Since we broke track for one of these sightings, we were able to snap a few quick photos of the rays before returning to our survey, one of which you can see below. From a distance, these groups of rays, which varied from 50-150 individuals, look similar to water lilies floating on the surface of the water.
Learn how divers care for the cownose rays in the Giant Ocean Tank at the Aquarium! And here is an interesting video of the Aquarium's cownose ray swimming in the GOT.
As the right whale season draws to a close, things have quieted down a little bit in the waters off of Jacksonville where we fly our Central EWS surveys. It's regrettable to see the whales begin to leave, but it's the way it should be: we wouldn't want a lot of whales hanging around when there's no one here anymore to locate them for vessel traffic.
Interestingly, the sparse sightings we have been seeing over the past few days have been largely mother-calf pairs. In fact, for the past five days we have seen different mother-calf pairs each day! It's as if the mothers are marching through our survey area on their way back north-- like moms on parade. I think the whole team has enjoyed seeing all the mothers we've been watching throughout the season, as they're such a crucial indicator of the health of this population. We have been able to watch the calves grow from tiny gray squirts into strapping, strong youngsters who look plenty fit enough to survive the migration north and their first summer on the feeding grounds.
However, we still don't have a final count on just how many new North Atlantic right whales have taken their place in the population this season. In the past couple days we have had two brand new mothers, bringing the current count up to 18. This great number gives good riddance to any worries about the productivity of the calving season we might have been harboring at the beginning of the year, when new moms appeared few and far between.
The calves of #2642 (left) and #3123 (right) have grown very large, and even have clear budding callosity patterns.
When I return north and visit the waters of Cape Cod Bay in two weeks, I'll be very excited to see if any new mothers show up that we didn't happen to see here on the calving grounds. But more thrilling will be to rendevous with the mothers and calves I saw in the southeastern U.S. once they reach the other end of their journey. I hope I find them healthy and thriving!
Photos credited to: New England Aquarium; Suzie Hanlan.
Many cetacean species are only slightly sexually dimorphic (oftentimes just a slight difference in size), so it’s nearly impossible to determine gender in the field. However, if you’re fortunate enough to see an animal roll over at the surface of the water, gender can be determined with the click of the camera. If an animal’s ventral side is exposed, the presence of genital slits can be determined. After reviewing the photos taken from the plane, we were able to determine that #1701’s calf is indeed male.
Gender of individuals in a population, especially one that is as critically endangered as the North Atlantic right whale population, is an extremely important demographic characteristic to monitor. A species needs an appropriate adult sex-ratio that fits their social system in order to ensure reproductive success. Reproductive success depends on many factors – sex-ratio being just one of these factors. Just by determining #1701’s 2010 calf’s gender, this will ultimately help with future conservation efforts for the entire population!
Now that you have your thermal layer on its time to step into your full Nomex fight suit and your close-toed shoes. Nomex is a fire retardant material and relatively light weight so provides little thermal protection; however, it can feel extremely warm when surveying in the increasingly warm days of late March. OK, now over your flight suit goes your Switlik life vest. The life vest is constructed with dual inflation bladders. Only one bladder is needed to inflate for full flotation (in case the other gets punctured or does not inflate). Make sure you know where the inflation cord is and the manual inflation tube (in case the CO2 cartridges malfunction) and please don't forget to secure your leg straps. The leg straps keep the vest secure and tight around your chest; when inflated this allows for good positioning in the water. Without the legstraps and overall proper adjustment to the vest, inflation could pull the vest up around your neck and it could slip right over your head (depending on the size of your head). Proper life vest adjustment it very important so please make all the necessary adjustments before climbing in the plane.
Now lets dive inside the pockets of the life vest: in the left side pocket you will find your safety whistle, signaling mirror, blunt tip knife, safety streamer, thermal blanket and strobe/flashlight combo. The right side pocket holds your PLB (Personal Locating Beacon). The PLB is the latest generation of personal EPIRBs (Emergency Position Indicating Radiobeacon) that, once activated, sends a GPS location to rescue agencies via satellites. Everything in your vest is tethered securely so it won't fall out or float away if in water.
Photos credited to Kelly Slivka.
It's very hard work to prepare a plane for surveying, since our unique purpose for flying creates unique needs in the plane. Days are spent wiring the GPS, the radios, the computer, and our headphones in order to allow for us to collect data and operate while not taking our eyes off the sea. Our pilot Mike even had to borrow our field house's oven to cut a special window that will hinge open, allowing us to photograph clearly. I'm ever-impressed with the dedication of everyone involved in this project.
One of my favorite aspects of field work is the need for constant adaptability. Never a dull moment here on the calving grounds!
The recreational vessels were hailed over the marine radio, informed of the relative location of the animals, and notified of the 500-yard approach rule for right whales. Eventually, Florida Fish and Wildlife Conservation Commission (FWC) dispatched an enforcement vessel to intercept recreational vessels moving too quickly through the area and to help avoid whale-boat interactions. Fortunately, no whales were struck that day thanks to NEAq actions, FWC efforts, and the cooperation of many recreational boaters and fisherman off the coast of Florida.
