Marine Mammal Minutes

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.

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.

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.

What Caused this Dolphin's Demise?

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!

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.

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.

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.

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.