Dead seabirds washing ashore on New England beaches

            Walking on the beach at the north end of Block Island last month, Matt Schenck stumbled upon two dead and decomposing seabirds, which the avid birdwatcher identified as great shearwaters. While gulls of various species are commonly found dead on local beaches, shearwaters are an extreme rarity.

            Except this year.

            Hundreds of great shearwaters have turned up dead on beaches on Long Island and southern New England this summer, and no one seems to know why. In addition to the birds on

Dead great shearwater on Block Island (Matt Schenck)

Block Island, birders and biologists have reported dead shearwaters on Rhode Island beaches in Tiverton and Charlestown.

            Shearwaters spend most of their lives far out to sea, where they soar just above the waves as they forage on small fish and other marine creatures near the surface of the water. Four species of shearwater – great, sooty, Cory’s and Manx – are typically seen in Rhode Island waters, though they seldom travel within sight of land. Most breed on remote islands in the South Atlantic.

            According to Josh Beuth, a biologist for the Rhode Island Department of Environmental Management, shearwaters have been observed in large numbers from the shore this year, including from Jamestown, Newport and Point Judith. They have also been seen regularly from the Block Island ferry.

            “There has been an abundance of sand eels in our local waters, which are a forage fish for shearwaters,” said Beuth. “As a result of them being closer to shore than usual, it would be more likely that they’d wash up on shore if they died.”

            While prey may be abundant, some biologists – including Linda Welch, a U.S. Fish and Wildlife Service biologist who studies great shearwaters off Cape Cod – have noted that many of the dead birds are juveniles that have been thin or emaciated, suggesting that the birds have starved.

            The dead birds began to show up on beaches in late June, which is about when they should have arrived along the East Coast after their long migration from their breeding grounds in the South Atlantic. By then they were likely stressed and tired and hungry, which may have made them susceptible to any number of potential sources of mortality.

Wildlife pathologist Joe Okoniewski examined some of the dead shearwaters found on Long Island beaches, and he told the New York Times that the birds were not only thin but anemic. “The big mystery is: Why are they thin? On the surface, it looks like you know what happened – they starved,” he said. “But when you ask why, it becomes much more of a mystery.”

It is especially mysterious if prey is seemingly abundant, as it has been this summer in Rhode Island waters.

Robert Kenney, an oceanographer at the University of Rhode Island’s Graduate School of Oceanography, speculates that toxic algae from red tides may be playing a role in the bird deaths. He said that a number of northern gannets, another species of seabird, have been found dead on Cape Cod beaches this summer. The only difference, he said, is that they are “in good condition, except for being dead.” He thinks that toxic algae may have also contributed to the deaths of some of the numerous whales that have been found dead along the East Coast and in the Gulf of St. Lawrence this year.

Among those trying to find an answer is Julie Ellis, director of the Seabird Ecological Assessment Network at the Tufts University Veterinary Medical Center, which uses volunteers throughout the Northeast to regularly walk beaches to collect dead birds for study. She is reaching out to a number of animal diagnosticians throughout the region in hopes that together they can come up with a consensus of what is causing the shearwater deaths. She hopes they will have an answer next month.

This article first appeared on EcoRI.org on August 10, 2017.

Mako sharks killed at far higher rate than officials estimate

Brad Wetherbee and his research team have been capturing and tracking the movements of mako sharks since 2004, and more than 25 percent of those affixed with satellite transmitters have been caught and killed by commercial or recreational fishermen.

            That mortality rate is more than 10 times the rate estimated by the international body responsible for managing the world’s mako shark fishery and far higher than is sustainable.

            Wetherbee, a shark researcher at the University of Rhode Island, along with Mike Byrne

Tagged mako shark (Photo by George Schellenger)

and other colleagues at the Guy Harvey Research Institute at Nova Southeastern University, published a paper in last week’s edition of the journal Proceedings of the Royal Society B documenting the mortality of the sharks they have been monitoring. They hope it will influence the fishery managers to take steps to reduce the catch of mako sharks.

