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The Wonders of the PacificCocos

Galápagos

Malpelo

Socorro

Hawaii Palau

E E A S T E R N P A C I F I C E

BIGGAME

DIVINGIf you are looking for high-energy

encounters with the big stars of the ocean,the Eastern Tropical Pacific is the place for you –

rugged, unforgivingand, at times, terrifying

Words and photographsDouglas David Seifert

A marine iguana (Amblyrhynchus

cristatus) on Isabella Island in

the Galápagos


Above, oceanic bottlenose dolphins returning from nocturnal hunting

Below, the manta rays of Socorro are renowned for their curiousity

Right, scalloped hammerhead sharks gather around seamounts during the day

Jacks and a moray eel out hunting

creolefish


When the topic turns to the ultimate in adventures underwater, one geographical location springs to mind: the Eastern Tropical Pacific Ocean. Here, around the isolated and far-flung islands of the Galápagos, Malpelo, Cocos and the Revillagigedos, virtually anything imaginable involving the big animals of the sea is not only possible, but is often routine! It is the one locale where witnessing mind-blowing phenomena and being a participant in extraordinary encounters beyond the imagination has a very high probability.

This call to adventure is answered in the waters adjacent to a select few islands – 26 in total (three solitary islands and two archipelagos)scattered across an enormous seascape. This vast expanse of ocean is in a perpetual state of turbulence from competing current flows and wind-driven waves travelling vast distances. The waves unleash their accumulated energies with an explosive power upon these island specks – the first terrestrial obstacles they encounter. The topography is not pretty in a classical sense. The underwater vista lacks the multitude of colour and variety of living structures of a healthy Indo-Pacific coral reef. There is, in fact, relatively little coral – a few species of stony coral rather weathered in appearance.

It is a forlorn, stark, and primeval backdrop: massive stone formations the size of houses or city blocks; sheer cliff faces extending above sea level and descending into the depths; escarpments and ledges, overhangs and undercuts; gargantuan rocks and massive boulders dominate the subsea terrain. The colour palette below the surface is limited to a pale khaki to chalky-white in places, with fissures and gouges of black, otherwise it is a universe of greys from light to dark. The stark contrast between the scale of the formations and the absence of distracting or pleasing colour makes for a very dramatic but uneasy arena. To be sure, the seascape has a handsomeness – the word people use when they mean strong-featured but not soothing or serene – and a rugged kind of beauty of naked geological formations and structures well-worn over time. The rock faces are minimalist in the extreme and austere, not featureless, but scarred with crevices.

‘It is the sudden appearance of a big animal or animals that transforms a lacklustre sea-scape into an amphitheatre of the fantastic’

Rock clefts are filled with long-spined sea urchins, home to eels and nocturnally active fish, as well as invertebrate and fish species that provide parasite removal cleaning stations. Spiny lobsters wave their antennae as if conducting symphonies while tucked back into recesses as deeply as they can wedge themselves. Guineafowl pufferfish and hogfish meander from crevice to crevice seeking unwary crustaceans caught out in the open. Colonies of pale purple barnacles by the thousand have affixed themselves to the rocks as best their biological adhesive allows. Tiny blennies stare out from abandoned barnacle shells and cracks in the rocks. Floating in the midwater are swarms of creolefish, picking plankton from the water column and moving rapidly, en masse, to safety whenever a predatory snapper or hunting pack of jacks enter the area. In addition to the fish that are found in other parts of the Pacific, there are, in the entirety of the Eastern Tropical Pacific, 1,200 endemic fish species. Perhaps because the setting is so similar, and repetitive, and, after a time, even monotonous, it is the sudden appearance of a big animal or animals that transforms a lacklustre seascape into an amphitheatre of the fantastic. Just as an empty stage helps an audience focus upon a main character in a performance, so too does the sudden appearance of a giant oceanic manta ray – or a school of hammerhead sharks, for example – relegate the dull and austere surroundings to abackground role which enhances the star attraction.

THE MARINE CAST LISTThe roll call of animals that are often encountered during a week’s scuba diving here ticks a good many boxes for those driven by bucket list aspirations: scalloped hammerhead sharks in sizeable schools; enormous oceanic manta rays; bottlenose dolphins; schools of bigeye jacks; silky and Galápagos sharks; moray eels; sailfish; hawksbill and green sea turtles; balls of baitfish attacked on all sides by opportunist predators; whale shark appearances; fast-moving tuna on the hunt… The islands of the Eastern Tropical Pacific are the Revillagigedo Archipelago of Mexico; Cocos Island, Costa Rica; Malpelo Island, Colombia; and the Galápagos Archipelago, Ecuador. (There is also one distant island atoll at the western frontier of the Eastern Tropical Pacific, namely Clipperton Island, claimed as French Overseas Territory, which is the most remote of them all. The limited number of expeditions visiting Clipperton have failed to find anything approximating the impressive marine biodiversity found at the other two islands and two archipelagos.) Each of these remote, remarkable islands shares a common trait: they are the terrestrial-protruding outcrops of underwater mountains, all of which rise precipitously from the surrounding sea-floor plateau 350–1,000m (or more, in the case of Malpelo). These

Left, the ‘treasure islands’ of the Eastern Tropical Pacific surrounded by a complex network of currents

Right, the unforgettable

visage of a red-lipped batfish

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mountain-peaks-cum-oceanic islands are the uppermost formation of rock ridges made up of crags and seamounts (underwater volcanic mountain remnants) They are incrementally (on the order of two inches or so per year), moving along their respective oceanic plates (the Cocos Plate, Nazca Plate, and Pacific Plate) through the action of plate tectonics. These massifs are geological formations characterised by sheer profiles that deflect deep-water undercurrent flows. This creates upwellings of nutrient-rich water from colder, deep-water currents and down-wellings of warmer surface waters. The warmer waters have a greater concentration of dissolved oxygen which is transported to depths that would otherwise be cooler and oxygen- deficient. This dynamic dramatically expands the range of habitable environments for many species. Such vast natural forces create an area of high productivity, which concentrates and retains every component of the ocean’s trophic level, from the primary producers (phytoplankton) to primary consumers (zooplankton), to secondary consumers, tertiary consumers and apex predators. This concentrating effect is crucial, for although the Eastern Tropical Pacific has the richest biomass of sea life per square kilometre than any other region of the world, it is also immensely large and spread out. Multitudinous organisms are scattered far and wide, except at these island way stations at the oceanographic confluence of geology and currents.

