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Far more than I could have imagined
“…both in space and time, we seem to be brought somewhere near to that great fact, that mystery of mysteries –the appearance of the new beings on this earth…”. Possibly Charles Darwin’s most famous quote about the unique character of the wildlife he witnessed in his visit to the Galapagos Islands in 1835.
Report by Jonathan R. Green
Plunging into these crystal clear blue waters for the first time off black rock cliffs and boulder slopes, I could see how Darwin might be impressed with the diversity of life.
My first backward roll would change everything. Decisions about returning to the UK or Europe suddenly dissolved as my eyes focussed on the heaving masses of marine life. Schools of fish so dense I could not even catch a glimpse whatever was beyond. Turtles swimming lazily around between sea lions that darted here and there, alternately herding the fish then scattering them by piercing the heart of the school. With a flick of the fin a sea lions can pirouette and spin on their own axis, cavorting, tumbling, playful and curious. Sharks patrolling the blue, languid but lethal when prey is perceived. Jacks, Creole fish, brightly coloured Moorish Idols swaying with the swell, Parrotfish displaying between bouts of munching on coral heads amongst red clouds of Cardinal fish.
This was more, far more than I could have imagined after diving the temperate and often turgid waters of coastal Britain. The adrenalin rush was of unbelievable. I was hooked, addicted for life to this turquoise aqua vita.
About when I thought things couldn’t get any better I saw my first whale shark. Swept out into the blue waters off the volcanic platform of Darwin Arch and whilst carrying out a routine safety stop an enormous shadow dressed in bright polka dots just APPEARED. The World’s largest fish, the biggest shark of all time, (yes including Megalodon), came straight toward me. I watched in absolute awe as this creature from the deep swam by only metres below me, not deviating from its path and the only indication that it was aware of our presence the rolling of an eye in our direction. One minute it was there eclipsing everything else, the next disappearing with the same facility with which it appeared.
Although perhaps an insignificant encounter for the whale shark this moment for me was pivotal as my curiosity gave rise to the beginnings of a study that later led to the creation of the Galapagos Whale Shark Project.
For the last two decades, little by little, together with a team of international scientists and volunteers we have pieced together part of a puzzle that spans all the Oceans of the World. From the month of June until late November a parade of these giants passes by the eroded remains of a very small outcropping volcanic cone. Situated to the very north of the Galapagos Archipelago, Darwin Island and its, now world famous, Darwin Arch. Why they come here, in the hundreds and maybe thousands remains a mystery. Nearly all are mature, longer than 10m, females. They spend little time in the area, usually no more than 48 – 72 hours before resuming their journey, often north and west into and along the rugged Galapagos Rift System Valley that marks the boundary between the massive oceanic plates of Cocos to the north and Nazca to the south, on which the Galapagos Islands are located. They come here not to eat, for they are usually seen with mouths closed. Many appear to have distended bellies but so far the study has failed to find the evidence to confirm pregnancy. The reason must be related in some manner to their reproductive cycle but whale sharks guard their secrets closely. Whatever that reason is, Darwin seems to hold the key. Only further investigation might provide us with the answers we so desperately seek if we are to afford them protection, as individuals and as a species, upon their ocean wide travels.
With this in mind we began tagging individuals in 2011 with different types of satellite tag. Towed SPOT (GPS) tags gave us an insight into their movements after leaving the Galapagos and PAT tags (Pop up Archival Tag), gave us data about diving behaviour. In 2020 we deployed SPLASH10 tags (on a clamp that is affixed to the dorsal fin) which will provide us with movement location as well as diving behaviour. Partnering with the BBC and the Blue Planet II team we also deployed camera tags, affixed to the leading edge of the dorsal fin and with a timed-release mechanism that allowed us to film interactions with other species, such as Silky sharks, Giant Trevally Jacks and Galapagos sharks. Bit by bit we began to build up a clearer picture of their movements and behaviour on a local and regional basis but we still lacked confirmation of pregnancy and / or birthing. Sporadically we could see that the sharks would dive to more significant depths than shown by daily behaviour. Apparently random dives down to 500-600m for no obvious reason were a common feature for all the sharks we placed miniPATs on. Could this be associated with birthing? The dives seem to match benthic features and depths. Perhaps the females are pupping at depth in order to give birth at depths beyond those usually frequented by most of the predators found in this area.
In 2018 we carried out the first successful ultrasound examinations and blood sampling of whale sharks in the wild. This had been done previously only with individuals in aquariums. For the first time ever, we were able to identify parts of the reproductive system, the ovaries and found egg follicles inside. Although the hoped-for embryos were not found we hope to carry out another ultrasound next year (July 2021) to attempt this again, selecting the most “pregnant looking” females. The blood samples also failed to confirm pregnancy but this is only the first of several attempts that we will carry out at different times during the season in order to attempt to prove these females are indeed close to pupping. There is an enormous amount of work still to be carried out before we will really understand the natural history of these animals but that is what makes this challenge al the more interesting and provides us all with the inspiration to succeed.
Diversity of life
Historically the Galapagos Islands are connected in most people’s minds with natural selection and evolutionary processes. Charles Darwin during his visit on board HMS Beagle in 1835 could only wonder about much of the life beneath the waves. Although an avid naturalist and father of the theory of evolution, most of his work was focussed on terrestrial species. Immersing oneself in the waters around the Galapagos Islands bring an equal or even greater wonder as visits with giant tortoises, land iguanas and blue footed boobies on land.
