Posts Tagged ‘Bob Prescott’

Yikes! 11-Foot Blue Shark in Wellfleet Bay

Saturday, October 25th, 2008

Male Blue Shark (Prionace glauca) in Wellfleet Bay

Holy mackerel!  Has Jaws wandered into paradise?  Who will save the children?  Who will save the turtles?  Where is Quinn when you really need him?

Amazing Find on the Tidal Flats off Lieutenant Island

Not often does a large pelagic shark find its way into the shallows of Wellfleet Bay.  They prefer the deep, cool waters of the Atlantic Ocean.  On a few occasions in fall, Don has encountered basking sharks scooping plankton from high tide flooded creeks and coves within the Wellfleet Bay estuarine system.  But an 11-foot blue shark is a surprising find on the tidal flats off Lieutenant Island.  Yes, Virginia, the very same tidal flats where kids from four to one hundred four play all summer long, and much more importantly, where we all go wading in chest-high water for terrapins.  Kind-a gives you goose bumps down your spine, doesn’t it?  No doubt we’ll add another risk waiver form for interns and volunteers for the 2009 research season.

Sue Wieber Nourse Provides Sizing Perspective

Sue, proudly sporting her Williams sweatshirt, provides sizing perspective for the leviathan.   This male shark measured 3.37 meters (almost precisely 11 feet) from the point of his snout to the trailing tip of his caudal fin.  The fork length (snout to center of caudal fin fork) was about 8.5 feet.  And, yes, the more scientific length is the fork length measurement, but the 11-foot shark headline reads so much more impressively than an 8.5-foot shark. 

The dorsal fin rose 28 centimeters (11 inches) above his back. 

We had no scale nor a means to get one to the scene.  The only estimate of weight comes from Don Lewis as he moved the critter for various measurements and then for the necropsy.  His back suggests a weight in the range of 250+ pounds, supported by estimated shark length-to-weight charts.

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Blue Shark from Tooth to Tail

What an extraordinary opportunity to examine such an apex predator at close quarters!  October’s low sun angle enhanced the shark’s blue hue, casting long, deep shadows that magnified his powerful form.  These signal moments spark heightened excitement for humans when adrenaline spikes as you approach animals that can actually eat you.  “Lions and tigers and bears, oh my!”  No question; you can add blue sharks to that mantra as they are listed among the top ten “world’s most dangerous sharks.”

You appreciate the animal’s lethal power as you take measurements, none more impressive than teeth size, mouth width and gape.  Once adrenaline levels subside, a feeling of sadness and a sense of loss rise.  The unexpected death of such a magnificent creature that fills a critical niche in the ocean ecosystem is disconcerting.  We hope that a quick in situ necropsy might provide a clue to this blue shark’s demise.

Bob Prescott & Brad Timm Observe as Don Lewis Prepares for Necropsy

Since “Quinn” is long gone and Greg Skomal wasn’t in town, we did the best we could without a shark expert on hand.  Between Bob Prescott (Wellfleet Bay Wildlife Sanctuary director), Sue Wieber Nourse (Jaeger Chair for Marine Studies at Tabor), Brad Timm (UMass Amherst) and Don Lewis (Turtle Guy), we managed a quick examination of the blue shark’s internals.  The animal was extremely fresh.

Powerful Blue Shark with Wellfleet Bay in Background

In summary, we found no smoking gun.  No identifiable premortem injuries or abrasions. Lots of parasites in and on the liver, in the stomach and in other cavities.  Nothing else in the stomach except for a few remnant fish eye lenses and nothing else we could detect within the gastro-intestinal tract.  The GI sysem was largely devoid of food.  We collected samples of parasites, liver tissue and tissue from beneath the dorsal fin.  We have no conjecture beyond mere guesswork about the cause of death.

