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A FASCINATING EXAMPLE OF CO-EVOLUTIONARY ADAPTATION

Mon, 06 May 2024 16:09:48 GMT

Can you identify the small brown oblong structures on the skin between the two toes on the hind flipper of this gray seal? If you guess some type of warty growths, look closer. The one to the right of the scalpel blade handle has legs. Another guess might be fleas or ticks. As far as we know, pinnipeds don’t get ticks or fleas. Next you decide that the legs are a giveaway so you figure it has to be some type of insect or crustacean? With your great knowledge of whales, you recall that whales have lice, a type of crustacean, so you figure it has to be a crustacean like whale lice? Now you are half correct! In seals, lice are classified as insects and not crustaceans! Seal lice, Echinophthirius horridus, are one of the world’s few true insects that have adapted to survive in a marine environment.

If your response is “What’s the big deal? Insects are everywhere on this planet," think again and name a few true marine insects for me. I never gave this question much thought either, but consider that the oceans occupy over 90% of the living space on this planet? Why are there so few insects there? Besides a few water striders on the surface of a salt water marsh or possibly some insects with immature stages of their life cycle occurring underwater in a shallow salt pond, I would have had to consult an entomologist for an answer.

So, what went on here? What led seal lice, one of the many insects in the history of the world to adapt to this amphibious marine lifestyle? Studies by paleobiologists have concluded that when the ancestral pinnipeds first entered the oceans and transitioned to seals about 45 million years ago, their attached terrestrial lice not only went along for the ride, but they also had to adapt or perish to this changing environment. Not an easy feat!

Consider the challenges that these lice had to make in order to be successful insects in the ocean:

1. They needed an ability to tolerate the high salinity of the marine environment.

2. They had to tolerate the great hydrostatic pressures placed upon them during their hosts deep ocean dives.

3. Their tolerance of the very cold temperatures during winter when their host hauled out on land or on those frigid deep underwater dives of hundreds of feet was required.

4. They needed a method of dealing with long periods of hypoxia (low oxygen levels) when under water for weeks to months at a time when their pinniped host was at sea.

5. Their anatomical development of an efficient means of being able to hold fast to a seal’s hair while underwater was required to prevent them from being dislodged and certainly lost at sea. Hooked claws developed at the end of each appendage to achieve this ability to hold on, especially against the drag forces exerted upon them when the host would swim at speeds of 18km/hr.

6. Seal lice had to also learn to synchronize their reproductive cycle with the periods of time that a seal hauled out on the beach to give birth, nurse and reproduce.

7. During all these adaptations, the lice have still found the time to become or retain their ability to be vectors of disease. Because E. horridus sucks blood from their host, a common mode of vector borne disease transmission, researchers have looked inside lice and found the immature third stage larvae of the seal heartworm, Acanthocheilonema spirocauda and concluded that seal lice are the intermediate host of the parasite. Other interesting louse bearing molecular finds are the presence of Anaplasma phagocytophilium (a rickettsial organism that infects people, domestic dogs and others), Mycoplasma phocacerebrale (the cause of Seal Finger in people), and Bartonella henselae (the cause of Cat Scratch Fever) in addition to other infectious agents. At this time it is unknown whether seal lice can transmit those infectious agents to other seals.

Interesting facts:

Echinophthirius horridus magnified and one species of a number of identified species in the family, Echinophthiriidae. Echinophthiriidae are unique in their ability to infest pinnipeds (walrus, earless seals, sea lions, fur seals) and North American river otters. Most louse species show some host specificity, meaning they are selective in choosing which animal species they will infect. Notice the dark hook like structures on the end of the 6 legs used to hold onto the seal hairs. The smaller two front legs may also have a sensory function. These lice lack eyes. Gray and Harbor seals along with 6 other species of earless seals in the Northern Hemisphere may be hosts of this ectoparasite.

TWO COMMON GRAY SEAL PARASITES WITH DEVASTATING EFFECTS

Tue, 23 May 2023 22:43:57 GMT

Late spring/early summer is a common time of year to see young of the year gray seals pups haul out on many of Nantucket beaches to rest, sleep, warm up and recharge their batteries. Earlier in the year, most were born on one of Massachusetts’ desolate beaches, possibly during windy, cold or freezing temperatures.

Born with a fluffy white lanugo hair coat and minimal body reserves for warmth, they had to rely on the life-sustaining maternal bond established at birth between themselves and their mothers for survival. If they were fortunate enough to be born to a mother with good nursing skills, who was provisioned well enough to produce the required high fat content milk needed to rapidly build up a substantial blubber layer, then they were beyond one of the first major hurdles in their neonatal life.

During those early neonatal weeks, mom would stay by her pup’s side, overseeing its safety and nutrition until weaning, which occurred around 17-21 days of age. Hopefully during that time, our pup developed a thick blubber layer to maintain its body temperature during exposure to cold air and water as well as provide enough calories to sustain the pup’s metabolism as it went through the high energy and protein requirement of replacing the lanugo coat with a more permanent hair coat.

At this point, one would hope that the challenges of life would become easier for our young seal, but mother nature is unrelenting. The next hurdles were to learn how to enter the water, swim and forage for itself.

