Rose Atoll, A World Treasure in Peril
by Phillip Colla and Harrison “Skip” Stubbs, Ph.D.
This blog post is now available as a downloadable PDF article.
This post was originally published in Ocean Realm Magazine in the Spring 1997 issue, one of a series of articles I contributed to Ocean Realm in the ’90s. In August 1995 a thirteen-member inter-agency scientific team of which Skip and I were a part visited Rose Atoll National Wildlife Refuge to assess injury caused by the 1993 grounding of a Taiwanese fishing vessel. While the specific injuries to Rose Atoll are unique and the coralline algae composition of the atoll is uncommon, many other isolated atolls worldwide face similar dangers. It is their remote nature, and the unique assemblages of life that they often support, that make such atolls special. Yet their isolation also means that little, if any, enforcement to protect them from damage by fishing and shipping activities exists. The authors collected photographic and videotape evidence in support of litigation and ongoing injury assessment and research efforts. Rose Atoll NWR is jointly managed by the United States and American Samoa governments and on January 6, 2009 became a National Marine Monument.
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| Rose Islet. Image ID: 00839 Location: Rose Atoll National Wildlife Sanctuary, American Samoa, USA View this Image in Google Earth! |
Remote, tiny and unprotected, Rose Atoll stands alone at the eastern extreme of the Samoan archipelago, 14 degrees south of the equator and southernmost among National Wildlife Refuges. Among the world’s smallest and most pristine atolls, Rose is a nearly square reef surrounding an azure lagoon dotted with coralline bommie towers. Tiny Rose Island rises above the waterline at the atoll’s eastern corner. Rose Atoll’s beauty lies not only in its geometry but in the vibrant pink hue of its reefs — it is one of the few atolls whose primary element of construction is the pink calcareous coralline alga Porolithon.
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| Rose islet and Pisonia trees. Image ID: 00830 Location: Rose Atoll National Wildlife Sanctuary, American Samoa, USA |
Rose’s reef system is of the classic spur-and-groove type: massive coralline shoulders extending outward from the atoll separated at regular intervals by deep troughs, grooves through which open ocean wave energy is funneled back to sea. The shallow reef flat surrounding Rose’s interior lagoon is broken only at the atoll’s northern corner by an ava, an opening through which water, elevated within the lagoon by a constant influx of waves, rushes out in a perpetual current. Where the submarine outer reef graduates from a ledge to reef flat is the forereef, an abrupt ten-foot wall of cement-hard coralline algae just beneath the waterline. Crucial to the health of the entire atoll, the forereef acts as a structural armoring that reflects and dissipates wave energy and protects the reef flat from erosion. Injury to the forereef could change gross reef structures and alter established current patterns about the atoll, allowing new avenues of erosion to threaten the atoll’s fragile island.
An Eden in the center the Pacific, Rose Atoll is lonely and beautiful, but virgin no more. The pristine nature of Rose Atoll was violated in October 1993 when the Taiwanese fishing vessel Jin Shiang Fa ran aground on the atoll’s southwest arm. The destructive effect of this event on Rose Atoll was, and continues to be, many-faceted and difficult to quantify.
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| Debris, wreck of F/V Jin Shiang Fa. Rose Atoll National Wildlife Sanctuary, American Samoa, USA. Image: 00807 |
Debris, wreck of F/V Jin Shiang Fa. Rose Atoll National Wildlife Sanctuary, American Samoa, USA. Image: 00827 |
Propellor and debris, wreck of F/V Jin Shiang Fa. Rose Atoll National Wildlife Sanctuary, American Samoa, USA. Image: 00810 |
Structural reef injury to the southwest arm of the atoll was extensive. The Jin Shiang Fa hit the reef obliquely, plowing a deep trench through several reef spurs before coming to rest hard aground. Debris washed overboard, including fishing line, nets, garbage and plastics, snagging on coral heads at the wreck site and in the lagoon. For months, major hull sections remained perched on the reef ledge against the forereef and gradually broke apart in pounding waves, slamming into the forereef wall and carving deep gouges in the brittle coralline reef structure before being towed off the ledge and dumped into deep water by a salvage tug. Remaining are many fragments of the boat that may never be removed. Mangled refrigeration pipes and balls of line are wedged in the reef ledge and the forereef wall. Thirty-foot long hull plates, boiler tanks and much of the vessel’s superstructure slid in pieces down the outer slope of the atoll, leaving behind a swath of crushed reef. In 1994 many of these massive fragments returned to the shallow reef ledge, lifted by hurricane waves, while some pieces came to rest on the reef flat or all the way into the lagoon. Virtually all of the hull debris is still subject to wave movement and continues to erode and weaken the protective forereef, sending a smothering layer of sand up onto the reef flat.