Open Wide and Say, “Ah”

First Cold-Stunned Sea Turtle of 2008 Rescued

Friday, October 24th, 2008

The Cape Cod Times, “Kemp’s Ridley Turtle Found Stranded,” reports this morning, “The first cold-stunned Kemp’s ridley [sea] turtle of the stranding season was rescued in local waters yesterday [October 23rd], according to the Massachusetts Audubon Wellfleet Bay Wildlife Sanctuary.”  Bob Prescott, director of the sanctuary, noted that the turtle weighed about 8 pounds and was estimated at around four years old.  It had an old boat propellor injury on its left front flipper that may have weakened the turtle and predisposed this animal to early cold-stunned stranding.

Cold-Stunned Kemp’s Ridley Sea Turtle (File Photograph)

Cold-stunned strandings of endangered sea turtles occur each fall in Cape Cod Bay.  These juvenile reptiles, usually two to five years old, become trapped by walls of cold ocean water within the warmer hook of Cape Cod during normal southward migration as temperatures drop early each fall.  When bay water plunges to around 50F, these turtles become cold-stunned, enter a stupor-like state and are tossed on the beach by sustained winds.

The earliest standed turtles, usually found in late October or early November, have the smallest mass, weighing in at five pounds or less.  As the season progresses, larger and larger animals succumb to cold-stunning and are tossed by autumn storms onto the beach.  Species include Kemp’s ridleys, green sea turtles and loggerheads, which are the more massive and usually the last ones to strand.  Occasionally, a hybrid or a hawksbill has been known to strand on Cape Cod beaches.  All strandings, with only an exception or two to prove the rule, occur on bayside beaches from Provincetown to Sandwich, with the greatest numbers found between Truro and Dennis.

Yesterday afternoon’s turtle was discoverd by beach walkers on Sandy Neck beach in Barnstable, brought to the Wellfleet Bay Wildlife Sanctuary for stabilization, and then transported to New England Aquarium for medical treatment and rehabilitation.

Two-Year-Old Kemp’s Ridley Sea Turtle Rescued from Chapin Beach, Dennis

You may recall that the Turtle Journal team rescued a small, pre-stunned Kemp’s Ridley at nearby Chapin Beach in Dennis on September 5th (see Saving a Critically Endangered Sea Turtle).

What to Do if You Find a Sea Turtle

Sea turtles are federally protected and cannot be legally handled without an appropriate license.  If you see a sea turtle in distress on the beach, NEVER return it to the water.  Move it above the high water mark, cover it with dry seaweed to prevent additional hypothermia, mark the spot with some gaudy flotsam and call Wellfleet Bay Wildlife Sanctuary at 508-349-2615 as soon as possible.  If your call comes “after hours,” you may leave a message on the sanctuary line or you can call the 24/7 turtle hot line at 508-274-5108 any time of the day or night.  The Turtle Journal team will answer your call and respond immediately to rescue the animal.

Northeast Diamondback Terrapin Working Group Meets at Wellfleet Bay Wildlife Sanctuary

Saturday, September 27th, 2008

Mass Audubon’s Wellfleet Bay Wildlife Sanctuary hosted the 3rd annual meeting of the Northeast Diamondback Terrapin Working Group on September 27th.  Bob Prescott, sanctuary director, and Don Lewis, the Turtle Guy, welcomed more than 30 participants from New England and New York.  Chuck Landrey coordinated the meeting agenda, and Russ Burke, Hofstra University professor, chaired the meeting.

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Particpants Assemble in Wellfleet Bay Wildlife Sanctuary Auditorium

After registration and coffee, the meeting kicked off at 10:00 am with opening remarks by Chuck Landrey, the northeast regional coordinator, followed by Russ Burke, DTWG chair.  Bob Prescott and Don Lewis welcomed participants to the Wellfleet Bay Wildlife Sanctuary and presented a very brief overview of Cape Cod geography and terrapin populations from the SouthCoast to the Outer Cape.  Russ topped off the opening session with an update on terrapin research activities within Jamaica Bay and the challenges of wildlife conservation within bounds of the 11th largest city in the world.