I begin to day’s blog at this next hurdle in our young seals’ life, pictured above, who stranded along the south shore of Nantucket in May of 2021. The initial examination revealed an underweight seal of the year (approximately 5 months old), weak, with diarrhea, labored breathing and depressed mental attitude. The search for an off-island rehabilitation facility was made in hopes of providing some much needed care, but as is often the case, there were no openings available. Over the following 12 hours the seal was monitored, but with its rapidly deteriorating condition a decision was made to humanely euthanize.

Part of the function of the Marine Mammal Alliance Nantucket Stranding Team’s mandate through our permit with NOAA is to try to determine cause of death in those animals that strand and die on Nantucket. In most cases this requires a necropsy which is the term for an autopsy done on an animal.

So what were the findings? Why did this pup who had overcome some major challenges in its early life finally fail to thrive? The answer is that two parasites, commonly seen in young seals, were causing significant pathology. The large lungworm of seals, Otostrongylus sp., were present aggravating a severe pneumonia. Also present were the acanthocephalan, Corynosoma sp., commonly called the thorny headed worm, which was causing intestinal perforations and peritonitis.

This pictu re shows multiple large lungworms residing in and obstructing the opened left mainstem bronchus (blue arrow) above and in the right mainstem bronchus (white arrow) below. The lungs are mottled and hemorrhagic from the parasites and a concurrent pneumonia. The scissors on the right are within the cut lumen of the trachea (windpipe) (yellow arrow). It is not hard to imagine the burden placed on this seal to perform normal respirations, let alone hold his breath for the dives needed to feed on his own.

This photo shows a segment of the intestinal tract with three white thorny headed worms moving through the intestinal wall and just to the right of them is an intestinal perforation (craterlike in appearance) contaminating the peritoneal cavity with infective material. A life- threatening infection of the entire abdominal cavity, called peritonitis, was well underway.

Both of these parasites were acquired when our seal pup transitioned from milk to eating fish. For the lungworm life cycle, adult worms in the airways of a seal produce larvae that pass up the airway to the back of the throat, where they are swallowed and then pass in the stools of the seal. These are then eaten by fish where the larvae become infective while encysting in the intestinal wall of the fish. When another seal eats the infected fish it picks up the lungworm.

A very similar life cycle is carried out for the Corynosoma sp. parasite, but in this case the adults produce eggs that pass in the stools and are ingested by an amphipod or isopod as a first intermediate host. Fish then ingest the first intermediate host to become the second intermediate host and the seal becomes infected when it eats the fish.

The more I learn about our marine environment and its creatures, the more I am amazed at the gauntlet of life that its inhabitants have to endure in order to survive. It is a perilous world out there for them, so we should all do our best to minimize the stress that they already have to endure. Remember when approaching seals on the beach, observe seals from a distance (>150feet), use binoculars and report any stranded, alive or dead marine mammals to the MMAN hot line.

LET’S GET UP CLOSE AND PERSONAL TO A HUMPBACK WHALE’S SKIN

Wed, 16 Nov 2022 17:51:18 GMT

One thing that can’t be experienced on a whale watch is a close-up examination of the ecological niche that is present on the surface of a humpback whale. In this blog, I will give you a close-up appreciation of this interesting area.

Recently a two year old male humpback whale died and washed up on the beach in Madaket.

There are three different crustaceans in the photo above? Take a moment to find them for yourself, then read on.

The first crustacean is the most numerous and is known as the acorn barnacle (Coronula diadema). This humpback whale has a number of them, varying in size from the large central one to multiple smaller ones scattered over the surface. These barnacles typically attach and develop on the whale’s rostrum, fins and around their genital region. They can be quite numerous and contribute a considerable amount of weight to the whale. A report quoted 1,000lbs. of barnacles on one whale, which seems like a lot until one considers the total weight of an adult whale can be 80,000 lbs. Barnacles can cause drag on the whale as it moves through the water or possibly a skin infection if they penetrate the skin too deeply, but for the most part they cause no harm. A possible benefit is provided when males fight for females during their "heat runs.” The jagged edges of the barnacles could inflict injury to their rivals.

Barnacles are hermaphroditic in that they have both male and female reproductive systems. That being said, they still need other barnacles in order to reproduce since both reproductive systems are not usually functioning at the same time. Since they can't move around as adults to complete their reproductive duties, they will colonize areas on the whale to be close to one another. Transfer of genetic material occurs by one barnacle extending its penis to reach a nearby receptive barnacle. The extended penis may be 7-10 times the height of the impregnating barnacle, leading some to speculate that barnacles, for their size, are the most well-endowed creatures in the animal kingdom (I'll never think of Barnacle Bill the sailor in the same way after learning that fact!).