THE CHALLENGE OF SURGE AND CURRENTS For those seeking to experience the Eastern Tropical Pacific, it has to be said that the conditions can involve some of the most difficult diving and most uncomfortable diving you can contend with, not to mention the factor of a very real possibility of physical danger. To dive the islands of the Eastern Tropical Pacific, one will often be faced with strong currents, to either ride along with as part of a dive plan, or to scrupulously avoid, as part of dive survival. Sometimes a combination of both strategies is required to maximise the opportunities to encounter big marine animals that themselves do not fear currents but effortlessly utilise them. There are currents so strong, so intense and powerful that humans cannot make headway against them and any resistance is futile. Currents that can take the unwary great distances out to sea and away from the reference of the island; or worse, downcurrents that can seize a diver and pull him or her down into the abyss rapidly, forcefully, one hundred metres or more – and beyond the diver’s ability to reach the surface alive. It is a place for caution and respect – the foolhardy and the reckless are rarely seen again. Just as vexing as currents is the frequent occurrence of surge. Surge is the massive, rhythmic, displacement movement of an area of water. Large wave swells pulse across the Pacific then abruptly encounter a

From February to April, humpback whales migrate to the Revillagigedos Islands to breed and nurse their young


stationary obstacle, such as a remote island in their path. With surge, a diver is lifted towards the surface, uncontrollably and rapidly, and then pushed downward just as quickly and unpredictably with every pulse of waves. Sometimes the peak and trough can separated by as much as ten metres. The change in pressure of ten metres in a matter of seconds can be very difficult for many divers and can cause barotrauma to the ears. Once one is resigned to strong currents and surge, there are thermoclines of cold water intruding unpredictably into a tropical dive venue to deal with, plus occasional diminished visibility and then the presence of large marine predators. Only when comfortable with all of that, can one competently consider diving in a place where anything is possible. As a distinct body of water, the Eastern Tropical Pacific seascape comprises an area of 21 million sq km – roughly, an area greater than the size of three Australias or two Europes – and geopolitically includes the sovereign waters of 12 nations. Its terrestrial border is the west coast of the American continent, straddling both hemispheres and extending south to north – from Cabo Blanco, on the coast of Peru, South America,

moving northwards up through Ecuador and transiting the equator to include Colombia. It continues onwards, along the coasts of the Central American countries of Panama, Costa Rica, Nicaragua, Honduras, El Salvador, and Guatemala, and continuing on into Mexico, following the coast, incorporating both the shoreline of the Sea of Cortez and its waters, continuing around the southern tip of the Baja California peninsula and north again to Bahia Magdalena on Baja’s west coast. From Bahia Magdalena, the boundary extends, in a southwesterly direction, far offshore out into the Pacific. The westernmost boundary is considered to be the 150 degrees West longitude, where it merges with the North and South Equatorial Currents and they coalesce into the Eastern Pacific Barrier – a 5,000km-stretch of water without landfall until the Kiribati (Christmas) Islands. The northwest and southwest margins are where cold-water currents moving from higher latitudes to lower latitudes deflect westward – Humboldt Current in the south and the CaliforniaCurrent in the north. The Humboldt Current, also known as the Peru Current, fuelled by winds and the South Pacific Gyre, is the largest upwelling system in the world, bringing cold, nutrient-laden waters from the far south of Chile into the Tropical Eastern Pacific. Although this seascape represents less than one per cent of the global ocean surface, it is estimated that it is

‘Malpelo offers up the stuff of interminable bragging rights… enormous schools of silky sharks numbering in the high hundreds‘

home to as much as 50 per cent of the world’s oceans biological production, with the Humboldt Current alone accounting for 20 per cent of the planet’s total fish landings, primarily in unimaginable quantities of sardines, mackerel and anchovies. The Humboldt Current bathes the Galápagos Archipelago with a profusion of life and the fuel required to drive the entire spectrum of the oceanic food web. Its counterpart at the northern extent of the Eastern Tropical Pacific is the California Current. The California Current fulfils the same role as the Humboldt as it flows southward along the coast of North America, with its origins off the coast of British Columbia, Canada. It brings nutrient-rich water down the western seaboard of the United States to terminate at Baja California and brings its superabundant productivity to the Revillagigidos Archipelago. The dynamic marine environment found at these oceanic islands is reliant upon the perpetual interplay of competing currents vying for dominance seasonally. Current is life, and currents drive the seasons in the sea in the Tropical Eastern Pacific. Cocos Island, 550km from Puntarenas, Costa Rica, and Malpelo Island, 500km from Buenaventura, Colombia, are separated from each other by 627km of open ocean, yet their seascape is defined by their shared current influences – the Panama Current, the North and South Equatorial Countercurrents, and the Colombian Current. To humans, the distances between the two islands are vast, but to the marine life, they are, to a degree, interconnected. A recent study of hammerhead shark migratory movements documented connectivity between Malpelo and Cocos Islands, as well as connectivity with the northernmost of the Galápagos Islands, 1,200km distant from Malpelo.