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Opening Presentations by Chuck Landrey, Russ Burke, Bob Prescott & Don Lewis

As entertaining as these opening presentations were, participants earned a nice break before hearing more research updates by Charlotte Sornborger of Barrington, Rhode Island, and Barbara Brennessel, professor at Wheaton College.  Eric Strauss, research associate professor at Boston College, talked about environmental studies and the ecological field station at Sandy Neck in Barnstable where he and Peter Auger have conducted long-term terrapin research.

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Second Round of Presentations by Charlotte Sornborger, Eric Strauss and Barbara Brennessel

Lunch break offered an opportunity for Sue Wieber Nourse and I to zip over to Lieutenant Island to check for emergence nests.  Three days of pouring rain and the tropical front accompanying Hurricane Kyle presented conditions favorable for late hatching terrapins to emerge through the soften soil.  At the intersection of a one lane dirt road and a driveway on Marsh Road, we discovered an emergence hole with a tiny diamondback terrapin hatchling poking its head out.  Excavating the egg chamber we rescued four live hatchlings and found two premature hatchlings that had been crushed inside the nest by vehicular traffic.

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Saving Turtles for Lunch from a Vulnerable Road Nest

The afternoon session was devoted to an exchange of information and views on a variety of terrapin research issues as enumerated by the following charts.  Topics included headstarting, how do hatchlings know home, list of predatory and beneficial plants, hatchling survival rate, relationship between age and salinity tolerance, unpublished data on diet, terrapins in captivity, legacy data sets, where do hatchlings hang out, starting a basic terrapin conservation program, capture-mark-recapture methods, tracking methods, mating aggregations, nest protector design and temperature, terrapin survey methods, and how do you know what terrapins are doing when not nesting.

Terrapin Research Topics of Interest to Participants

After a very long and productive day, during which Hurricane Kyle had deluged the auditorium windows and walls with rain, the time had come for a soagy field trip.  Participants assembled in the Nature Center and began the trek along Goose Pond Trail to Cape Cod Bay where we would release the female and male terrapins that Sue and I had captured on Wednesday (see The Last Terrapins).  Then, we would walk over to Try Island to check the remaining protected nests and to share an insight into nesting habitat here at the northernmost outpost for diamondback terrapins.

Bob Prescott (with Binoculars) Leads Participants Down Bayside Boardwalk

En route to the bay, we stopped by an exemplar area of salt marsh die-off to talk about this phenomenon on the Outer Cape.  I spotted a large male squareback marsh crab, one of the prime suspects in the die-off, guarding its muddy burrow.  Bob dove into the ooze and bare-handed the critter; a noble feat since we normally use 3-mil plastic gloves for this work due to the ferocious tenacity of these crabs.  Bob showed off his catch to clicks of rain-drenched cameras.

Bob Prescott Shows Large Male Squareback Marsh Crab to Conference Participants

As downpours resumed, we reached a creek leading to the bay and released our turtle guests back into the wild.  Afterwards, we examined the nesting habitat on Try Island and elsewhere along the Goose Pond Trail, arriving back at the Nature Center tired, soaked and completely satisfied with a most informative and fun filled day.

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Hurricane Kyle Field Trip at Wellfleet Bay Wildlife Sanctuary

Sad Tale of Three Dead Leatherback Sea Turtles

Monday, September 8th, 2008

Leviathans of the sea and giants of the reptile family, leatherback sea turtles define the term superlative.  Ranging in weight up to a ton and the size of a small Volkswagen, no one who has encountered one of these living relics in the wild comes away from the experience unchanged.  They are simply magnificent beasts that peacefully ply the world’s oceans in search of slurpy jellyfish.  The open mouth of a leatherback sea turtle (see below) is perfectly configured for this quest and is the last thing that a jellyfish senses before the lights go out.