After breeding, the barnacle will spawn 10,000-20,000 free-swimming larvae that hope to latch onto a whale as it swims by. Some marine biologists speculate that whale barnacles synchronize their reproduction when whales are in close proximity during breeding season. Some researchers feel that the larvae may pick up a chemical scent from the whale, which stimulates it to grab onto the whale. In any event, the larval barnacle eventually finds its host and then moves around on the whale’s skin surface to find its desired location. It then produces a sticky cement to hold fast onto the whale as it grows. In growing, the barnacle pulls the surface of the whale’s skin into tube like cavities in its shell for a more secure attachment. Once settled, the barnacle can enjoy the benefits of the whale finding food (plankton) for both of them.

An acorn barnacle has a life span of approximately 1 year. These white circles are scars left on the humpback’s skin after the barnacles that resided there either died and fell off or were knocked off during breaching or rubbed off when rubbing against other whales. These scars can persist for 10-20 years.

The second crustacean is the Gooseneck barnacle (Cochoderma auritum) and two can be seen attached to the side of an acorn barnacle in the upper left-hand corner of picture #2.

Finally, the third crustacean in the picture is the whale louse. There are a number of them in the second photo, but the most obvious one is just to the left of center at 9 o’clock. These are crustaceans related to skeleton shrimp and not insects like most other lice. Whale lice feed off of the whales flaking skin and algae that settles on the whale. Minor damage can occur, but nothing that leads to significant disease. It is estimated that approximately 7,500 lice may live on the average adult humpback whale.

WHEN PARASITES MISBEHAVE

Sat, 15 Oct 2022 16:38:19 GMT

What Caused this Dolphin's Demise?

In the spring of 2021, the Marine Mammal Alliance Nantucket hotline received a telephone call from a concerned citizen about a dolphin floundering in the surf near Nobadeer Beach. When the rescue team arrived they found a Short Beaked Common Atlantic Dolphin, disorientated and struggling in the wash. The dolphin was alone and seemed to be in good body condition with no external injuries or signs of what was causing his distress. A decision was made to relocate him to calmer waters. From there he was taken to Jetties beach and released, only to make a feeble attempt to swim away, then quickly reversing course back toward shore where he died.

Our stranding permit legally allows us to deal with marine mammals in distress and to investigate the possible reasons for a dolphin’s stranding. The best way to proceed in this sad case was to perform a necropsy (an animal autopsy) looking for the cause of this animal’s demise.

During a necropsy, the dolphin’s body was examined both externally and internally for diagnostic clues. Our external exam showed a dolphin in good physical condition with no reasons as to why he stranded. Internal organs were then examined with the naked eye and tissue samples were collected for a pathologist to examine under a microscope.

The internal exam was unremarkable until an examination of the brain was begun. External examination of the brain revealed an indented lesion in the left cerebral hemisphere. On cut section of the brain there was an obvious cavitated area underneath this lesion and in other areas of the brain that should not have been there. Microscopically, the pathologist examined these lesions and found associated with them the eggs of an air sinus parasite called Nasitrema.

Normally the Nasitrema parasite might cause a mild inflammation of the nasal air sinuses where it normally resides, but when it gets into an abnormal location like the brain, serious damage can occur.

So how did this parasite egg find its way into the dolphin’s brain? In order for the egg to be found there, the adult trematode (fluke) that lays the egg had to migrate from its normal air sinus location into the brain. In medicine this is called aberrant (abnormal) migration and the damage caused was the reason for the stranding and the dolphin’s death. By misbehaving, this parasite killed its host.

Nasitrema eggs deposited in the air sinuses prior to the aberrant migration were also aspirated into the lungs causing a mild pneumonia, but the neurological damage was the main cause of death.

WHAT DOES MMAN DO WHEN A LIVE SEAL IS REPORTED ON THE BEACH? Part 1

Sat, 23 Jul 2022 12:21:32 GMT

It is important to acknowledge that it is totally normal for seals to haul out on the beach to rest, warm up, sleep, mate, give birth, nurse, molt, avoid predators, etc. In fact, many people do not realize that seals may spend 30-40 % of their life cycle on the beach engaged in these activities.

Seals and their contribution to Nantucket’s biodiversity, plus their role in maintaining a heathy ecosystem, is rapidly being accepted and appreciated by the public. The members of MMAN stranding team would like to keep it that way, so we request that the public make us aware of any seals that haul out on the beach so that we can take the appropriate actions to evaluate their health and maintain seal and human safety.

ASSESSING A SEAL'S CONDITION:

All marine mammals are legally protected by the 1972 Marine Mammal Protection Act. This law requires the public to give seals a 150 foot perimeter of space around them so that they are not excessively stressed and their behavior is not changed. Unless legally permitted to get closer, like stranding team members are, closer viewing by the public should be done with binoculars.

Stranding team members also use binoculars on the initial response. We look at body condition in the initial evaluation of health, looking for any signs of malnutrition. A healthy seal has a football shaped body with well-hidden pelvic and shoulder bones. There should be no depression behind the head in the area of the neck due to lack of blubber. Compare the two seals below. Both are about the same age with the robust, healthy pup on the left and the emaciated, unhealthy pup on the right. There are a number of gradations in between these two body scores. Unlike ourselves, fat in seals is a sign of health.

Photo #1 Below is a healthy seal. Photo #2 below is an underweight seal.