MALPELO ISLANDOn its best days, Malpelo offers up the stuff of interminable bragging rights: a place where, at the right season and with good luck, one may encounter enormous schools of silky sharks numbering in the high hundreds. Whale shark sightings are commonplace. Schools of hammerhead sharks provide a focus to many of the dive sites and often in relatively shallow water. Malpelo is renowned for its unique aggregation of fine-spotted moray eels (Gymnothorax dovii) that may be found by the dozen or more, cohabiting on the current-swept, barnacle-encrusted boulders of the rocky undersea topography of a site called Altar of the Virgin. If one descends to 65m, at the dive site called Bajo del Monstruo, there is a possibility of seeing the rare, 4m-long, smalltoothed sand tiger shark (Odontaspis ferox). At many locales, schools of bigeye jacks move with the surge as waves move volumes of water up and down the rock faces of the island, the energy that has travelled across kilometres of open ocean releasing itself

Left, Malpelo is home to unique aggregations of fine-spotted moray eels

Below, the schools of scalloped

hammerhead sharks in the

area have survived years of

overfishing

Above, yellowfin tuna on the prowl

Below ,whitetip reef sharks at Roca Patida

in an explosion of froth and crashing sea. The island itself is home to a small contingent of Colombian Navy personnel, stationed at the top of Cerro de la Mona, 100m above the wave-crashed boulders that ring the large rock that makes up the majority of the island. There are no beaches or landings, it is simply an isolated rock with a few pinnacles arrayed around its base. Masked boobies tend to nests among the crevices in the massive rock face and the walls are streaked with guano, as they have been since time immemorial. Malpelo appears fairly lifeless, but is home to a few endemic lizards and an endemic crab. It has no discernible vegetation, save lichen, and it calls to mind the phrase ‘godforsaken rock’, to which no doubt the naval officers stationed upon Malpelo for long periods of time might agree. But when the action is on, the sealife is abundant and conditions manageable, the phrase ‘godblessed’ may come to mind as well. In 1995, the Malpelo Fauna and Flora Sanctuary was created to advance conservation measures, however, illegal fishing regularly occurred. In 2005, the government extended the sanctuary from 65,450 to 857,500 hectares. In 2006 it was declared a UNESCO World Heritage Site. Yet, in spite of being 500km from shore and surrounded by deep water, adjacent to a 4,000m-deep trench, Malpelo can at times, also offer… nothing. There are times when the water clarity is reduced to a green soup with less than 10m visibility. There are also times when the hammerhead sharks are few and far between. Usually, it is when there are no dominant currents bringing their magic to this isolated collection of rocks. The water may be too warm, or it may be too cold, or, for whatever reason, the circumstances work against concentrating sea life near the rocks and diveable depths and the trip is a bust. It is one of the biggest gambles for the traveller seeking the adrenalin rush of big-animal action. Sometimes, it just doesn’t work out at all. And there is rarely a rhyme or reason, only opinion and some superstition about luck.

COCOS ISLANDIsla de Coco, to give its Spanish name, is high-peaked, with four mountains and 100m cliffs on all sides; 8km by 3km in size; a lush, green island, which receives 7,000mm of rainfall annually, and boasts as many as 200 waterfalls. It has two major bays with beaches, and many substantial islets adjacent to the central island. It is located 550km from Puntarenas, Costa Rica, and has held a great fascination for many of its visitors over the centuries, serving as the inspiration for Robert Louis Stevenson’s Treasure Island and Michael Crichton’s Jurassic Park, as well as the original film of King Kong. It has been a Costa Rican National Park since 1978 and was designated a UNESCO World Heritage Site in 1997. Its offshore dive sites Alcyone and Dirty Rock are world-renowned for consistent schooling hammerhead


Clarion angelfish

Below ,whitetip reef sharks at Roca Patida

Left, shoaling salemas overwhelm a predator’s ability to target an individual fish


reef sharks that cooperatively hunt in packs in the late afternoon and especially at night. In recent years, a number of tiger sharks have taken up residence at Cocos and are most frequently seen around Manuelita Island. Though not predictable, whale sharks and manta rays often make surprise appearances to divers at various Cocos Island dive sites. At 30m, on the sand and rubble slope of Lobster Rock, the odd-shaped and bottom-dwelling rosy-lipped batfish, (Ogcocephalus porrectus) (uncharitably described by one prominent writer as having ‘the face of a mummified hooker’) can sometimes be found. It perches upon its fins, as if on tippy toes, searching the rubble for tasty crustaceans, and holds itself motionless to avoid attracting any predators. At certain times of the year, large schools of small fish pass through the area, where they hunted are relentlessly by yellowfin tuna and bottlenose dolphins, wahoo and rainbow runners, silky and Galápagos sharks, and seabirds. These small fish form polarised schools in an effort at defense through overwhelming numbers but predators opportunistically hunting together can reduce these vast schools into bait balls and ultimately into a fine rain of fish scales drifting into the depths in a matter of days.

THE REVILLAGIGEDOS ARCHIPELAGOThis is called Mexico’s ‘Little Galápagos’ due to its isolation and unique endemic species on land. The islands have recently become well-known for their spectacular marine life. The four Revillagigedo islands are located southwest of Cabo San Lucas, at the tip of Baja California. The ‘closest’ island to the mainland is San Benedicto, 390km offshore.