Changes to the atoll precipitated by the release of toxic chemicals may ultimately prove to be more devastating than the grounding itself. The Jin Shiang Fa’s fuel tanks broke open along with a refrigeration system, spilling approximately 100,000 gallons of diesel, 500 gallons of lube oil and 2,500 pounds of ammonia that eventually spread over portions of the outer reef, reef flat, lagoon and ava. A survey conducted two weeks after the grounding, while the vessel was still leaking oil, found evidence of extensive die-off of reef invertebrates (including Tridacna clams and Echinometra urchins) and major reef-building coralline algae (Lithophyllum and Porolithon). Five months later, most of the southwest reef was covered with invasive filamentous cyanobacteria (blue-green algae) which overgrew the reef-building coralline algae. These patches of cyanobacteria marked areas of stressed or dead coralline algae since, for healthy coralline algae, growth occurs just below a thin surface layer that is constantly sloughed off as a natural defense.
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| Paul W. Gabrielson, Ph.D., collecting algae and coral samples. Rose Atoll National Wildlife Sanctuary, American Samoa, USA. Image: 00824 |
Debris from wreck of F/V Jin Shiang Fa. Rose Atoll National Wildlife Sanctuary, American Samoa, USA. Image: 00793 |
Debris, wreck of F/V Jin Shiang Fa. Rose Atoll National Wildlife Sanctuary, American Samoa, USA. Image: 00814 |
Our survey dives at Rose Atoll were superb. Along the outer reef we could constantly hear the vocalizations of the South Pacific humpbacks that swam near us several times. Well away from the wreck site, vast tracts of pastel pink coralline algae and clear water dominate the underwater landscape, a canvas across which is painted a menagerie of wary gray and black-tip reef sharks, swirling blue-spotted jacks and parrotfish schooling by the hundreds. Near the ava sea turtles cruise the reef, soon to mate in the lagoon and nest on either Rose Island or a small sandbar generously named Sand Island. Sixty-foot coralline towers in the lagoon are home to dense communities of Tridacna clams and strange clusters of procreating nudibranchs.
Yet each dive brought us a measure of dismay to temper our sense of wonder. The physical damage from the Jin Shiang Fa is stunning and contrasts harshly with the sections of pristine reef that we had seen earlier. A deep hull scar leads directly to the grounding site where the engine block and propellers, massive enough to resist hurricane waves, sit in the deep bowls that they have gouged out of the shallow reef ledge. Along the forereef and ledge, thick coralline algae structures lie broken underneath the pipes, hull plating and antenna tower that litter the wreck site. Coral heads are wrapped in balls of fishing line replete with steel hooks poised to snag passersby. Chinese videotapes, hip waders, plastic tarps, storm boots and large metal tanks are spread across the sandy floor and the coral rubble slope inside the lagoon.
Most troubling were our reef flat observations. It seemed that the chemical spill injured the coralline algae, as well as the community of invertebrates that normally graze on cyanobacteria, enough to unnaturally trigger a succession of species that are replacing or smothering the reef-building Porolithon. Cyanobacteria, although ephemeral, was first to recruit and overgrow the reef flat. By our visit it had given way to the finely-branched, non-reef-building coralline alga Jania, which had spread to include about one-third of the entire reef flat, well beyond the wreck site. We found that, although earlier aerial surveys provided useful information on the gross effects of the ship wreck, ground-based and underwater field work is the best way to investigate the temporal dynamics of this tragedy. Unfortunately the remote location of Rose Atoll, which so long kept it pristine, may now hamper scientists who try to monitor its future.
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| Brown booby. Rose Atoll National Wildlife Sanctuary, American Samoa, USA. Image: 00914 Species: Sula leucogaster |
White (or fairy) tern. Rose Atoll National Wildlife Sanctuary, American Samoa, USA. Image: 00872 Species: Gygis alba |
Brown boobies. Rose Atoll National Wildlife Sanctuary, American Samoa, USA. Image: 00908 Species: Sula leucogaster |
Since we originally joined the science team to assist with underwater surveys of the wreck site, neither of us was prepared for what we would witness during our visits ashore, a spectacle of wildlife that emphasizes the critical importance of the atoll for nesting and roosting seabirds. While essentially only twenty acres of compacted coral rubble, tiny Rose Island manages to support a small forest of rare Pisonia trees and a rich assemblage of wheeling, diving, nesting, hatching and crying seabirds. Chicks and eggs seem to be under every bush and tree while juveniles walk openly about, fearless. Inquisitive boobies — red-footed, masked and brown — hover above the shoreline in large groups, crying incessantly. Brown noddies and sooty terns flush from the cover of Pisonia, soon to return to their stumbling chicks and nests laid on the barren coral rubble. Red-throated frigate birds hover high above, sky-borne pirates poised to steal a lesser bird’s catch. Diminutive white terns gracefully flutter about among the trees, pure alabaster but for their large black eyes and exotic blue beaks — could there be more delicate and enchanting creatures?