Attitude is also important to note. If the seal pops up its head and looks like it is at attention or cowers and looks anxious, it is nervous and getting ready to flee. This is normal behavior. You are getting too close and should stand back! This is especially important if there is an entanglement of fish netting or marine debris on the seal. Frightening the seal into the water will foil any opportunity for stranding team members to arrive to disentangle.

Photo #3 below shows a young seal at attention and anxious. Photo #4 below shows a person too close, upset entangles seal.

More information on beached seals to come in Part II!

Marine Mammal Alliance Nantucket’s Stranding Team’s Duties when a Dead Seal is Reported on the Beach

Sat, 04 Jun 2022 11:46:54 GMT

Nantucket’s marine mammal stranding team maintains a 24hour hot line telephone number for members of the public to contact us whenever they find a live or dead marine ma mmal on the shores of Nantucket, Tuckernuck or Muskeget. Many might ask why we care about dead animals, but a wealth of information can be acquired from them.

In order to maintain our federal permit to approach live or dead stranded marine mammals, we are required to collect data for the federal government, which they use to identify changing trends in the ocean environment. Our information, as well as that from other stranding teams across the United States, helps formulate the federal policy decisions made to manage our marine ecosystem in the best possible way.

Important data that we collect includes location, date of stranding, species, length and sex. Body condition pertaining to state of nutrition, disease, signs of any injuries, shark bite wounds, human interactions like fishing gear entanglements, propeller wounds or other signs of a vessel strike, gunshot wounds, signs of chemical or oil spills, etc. are all important to note. Occasionally, necropsies (animal autopsies) are done to provide answers to an animal’s demise.

Once the data is collected, we will mark the body with spray paint and/or apply a small metal tag to a rear flipper. So if you see either of these markers you know the stranding team has been there and that the marine mammal information has been recorded. There is no need to contact us about that individual case.

Marine Mammal Alliance Nantucket is Sometimes for the Birds!!

Sun, 14 Mar 2021 20:59:51 GMT

Did you know that the Marine Mammal Alliance Nantucket Stranding Team helps more than just marine mammals? Our Hot Line number is commonly called to report injured wildlife, including sea turtles, Mola molas, and frequently injured birds. Many of these injured animals are severely debilitated and close to death when they are picked up, but occasionally there are those cases where they are rescued early enough to avoid a difficult treatment and convalescence. The following case is one such example that I treated prior to retirement and I present it to you as if you were the doctor making the diagnosis. Play along and see how good your skills are in making the diagnosis to help this bird.

This spectacular male Common Eider was brought in to the Offshore Animal Hospital after being found at Low Beach in Sconset during a snowstorm. The good Samaritan who rescued the bird said that the bird could run, but not fly. A physical exam revealed a bright and alert patient in good physical condition with no broken bones. Commonly birds are radiographed to aid in the diagnosis, so that is what was done. I present you with front to back and side view radiographs of the affected bird. These radiographs indicate two life threatening episodes that this bird has experienced. One is an older incident that could have acutely ended his life and the second one is todays concern, that if not diagnosed and treated, would cause a slow and agonizing death. Take some time to see if you can pick out these two life threatening conditions.

If you are not quite sure about the immediate problem, compare the radiographs here with the radiograph below and see if you can identify any difference? What is missing in the post treatment radiograph below? Is the missing object something you recognize? If you identified a mussel lodged in the lower esophagus of the radiographs above, then you are well on your way to saving this bird.

The mussel shell was our bird’s immediate life threatening problem because it was obstructing the esophagus so that he could not swallow. How about the previous life threatening problem that could have acutely ended his life? This is a little more challenging since it isn’t as large as the mussel shell. (Hint: It is somewhere in the bird’s abdomen and is very white). If you still are unsure, look in the area of the gizzard. What is the gizzard you might ask? Think about your Thanksgiving Day turkey with it’s little bag of giblets (heart, liver, neck and gizzard). The gizzard is that thick muscular structure that most of you have seen in the bag that is part of the bird’s digestive tract. The gizzard contains little pebbles that the bird has swallowed that aid in grinding up its food. In eiders, a bird that eats the whole mollusk, the gizzard is necessary to pulverize the shell so the contents can be digested. The gizzard is the large, somewhat rounded structure in the lower section of the birds belly. You have located the gizzard when you see the multiple varying sized pebbles within it.

Now, I assume you have found our little white object. What do you think it is? If you consider the spherical shape, its size and density (dense objects like bone or metal show up easily on radiographs) you have probably determined correctly that it is bird shot from a previous encounter with a hunter. Fortunately for our eider, it did not fatally injure the bird and is in a location that is not interfering with function. If you look at the side view radiograph, you will see that it is not inside the gizzard, which if it was and the metal was lead, then the bird would have probably died of lead poisoning months ago. Since it is not in the gastrointestinal tract or a joint, the lead does not get absorbed and we call it an incidental finding.

Now that we have a diagnosis, we can go ahead with our treatment plan to remove the esophageal obstruction. We first induced anesthesia with a mask and a gas anesthetic called isoflurane. Once he was sleepy enough, we placed an endotracheal tube into his airway to maintain the anesthesia while we worked around his bill to remove the mussel. This was done by milking the mussel up the esophagus until we could reach it with a long pair of forceps. In the last photo, you can see the mussel right before it came out.