San Benedicto has become famous to divers around the world for a dive site called El Boiler, so named because the top of it rises so close to the surface that in rough seas, or at low tide, the waters above it appear to boil. It is a small guyot, roughly oval-shaped, more or less the size and shape of a football field, that rises from the bottom 35m below and reaches to just below the surface on the northwest coast of the island. It is covered in patches of coral and is home to lobsters, octopus, and reef fish. The sides of the pinnacle are patrolled by jacks and silky sharks. And mantas. Lots of mantas. El Boiler is the most reliable location known for encounters with large, tolerant and even inquisitive oceanic manta rays (Manta birostris). It is not uncommon to have eight manta rays soaring the currents around El Boiler and visiting cleaning stations where clarion angelfish (Holacanthus clarionensis) flock to them and begin a service of pecking parasites from the surfaces of their bodies. The manta rays also carry hitch-hiking sharksuckers (Echeneis naucrates) and remoras (Remora remora). The later are often infested with parasites, making for an angelfish feast. For reasons unknown, the manta rays at San Benedicto appear to enjoy limited interaction with scuba divers,

Sharks and other predators surround a dense bait ball


slowing to an unhurried speed and stalling above the bubbles exhaled from the divers’ regulators, bathing in the expanding bubbles as they burst and dance along the mantas’ undersides. It is believed the mantas enjoy the sensation in the way that humans respond to tickling. There is a strict no-touching (and especially a no-manta-ray-riding) policy enforced by all boats that allows the manta rays to control their level of interaction with the divers rather than being molested by thoughtless and ill-mannered divers. Manta rays are also, often, commonly seen at the anchorage on the opposite side of the island. Nearly 50km to the south of San Benedicto lies Socorro Island. Socorro also has manta ray cleaning stations, as well as some pinnacles where schools of hammerhead sharks are often seen. Bottlenose dolphins visit sites, such as Cabo Pierce, almost daily ,and long encounters are a frequent occurrence.

A further 315km to the west of Socorro is the infrequently visited Clarion Island. Not much is known about Clarion other than it is still relatively unexplored. At 120km to the west of Socorro lies a lonely pinnacle, Roca Partida. It is situated upon a broad, flat-topped seamount, or guyot, in 80m of water, 30m jutting from the sea and 100m wide. Roca Partida is a magnet for sea life in the area: yellowfin tuna frequently race past the rock looking for unwary prey, while shoals of Pacific creolefish (Paranthias colonus) that form thick clouds in the upper water column disappear with an audible whoosh at the arrival of the hungry tuna. Silvertip sharks can be seen at 30m or deeper. Whitetip reef sharks lazily coast on currents next to the rock face, they also form languid pile-ups on the few ledges that are large enough to support them and keep the current and surge from unceremoniously evicting them from their perches and flinging them into the surrounding open

Both hawksbill and green turtles abound

Roca Partida, 120km to the west of Socorro

Left, El Boiler is the most reliable location known for encounters with large, tolerant and even inquisitive oceanic manta rays

waters. Manta rays frequently pass by, as do bottlenose dolphins, whale sharks and Galápagos sharks. From February to April, humpback whales migrate from their high-latitude feeding grounds to utilise the Revillagigedo Islands as a breeding ground and for delivering and nursing their offspring. In recent years, there have been many documented encounters between divers and humpback whales at Roca Partida in particular, where whales have shown an extraordinary tolerance towards scuba-diving interlopers, allowing close approaches and photography from mere metres away from these 14m-long giants. For decades, fishermen have made the long and turbulent crossing from the mainland to reap the marine riches of the Revillagigedos, often to the extent of virtually strip-mining the region of all fish, sharks in particular. Fortunately, the Mexican government has declared the islands a Biosphere Reserve and a Marine

Protected Area, with a complete ban on fishing within 12km of each island. Unfortunately, enforcement has been inconsistent at best, and sometimes non-existent. Few other places can offer visiting divers reliable encounters with giant manta rays, whale sharks, dolphins, humpback whales, tuna, pelagic fish and many shark species. It is of vital importance for the islands to be protected as a national priority for the future of the people of Mexico and for the biological heritage of the entire world. This summer issues around the policing of illegal fishing have been improved and the Revillagigedos Archipelago joined the United Nations World Heritage List.

THE GALÁPAGOS ARCHIPELAGOTo the far south of the Eastern Tropical Pacific, straddling the equator at 970km west of Ecuador, are Las Encantadas – the Enchanted Islands – known as

A diver surrounded by a school

of jacks


Galápagos. The 19 islands of the archipelago are spread out across 45,000 sq km of the Eastern Tropical Pacific. Due to nearly two centuries of research, beginning with shore visits and specimen collection during the first geographical and zoological survey of the islands by the HMS Beagle and its young naturalist Charles Darwin in 1835, through years of dedicated research by scientists affiliated with the leading centres of learning from around the world, the islands are internationally renowned as the tangible, natural showcase for endemism and the living exposition of both the theory of evolution via natural selection and the hypothesis of island biogeography. In these isolated islands, terrestrial and avian animals evolved so suited to the intricacies of their immediate island environment that they live nowhere else, such as the various subspecies of Galápagos giant tortoise (Chelonoidis nigra); the various subspecies of finches and mocking birds; the marine iguana and Galápagos penguin, as well as many others. The warm surface waters delivered by the south-westward flowing Panama Current maintain a tropical boundary current for the northeastern Galápagos. Its influence manifests itself with warmer surface sea temperatures at the two northernmost islands of Darwin and Wolf. From January to May, the northeast trade winds dominate and the Panama Current influences the Central Galápagos with warmer surface temperatures as well, displacing the influence of the cold-water Humboldt Current that dominates from June to December. Darwin and Wolf Islands offer essentially tropical diving, albeit with a cooler water thermocline – a crucial element that makes the area so appealing to scalloped hammerhead sharks. Darwin and Wolf Islands together are considered to be one of the best locales in the world to predictably see schools of scalloped hammerhead sharks, Galápagos sharks and, in season, whale sharks. Recent research has determined that as many as 695 pregnant female whale sharks may visit Darwin Island annually as a rest stop on a migration route to pupping grounds estimated to be somewhere in the northwest part of the Eastern Tropical Pacific. The Cromwell Current, also known as the Equatorial Undercurrent, flows eastward at depth bringing colder water and further nutrients and oxygen-rich waters. It creates an upwelling to the west of Isabella Island, which accounts for the presence of numerous whale species and fuels the massive schools of small fish that are the main prey of sea lions, sharks and other piscivore predators such as penguins. On the west coast of Isabella Island lives the world’s only marine lizard, the wholly vegetarian marine iguana (Amblyrhynchus cristatus). The cold waters are the perfect habitat for the type of macrophytic algae they eat – warmer waters have other marine plants dominating that are not suitable food for the iguanas and thus, although the warmer water temperature