            ““Makos are caught in all kinds of fisheries all around the world – gill netters, long liners, commercial, recreational,” he said. “They’re the shark everyone wants to catch because they’re good to eat – like a shark version of swordfish. But if our results are anything close to the true mortality rate, then they’re in trouble.”

            Wetherbee admits that his results may not be reflective of the mortality the sharks face everywhere, and he said that there are some people who think that makos are being fished sustainably. But he also believes it would be irresponsible not to report the mortality rate of his study specimens.

            “The fishery managers are faced with a lack of data about mako mortality,” Wetherbee said. “But based on our experience, the sharks are being killed at a much higher rate than they’re estimating, which means overfishing is probably occurring.”

            Wetherbee and his colleagues tag as many as 20 mako sharks each year – though some years they catch far fewer – off the coast of the mid-Atlantic states, the Yucatan Peninsula of Mexico, and Rhode Island. Each one is affixed with an electronic tag that provides data for approximately one year about the daily movements of the sharks.

            “So we know where they are in near-real time,” he said. “When they’re caught, we can follow them right to shore to someone’s dock or their house.  We were surprised how often that was happening.”

            His tagged sharks have been caught and killed by fishermen in the waters off Canada, Cuba, Mexico, Portugal, New Zealand and throughout the East Coast of the United States.

            Last summer, Wetherbee made a public plea to fishermen in southern New England when one of his tagged sharks was tracked to local waters just as a number of shark fishing tournaments were scheduled. He asked anyone catching a mako shark with a satellite tag to release the animal unharmed. The shark survived the tournament season but was killed by fishermen off North Carolina a few months later.

            Wetherbee said that those responsible for managing the mako shark fishery are expected to issue an updated stock assessment this fall, and he expects they will take into consideration the results of his research. He also hopes that new policies will be proposed to reduce the number of mako sharks caught in the commercial and recreational fisheries.

            “I’m not sure what they’ll do, but I hope they at least recognize that however they’re currently keeping track of mako shark mortality doesn’t appear to be very accurate,” he said. “Our data should help them get a better idea of what’s going on and give them more information to manage the population.”

            Wetherbee and his colleagues also believe that the use of satellite tracking data for estimating shark mortality is a novel methodology that may be useful in other fisheries.

            “Using electronic tags to learn the fate of individuals in a fishery is a pretty new way of estimating mortality,” said Mahmood Shivji, director of the Guy Harvey Research Institute. “But there’s no mistaking when a tag is reporting from shore that the shark is dead. It’s a known fate, as opposed to the estimates currently used. There’s promise for researchers to use the same technology on other species for estimating mortality.”

Commercial trawling damages fragile seafloor habitat

Commercial fishing gear that is dragged along the seafloor to capture species that live on, in or near the ocean bottom has long been criticized for damaging sensitive habitats and catching innumerable non-target species. It disturbs sediments, destroys corals, and removes many of the organisms that commercial species feed upon.

            But a new study of the predominant bottom trawling methods used in the North Atlantic found that some gear is more damaging than others.

Scallop dredges at a pier in The Netherlands (Jeremy Collie)

            Jeremy Collie, an oceanography professor at the University of Rhode Island and a member of the international team of scientists that conducted the study, said that trawling is controversial because it can affect entire ecosystems.

            “It’s a serious problem, but we’re finding that it’s a very localized problem,” he said. “The distribution of where bottom fishing takes place is patchy, and the habitat we care about is patchy. Where those two things intersect is where the problem is.”

            The researchers examined 70 previous studies on the effects of bottom trawling to determine which methods were most harmful.

            Otter trawling, which is used to catch cod, haddock, flounder and other fish near the bottom and is the most common fishing method in New England, uses two large metal doors to hold open the net as it drags along the seafloor. It was found to be the least harmful of the methods assessed. Otter trawls killed six percent of the marine organisms in its way each time the net passed, according to the study published July 17 in the Proceedings of the National Academy of Science.

            The researchers also studied beam trawling, a method that uses a metal beam to hold open the net; towed dredges that drag a toothed metal bar along the seafloor, used in New England’s scallop fishery; and hydraulic dredges, which use a jet of water to loosen the seabed to capture surf clams and ocean quahogs living in the sediment.