But that is not the end of the story. Postoperative care is a large part of the treatment so we had to make sure he was going to eat and be strong enough for release. After several days of eating raw clams and becoming quite aggressive we were convinced that he was ready to be returned to Low Beach. So off he went to join his buddies with some unbelievable stories to tell I’m sure.

Quiz: What's this???!!

Wed, 17 Feb 2021 23:13:52 GMT

Let's have another quiz.

Question: If presented with this scary photograph and no other information, would you be able to identify the animal? Those teeth are approximately 1.5 inches in length and to me, look pretty deadly. If I also told you that the creature was about 12 feet long and is occasionally seen on Nantucket, would you be surprised? As a final bit of information, would you be impressed to know that when startled, this animal could release a dark ink-like fluid to cloud the water to aid in it's escape? Read on to find out the answer.

Answer: If you are knowledgeable about marine mammals, you have probably guessed correctly that this is an open mouthed view of a Pigmy Sperm whale (Kogia breviceps). It stranded on Cisco beach several years ago in late December. Identifying features include a shark like head with an underslung jaw, 24-36 long, sharp, inwardly curved teeth only on the lower jaw, a false gill slit (see the curved white line between the eye and the pectoral fin) and a small sickle shaped dorsal fin located posterior to the mid back. They normally live in the deep waters near the edge of the continental shelf and when seen in this offshore environment, are usually solitary or in small groups floating on the surface.

Pup Rescued from Traffic

website@sitemodify.com (Website Editor) — Wed, 17 Feb 2021 22:38:52 GMT

Abandoned Seal Pup Seeks Mom at

Real Estate Office Then Salt Marsh Center

One late afternoon in February, MMAN got a call that a seal pup had been spotted crossing the road on Easton Street near the White Elephant Hotel. Team member Peter Meerbergen and Stranding Coordinator Jillian Lucchini searched the area to no avail. Finally they spotted tracks in the snow leading to the steps at Great Point Properties at the corner of Easton and Beach St.

The frightened grey seal pup was huddled behind the hydrangea. Peter and Jillian managed to get him into a kennel and relocate the little guy to a quieter beach at Brant Point, not too far from where we believe he came out of the water. He immediately returned to the water, to their great relief. The full white lanugo coat indicated that he was a neonate and may still be relying on his mothers milk! He was incredibly vocal so we hoped mom might come back. Reuniting with mom is always the best option for wild babies so we want to encourage that as often as possible.

Later that same evening at 7:30pm, MMAN received another Hotline call about a seal pup trying to cross the road at the corner of Washington and Francis Streets, in front of the Saltmarsh Center. Team members Susan Rohrer and Burton Balkind responded and met local police. Stranding Coordinator Jillian Lucchini put dinner on hold and came to assess the situation. It was the same pup!

The tiny pup had swum from Brant Point to Francis Street, likely searching for his mother. At that point it had to be presumed he was abandoned. Mothers will not return to pups in high noise, human and boat traffic areas. The pup was highly stressed by his adventures over the course of the day. With the advice of MMAN's volunteer veterinarian, Dr. Steve St. Pierre, it was decided to kennel the pup overnight until he could be transported off island to the National Marine Life Center in Buzzards Bay for care.

This is the fourth Nantucket grey seal pup transferred to NMLC since December. He is currently settling in at the rehab facility and has been named after the mischievous Greek god Hermes.

MMAN wants to send a huge thank you to

Great Point Properties

for calling our hotline, the

Nantucket Police Department

for their quick response to the location, to

Hy-Line Cruises

for their continued support in transporting Nantucket pups off island and of course to

National Marine Life Center

for all of their hard work in caring for these animals.

It takes a team and we have a great one!

#marinemammalrescueack #MMPA #nantucket #wildliferescue #wildliferehab

All photos taken under permit with NOAA/NMFS by a MMAN team member.

Hermes in Rehab. Photo courtesy National Marine Life Center.

Sconset Whale Bone

website@sitemodify.com (Website Editor) — Wed, 17 Feb 2021 22:38:49 GMT

Sconset Resident Has Bone To Pick With

Marine Mammal Alliance Nantucket

While Tucker Orbison was beach combing at Low Beach in Sconset in February, he came upon a significant object that he knew would interest someone. Instead of taking this object home, which would have been illegal without a federal permit, he contacted the Marine Mammal Alliance Nantucket stranding team (MMAN) to inform them of his find. That set the wheels in motion for the team to mount a recovery of what he found. One half of the lower jaw of a juvenile humpback whale skeleton to be exact.

So, what does the stranding team plan to do with this 200 lb. object?

As part of the stranding team’s agreement with the federal government, to continue to hold their federal permit, they have four mandates. Those include to provide a rapid response to stranded marine mammals, to protect the public when approaching these marine mammals, to advocate for the protection of all marine mammals and to collect and disseminate scientific and collected information for the government and for public education.

