The Project

What we have discovered so far in Galapagos?

Observational findings


Over the last two decades, a number of dive masters, led by Jonathan R. Green, have contributed to a database of sightings of whale sharks in the Galapagos Marine Reserve, (GMR), which provides baseline information on seasonal frequency and distribution. Thanks to this database, Green was able to make some preliminary findings about whale sharks in the GMR. These include the following:


  • Whale sharks occur on an individual basis throughout the archipelago.
  • Whale sharks may be observed on an occasional basis throughout the year.
  • They are observed in far greater numbers during the cool “garua” season, from June to December.
  • The first seasonal appearances are in the southern parts of the archipelago, (April / May) with increasing frequency northwards as the season advances.
  • The majority of sightings are in the waters surrounding the northern islands of Wolf (Wenman) and Darwin (Culpepper), with the dive site known as the Arch of Darwin having the greatest frequency of sightings for the whole archipelago (>90% of all reported sightings).
  • From identifying markings such as scars and bite marks, individuals may be recognised and repeat sightings in different years recorded.
  • Repeated sightings of the sharks throughout the season have been confirmed, but are not common, leading to the belief that individuals do not spend the entire season in the GMR.
  • Almost all sightings where sex has been confirmed have been female with the exception of 5 males over this entire period.
  • All adult females observed appear to be in an advanced state of pregnancy.
  • Fewer sightings are recorded around full moon so their activity may be lunar related.
  • Numbers may be related to water temperatures, with fewer sightings when SST is higher, as typically occurs towards the warm season, December to end of May.
  • A total absence during El Niño Southern Oscillation, (ENSO) climate events.

Initial findings


With the move from passive observation to active data collection, using the methods described HERE, we have been able to understand more of whale shark presence and movements within the GMR and at a regional level. Particularly with the satellite track data and photo ID work we now know the following:


  • Whale sharks spend on average between 48 – 72 hours in the area of Darwin Arch.
  • They tend to depart northwards then proceed west with high fidelity to the Galapagos Rift Valley that runs E – W between the Cocos Plate and Nazca Plate.
  • All the sharks that depart north west return to Darwin later the same season before heading south.
  • They display seasonal synchronous behaviour heading south between November - January.
  • There is no connectivity with any of the known aggregations thus far on a regional or global level.
  • Tracks show clear connectivity between Galapagos – Cocos – Malpelo Islands.
  • Tracks show clear connectivity with the Ecuador / Peru shelf break, (continental drop off).
  • Whale sharks do not return to Darwin Arch in consecutive years, (with one recorded exception).
  • Frequency of return to Darwin Arch is between 4 – 7 years.
  • They appear to use Magnetic Orientation Behaviour, (MOB) for long distance movements, (using the earth’s magnetic field and sea floor magnetic anomalies) and they may use sea mounts, fracture systems and even ocean plate boundaries as virtual markers or waypoints.

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