            Hydraulic dredges caused the most damage, killing 41 percent of animal and plant life on the seabed.

            “The degree of damage caused by each gear type can be characterized by how far the gear penetrates the seafloor,” Collie said. “The further it penetrates, the more damage it causes.”

            While some critics have argued that the most damaging gear should be banned, Collie said that approach could close entire fisheries, since each gear type is designed to harvest a targeted species.
            "Rather than banning a particular type of gear, spatial management can be used to restrict them to particular areas or to prohibit their use in closed areas," Collie said. "The information from our studies should help to inform spatial management."

            In addition to calculating the mortality caused by each bottom trawling method, the study also estimated how long it would take for various habitats to recover from trawling.

The study found that sandy habitats that are typical of large areas of the continental shelf are likely to recover from trawling in just a few months, especially if they are only trawled once or twice each year. But habitats with gravel or cobblestones could take a decade or more to recover.

“And in areas that might have biogenic epifauna, like cold water corals or glass sponges, recovery times could stretch from decades to centuries,” Collie said. “Those species grow slowly, or once you wipe them out, it’s harder for their larvae or juveniles to re-establish themselves.”

This study is part of the Trawling Best Practices Project, which is examining the impact of trawling worldwide and plans to publish trawling guidelines for the fishing industry that focus on preserving the marine ecosystem.

“From my perspective, we want to identify the vulnerable habitats and protect them, recognizing that they are a small fraction of the total area,” Collie said. “For the New England shelf, there are large areas that we don’t need to be concerned about and large areas of sandy sediment where trawling effects are not a concern. Small areas like gravel and complex habitats, and those that are fished by scallop gear, are the areas we need to focus in on.”

The next step in the project is to complete a global analysis of what Collie called “the footprint of fishing” that will identify the areas where trawling effort is greatest. The researchers will also examine the indirect effects of bottom trawling – how trawling affects the ability of certain habitats to produce fish. The project will conclude with the creation of a methodology that fishery agencies around the world can adopt to better manage their fisheries.

This story first appeared on EcoRI.org on August 4, 2017.

Fish haven

            At the public boat ramp to Quonochontaug Pond in Charlestown, a dozen volunteers wearing rubber boots and work gloves loaded thousands of pounds of clam and oyster shells into black plastic fish totes, then rolled them along a 50-foot conveyor and onto a small maroon barge. From there, the empty shells were transported to the eastern and western edges of the pond and carefully dropped over the side.

After a week of work in mid-May to ensure that the proper quantity of shell was placed in the proper locations, construction was complete on nine oyster reefs to provide habitat for juvenile fish. It will take a year or more to determine if the effort is a success, but biologists from The Nature Conservancy and the Rhode Island Department of Environmental Management are

Oyster shells are delivered to site of new reef. Photo by Mike Derr

confident that the new reefs will soon be home to juvenile striped bass, tautog, black sea bass, scup, and summer and winter flounder.

“Shellfish reefs are an important habitat for juvenile fish, but the amount of shellfish reef in Rhode Island is greatly reduced compared to what we historically had,” said Eric Schneider, DEM’s principal marine fisheries biologist.

“The idea is that there are certain areas in the ponds that don’t have good structure – reefs, rocks, something that gives fish somewhere to hide – but if we build some structure, the fish will come,” added The Nature Conservancy’s Scott Comings.

The biologists said that about 95 percent of the state’s oyster population has disappeared since the mid-1900s, largely due to over-harvesting, poor water quality and diseases. In the mid-Atlantic states, researchers found that juvenile fish move right in to man-made reef habitat in areas where it no longer exists. So the Conservancy and DEM decided to give it a try.

The project got started at Ninigret Pond, where 130 tons of shell were used to construct eight reefs in 2015. Each began with a base layer of clam shells that was then covered with a thick layer of oyster shells piled up to about two feet below the waterline at low tide.

“After it’s spent some time in the water, you start to get a host of species like crabs and snails and starfish colonizing the area,” Comings explained. “It becomes a little hub of life, a mound of shell that moves and changes just as nature would intend.”

Monthly surveys of each reef using fish traps, video cameras and other techniques found that many of the expected marine species have moved in and taken up residence, including several of the targeted fish.