might make their energy requirements less demanding, as ectothermic animals, they would in effect starve to death. In times of elevated sea temperatures, such as El Niňo Southern Oscillation events, the algae has a swift die-off and the marine iguanas starve and their population numbers crash. On several islands dominated by colder waters and host to profusions of small species of schooling fish, the world’s only tropical penguin, the Galápagos penguin, (Spheniscus mendiculus), can be encountered. The continual battle for dominance of the competing sea currents regulates the sea temperatures which in turn determine which animals will live and thrive in the Galápagos Islands, with the patchwork of cold-water and warm-water environments offering specific niches. There is nowhere else in the world like the Galápagos Islands and since 1986 the islands have been declared a Biosphere Reserve by UNESCO, which was extended to include the marine element in 2001.

THE BEST OF DIVES, THE WORST OF DIVESIn order to experience the best diving sites of the Eastern Tropical Pacific, one must not only make a substantial financial commitment but also have to tolerate a plane journey to the host country, and upon arrival, an overnight stay, and then undergo a tedious, long and frequently uncomfortable boat journey, of 24 hours or more, each way, across a vast expanse of open ocean to arrive at the particular island chosen that serves as the dive destination. The amount of time required to reach these crown jewels of the Eastern Tropical Pacific can be a soul-destroying barrier to entry for many divers, but for those who endure, the rewards can be out of this world. It truly is the only place where the big animals of the sea – schools of scalloped hammerhead sharks, whale sharks, manta rays, dolphins, shoals of fish, whales, sea turtles, and more – may be encountered in great numbers, or all at once.

However, this description of the delights of this special region sounds irresistible, too good to be true… Beware: it is. A visit can really be either as good as the description suggests – and, occasionally, even better – or the converse occurs, with almost no middle ground. The Eastern Tropical Pacific is also, enigmatically, a place where one can be confronted with almost nothing interesting or out of the ordinary – and without appreciable cause, without pattern,without warning. And so, to seasoned divers, it is aport of call alternately exhilarating and frustrating,dogged by luck, bad and good, and a destination thatrequires determination and stamina to visit, becauseit is a place where adventures with big animals canand do happen. The Eastern Tropical Pacific Oceanis a place that can take your breath away, or boreyou to tears. It can be the best of dives; the worst ofdives… But you would be a fool not to experience itfor yourself. n

Left, hundreds of pregnant female whale sharks visit Darwin Island annually as a rest stop on a migration route to pupping grounds, estimated to be somewhere in the northwest part of the Eastern Tropical Pacific

Douglas David Seifert joins the nightly pavane of reef manta rays off the island of Hawai’i

Shall we dance?

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Just offshore of the Kailua-Kona International Airport runway in Hawai’i is Makako Bay and most nights it is a scene of curious human activity: a flotilla of up to two dozen boats are rafted to one another, bow to stern, as they crowd seven permanent moorings. Their navigational lights and deck lights twinkle in the dark. Surrounding the boats in an area roughly the size of two tennis courts, dozens and dozens of snorkellers cling to floatation boards, their faces directed downwards. Heads pop up frequently and you can hear gurgling shrieks of delight and screams of excitement. The flotation boards have powerful, built-in underwater lights directed downward. Directly below the snorkellers are scuba divers, a lot of scuba divers – fifty or more, depending upon the night – kneeling upon the sand and rock bottom, at a depth of ten metres, and forming a large circle. They, too, have underwater torches. However, their powerful beams of light are directed upwards, as are their attentions. At the centre of this circle of genuflecting divers are several plastic crates filled with dive torches switched to maximum power. From a distance, the scene looks very much like an underwater campfire, as it is so fittingly referred to by the operators. The lights attract a dense concentration of tiny planktonic animals, primarily copepods, which emerge and gather at night to feed upon phytoplankton. The copepods congregate in swarms often profuse enough to form a palpable, opaque cloud and thus attract the true star attraction of this spectacle, the reef manta ray (Manta alfredi). The scene is a three-dimensional carnival: snorkellers at the surface, divers kneeling on the bottom encircling the campfire light boxes and, in between, dozens of manta rays swimming the blackness of the mid-water. The mantas’ white underbellies catch the light, illuminating their otherworldly diamond- shaped bodies and horn-like cephalic fins flanking their mouths, as they swoop and bank. They approach the plankton clouds swirling in the light beams and ▶


To constantly stay on the move manta rays have

to consume large amounts of food

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The horn-like cephalic fins help channel the plankton into the manta ray’s gaping mouth