Such magical visits ashore afforded us time not only to intimately observe these captivating and naive birds but also to contemplate a sobering thought that is at the heart of our team’s work at Rose Atoll: This solitary speck of land atop the atoll, cradling a unique abundance of life, is nothing more than a fragile rubble aggregate, subject to the whim of tides and currents that may have already begun to change in the wake of the grounding.
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| Paul W. Gabrielson, Ph.D., collecting algae and coral samples. Rose Atoll National Wildlife Sanctuary, American Samoa, USA. Image: 00824 |
Wreck of F/V Jin Shiang Fa. Rose Atoll National Wildlife Sanctuary, American Samoa, USA. Image: 00709 |
Debris from wreck of F/V Jin Shiang Fa, lagoon talus slope. Rose Atoll National Wildlife Sanctuary, American Samoa, USA. Image: 00789 |
Rose Atoll’s coralline algae reefs have managed to withstand natural disturbances such as hurricanes, varying salinity and changes in sea level. Can they also adapt to the unnatural changes caused by the Jin Shiang Fa? Of greatest concern is the death of the slow-growing, reef-building coralline algae through local structural reef injury and widespread toxin-induced die-off and replacement. The disappearance of these coralline algae may lead to long-term bioerosion that ultimately weakens the reef, altering current patterns and threatening the existence of Rose Island, its forest and its avian inhabitants.
Rose Atoll’s misfortune may ultimately serve to illustrate how delicate the link is between reef welfare and the existence of remote seabird and turtle nesting sites, and how vulnerable such ecosystems are worldwide. Groundings such as that of the Jin Shiang Fa injure tropical reefs and atolls, yet few such incidents occur in countries with the means and interest to carry out damage assessments, sponsor follow-up research efforts, or attempt to mitigate injury to the reef. By chance, had the Jin Shiang Fa ran aground elsewhere, would anyon
Kelp Forest Reminiscing
As he has with all of my past articles, Skip Stubbs critiqued my writing and offered important advice.
Kelp forest underwater photography. This story was originally published as a pictorial in Ocean Realm Magazine in the Spring 2001 issue, the last of a series of articles I contributed to Ocean Realm in the ’90s.
This blog post is now available as a downloadable PDF article.
My first experience with seaweed was as a kid combing the shores of Newport Beach where I grew up. After storms my brother and I would find clumps of the brown stuff pushed up the beach. We would pick through them to pop the small bubbles attached to the leaves. If the seaweed was fresh and still had its rootball attached, we would break it apart to reveal a mix of tiny animals: brittle stars, baby octopus, urchins, crabs, little shells and worms. The glimpses of marine life that seaweed brought to our shore triggered a childhood curiosity in the ocean and its inhabitants. Yet it was not until I began diving in kelp that I gained a fuller appreciation of the ocean world.
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| Kelp forest. San Clemente Island, California, USA. Image: 04651 |
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| Jack mackerel schooling amid kelp forest. San Clemente Island, California, USA. Image: 00256 |
Kelp plants growing toward surface and spreading to form a canopy. San Clemente Island, California, USA. Image: 01293 |
Kelp fronds and forest. San Clemente Island, California, USA. Image: 01497 |
It is my spirited opinion, one that I enjoy defending over a beer after a long day on the water, that diving amidst giant kelp is the most magnificent diving in the world. I am fortunate enough to have had some amazing experiences underwater — watching swarms of hammerheads soar overhead, riding the broad back of an accommodating manta, being eyeballed by an inquisitive whale. However, the diving I consider most dear is that found in the splendid kelp forests along the coast and offshore islands of California. Vast beds of giant kelp (Macrocystis pyrifera) line the shore, rising from rocky reefs nearly 100ft deep to reach the surface before spreading out to form a thick floating canopy. Underneath this canopy, the sensation of swimming amid the columns of kelp plants is akin to flying through a terrestrial forest. Corridors between kelp stalks lead to wide openings in the forest in which schools of fish hover. Shafts of light filtered by the canopy above fall across kelp to the reef below. When the current shifts and bends the kelp stalks in a new direction the topology of the forest changes, creating new avenues and rooms to explore.