Where do all those empty shells come from? Local restaurants, of course. Most originate with diners at Matunuck Oyster Bar, but other restaurants occasionally participate as well. The 20,000 oysters consumed at last year’s Newport Oyster Festival are also being used in the reefs.

“This project offers me something to do with the byproduct of our oysters without sending it to the landfill,” said Perry Raso, owner of Matunuck Oyster Bar. “It’s important that we incorporate sustainability into our business model, and while it might not be easy to see the benefits of going through all this effort, we’re happy to do something that’s good for the environment.”

After the shells are collected from the restaurants, they are stored in massive piles for “seasoning” at the Great Swamp Management Area in South Kingstown, where they are turned over several times during a six-month period, just as one would turn a compost pile for better decomposition. The turning ensures that all of the shells are exposed to the air so any leftover flesh decomposes. The shells are certified by the Coastal Resources Management Council as restoration material before they are deployed in the ponds.

After the reefs are constructed, they are “seeded” with year-old live oysters – wild strains from Green Hill Pond and the Narrow River, as well as the variety used at aquaculture farms – in hopes that the empty shells will eventually be covered with living oysters. The biologists also hope that larval oysters drifting with the currents from nearby oyster farms will settle on the new reefs.

“Oysters need something to set on, so without the reef they have nowhere to go,” Comings said. “But while we hope the oysters thrive, this project is really about benefiting juvenile fish.”

Next year, DEM and the Conservancy will build one more series of reefs in another coastal pond before shifting to sites in Narragansett Bay.

This article first appeared in South County Life magazine on August 1, 2017.

Is it lights out for the firefly?

            Remember the summers when so many insects would splatter on your car’s windshield that you had to scrub them off to get a decent view through the glass? You probably haven’t had to do that nearly as often as you used to. And while you may be happy to avoid that chore, it is an unfortunate sign that insect numbers have declined dramatically in recent decades.

            Researchers have found that the total mass of insects in some areas has declined by as much as 80 percent since the 1980s, and that has dramatic implications for wildlife, especially for bats and insect-eating birds like flycatchers, swifts and swallows.

            One of those insects that is noticeably absent from many fields and forests these days is the popular firefly. I remember fondly the summer days of running through my neighborhood

Cartoon by David Chatowsky in Newport Daily News

fields and forests just after dusk trying to catch lightning bugs in a glass jar, then watching the captured insects blink on and off until bedtime. It’s an experience that few of today’s children have had, since fireflies are harder and harder to find in any numbers.

            An excellent new book called Silent Sparks by a Tufts University professor sheds light on the natural fireworks display put on by native fireflies. Sara Lewis calls the flickering lights a “spectacular bioluminescent courtship display” in which males emit a specific pattern of illuminated pulses. The males of the most common firefly species in New England, Photinus greeni, produce a distinctive pair of pulses separated by 1.2 seconds, followed by a four second pause before repeating the pulses. If he’s lucky, an interested female will reply with a single prolonged flash that rises in brightness before fading.

            “Each time he shines his light, the male pauses for an instant in hopes of spotting a female,” she wrote. “So tonight it’s wink, wink, hover and hope…wink, wink, hover and hope.”

            Sadly, that hope is more and more turning to hopelessness. Even in locations where firefly numbers are relatively high, males often struggle to find a mate, since females are often outnumbered by males 20 to 1. In many areas, males may flash for days without getting a response.

            Repeated flashing by fireflies can be costly, as the illumination not only signals their location to receptive female fireflies but also to predators seeking to eat them.

            The reasons for the disappearance of fireflies – and so many other once-common insects – is unclear. Habitat disturbance is an obvious one. Most firefly species are found around fields and forests and marshes, which in many areas have given way to pavement and houses and shopping centers. Pesticides and other pollutants are likely contributing factors as well.

            Surprisingly, light pollution has also been implicated in the decline of fireflies. Since the insects use their flashing lights to communicate, the abundance of man-made lighting from streetlights, stores and cars is believed to make it difficult for the insects to signal each other. And those species that synchronize their flashes during courtship get out of sync when a car’s headlights pass by.

