pending on his pearl culturing process and a start-up company he calls Mercenaria, named for the Latin name of the quahog. While working full time as a seafood importer, he is culturing pearls as fast as he can and waiting for them to grow to harvest size at an undisclosed aquaculture farm somewhere in southern New England. The 18-month process means he won’t have pearls ready to sell until 2020, but that is giving him the time he needs to find business partners, jewelry designers and others with the expertise to help him build his business.

            Quahog pearls are noticeably different from those produced by oysters, according to Breen. Like the colors on the inside of the quahog shell, they can range from white to dark purple. And because they are made of calcite and aragonite, rather than the calcium bicarbonate of oyster pearls, they refract the light differently.

            “It has a different kind of shimmer to it, a brilliant depth to it in the light. That’s what distinguishes it,” he said. “So if you want to be connected to the ocean and high fashion, then the Mercenaria pearl will be something you can treasure and take around the world as a new means of expressing your love of the ocean.”

This article first appeared in the May issue of Newport Life magazine.