Near noontime one of the survey planes radioed in to us with a sighting of an adult right whale who had never been biopsied in its 21 years of life, so we steered northeast toward where the whale was seen by the plane. About an hour and a half later we were pulling up to the spot of the sighting, about 20 miles off Brunswick, Georgia, and we slowed to survey the area to try to relocate the whale. I was in the lookout tower at this point, and I scanned the horizon for whitewater or a spout, tell-tale signs that we'd found our target whale. For miles and miles in every direction there was nothing but deep green water and pale blue sky.
Photo Credit: Kelly Slivka.
Suddenly I felt the biopsy boat shudder to a crawl and I peered ahead of us. Something strange was floating in the water 50 feet from the bow. It was brownish in color and roughly textured, and I initially though it to be the trunk of a palm tree. One of us shouted that maybe it was an old tire, and as we got closer, Clay, who was steering the boat, offhandedly commented that it looked like a dead alligator.
Well, he was more right than any of us would have ever imagined. As we pulled up alongside the mysterious object its nature became clear to us, and we suffered initially from absolute disbelief: here, in wide open waters where we expected to see whales, swam a large, very-much-alive alligator! It's hard to say if it just didn't read its map right or if it was exploring new horizons, but it was certainly one of the more bizarre things I've ever seen out in the ocean.
View Alligator Sighting in a larger map
Map displays the approximate location of our sighting of the sea-worthy alligator, 20 miles off shore from Brunswick, GA.
(Check out this previous blog of a great white shark sighting!)
This trend is a bit of a treat for us, as off-shore waters are much more translucent and beautiful than the murkier in-shore waters, which are usually mucked up by the many river deltas up and down the coast. The accompanying photos were taken out in the deep blue and allow for a marvelous look at the whales' bulky bodies as they coast beneath the surface.
In this blog, examine for yourself the development of one individual's callosity in the series of images posted here; first, in the waters off the coast of Georgia, as a calf of a little more than one month in age (above); second, about 6 months later in the Bay of Fundy (below); and third, at 11 months of age with a distinctive callosity, seen back here in the calving grounds still with its mother (bottom).
Callosities are large patches of raised epithelial tissue, gray or black in color. They are composed of cornified skin, like a callus, and they form in many of the same places as hair does on men (i.e, along the jaw and above the eyes and lips). This tissue eventually becomes infested with thousands of light-colored cyamids (whale lice) which contrasts against the surrounding areas of black skin, thereby defining the callosity outline. (Check out this other blog to see an incredible close-up photo of whale lice, albeit a different species which colonizes the Southern Right Whales rather than the North Atlantic right whale.)
When a calf is born, a different species of cyamid, orange in color, is thought to be transferred to the calf from the mom's genitalia and mammary slits. These orange cyamids (shown in the above image of the 7-month-old) have no free-swimming stage but do move around on the calf, often concentrating on the lip ridges and other areas of the head; however, the location of these cyamids bears no correspondence to the whale's adult callosity topography. As the calf matures, the light-colored cyamids transfer from the mother and begin colonizing the calf in the areas of the cornified skin, developing into a callosity pattern which can be used to identify individuals. For instance, in the adjacent picture, the 11-month-old (shown on left) would be described as having a 'broken callosity, with long peninsular coaming (LPC), no lip callosities, and 2 post-blowhole-callosites'. (See more about Right Whale Head Codes here.). Interestingly enough, the mother (seen on the right) also has a very similar callosity pattern, except that she has a single post-blowhole callosity. This lends even more credence to Philip's speculation that whales may inherit callosity patterns from their parents. Learn about right whale photo-id in depth here and practice your own matching skills with the Aquarium's interactive Right Whale Matching Game. You may also like the Aquarium's callosity page for a great look at cyamids.
Photo Credit for top image: Stephanie Grassia, Wildlife Trust. Taken under a Scientific Research Permit issued by the National Marine Fisheries Service/NOAA.
Photo Credit for middle image: Marilyn Marx, New England Aquarium
Photo Credit for bottom image: Suzie Hanlan, New England Aquarium
At this time, we are uncertain whether the calf is still alive but since the small calf was not seen by the observers in the plane, the individuals in the biopsy boat (who biopsy darted one of the individuals (#3190) in the SAG that day), or our ground contact who reviewed the more than 100 photos of the SAG, we believe that it did not survive. This means that Skittle's calf must have died sometime between our first sighting of the calf on February 24th and the day we obseved the SAG on March 1st. Despite the sadness of this event, the data we were able to collect concerning Skittle, her calf, and the remarkable post-birth behaviors is valuable information that will give scientists a better understanding of the biology and ecology of right whales.
In the map below, the unshaded area is the EWS area (North, Central, and South combined) which typically houses the densest distribution of right whales on the calving grounds. The shaded area shows where many sightings have taken place this year, much farther south than usual.
View Northern Florida in a larger map
Below is a figure that shows where new "Dynamic Management Areas" (DMAs) have been placed outside of the usual "Seasonal Management Areas" (SMAs). SMAs are in place between specific dates off the coasts of South Carolina, Georgia, and Florida during which right whales can be found in these waters. Within the management area and between the specific dates, vessels are told to exercise caution and maintain low speeds in order to minimize the risk of colliding with a right whale. But the placement of voluntary DMAs ensures that the whales are protected by SMA measures even if they are found outside of the SMA areas.
this diagram constructed by NOAA/NMFS that integrates all the right whale sightings throughout this season with a map of coastal sea surface temperatures.
Learn more about NOAA's efforts to protect right whales in the Southeast here and here.
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