The lights encourage the plankton to gather together in dense concentrations

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Mantas rays consume two per cent of their body weight in food

each day

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▶loom so close that one can have a detailed look into their unblinking eyes as they pass. The scene is mesmerising, unlike anything but dreams and Hollywood fantasies – but oh-so-much better because it is really happening. Being underwater at night, with its attendant weightlessness and the insulation from distractions of scent and sound and ability to speak, heightens the alien-ness of the experience and adds its own particular spice. Manta rays are cartilaginous fish, essentially large, flattened sharks, and like all members of the shark and ray family, do not possess a swim bladder to aid buoyancy. Accordingly, they must swim constantly throughout their lives. In order to do so, a manta ray must continuously feed to fulfil the caloric demands of a metabolism ceaselessly on the move. They do not have the ability to swim backwards, so all of their lives are spent moving forward, with their mouths leading them on a search of food. They are filter-feeding planktivores and have a modified pair of fins flanking their mouths, called cephalic fins. The fins, which can furl into a hydrodynamic cone shape when travelling and not eating, are spread wide and outward, functioning as paddles to funnel the flow of water – and the plankton suspended within – into their cavernous mouths when feeding. The plankton are trapped and collect upon gill rakers as water passes through the mouth and out through the gill slits, also providing respiration. When ample plankton are congregated on the gill rakers, the manta ray closes its mouth and swallows, then continues until the food is depleted. Manta rays (as observed in captivity) consume two per cent of their weight in food per day and the reef manta rays in Hawai’i vary in size and weight, with a range of 180–600kg. The most efficient way for a three or four metre manta ray to capture the maximum number of copepods that are themselves each less than 2mm in length, is by ram filter feeding or barrel-roll feeding through the densest concentration of copepods. While in the near-trance of binge foraging, manta rays exhibit remarkable spatial awareness – even in the dark, a manta ray can seemingly detect a GoPro held at arm’s length from a kneeling diver and pass close to it without collision, often within millimetres. Kona’s manta rays were first observed feeding in the shallows near the Kona Surf Hotel (now the site of the Sheraton Kona Resort at Keauhou Bay) in the late 1980s. The hotel’s lights seemed to have

something to do with manta rays appearing and it was quickly surmised that the lights attracted the plankton the mantas fed upon. Dive operator Jim Robinson at Kona Coast Divers first began to experiment with manta night dives in the slightly deeper waters further offshore from the hotel, in 1991. He had special, powerful, underwater lights constructed and gradually mantas began to feed in their glow. Over time, the manta rays became accustomed to the artificial lights that attracted the copepods and a once-a-week manta ray dive was conducted. Word about this unique encounter began to spread among the scuba diving fraternity. Soon, twice-weekly dives were conducted, then thrice-weekly – multiple operators began to run trips and ultimately the manta ray night dive became a nightly excursion. Eventually, the Kona Surf Hotel went out of business and its lights were extinguished. The mantas moved on. A new location was established at Garden Eel Cove in Makoko Bay near a manta ray cleaning station visited by the dive operators. A tentative night dive was conducted with underwater lights and from the first effort, manta rays appeared and began feeding. The dive operators had found a location where the manta rays’ food was occurring naturally and in quantities that attracted mantas that were in the area, the divers’ lights ‘merely’ concentrated that prey. Some manta ray individuals began to habituate the area beyond their daylight cleaning station visits. One manta ray, named Lefty, for its damaged cephalic fin, was first observed by a diver in 1979, some 37 years ago. From nightly observations, the Manta Pacific Research Foundation has created a photo-identification database that currently has more than 250 named manta rays. An alarmingly high number of the manta rays have deformities caused by humans – absent cephalic fins (sliced off during entanglements), broken cephalic fins, fishing tackle embedded, scars from collisions with mooring lines and ropes… It makes one ponder how many manta ray deaths caused by human impacts go unseen. How many manta rays appear on any given night is a mystery that has everything to do with the abundance of copepods, and their life cycle, whether manta rays have an abundant food source in another location, and factors known only to manta rays. Some nights may have two or three manta rays; other nights may have a dozen to several dozen. On one magic night in 2014, 46 individually identified mantas were seen at Garden Eel Cove, and, up the coast, a further five mantas at ▶


More than 250 individual manta rays have been identified around Makoko Bay

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On a single night 46 individual mantas were recorded


Many of the mantas have been injured

▶the Sheraton’s Manta Village dive. Other infrequent visitors to the manta night dive are dolphins and sometimes a semi-resident monk seal. Of more concern than how many manta rays show up, is the mind-boggling number of snorkellers and divers and the boats. It is a rare night that does not have fewer than a dozen boats and more and, more frequently, twenty boats can be in the same small area, jockeying for position and moorings. On particularly crowded nights there may be as many as 300 snorkellers and divers. In a gold rush mentality, new operators are racing in to profit from the ever-increasing numbers of tourists. Snorkel boats are drawing mantas away from the campfire by placing their floatation boards with powerful lighting wherever they please. The campfire is more than just a collection of underwater lights, it is a coalition of like-minded operators working together to maintain a high-quality and safe experience for guests and animals. Now the state authorities are planning to step in to regulate the industry. The Manta Pacific Research Foundation estimated in 2004 that 10,000 to 12,000 divers and snorkellers dived with the manta rays and brought in an estimated $2.4 million to local economy. Currently – and no one can say precisely – it now appears that 20,000 to 25,000 divers and snorkellers are visiting the site annually and the economic benefit to operators and the local economy could be more than five or six million dollars.

Some veterans of manta dives over the years grumble that the number of mantas are declining. Honestly, no one really knows. What is astounding is that no one has been killed by a boat strike with all the boats with undiscerning propellers jockeying for position in the darkness. It is a testament to the operators that safety, though perhaps pushed to its limits, is still a prime concern of the captains and crews.

One bright ray of hope that has sprung from manta awareness in Hawai’i has been the passing of legislation making it is illegal for anyone to knowingly capture or kill a manta ray in Hawai’ian waters, thus setting a precedent and making Hawai’i the first state in the US to protect manta rays.

