Secrets of the Deep: Until Recently, the Whale Shark Was Something of Enigma to Science. but Pioneering Research by the Galapagos Whale Shark Project Is Shedding New Light on This Giant of the Ocean. Technical Director Jonathan Green Reports

By Green, Jonathan | Geographical, October 2012 | Go to article overview

Secrets of the Deep: Until Recently, the Whale Shark Was Something of Enigma to Science. but Pioneering Research by the Galapagos Whale Shark Project Is Shedding New Light on This Giant of the Ocean. Technical Director Jonathan Green Reports


Green, Jonathan, Geographical


[ILLUSTRATION OMITTED]

When an animal the size of a very large double-decker bus makes a sudden 90[degrees] turn, it has to be for a good reason. As the satellite tracks started to come in from whale sharks that we had tagged off the Galapagos, they clearly showed that as the sharks were swimming away from the islands, they were all reaching a certain point and then making a very abrupt change in direction.

However, it wasn't until we overlaid the tracks onto a map of the sea floor that we could see that these movements were apparently in response to geological features deep in the ocean that the sharks couldn't possibly see. The more we analysed their movements, the more obvious it became that they were using seamounts, faults, fissures and even plate boundaries for navigation. But how?

RIGHT TO ROAM

Since the whale shark was first described in 1828, we've learnt little about its natural history. The largest fish in the ocean--growing to lengths of up to 18 metres and a weight of more than 30 tonnes--it's predominantly a filter feeder. Found in all the world's seas, apart from the Mediterranean, it's reputed to travel long distances, and while we know that it's ovoviviparous (giving birth to live young that hatch from eggs within the female), we don't know where it breeds or gives birth.

One of the more intriguing aspects of whale shark behaviour is their propensity to gather in large aggregations on a seasonal basis. Perhaps the most famous takes place around Ningaloo Reef off Australia's west coast. During the late 1970s, whale sharks were observed there in large numbers, feeding on fish larvae and the eggs from spawning corals.

Since then, about a dozen aggregation sites have been identified around the world. As well as around the Galapagos, these include areas off the coasts of India, Madagascar, Mozambique, the Philippines, Indonesia, Belize, Baja California and the Yucatan Peninsula in Mexico, where more than 400 individuals were spotted during one aerial survey.

The Galapagos Whale Shark Project (GWSP) was established to study the population of sharks that visits the islands each year between May and December. This period coincides with the cool season, when the rich Humboldt and Cromwell currents are at their strongest.

FEMALE DOMAIN

In more than two decades diving these waters, I've observed that the majority of sharks that congregate here are adult females ranging in length from about eight to 16 metres, and most appear to be in an advanced stage of pregnancy. There are very few sightings of males or juveniles, a factor that differentiates this from practically all the other known whale shark aggregations worldwide.

This is surprising in itself, but even more so is the fact that around 99 per cent of these sightings are at one geographical location in the far north of the archipelago--close to a tiny island called Darwin, with its renowned dive site, the Arch.

One of the GWSP's primary aims is to find out more about whale shark movements on a local, regional and, hopefully, global scale, as well as establishing their reasons for homing in on Darwin. With this in mind, this year, a group of scientists from the Galapagos National Park, the Charles Darwin Foundation, Conservation International, Ecuador, and the University of California, Davis--with funding from the Rapier Family Trust--undertook one of the most ambitious whale shark tagging programmes to date. The fieldwork, carried out in three 15-day sorties, involved attaching satellite tags to each individual we encountered, photo identification, laser telemetry and tissue sampling.

SPACE-AGE TECHNOLOGY

In order to identify individual sharks, we used a modified version of software initially developed by NASA for the mapping of constellations and deep-space objects. The characteristic white spots of the whale shark resemble the human fingerprint in that each pattern is unique to the individual.

The rest of this article is only available to active members of Questia

Sign up now for a free, 1-day trial and receive full access to:

  • Questia's entire collection
  • Automatic bibliography creation
  • More helpful research tools like notes, citations, and highlights
  • Ad-free environment

Already a member? Log in now.

Notes for this article

Add a new note
If you are trying to select text to create highlights or citations, remember that you must now click or tap on the first word, and then click or tap on the last word.
One moment ...
Project items

Items saved from this article

This article has been saved
Highlights (0)
Some of your highlights are legacy items.

Highlights saved before July 30, 2012 will not be displayed on their respective source pages.

You can easily re-create the highlights by opening the book page or article, selecting the text, and clicking “Highlight.”

Citations (0)
Some of your citations are legacy items.

Any citation created before July 30, 2012 will labeled as a “Cited page.” New citations will be saved as cited passages, pages or articles.

We also added the ability to view new citations from your projects or the book or article where you created them.

Notes (0)
Bookmarks (0)

You have no saved items from this article

Project items include:
  • Saved book/article
  • Highlights
  • Quotes/citations
  • Notes
  • Bookmarks
Notes
Cite this article

Cited article

Style
Citations are available only to our active members.
Sign up now to cite pages or passages in MLA, APA and Chicago citation styles.

(Einhorn, 1992, p. 25)

(Einhorn 25)

1

1. Lois J. Einhorn, Abraham Lincoln, the Orator: Penetrating the Lincoln Legend (Westport, CT: Greenwood Press, 1992), 25, http://www.questia.com/read/27419298.

Cited article

Secrets of the Deep: Until Recently, the Whale Shark Was Something of Enigma to Science. but Pioneering Research by the Galapagos Whale Shark Project Is Shedding New Light on This Giant of the Ocean. Technical Director Jonathan Green Reports
Settings

Settings

Typeface
Text size Smaller Larger
Search within

Search within this article

Look up

Look up a word

  • Dictionary
  • Thesaurus
Please submit a word or phrase above.
Print this page

Print this page

Why can't I print more than one page at a time?

Full screen

matching results for page

Cited passage

Style
Citations are available only to our active members.
Sign up now to cite pages or passages in MLA, APA and Chicago citation styles.

"Portraying himself as an honest, ordinary person helped Lincoln identify with his audiences." (Einhorn, 1992, p. 25).

"Portraying himself as an honest, ordinary person helped Lincoln identify with his audiences." (Einhorn 25)

"Portraying himself as an honest, ordinary person helped Lincoln identify with his audiences."1

1. Lois J. Einhorn, Abraham Lincoln, the Orator: Penetrating the Lincoln Legend (Westport, CT: Greenwood Press, 1992), 25, http://www.questia.com/read/27419298.

Cited passage

Welcome to the new Questia Reader

The Questia Reader has been updated to provide you with an even better online reading experience.  It is now 100% Responsive, which means you can read our books and articles on any sized device you wish.  All of your favorite tools like notes, highlights, and citations are still here, but the way you select text has been updated to be easier to use, especially on touchscreen devices.  Here's how:

1. Click or tap the first word you want to select.
2. Click or tap the last word you want to select.

OK, got it!

Thanks for trying Questia!

Please continue trying out our research tools, but please note, full functionality is available only to our active members.

Your work will be lost once you leave this Web page.

For full access in an ad-free environment, sign up now for a FREE, 1-day trial.

Already a member? Log in now.