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| Kelp canopy. San Clemente Island, California, USA. Image: 02118 |
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| Kelp forest. San Clemente Island, California, USA. Image: 02409 |
Kelp bed. San Clemente Island, California, USA. Image: 02502 |
Divers and kelp forest. San Clemente Island, California, USA. Image: 02988 |
Central and Northern California kelp forests are bathed by cold, nutrient-laden currents. The waters here are generally not clear but are rich with animal life. Invertebrate displays on the rocks below the kelp forest are some of the most profuse and interesting in the world and it is common to see large schools of rockfish and pelagic jellies hovering among the kelp. Kelp forests here breed some of the world’s hardiest divers, those who manage year-round dry suits, beach entries and surface swims, winter swells and the distinct possibility of meeting great white sharks in murky water just to dive in Macrocystis.
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| Kelp canopy. San Clemente Island, California, USA. Image: 06119 |
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| Giant kelpfish in kelp. San Clemente Island, California, USA. Image: 05141 Species: Heterostichus rostratus, Macrocystis pyrifera |
Northern kelp crab crawls amidst kelp blades and stipes, midway in the water column (below the surface, above the ocean bottom) in a giant kelp forest. San Nicholas Island, California, USA. Image: 10215 Species: Pugettia producta, Macrocystis pyrifera |
Kelp forest. San Clemente Island, California, USA. Image: 04675 |
Further to the south, Santa Barbara and Catalina Island kelp forests offer somewhat less profuse animal life but warmer and clearer waters. While I don’t dive these two islands often anymore, I do dive kelp originating from these islands throughout the summer: drift kelp. I was introduced to the notion of seeking out floating paddies of kelp by bluewater photographer Mike Johnson and have been hooked ever since. It is a strange pursuit, driving miles of open ocean in search of drifting kelp in the hope of finding something under it. You see, kelp plants that lose their hold on the reef continue to float and grow, drifting with the winds and currents until they are beached or reach warm water. Along the way they gather a variety of passengers including juvenile fish, Medialuna eggs, barnacles and pelagic nudibranchs. Paddies and their passengers further attract a variety of open ocean life: diving birds, bait fish, yellowtail, tuna and marlin, blue and mako sharks. Perhaps the oddest of these visitors is the ocean sunfish (Mola mola), which recruits small fishes at paddies to clean it of parasites — a cleaning station for the largest bony fish in the world, miles from shore in deep oceanic water, circling a scrap of drifting seaweed.
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| Ocean sunfish schooling near drift kelp, soliciting cleaner fishes, open ocean, Baja California. Image: 06308 Species: Mola mola |
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| Blue shark underneath drift kelp, open ocean. San Diego, California, USA. Image: 01006 Species: Prionace glauca |
Pacific white sided dolphin carrying drift kelp. San Diego, California, USA. Image: 00043 Species: Lagenorhynchus obliquidens |
Half-moon perch, offshore drift kelp. San Diego, California, USA. Image: 01933 Species: Medialuna californiensis |
When the goal is simply to swim in and admire a kelp forest, nothing beats the (relatively) warm clear waters of Southern California’s San Clemente Island in late summer. On a good day the panorama at San Clemente is stunning: kelp in all directions reaching from seafloor to surface, summer sun and canopy shadow constantly changing, fish swimming the avenues of the forest and visible over a 100′ away. One is enveloped — literally — by life as far as one can see, an effect I have experienced only a few times, and fleetingly, elsewhere in the ocean. On a day like this I will spend as much time in the water as possible, staying just below the surface to take advantage of the wonderful quality and variety of sunlight in the canopy, waiting for subjects to photograph against a backdrop of kelp. There are always garibaldi, kelp bass, various wrasses and juvenile fish hidden among kelp fronds to photograph year-round. It is September and October — the magical Indian summer months at Clemente — that are my favorite as they have brought torpedo and bat rays, seals and sea lions, huge schools of salema and mackeral and enormous sea bass though the forest in front of my lens: wonderful animals in a spectacular setting to spite my limited ability to capture them on film.
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| Garibaldi in kelp forest. San Clemente Island, California, USA. Image: 01055 Species: Hypsypops rubicundus, Macrocystis pyrifera |
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| California bat ray in kelp forest. San Clemente Island, California, USA. Image: 00267 Species: Myliobatis californica, Macrocystis pyrifera |
Jack mackerel and kelp. San Clemente Island, California, USA. Image: 00380 Species: Trachurus symmetricus, Macrocystis pyrifera |
Kelp fronds. San Clemente Island, California, USA. Image: 03423 Species: Macrocystis pyrifera |
See more kelp forest photos.