The manta ray night dive is an experience unparalleled, and for those fortunate enough to spend a night or two beneath the waves off Kona and be a part of the spectacle of manta rays feeding, then it is truly ‘Such stuff as dreams are made on…’ n •Douglas would like to thank Keller Laros of the Manta Pacific Research Foundation www.mantapacific.org and Jack’s Dive Locker www.jacksdivinglocker.com; Jesse Andrewartha, who endured long hours in the planning and execution of the lighting for the photographic shoot; Doug Perrine for continuing to inspire; overworked and unpaid underwater assistants Brittany de la Valdene and Lauren Goddard and especially to my wife Emily for organising all the many details that made this expedition a success.

P O R T F O L I OS P A W N I N G

T H E G A T H E R I N G SVast aggregations of reef fish gather in a mysterious cycle off Palau and

put on some of the most stunning performances - feverish dancing, brutal head bashing, strange colour changes and finally mass spawning.

Words and photographs by Richard Barnden

As bumphead parrotfish start to gather, the first unusual thing you notice is that

their bumps start to turn bright white

T H E G A T H E R I N G S


This is one of the most stupendous sights you will ever see underwater. A vast and mysterious gathering of fish that are normally solitary and rarely seen by divers – as many as 50,000 blue-lined sea bream coming together in a tight cloud, getting closer and closer, swirling as an agitated swarm just off the reef. These brightly coloured snapper, with undulating blue-and-orange stripes over a yellow body, have a somewhat mysterious life. It is thought they live alone, deep in the nooks and crannies of the reef or finding solitary shelter in the vast openness of the sandy lagoon. However, on a few occasions during the months of March and April, they do aggregate in prodigious numbers for a crucial moment in their life cycle. As the moment draws closer, the dense schools separate like curtains, as slowly moving bull sharks or lemon sharks cruise through them patiently, ready to pounce on any stragglers. The swarm gets even denser – gripped by what seems to be some sort of manicpurpose, and suddenly a few break for the surface anda spray of white eggs cloud the water. Males quicklyfollow, fertilising the tiny buoyant eggs with their sperm. It is dramatic theatre. A grand moment on a ginormous scale. But it is over relatively quickly. You feel privileged and extremely lucky to have witnessed such a wonderful, elusive event. Yet in the waters around Palau, divers can now witness a number of these spawning aggregations. From bumphead parrotfish with glowing white heads, to camouflage grouper scrapping over establishing their stomping grounds. This is some of the most fascinating and little understood natural behaviour you can encounter underwater. Local fishermen around the world sometimes have a reasonable knowledge of the peculiar confluence of tides, moon cycles and currents which all help trigger such transient aggregations, and where they have fully cracked the code no doubt reap the bounty. Science is starting to catch up and researchers realise increasingly how complex yet crucial these gatherings are to fish stocks worldwide. Palau played a key role in our modern understanding of spawning aggregations. In the mid-Seventies Robert E Johannes, a tropical marine ecologist, came to the islands and pioneered the idea of integrating local

The blue-lined bream get closer and closer together in vast, fast-moving

schools as the spawning picks up pace

knowledge from fishermen, with western concepts of management, and applying it directly to resource conservation and fisheries management. He went on to write Words of the Lagoon – a ground-breaking book on spawning aggregations, fish behaviour and local fishing practices in Palau. This led to the establishment of innovative conservation programmes with the active cooperation of local fishermen, where such spawning grounds were protected at key points of the year. These bans on fishing on key reefs during spawning, locally known as ‘Buls’, have played a vital part in today’s healthy fish populations around Palau. Other parts of the world haven’t fared as well. Aggressive commercial exploitation of known spawning aggregation sites has led to the devastation of fish populations. Researchers at Science and Conservation of Fish Aggregations (SCRFA), formed in 2000 to raise awareness of the vulnerability of such aggregations and the key role they play in the life of our oceans, warn that modern fishing capabilities are too destructive to be allowed to target the easy pickings of these gatherings.

CRACKING THE CODEI came to Palau in 2003 to work as a video and photo pro on a liveaboard. A few years later with Paul Collins, I founded Unique Dive Expeditions which would later become a part of Sam’s Tours – one of Palau’s leading dive operators – and we started to specialise in spawning aggregations. The idea that you could understand, even predict, when such events were going to take place was tremendously exciting. But the more we looked, the more complex it became. Palau is a special place for spawning aggregations. It has marine lakes, rock islands, mangroves and a large lagoon, making it the perfect place for young juveniles to grow and survive away from the dangers of bigger, reef-dwelling predators. And Palau’s southern lagoon dive sites are all in a relatively small area compared with other world-class diving destinations, where a liveaboard may cruise hundreds of miles in a single, week-long trip. As a dive guide this has its advantages. Diving the same sites day in, day out, month in, month out, you get to know each site extremely well. By keeping detailed logbooks each day and having an eye out for fish behaviour, we started to notice distinct patterns emerging and began to build up a database of possible spawning events around moon cycles each year. For divers to witness such events, we needed to know exactly when they occurred, not just the month or even the point in the lunar cycle, but precisely when to be at the site, kitted up and ready to dive. After spending the past seven years studying these aggregations, we are now offering four regular types of spawning dives, and our knowledge is increasing each year. Each species of fish has specific spawning patterns and styles and follows its own reproductive calendar. Some aggregations, such as the twinspot snapper

In the final madness, twinspot snapper rub against each other in a frenzy

Philippines

Sulawesi

Borneo

Palau


A bull shark closes in during the final moments eager to pick off tiring fish

Clouds of gametes are released by the female

snapper

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(Lutjanus bohar) and the bumphead parrotfish (Bolbometepon muricatum), will spawn every month. Other aggregations, such as the blue-lined sea bream (Symphorichthys spilurus) and camouflage grouper (Epinephelus polyphekadion), will only spawn once or twice each year.

