Bali 2015

Galapagos 2011

San Diego 2010

Bali 2008

San Diego 2006

Japan 2006

South Africa 2006

Japan 2005

Indonesia 2004

South Africa 2004

Taiwan 2000

Our team is investigating the Molidae through two complementary approaches–pop-off satellite archival tagging of individuals and genetic analysis of global populations.

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Our tagging work involves special tags called pop-up archival transmitting (PAT) tags. PAT tags are secured using a plastic anchor inserted at the posterior base of the dorsal fin. While attached, the tag records and logs temperature, depth and light intensity. From light intensity, day length and local noon are calculated. This information in conjunction with sea surface temperature measurements is used to document location. After a pre-programmed time, the tag releases floats to the surface and uploads its data to satellite. Thus, daily information on movements and behaviors are obtained without having to relocate either the fish or tag. Should the tag release early or the fish die and sink, the satellite tag will automatically surface and initiate transmission. (For more information on satellite tags see

Our team has tagged Mola mola off San Diego (California), Capetown (South Africa), Kamogawa (Japan) and Queensland (Australia).

We have also tagged Masturus lanceolatus off Hua Lien (Taiwan).

To date, six tags have reported and we are in the midst of analyzing our data. We’ll be posting our exciting results soon so stay tuned. The sunfish have some dark secrets to divulge.

The mola team recently returned from a successful tagging trip to Japan where 2 more tags were deployed on Mola mola with the help of the Kamogawa SeaWorld and the Fisheries Cooperative Association of Kamogawa. These tags are due to release on Halloween 2003. Whilst over in Japan, the team also discovered a 1996 record of a Japanese Mola mola that appears to be a new world record! Check out:
The mola team is also planning to tag more sunfish this July and August off the coast of California. And come December, theyll be heading to South Africa.

Hundreds of tissue samples have been analyzed from mola populations spanning the globe. Some striking differences between certain populations are emerging. We may even have two new species of giant ocean sunfish. So stay tuned on the genetics front as well.

While unpopular in Europe and the United States, molas are eaten throughout Asia. Taiwan and Japan are the largest markets. All parts of the mola are eaten including the skin, fin muscles, backbone, testes, and gut which is viewed as a delicacy. In Taiwan, the gut is served as "Dragon Intestines."

Video Fish Scientist Humor - YouTube

Unlike their pufferfish relatives, e.g. Fugu, molas do not carry the deadly neurotoxin, tetratrodotoxin (Saito et al 1991).

Mola mola is the most common bycatch of the drift net fishery, which targets broadbill swordfish of California and Oregon. According to reports from the National Marine Fisheries Society Southwest Region, between 1990-1998, 26.1% of the drift net catch consisted of the common mola, which translates to a catch of 26,503 individuals. 42.1% of the total discards were mola (Rand Rasmussen, pers comm).

In the Spanish driftnet swordfish fishery on the Mediterranean side of the Gibraltar Straits, Mola mola constituted 71% of the entire catch in 1992, 93% in 1993 and 90% in 1994 (Silvani, L. et al, 1999).

Until we establish baseline data on these fishes, we have no way of gauging how such capture rates are affecting the wild stock.

Taiwan 2000

Recipe for successful fieldwork in Taiwanese waters

Necessary ingredients:

  • 2 guiding hands of Dr. I.C. Liao
  • 20+ helping hands from Taiwan Fisheries Research Institute (TFRI) staff members, especially Mr. Stephen Huang
  • 1-3 satisfied government officials
  • 60+ helping hands from fishermen and set net operators in Hua Lien
  • 3-5 experienced SCUBA divers
  • Numerous sunfish of good size and health
  • 1-50 press representatives to spread the word
  • 1 or more strong blessings from Matsu

In December 2000, under the guidance of Dr. I. C." Liao, the international team of Drs. Tierney Thys, Heidi Dewar and Hong Young Yan successfully began research to document the behavior of giant ocean sunfish in Taiwanese waters." This project would never have been possible without the encouragement and enthusiastic support of Dr. Liao and the tireless assistance of the Taiwan Fisheries Research Institute (TFRI) staff, especially Mr. Stephen Huang.

"From the moment of landing in Taipei, we were welcomed with open arms. We became an instant team working together towards a common goal. International boundaries dissolved and we found we had not only discovered reliable and competent collaborators but also long-lasting friends."

Our fieldwork involved a number of complications. Firstly, we met with three government officials who needed to inspect our pop-off satellite archival tags before any fieldwork could take place. Following this, we had to travel from Taipei to Hua Lien--a transit thankfully made possible by Dr. Liao's gracious assistance." After reaching the coast and partaking of a sumptuous feast (one of many to come) we met with local fishermen to learn of their experiences with sunfish and ask permission to sample their catch as well as tag and release several of their valued commodities. All the fishermen hold the greatest amount of respect and admiration for Dr. Liao and TFRI so our demanding task was made far simpler than could have ever been imagined.

As luck would have it, many molas had been recently caught in the set nets. We were able to procure numerous tissue samples for later genetic analysis at the fish market shortly after arriving in Hua Lien." A true bonanza!

Early the next morning, we headed to the docks and secured the necessary permits." Accompanied by an expert dive crew, organized by Dr. Yan beforehand and headed by Mr. Anthony Kuo, we made our way to the set nets, picking up more crew along the way. Before the day was out, we had successfully tagged our sunfish, learned an enormous amount from the fishermen and made tremendous progress towards achieving our goals.

The remainder of our trip involved flying to the other side of Taiwan and tagging a beloved baby whale shark named Junior, a sweet animal that had been hosted by the compassionate staff at the Penghu Aquarium of TFRI." This trip revealed to us the tremendous impact Dr. Liao has had on helping to inspire conservation in the hearts and minds of the Taiwanese. The impressive Penghu Aquarium was a beautiful sight to behold.

On a second trip to Taiwan the following year, accompanied by Dr. Hong Young Yan, Dr. Thys was able to train the staff at the Penghu aquarium to deploy the satellite tags themselves. Despite his heavily loaded schedule, Dr. Liao was able to accompany us through the whole field trip. What impressed us the most was we again saw how his wide name recognition in Taiwan helped our project. For instance, the chief of Hua-Lien Fishermen Association allowed us free access to his set nets for study use and deliberately altered his operation schedule to fit our needs. The proprietor of a local diving shop refused to charge us rental fee of air tanks because of Dr. Liao paid a visit to his shop which he considered a great honor."

As our data begins to flow in, we look forward to continued collaborations with Dr. Liao and the stream of publications still to come." We commend him on his long and illustrious career with TRFI and extend many congratulations on a job well done! We feel extremely honored to have had the opportunity to work with him.


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