Keywords: kelp forest, macrocystis pyrifera, photography, stock photo, california
Heat Run: Humpback Whale Behavior Photos
Humpback whale underwater photography. Originally titled “Heat Run”, this appeared in Ocean Realm Magazine in April 1995, the first of a series of articles I contributed to Ocean Realm in the ’90s.
This blog post is now available as a downloadable PDF article.
Each winter North Pacific humpback whales (Megaptera novaeangliae) converge on Hawaii to calve, form consort pairs and eventually mate. These social activities often culminate in “heat runs”, exciting and only partly understood spectacles of competition unique among cetaceans. It should be pointed out that the term heat run is colloquial suggesting the female whale involved is “in heat” (estrous). In fact there is little direct evidence that estrous is occurring in these events. But since the behaviors involved are thought to be related to courtship and mating, and since heat run continues to be widely used (and not just in Hawaii), I have chosen to leave it in this account. If I were to write this today, I would probably elect to use “competitive group”, “rowdy group” or “surface active group”.
“We’re out of gear.” The props have stopped spinning and humpback pod 1994-181 has surfaced, heading directly toward our research boat. Slipping into the water I immediately sense their presence. An immense deep thrumming sound sets my hair on end, as if I were inside a huge cathedral organ. The mother-calf-escort trio appears 80 feet away and the male escort is singing, a behavior typically observed only in solitary resting males. As the escort glides below, the mother and calf come directly toward me while I hang motionless 15 feet deep. I am awestruck, alone with three enormous humpback whales, all of us breathholding in deep blue water. The mother brings her calf near to examine me, undoubtedly the first human it has seen. I must lift my legs to allow the mother’s 12 foot long pectoral fin to pass underneath. Her calf’s body coloration is just emerging and it is without significant diving ability, staying just below the surface and hugging closely to its mother but on my side, an indication of the mother’s acceptance of me. This calf is so close I could touch it! I take a few photos, recording the whales eyeballing of me as they pass. In contrast to the infant whale’s awkward swimming motions, the mother lifts her fluke in an easy kick, an uncommon opportunity for a tight underwater fluke shot as they move by.
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| North Pacific humpback whale, cow/calf. Image ID: 00140 |
Before losing interest and swimming off, pod 181 offered us four more close passes, enough to capture scientifically valuable video images and identifying photographs. In terms of information, this pod provided an ideal encounter. Photographs revealed the mother was previously seen in 1993 in the company of several identified males, one of which could be the father of this calf. This represents a rare potential escort-mother-calf link, a connection important to the study of the long-term social affiliation characteristics of humpback whales. In addition, the male currently escorting the mother in pod 181 may sire her next calf. Beyond the social affiliation implications, pod 181 also symbolized the assumed culmination of a winter social activity among humpbacks known in Hawaii as the heat run, a beautiful, violent and unique phenomenon believed instrumental in determining courtship and mating associations and ultimately resulting one year later in that most characteristic and endearing humpback group, the mother and calf.
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| Molokai and water pools, viewed from west Maui. Image ID: 00253 |
Once a single land mass of four volcanoes, the islands of Maui, Molokai, Lanai and Kahoolawe now seem like an enormous hand sunken so only the palm and fingertips are visible. Wild and lonely Pacific waters swirl through these fingers and temporarily find calm in the wind lee of Maui, dominated by towering Haleakala volcano and the cloud-ringed West Maui mountains. In this lee, tucked tightly against the coast from Maalaea to Olowalu, humpback mothers regularly bring their new calves to swim in the shallow nearshore waters, to nurse and to gain strength for their coming journey to Alaska. Lanai also has a lee shore where, in addition to mothers and calves, subadult whales are often found socializing, singing and lamenting after being rudely “dropped off” by a mother who has gone to find this year’s mate. But away from shore, calm frequently gives way to weather as the trade winds funnel through the Pailolo channel and streak across Maui’s low-lying midlands into the four island basin, creating shifting windlines that can change glassy calm water into whitecapped swells within minutes. It is here, on the open water among volcanoes and clouds, wind and waves and blazing sun, that Dr. Dan Salden studies the Hawaiian humpback whale.