Mouth of 650+ Pound Male Leatherback Sea Turtle

Unfortunately, we humans offer them a complex series of lethal obstacles to avoid during their peaceful voyages.  Gill nets drown them, longlines hook them, propellers slice them, weirs trap them and lobster buoys entangle them.  Especially during the summer months in Cape Cod and Buzzards Bays as they chase plentiful jellyfish, endangered leatherbacks face a host of potential threats.

Male Leatherback Arrives at Wellfleet Sanctuary for Necropsy

A freshly dead 650+ pound male leatherback beached in Provincetown on Sunday and Mass Audubon’s Bob Prescott, the state sea turtle stranding coordinator, conducted a necropsy at the Wellfleet Bay Wildlife Sanctuary to determine the cause of death and to gather scientific information to help us conserve this endangered species.  In addition to his staff, Bob (with large caliper below) was assisted by Kara Dodge, a PhD candidate at UNH and former NOAA sea turtle coordinator, and the Turtle Journal team.

Bob Prescott (Calipers), Don Lewis (Camera) and Kara Dodge (Scalpel)

Too large for normal scales, the mass of leatherbacks is determined by weighing the Mass Audubon pickup truck at the dump with the turtle inside, and then re-weighing the truck without the turtle.  The post revealed that this animal had been very healthy.  “It had everything going for it,” stated Bob and Kara.  Both flippers showed signs of a recent entanglement, but nothing so severe that these wounds would have caused death.  Instead, the cause of death was determined to be drowning.  The likely scenario for the death of such an inherently healthy animal is that it got entangled in a buoy line with both flippers wrapped in the rope and perhaps its body trunk as well.  With the last series of spring tides, the turtle may not have had sufficient line to reach the surface.  Like all turtles, leatherbacks are air breathers and will drown if held under water for a sustained period.  How this drowned animal had then become disentangled from the lines that had been wrapped tightly around its flippers is merely a matter of conjecture.

This evening we received a call from Bob Prescott that there had been a report of a dead leatherback on a Westport beach near Horseneck.  We drove out to the site and after about 30 minutes of searching, we discovered a badly decomposed and deflated leatherback sea turtle.  Talking to a local resident, we learned it had been bouncing along the beach for at least the last three days.  We estimated the carapace at approximately 161.3 centimeters, but decomposition and deflation may have altered any accurate rendering of its precise size.  Bones were exposed throughout from head to back to flippers.

Decomposed Leatherback Sea Turtle in Wesport, MA

Another decomposed, 600 pound leatherback washed ashore at Pico Beach in Mattapoisett Saturday night (http://www.southcoasttoday.com/apps/pbcs.dll/article?AID=/20080909/NEWS/809090352/-1/NEWS).  Dealing with one dead leatherback is serious as population numbers of this critically endangered species continue to plummet.  Finding two dead leatherback carcasses in a weekend is a tragedy; but three dead leatherbacks fall beyond emotions and words.  Yet, a ray of turtle hope winked through the afternoon when a call came into the Hotline.  A woman found a small 1/2 dollar size turtle in Plymouth, Massachusetts as kids were placing it in the ocean and the animal was being forced back to the shore by wave action and its own volition.  She thought she had discovered a baby sea turtle, or perhaps a diamondback terrapin hatchling.  A few questions cleared up the mystery.  Color?  Dark, almost black.  Long tail?  Yes, very long.  Bump along the tail?  Yes, like an ancient dinosaur.  Jagged edge along rear of carapace (top shell)?  Yep.  Does it have a yellow “button” in the middle of its tummy?  Yes.  Congratulations!  You are the proud holder of a snapping turtle hatchling.  With just a few more questions we discovered the local fresh water source from whence the hatchling probably came, either through its own design or more likely with the help of local kids.

Snapping Turtle Hatchling

You’re right.  Snapping turtles aren’t endangered and they’re not leatherbacks.  But that doesn’t diminish the joy in helping a hatchling find hospitable habitat where it might have a fighting chance of survival.  Saving one turtle … even a snapper … isn’t a bad way to close the day.