The diversity of life around these apparently barren islands is thanks to a combination of geographical location and ocean currents, as the islands are swept by powerful and frigid currents that originate in Antarctica and warm tropical currents that flood in from the Panama and Central America region. This mixture of hot and cold not only serves as a conveyor belt of life forms but also as a cauldron of biological richness that provides the primary productivity that fuels species from the bottom to the very top of the food chain.
The first divers to visit the Galapagos were early scientists. William Beebe of “World’s End” fame carried out numerous dives during his expedition on the Arcturus in 1925 discovering many species new to science. Subsequently international lobster fishing fleets in the late 1960’s and 70’s exploited the islands, a fishery that became more locally based from around 1980. Much of the early dive tourism was initiated from information from the lobster hookah divers that knew the waters surrounding the inhabited islands intimately and had explored some of the outlying islands such as the western areas of Isabela, Fernandina and even Wolf and Darwin. My personal experience began in 1988 at which time most dive trips were fifteen days if you really wanted to see the most diverse areas and wildlife and three-week trips were not uncommon. During this time, we would spend some days just exploring, looking for seamounts and generally just dropping in around coastal areas to see what we could find. Often, we found nothing exceptional but on occasions we found places that had never truly been explored and are now the principal dive sites that every diver dreams to visit.
It is difficult to pinpoint exactly why someone wants to dive the Galapagos waters. Marine megafauna such as the wide selection of sharks may be one. From the more diminutive Galapagos Horn Shark to the greatest of all sharks, living or demised, the Whale Shark, Rhyncodon typus, that frequents the islands during certain times of the year. Turtles, Giant Manta rays are quite common at some dive sites and Galapagos sea lions provide endless entertainment. Perhaps it is the diversity of life that is so fascinating. Sub-polar species such as Galapagos penguins flit by tropical Moorish Idols and pre-historic Marine iguanas that are browsing on the algae in the shallows. Huge Sunfish, or Molas, hover above cleaning stations, like orbs in a celestial sea, whilst unlikely-looking Red-lipped Batfish manoeuvre across the sand substrate below. Between them Flightless cormorants forage under lava ledges, teasing out marine invertebrates such as sea cucumbers, octopus as well as small fish.
Sheer density of life
But not just the diversity is the attraction but the sheer density of life. Diving in the Galapagos is truly a journey into the past, a chance to see what our oceans were like before the industrial fishing era rendered so many parts of our blue planet into crystal desserts. To witness the parade of 500 or more sharks in a single dive is not uncommon. Even our safety stops are in the company of bottlenose dolphins, whilst seabirds such as juvenile Nazca boobies float on the surface above us gazing myopically down! Galapagos is the lost valley of the dinosaurs. A marine myth but one that actually exists for those more tenacious diver explorers that like to leave behind the beaten trail.
Evolutionary processes that have changed terrestrial life also forged new forms underwater. Although the marine environment is less isolated to the migration of particularly juvenile or larval forms, certain species, that cannot travel large distances through the oceans, undergo the same natural selective forces and events such as the El Niño Southern Oscillation, (ENSO), have led to unique or endemic forms in the ocean too.
The Galapagos Marine Reserve, (GMR) finally established as a Marine Protected Area in 1998, covers and enormous area, over 130 000 km 2 . One of the greatest benefits of dive tourism is the effect of having a presence, which can help as a deterrent to illegal fishing operations. Although still vulnerable, as the capture of the Chinese fishing vessel, the Fu Yuan Yu Leng 999, in August 2017 with thousands of shark fins showed, dive live aboard vessels can help patrol and report illegal activities to the authorities. Divers regularly help removal of fishing artifacts, long lines and FADs, (fish attraction devices), as well as removing plastic rubbish and submitting data of unusual sightings and images.
Increasingly Citizen Science programs provide masses of data that is often collected in remote areas where scientists are not frequently able to access. Darwin Arch, perhaps the most famous of the Galapagos dive sites and where over 90% of all whale shark sightings occur, is the farthest north of the entire Archipelago and too far for most researchers. Dive Masters and tourists visit this location every single week of the year and are instrumental in gathering images for global photo ID data banks.
The dive industry creates jobs for the local population but even more importantly is a clear example of how science, education and conservation can provide a future for the islands in the economic sense. Without tourist dollars the alternatives are fishing and exploitation of the resources in a very much short-term approach. Increasing awareness of how the health of the Ocean benefits everyone in the Islands gives new purpose to its protection.
You can dive the Galapagos any time of the year but conditions vary enormously between the dry cooler season, June – December and the wet hot season January – May. Ocean temperatures may fluctuate massively averaging 14 - 21°C in the dry season to between 23 – 28°C during the hotter months. Activity in the marine environment usually reflects the ocean temperatures, as productivity is highest during the cooler period as a result of the upwelling currents.
No matter when you go, the Galapagos Islands will work their enchantment and like those that travelled there before you, you will fall under the spell of one of the most unique and memorable destinations on Earth. If you have been wondering where to go, what to do and you are a diver that still has to experience the biggest shark of them all, the most diverse place on Earth, Galapagos is your destination.
More information:
www.galapagoswhaleshark.org
www.galapagossharkdiving.com