            So the next time you see the flashing of a firefly in the evening, celebrate the memories these cherished insects provide, and mourn the fact that few in the younger generation will be able to share those memories.

This article first appeared in The Independent on July 20, 2017.

Eelgrass declining in Rhode Island waters

           Michael Bradley calls eelgrass “the canary in the coal mine for estuarine health.” The flowering plant that grows beneath the surface of coastal waters and salt ponds provides nursery habitat for shellfish and finfish while also dampening wave energy, stabilizing sediments and serving as an indicator of clean water.

            But according to a recently issued report by the University of Rhode Island’s Environmental Data Center, eelgrass in Rhode Island is declining in Narragansett Bay and in

Eelgrass photo  courtesy of NOAA

most of the state’s coastal salt ponds.

            The report found 1,144 acres of eelgrass and other submerged vegetation in state waters, an 18 percent decrease from 2012. The largest declines occurred in Quonochontaug Pond (52 percent), Point Judith Pond (48 percent) and Little Narragansett Bay (25 percent).

            More than half of the state’s eelgrass occurs around Jamestown, which experienced a 19 percent decrease in eelgrass acreage. Ninigret Pond was the only coastal pond not to have a decrease, and the Narrow River was the only site that experienced a significant increase (45 percent) since 2012. 

            “It’s difficult to know exactly what’s going on,” said Bradley, a URI research associate and lead author of the report. “The reasons can be varied. An increase in water temperature could have something to do with it. Pollution in the water or soil could have something to do with it. And severe storms like Hurricane Sandy could certainly affect it. We need more surveys, more data and more analyses to get a better handle on what is determining eelgrass changes.”

            Eelgrass beds can also be degraded by algal blooms or disease or be physically damaged by human activities like shallow-water boating, dredging, and construction of docks and other structures.

            Data for the report was collected by aerial surveys funded by the Rhode Island Coastal Resources Management Council.

            Bradley said that the decline in eelgrass is worrisome. “If you care about shellfish, if you like to have scallops, if you care about commercial or recreational fishing, then you should care about eelgrass,” he said. “The bottom line is that’s where the little critters go to hide to become big critters that can become commercially or recreationally available.”

            Anecdotal reports suggest that eelgrass was abundant throughout Narragansett Bay a century ago, but most of it was wiped out during the 1930s and 1940s due to a naturally-occurring disease. When the first aerial surveys of eelgrass were conducted in 1996 by Save the Bay and the Narragansett Bay Estuary Program, they found just 100 acres of eelgrass in the bay.

            “Those results spawned a big restoration effort,” Bradley said.

            When Bradley conducted his first aerial surveys of eelgrass in Narragansett Bay in 2006, he found that eelgrass acreage had tripled to about 300 acres.

            “What we learned, though, was that technology has come a long way,” he said. “The survey methods were very different from 1996, based on new technology, so we have to be very careful when we compare the results.”

            The results of a 2012 survey showed a further increase in eelgrass acreage before declining in 2016.

            This year, Bradley intends to conduct an accuracy assessment of the 2016 mapping using underwater video cameras and global positioning systems to determine how much error is associated with the aerial survey method. He will also test the use of drones for conducting future surveys.

            What can be done to ensure that eelgrass doesn’t continue to decline in the state? That’s another question without an easy answer.

            “Anything we can do to help clean the bay would be useful. But there are not enough pictures and not enough numbers to base confident policy and management decisions on yet,” Bradley said. 

Recent right whale deaths have scientists worried

            The deaths of six North Atlantic right whales in the Gulf of St. Lawrence last month have raised alarms among whale biologists who fear for the future of one of the rarest whales on Earth.

            Robert Kenney, a marine mammal expert at the University of Rhode Island’s Graduate School of Oceanography, called the unexpected deaths “a major concern” because the population of right whales totals fewer than 500 animals and their numbers have been declining since 2011. The dead whales represent more than 1 percent of the population.

            While the deaths raise many questions, one of the first, according to Kenney, is what were they doing in the Gulf of St. Lawrence in the first place?