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| Humpback whales a the surface, volcano and clouds. Image ID: 00425 |
Dr. Dan R. Salden steers our small zodiac towards a large pod of surface active whales, at least twelve in number, swimming quickly across the Auau channel. From the strength and frequency of the whales’ distant blows we had earlier determined, while still several miles away, that the animals were exerting themselves tremendously. Positioning the boat alongside and slightly behind the pod, we match speeds with them and begin observing their behavior. Over the past thirty-one years Dr. Salden has mastered the art of approaching humpbacks without disturbing them. When the lead whale blows and makes a shallow dive the rest of the pod follows. Underwater the whales slow, turn and move directly below us. As they return to the surface we find ourselves amid the pod with whales beside, ahead and underneath the boat. Two whales glide just yards below the keel, each almost twice as long as our skiff. One has ghostly white pectoral fins spanning 30 feet tip to tip. The whales are clearly aware of our proximity and make no overtures toward us, exhibiting exceptional body control as they repeatedly pass within feet of the hull while working amongst themselves to establish position. As whales surface to breathe and dive again, we situate ourselves to photograph identifying markings and scars found on the underside and trailing edge of their flukes. These photographs will be matched against the Hawaii Whale Research Foundation’s (HWRF) database of “fluke IDs” in order to establish individual histories and verify repeat sightings. Dan is now truly in his element, photographing new flukes and pleased to recognize animals from past encounters. Their sequential blows are heard over the boat engines, massive exhalations of breath mixed with atomized water and carrying a thick fishy smell. Dan points out the pod’s two focal animals immediately in front of us — the female seems to be dictating the direction of the pod’s travel while flanking her closely is the escort, a whale whose bloody head nodules and scarred, raw dorsal ridge attest to recent violent encounters.
Suddenly a challenging male rushes in from the side, lunging forward and out of the water, its head completely aloft. Crashing its chin down upon the back of the escort, this new whale tries to displace the escort. The challenge has been made, and a “heat run” has begun. Within seconds, the escort parries the challenger’s head lunge with a peduncle throw, a behavior as exciting to observe as a full breach. Converting his forward momentum into a crack-the-whip rotation, the escort pivots about his submerged head, thrusting his entire fluke and peduncle (the muscular rear portion of his torso) out of the water and laterally at the challenger. An opening behind the female forms as the fighting males move away from the rest of the pod. Before a lesser challenger can fill the gap, the female slows and waits for the escort to rejoin her. Whales begin trumpeting loudly as they surface to breathe, a series of rolling “harumph-umph-umph” sounds that may be attempts at intimidation or simply the result of strenuous exertion. Additional challengers draw in tightly behind the escort, determining among themselves who gets to make a new challenge when the current conflict is resolved. The escort repeatedly blocks the primary challenger, actually pushing him sideways across the surface, then quickly resumes his position beside and behind the female to await his adversary’s next move. Giving up after several failed attempts to displace the escort, the primary challenger breaks off from the pod and departs. Another whale in the pod, who has perhaps been waiting “its turn”, takes his place and the battle continues.
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| North Pacific humpback whale, escort in competitive group makes fast close pass. Image ID: 06057 |
The “heat run” is a setting for spectacular acrobatics and provides an opportunity to study the humpback courtship process. The focus of the run is usually an adult female although there are all-male surface active groups. Typically she is without calf and swimming at speed so that the males pursue quickly, close to the surface. As the season progresses and calves appear more frequently, we encounter runs in which the pace is slowed by a mother with her calf. (In 1993 we observed a surface active group that formed around a sleeping mother / calf pair.) Today, the female is without a calf and has allowed an adult male to accompany her. This escort flanks her continually hoping ultimately to mate with her, wary of others who wish to usurp his position. Staying ahead of the female and escort and careful to keep out of the fray are three subadult whales just a few years old, not challenging the escort but instead apparently just observing the adult’s behavior in anticipation of their own future roles one day.
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| Humpback whale dorsal fin damaged during competitive group socializing. Image ID: 04334 |
The escort’s principal concern is a lineup of challenging males spread out behind him. Each challenger may attempt to displace him from his position with the female. Challenges are an escalating series of maneuvers that may stop at intimidation or culminate in physical injury. On rare occasions Dr. Salden has observed cooperation among challengers, teaming up to defeat the escort. Lesser challengers often engage in side skirmishes among themselves away from the pod, perhaps to establish a pecking order. A successful challenger may become the new escort if the female is accepting and if he can resist further challenges. Determining the gender and roles of the female, escort and seasoned challengers in an active group is straightforward: unlike the smooth skin of females who do not battle, adult males who have accumulated the skill and strength to challenge are scarred and often display dorsal fins that are merely stumps, sheared off by a past opponent’s attack. The dorsal ridge (the backbone leading from the dorsal fin to the fluke) is usually carved with gouges, rips, and white scars, grim testaments to the effectiveness of a humpback whale’s barnacle-encrusted chin as a hammering weapon.