Public education is where this bone comes into play. The MMAN team is in the process of developing educational programs for the citizens and tourists of Nantucket and feel this bone would be a great show and tell addition to their programs. Presently they are developing outside beach side talks for children and adults, to be given this summer while we are all most likely still practicing COVID social distancing.

S upport and learn more by visiting www.nantucketmman.org and call the hotline (833-667-6626) to report marine mammals in distress.

Fish Flatulence Index

Thu, 14 Jan 2021 23:42:40 GMT

Imagine you are walking down Main Street in Nantucket and you see the Inky newspaper at the Hub and it's headline reads, "This week's Fish Flatulence Index high, expect possible island ferry delays". Say what!!!!? Some islanders might think, "Oh great, first it was nesting plovers, then seals and sharks, but now we have to worry about fish farts too?" Would you be curious enough to buy the paper? I bet you would want to at least read the article to make up your own mind about its credibility. Is it just fake news and a ploy to sell more newspapers? Read on before you conclude it is a joke.

First, let's learn a little about the fish we are talking about. Here is photo of the fish, taken in Nantucket harbor last year. These are menhaden, locally know as Bunker or Pogies. They are filter feeders, feeding off of phytoplankton when young and moving onto zooplankton when they mature. They never take a fish hook, so unless you snag or net one, you are out of luck fishing for them. If you look closely at the photo, you can see many of the fish swimming with mouths open and gill covers abducted, allowing water to flow across their gill rakers to catch food particles before swallowing. It has been estimated that one of these

fish can filter up to 4 gallons of sea water per minute, making them very efficient at clearing our bays, harbors and estuaries of algae. (By comparison, an oyster filters approximately 50 gallons of water per day).

So back to the newspaper headline from above. Acoustic biologists have shown that a similar schooling fish, herring, possibly communicate by passing gas in what is called high frequency repetitive ticks. It may be one way in which the fish alert one another to their presence in the school. If menhaden do this, how could that be enough to slow down the ferries you might ask? The feeling is if the fish can hear this, then predators of the fish possibly could also. Enter the humpback whale! How does a humpback find this tasty food item which it thrives on? Is it a serendipitous discovery or related to one of their senses? They don't echolocate like tooth whales so eliminate that sense. Their eyesight is limited, especially in water with poor visibility and their olfactory system is poorly developed for smell. That leaves their auditory system, which we know is well developed from listening to recordings of their songs. If this is the mechanism, then one would need to acoustically measure whether these fish sounds happen or not. That is exactly what the Gotham Whale stranding team, one of our partner stranding team members out of New York City is proposing to do. If funding is obtained, then acoustic biologists will head to New York harbor to listen for these fish sounds.

Some scientists feel that menhaden are the most valuable fish in the ocean. This is not for their palatability to humans because they are a very oily and bony fish, but because other animals thrive on their nutrient value. Birds such as osprey, northern gannets, terns, gulls cormorants, marine mammals such as whales, dolphins, porpoise, seals, other fish like striped bass, bluefish, tuna, flounder are just a few of the food chain members above them that benefit from their presence. Indirectly we have all probably eaten menhaden ground up in feed for chickens, beef and pigs or through omega 3 fatty acid supplements.

I would think you could consider menhaden a keystone species. Aside from their support of other species as a food source, they are also important for the environment. In Nantucket Harbor, high nitrogen and phosphorus levels from septic systems, lawn fertilizers, runoff, etc. contribute to algae blooms that cloud the water and prevent sunlight from reaching our endangered eel grass beds. These and other benthic plants then die, no longer produce oxygen, decompose and dead zones are created. Menhaden schools act like giant water filters in our harbors, removing algae blooms and transporting those nutrients out to sea when they leave or when they are eaten by other predatory animals.

Over fishing has severely depleted menhaden populations. Large factory ships using spotter planes locate large schools and encircle them with huge purse seine nets, decreasing their population and range. There needs to be more done to limit this devastation, as well as other activities that are depleting our oceans of fish.

I carried this a little further by creating the fictitious Fish Flatulence Index (FFI). The FFI is my made up term for a way to quantitate the presence of gassy fish, analogous to the Pollen Index we always refer to in summer for hay fever sufferers. In my scenario, a high FFI would theoretically indicate an abundance of menhaden and the greater likelihood of humpbacks in the area. Assuming that this theory is correct and the fish flatulence noise is attracting humpbacks, then indirectly the humpback attracting fish may present a hazard to shipping and necessitate ships to slowdown to avoid collision.

If you have been on island this fall, you are probably aware of the frequency that humpbacks are being seen close to the north shore, lunge feeding on bunker. Multiple times I have seen them just 30-50 yards off the beach or along the rip close to shore at Great Point. Videos have been posted on social media of them in and near the entrance to the harbor or by people on the ferries shortly before entering and leaving the harbor. MMAN has been vigilant whenever we have had reports of their proximity to the shipping lanes to notify the Coast Guard and the ferry terminals of the whales' presence. The last thing that we want is to have a collision, which can be fatal to the whale and hazardous to people on board.