            “Right whales go to the same places to feed every year – the Great South Channel, the Bay of Fundy, the Nova Scotia shelf – feeding grounds they probably learned from their mothers in

North Atlantic right whale mother and calf (Center for Coastal Studies)

their first year of life,” said Kenney, who manages the sighting database for the North Atlantic Right Whale Consortium. “But recently they seem to be wandering farther afield. If there’s not enough food where they traditionally feed, they go to other places. That’s what we think is going on.”

            What caused the deaths of the six whales in the Gulf of St. Lawrence – the water body surrounded by Newfoundland, Quebec, Nova Scotia and New Brunswick – is uncertain. Preliminary results of necropsies on three of the animals showed evidence of blunt trauma from ship strikes on two of the whales and fishing gear entanglement on the third. But a news release from Canada’s Marine Animal Response Society said that other problems that "may have predisposed these animals to this trauma cannot be ruled out at this stage."
            Kenney is suspicious that a toxic algae bloom or some sort of disease may have been a factor. In 1987, a dozen humpback whales died from eating mackerel laced with a red tide toxin, he said.

            Right whales were nearly driven to extinction due to commercial whaling. They were slow to recover, though their population increased steadily at about 3 percent per year from the 1980s through 2010, with what Kenney called “a little blip” in the late 1990s.

            “That little blip is exactly the same thing that’s happening right now,” he said. “Survival rate didn’t change; that’s been relatively constant all the way through. What changes is the number of calves being born. At the end of the 90s the number of calves born dropped off for three years. Since 2010, the number of calves has been lower than the number needed to replace the average mortalities in six of eight years, and just barely positive in the other two.”

            Just five right whale calves were born this year, so the death of six whales last month ensures that the population will decline again, regardless of whether any other animals die during the rest of the year. Prior to the six deaths in the Gulf of St. Lawrence, one right whale died from a ship strike in April off Cape Cod, where the animals feed in late winter and early spring.

            “The decline in the birth rate is more concerning now because climate change might have a hand in the changes taking place in the food supply,” Kenney said.

            According to Kenney, the copepod the right whale’s eat, Calanus finmarchicus, may no longer be found in dense and long-lasting patches in the places the whales usually find them, due largely to warming ocean temperatures and the changing currents and circulation patterns.

            Kenney said that one reason he is worried about the health of the right whale population is that “too many are still being killed that don’t have to be.”

            In recent decades, most right whales have died from human causes -- ship strikes or fishing gear entanglement. The ship strike issue has improved, thanks to regulations requiring ships to slow to 10 knots when traveling through areas where whales are known to reside at certain times of year. But the fishing gear entanglement issue seems to be getting worse.

            “The National Marine Fisheries Service has been nibbling at the edges of this issue for a long time because they aren’t willing to impose severe measures on the fishery,” Kenney said. “The agency responsible for promoting the fishery is the same agency responsible for regulating marine protected species. That was a dumb idea when it happened during the Nixon administration and it’s still a dumb idea today.”

            The conservation community has proposed that fishermen be required to use ropes with a breaking strength of 1,700 pounds on their buoy lines in nearshore waters, and that the government support expanded testing of gear without any buoy lines. Research by NewEngland Aquarium and others on rope strength and the muscle power of whales has shown that most whales would be able to disentangle themselves by breaking 1,700-pound ropes. But the fishermen are using stronger and stronger ropes. Some ropes removed from entangled whales had breaking strengths up to 12,000 pounds.

            While Kenney is concerned about the right whale population, he is less concerned about the humpback whale population, despite the 47 humpbacks that have been found dead along the East Coast since 2016, including one that washed ashore on Jamestown and two on Cape Cod last month.

            North Atlantic humpbacks were removed from the federal endangered species list last fall, and Kenney said that as the population increases, higher levels of natural and human-caused mortality are expected.

            “Given the large number of live humpbacks along the mid-Atlantic this winter, I suspect that there are more than the usual number of juveniles chasing food relatively close to shore – like the one that was seen repeatedly just off the Narragansett Pier seawall – and putting themselves in harm’s way,” he said. “Ship strike and entanglement mortality for all species is highest in juveniles.”

This article first appeared on EcoRI.org on July 7, 2017.