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| North Pacific humpback whale, competitive male with wounded head nodules from colliding with other escorts during competitive interactions. Image ID: 02152 |
Interpreting heat run events from a boat can be difficult, especially with a large pod. The role of animals not directly involved in the conflict is unclear, and the gender of younger whales cannot be determined from superficial scarring. The role of each challenger is fluid, with males jostling for optimal position relative to the female. Whales with white pectoral fins are the most distinguishable underwater, even when 50-80 feet deep. Some individuals have other distinguishing features, such as dorsal fins — hooked, pointed, stumped or gouged — that are visible whenever they break the surface. The rest are usually known only by their fluke patterns, any unusual scarring, or perhaps by their maintaining a constant position in the pod throughout the run.
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| Humpback whale fluking up, ventral aspect of fluke visible. Image ID: 04150 |
When the whales have long down times we must enter the water with them to better witness how the skirmish is resolving itself. Allowed under HWRF’s research permit, underwater study offers opportunities to more fully assess the sex and social roles of key animals and to observe chance behaviors such as nursing and penile displays. (Although whales have internal genitalia, gender can be determined by observing the genital slit and surrounding features, located on the ventral peduncle anterior to the fluke.) Given a change in direction that results in the pod swimming toward the boat, Dan stops for us to enter before moving the boat out of the whales’ path. Only free diving equipment is used and special care is made to minimize water disturbance and to remain unobtrusive. Once the animals are in sight we swim parallel to them and do not dive below them unless they have already shown that they fully accept our presence in the water. For the fortunate few researchers allowed in the water these are often the most rewarding moments of our work, occasions to observe up to a dozen 40-ton whales at once, racing and jostling and flying by.
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| North Pacific humpback whales, socializing trio of adults. Image ID: 05933 |
Getting away from the departing boat’s prop wash is nerve-wracking — whales will be here in moments and I cannot see through the bubbles. Once into clear water I make out the female, leading the pod with four others some 50 feet behind her. Their sounds are a wild dissonance of low pitched calls quite different from the orderly singing of resting males. If they see me, as the female and two of the others do, the whales usually cruise by without changing their behavior. It is amazing to see them corkscrew in order to position both eyes for a stereoscopic view of me. The low contrast of grayish whale against blue water makes it difficult to see all the animals, especially some that pass behind or below. Battling whales that do not see me are a danger and I stay ready to move out of their path. The escort and primary challenger are now drawing near and are intent on one another, flukes pumping and heads driving furiously against each other. Diving, they leave a roiling footprint on the surface and pass within a body length of where I float. The escort has the advantage of bearing down on the challenger from above, pushing with his rostrum and using his pectoral fins to maintain position, while the challenger manages to twist and lash at the escort’s body with lateral fluke swipes. Although the combatants have not actively sought food since leaving Alaska in January, they are expending enormous amounts of energy. I feel insignificant in comparison. When they have faded from sight all that remains is a bubble trail that one whale left behind, a three hundred foot long contrail glistening in the sun, rising silently to the surface.
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| North Pacific humpback whale, male escort bubble streams alongside mother and calf. Image ID: 05926 |
Whales constantly enter and exit heat runs, some of which last an entire day. Distant animals may hear the activities and rush over to investigate. Defeated challengers and disinterested subadults often veer off and disaffiliate, perhaps later to breathhold (rest) or sing. On several occasions we observed two surface active pods cross paths. In the ensuing chaos whales shuffle between pods and wholesale changes in a pod’s temporal social hierarchy may occur.
In one sense, a breach is any behavior in which a substantial portion of the whale breaks the surface. But in practice, a breach is considered to be that most dramatic of events, when the whale launches itself headfirst out of the water with such force it becomes almost entirely airborne. Breaching associated with the heat run most often occurs when a humpback affiliates (joins the pod) or disaffiliates. In addition to the possibility that whales are visually scanning their environment while breaching, Dr. Salden feels the breach has a communication function as well, an opinion shared by other researchers and formulated from years of anecdotal observations. An expert in nonverbal communication, Dr. Salden suspects breaching is the humpback’s way of announcing It is I!, with any surrounding activities forming a context in which the breach must be interpreted. It may be an aggressive signal from an arriving whale (It is I, watch out!) or a parting shot from a disaffiliating whale (Remember me!). When accompanied by a breach, whatever the whale is communicating is “said” with emphasis. An adult whale’s full breach is the most exciting singular behavior humpback observers see. A mighty launch rockets 45 tons of twisting whale skyward, pectoral fins flinging sheets of water aside, ending in a slow motion body slam heard for great distances.