Today the eastern seaboard is in the midst of 3 UMEs (unusual mortality events) concerning 3 large whales species (North Atlantic Right Whales, Minke and Humpbacks). From 2016 to the beginning of November 2020, a total of 136 humpbacks have been reported dead along the eastern seaboard from Maine to Florida. Many of the fatalities have been attributed to vessel strikes. We should do everything possible to prevent these vessel strikes, even if it means the future measuring of fish flatulence.

Pox Virus in Pinnipeds and Cetaceans

Sat, 05 Dec 2020 21:45:45 GMT

Some marine mammal skin diseases have a zoonotic potential to stranding team members and the general public. In one report out of the University of Florida, these skin diseases can "result in localized skin infections in man that either resolve spontaneously or with appropriate medical therapy". They may be viral, fungal or bacterial in origin. Two viral infections that occur in marine mammals have been recently seen on Nantucket and will be discussed here. Pox viruses are generally considered host specific, but as with most things in life, there are exceptions.

Pinnipeds

In 1986, the California Marine Mammal Center reported of a case of seal pox that crossed species in their facility by being transferred from Harbor seals to Elephant seals and then to their captive seal lion patients. In 1987, a report was published of a seal handler who contracted seal pox from a captive gray seal under his care. Although the virus is highly contagious between seals, the potential for human infection is low. Most human cases are seen in people who have close contact with seals in rehab facilities. People usually get single nodules, often painful and may be accompanied by fever, myalgia and fatigue. The virus can be spread by direct contact with the virus from affected seals, from contaminated facilities, contaminated slickers, boots, feeding utensils, contaminated water as well as insects acting as vectors.

The seal pox virus has an incubation period of 3-5 weeks.The lesions start out as small firm nodules .5-2cm in diameter and .2-1cm in elevation. Nodules can be located anywhere on the body including the mouth, with the highest number appearing on the underside of the abdomen and the palmar surface of the front flippers. The nodules will eventually ulcerate and exude a small amount of purulent fluid then slowly regress leaving a darkly pigmented area of alopecia. Lesions will present themselves for 6-8 weeks, then take 2-8 weeks to regress. In the wild, seal pox is usually seen in juveniles since young pups are believed to be protected by maternal antibodies and adults have probably already been infected, recovered and are protected by their own antibodies.

When dealing with seal pox in rehabilitation facilities, strict sanitation measures are in order. Avoiding stress which can lower a patient's resistance, antibiotics to control secondary infection and antivirals like cidofovir (blocks viral replication) may be used. Most cases are self limiting and get better on their own.

Cetaceans

Pox occurs in whales, dolphins and porpoises and looks very different than pinniped pox. Most pox lesions are commonly seen in the area of the head, pectoral flippers, dorsal fin and tail fluke. Generally pox in cetaceans is not felt to cause significant systemic disease although its pathogenesis needs further study. It is often felt that stress, poor water quality, environmental contamination with chemicals or other significant underlying infections may be associated with cetacean pox.

Pox lesions in dolphins are described as ring, pin hole or tattoo lesions.The lesion that we observed on Nantucket was in a bottle nosed dolphin (Tursiops truncatus) that washed up deceased on the Point of the Breakers in 2019. There were tiny black dots that formed a ring like design with many of them coalescing into a larger design pattern. These lesions may persist for months to years. Unlike pinniped pox, cetacean pox is not know to infect people.

Quiz: Where was this seal pup born?

Tue, 08 Sep 2020 02:11:29 GMT

Let's have a little quiz.

I will first give you a little history. This young gray seal pup was found dead on the eastern shore of Nantucket in Wawinet, on April 15, 2015. Other than being underweight, there were no external wounds or signs of why it died. I can tell you for sure that it is approximately 4-5 months old and where it was born. Study the photo for the clue to where it was born and pick your answer from the following choices of known gray seal rookeries below?

1. Little Gull Island, Long Island (at the tip of Long Island in the area known as the Race)

2. Muskeget Island, Ma.

3. Seal Island, Maine

4. Sable Island , Nova Scotia

5. I don't have a clue!!!!

Answer: If you were observant enough to notice the brand on this seals back and you knew that only Canada brands seals in our area, then the answer has to be 4. Canada brands young seals to study life histories and population dynamics. We contacted Fisheries and Ocean Canada and found that they had indeed branded this young seal on January 18, 2015. So sometime after that date this young seal set out on his own, to forage and travel the distance to Nantucket, a distance of over 500 miles as the crow flies. This to me is an amazing feat for a 4-5 month old animal, especially in the dead of winter! It is no wonder that mortality rates may be as high as 30-55% during the first year of a seals life.

Seal Whiskers

website@sitemodify.com (Website Editor) — Fri, 04 Sep 2020 02:11:29 GMT

Have you ever thought about how seals find and catch their food, especially at night at depths with very little if any light at all?

If you blind folded and put earmuffs on a gray or harbor seal (they do have natural valves in their ear canals that normally close when they dive), and I told you they still easily find their swimming quarry, would you then wonder about their sense of smell? Little is known about their sense of smell, but their nostrils are normally closed while underwater. So how do they manage ?