THE BLUE-LINED SEA BREAM During the months of March, April and sometimes May, these strange but beautiful-looking fish form one of Palau’s largest recorded spawning aggregations to date. A rarely seen fish on the reef, these normally solitary fish hide inside the lagoon or on deep, sandy drop-offs, feeding on crustaceans hidden in the sand and normally away from the eyes of divers. As their spawning season approaches, individuals start gathering in two main areas of Palau – one on the northwest side called Tailtop and one in the south, around the island of Peleliu. When the month, day, tide and time come together and the sea bream are ready to spawn, as many as 50,000 can gather. The school moves from its aggregation area into stronger currents that will whisk their gametes to safety. The aggregation can reach from depths of 60m up to 15m – a tight mass of yellow fish moving in unison. Bull sharks, blacktip sharks and, often, lemon sharks are seen slowly swimming sedately through the school, waiting to pick off a tired fish.

THE TWINSPOT SNAPPER Also found in Peleliu and on other outer promontories in Palau, these fish aggregate around the full moon. Between 5,000 and 10,000 fish, depending on the month, can be seen schooling and spawning. During the day the school stays in a relaxed, though tightly formed ball in mid-water. It looks like a dark cloud as you approach. However, the early mornings are different. Just as the sun rises above, underwater the reef is barely visible as the dark cloud of snapper appears in the distance. They move out into the current with bull sharks and blacktip sharks patrolling the perimeter of the school. Suddenly, all hell breaks loose as multiple females shoot to the surface, with the males close behind. Visibility quickly plummets from 30m to 3m near the surface, as the milky gametes are released into the water column. Hungry black snapper move in, feeding on the feast of eggs.

THE BUMPHEAD PARROTFISH The spawning aggregation of bumphead parrotfish is one of the most recent discoveries. Hidden on the west side of Palau lies a sandy slope which, thanks to Blue Marlin dive operation, we now know is the site for one of nature’s strangest sights. Thousands of these jolly green giants gather in the early-morning gloom – they can weigh in at more than

Thousands of bumphead parrotfish gather in the early-morning gloom


The male parrotfish quickly follow the females in an effort to fertilise their dispersing eggs

45kg and be more than a metre in length. The males charge each other at full speed, bumping heads with a tremendous thwack. The bumps on their heads glow bright white and bright bands of colour appear on their bodies – this sexual dimorphism is the signal that the show is about to start. The huge school spills into the blue water and the fish begin schooling deeper and swimming at a faster rate. The mating ritual begins with males and females swimming backwards and forwards, white heads bobbing around in the deeper, bluish water. You wait patiently for the first female to make her move. Once this happens, large groups will rise and a mass spawning will happen in front of your eyes. Another female will break off from the school and rise closer to the surface, with eager males close behind.

Again and again, spawning ‘rushes’ happen all around you. The fireworks can last as long as 30 minutes, after which the exhausted bumpheads start to slink away. A thousand dwindles down to less than a hundred and soon all is quiet.

THE CAMOUFLAGE GROUPER This is our favourite spawning. It took us more than five years to solve the puzzle of when and where – its existence had been recorded in Dr Johannes’ book, but for more than a decade no one had actually witnessed it. This was down to a number of reasons – firstly, unlike the twinspot snapper and the bumphead parrotfish, these fish do not spawn every month. Much like the blue-lined sea bream, they are seasonal spawners,

Male camouflage grouper aggressively challenge each other to stake out key territories


It is thought that the male grouper fight for key spots on the reef, above which the females are expected to release their eggs

P O R T F O L I OS P A W N I N GP O R T F O L I OS P A W N I N G

DIVE DATAFor more information on land-based andliveaboard trips see:n Sam’s Tours Palau www.samstours.comn Siren Fleet sirenfleet.com

See amazing footage of spawning on theScience and Conservation of Fish website n www.scrfa.org

Check out more of Richard’s work onn www.richardbarnden.com


The females make a dash for the

surface, release their eggs, then

descend followed by the males

perhaps one, two or possibly a maximum of three times a year. So far we have found four spawning areas for this species, and I am sure there are a lot more. Like all these aggregations, cracking their mystery took considerable time in the water. Knowing roughly when and where the fish will aggregate was just the beginning. Early-morning dives, current, outgoing current, all had to be checked out. In 2015 I was aboard our dive boat with a gang of eager spawning-spotters checking out a likely channel. To my delight, the channel looked packed with hundreds of camouflage grouper. Could this be the time? I knew we had a great chance but nothing is 100-per-cent guaranteed in the ocean. I asked everyone to stay on board and prepare their equipment while I jumped in. I knew what tell-tale signs I was looking for. As soon as I jumped in, the channel was buzzing, some of the grouper were hanging in the channel and a school of black snapper was waiting nearby – things were looking promising. But showtime was still a few nerve-shredding hours away. Eventually, grey reef sharks, whitetip reef sharks and lemon sharks started to arrive. Moments later, the action began. Out of the corner of my eye, I saw what I thought was a spawning rush but couldn’t be sure. I swam in that direction, only to realise I was actually in the middle of a huge cloud of gametes. All around me, one after another, camouflage grouper began to rise out of the coral heads where they had been hiding and began desperately chasing each other to the surface, releasing more and more cloudy gametes. The lemon sharks frantically started to buzz around. Our air had run very low, and we had to make the call to ascend in the midst of chaos. But what a discovery, what an experience. n

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