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| North Pacific humpback whale, breach. Image ID: 00205 |
Underwater, a full breach is a frightening thunderclap, a painfully sharp crack. Captain Jill Mickelsen and I experienced a particularly memorable breaching session one day while in the water observing a mother-calf-escort trio off the north shore of Lanai. Strangely, as the mother and calf slowly circled us, the escort unleashed a succession of more than 25 breaches quite close to our boat. Wind chop, combined with his splashes, reduced the water visibility to less than 60 feet, forcing Jill and I to search continually for the escort deep below as he prepared to rush upward for his next launch. Occasionally, we could see him spiraling and pumping as he approached the surface and we could signal to the boat where he would emerge. More often we would simply hear his breach and realize gratefully that he did not land on us. Researcher David Glickman was able to capture these breaches in a video record that shows the escort slamming one pectoral fin against the water each time he landed, as if to add to his impact. He eventually stopped after the mother directed several peduncle throws at him. Did she tire of his show, or was her calf becoming distressed? No sooner was the breaching finished than Galapagos sharks appeared, swimming erratically with pectoral fins lowered. Had they been attracted by the surface activity or had the breaching been directed at them as a warning? In either case, we were swimming in waters filled with many large pieces of humpback skin shed during the melee — a whale-scented chum line! Four sharks quickly approached me from below, nipping at my fins. I have been told a video camera was still recording as I yelled for the boat and scrambled aboard, rattled.
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| North Pacific humpback whale, peduncle throw. Image ID: 02153 |
It is in large surface active pods that the potential for a heat run lies and that courtship roles become clear, although no direct evidence linking such social behavior to mating has yet been found. In-water observations allow us to examine facets of behavior not observable from the boat, including actions carried out in conjunction with social sounds. Courtship, mating and birthing activities likely occur in the North Pacific humpback wintering areas of Hawaii, Japan and Mexico. Still, the reproductive lives of humpbacks remain a mystery. Do humpbacks mate in Hawaii or on the journey back to Alaska? Where are the calves born, in sheltered waters or open ocean? Although we have recorded an uncommon underwater humpback penis display and analyzed a sample of humpback placenta, no confirmed direct observation of either mating or calving has been recorded. Pods exhibiting courtship behavior are thus valuable as they provide information about which whales are together this year, in anticipation of calves next year. These data will help us to answer broader questions about whether humpbacks form long-term social affiliations and what factors might influence such relationships.
The Hawaiian Islands Humpback Whale National Marine Sanctuary, designated by Congress in 1992, specifically recognizes the importance of the humpback whale and its winter habitat and will promote protection, research and education while monitoring both the whale and its Hawaiian environment. The Hawaii Whale Research Foundation studies humpback social affiliation and communication with the belief that if the behaviors of these magnificent animals are more fully understood, we may better offer recommendations that protect and preserve them. HWRF was founded and is directed by Dan R. Salden, Ph.D., past chair of the Department of Speech Communication at Southern Illinois University at Edwardsville. HWRF maintains a growing database of individually identified North Pacific humpback whales, including some that are known to winter in Japan and Mexico as well as Hawaii, and a video record documenting humpback behavior and social roles. HWRF is a publicly supported nonprofit organization staffed by a small group of volunteers. Five winter months of data collection and photo-documentation in Hawaii are augmented by year-round analysis, scientific publications, public service seminars and educational presentations. Field studies are governed by the provisions of NOAA Fisheries (aka, National Marine Fisheries Service) and State of Hawaii scientific research permits.
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| North Pacific humpback whale. Image ID: 00167
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More information about Dr. Dan Salden and Hawaii Whale Research Foundation can be found on HWRF’s website.
As he has with all of my past articles, Skip Stubbs offered important advice.
Some humpback whale behaviors often observed in association with surface active groups (heat runs):
Breaching
Underwater bubble displays
Mother / calf pairs
Lunging
Peduncle throws and tail lobs
Pectoral fin displays
Crucifix blocking
Keywords: humpback whale, megaptera novaeangliae, surface active, behavior, rowdy group, maui, hawaii, pacific.
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Updated: February 10, 2012




























