Studies have shown that seals have an ability to accomplish this feat through the use of specialized whiskers (vibrissae) on their muzzle. The next time you get close to a stranded dead seal, take a close look at the shape of their whiskers. They are wavy, somewhat asymmetrical in length and elliptical on cross section. These whiskers have the ability to detect wave patterns produced by fish swimming in their vicinity seconds after they swim by. Vibrations that the whiskers detect are transmitted to very sensitive nerve endings located in the dermis of the skin of the lips and then to the brain for interpretation. Not only can they detect the size of the fish, but also its direction when considering it for a meal.

This photo shows a seal whisker compared to a white cat whisker.

A Joyful Return to the Sea

website@sitemodify.com (Website Editor) — Wed, 02 Sep 2020 02:11:29 GMT

Marine Mammal Alliance Nantucket responded to a call from a concerned citizen about a seal on the beach along Hulbert Avenue on January 19, 2020. MMAN observed the apparently abandoned baby grey seal for 3 days, hoping the mother would return to feed him. Seeing no evidence of her return and a drastic loss of weight, MMAN safely captured the grey seal, with permission from NOAA, and transported him to the National Marine Life Center in Bourne where the staff carefully nurtured him back to health.

Quoddy, a male grey seal (named after the well-known Quoddy Head lighthouse in Maine) was severely dehydrated and emaciated, with a wound on his front flipper when he arrived at NMLC’s rehabilitation facility. Never having been in the water before, as seal pups spend their first few weeks on the beach being fed and monitored by their others, it was a slow progression for Quoddy learning how to eat fish and use the water access given. By the end of April he was finally ready to eat on his own and swim regularly. Quoddy gained an acceptable release weight and was eventually cleared from all medical issues.

In a historic decision, National Marine Life Center agreed to return Quoddy to Nantucket for release so the team who rescued him and the community that supports it, could witness his happy, healthy release into the wild right here at home. Little Quoddy was returned to Nantucket and released back into the wild on June 9 ^th , 2020 with a crown of about 60 well wishers from across the island softly cheering him on. It was indeed a moving, tearful moment to see all our efforts come to fruition. “Our heartfelt thanks go out to NMLC, Hyline-Cruises for transporting him both ways and all the MMAN volunteers,” said MMAN Stranding Coordinator at the time, Scott Leonard.

Dolphin Rescue in Hither Creek

website@sitemodify.com (Website Editor) — Sun, 15 Mar 2020 14:38:50 GMT

In early March of 2020 two Common Dolphins were observed swimming around in Hither Creek in Madaket. They were monitored for a couple of days and determined to be unable to leave due to shallow water, twisting and turning currents and likely weakness of one of the pair. Photographs revealed one being much thinner than the other and it is likely the healthy dolphin did not want to leave the sick one.

MMAN’s Stranding Coordinator at the time, Scott Leonard, contacted Misty Niemeyer, Stranding Coordinator for Marine Mammal Rescue and Research at IFAW over on Cape Cod. Misty and Field Biologist Michaele Wellman deployed to Nantucket the next day with stretcher, transport tent, medical and data capture supplies as well as dry suits for our team. Several of us had completed a cetacean stranding workshop just a few months prior at IFAW, so it was exciting to be able to put that education to use and help a live animal. Sadly, the weak dolphin was nowhere to be found, presumed dead and sunk, but the healthy one was still stranded in the Creeks area and needed assistance. MMAN Team members Scott Leonard, Hugh Lloyd-Thomas, Rain Harbison, Dan Simonds, Pam Murphy, DVM Steve St. Pierre and Captain Blair Perkins all responded.

Our options were to try to guide the dolphin out – an option quickly dismissed by veteran boat captain Blair Perkins, as the way out was long, twisty and presented too many occasions for the animal to beach. Instead, we chose to guide the animal to shallow water where team members could gently capture it. Using the boat, two kayaks and a device called a hookie lao (a long rope with smaller ropes hanging from it with small balls which would reflect the dolphins sonar to indicate a solid wall and no way out). Under Misty’s guidance, the animal was corralled and team member Dan Simonds leapt from the boat to make the capture. Securing the animal, we then maneuvered him onto a dolphin stretcher and brought him ashore for assessment. Vitals were monitored while blood samples were taken and a satellite tag placed on his dorsal fin. It was determined this dolphin was healthy enough to be transported to another section of the island where he could be released without risk of returning to shallow water. Secured in a three sided, fully padded tent made just for dolphin transport, he was loaded into Dr. Steve St. Pierre’s pick-up truck and driven to the Atlantic Ocean at Hoicks Hollow. Team members carefully walked the stretcher down to the water and, secured with safety ropes and throw bags, walked the tent into the water where the animal was released. At first he appeared to head right back toward shore, but after a few twists and turns headed out to the great Atlantic. All present were overjoyed and waited anxiously for news each evening of where Ping, named for the anticipated ping of his sat tracker, would be next. We were able to “watch” him head to known dolphin feeding areas so we felt confident he had found a pod to commune with. It was a wonderful, exhausting, uplifting 8 hour day for all involved. We couldn’t have done it without the expertise and quick response of SC Misty Niemeyer and her team from IFAW.