Every week is Shark Week in the Galápagos Islands
Did you know that the Galápagos Islands are the sharkiest place in the world?
In underwater censuses in 2013 and 2014, the Charles Darwin Foundation found that Darwin and Wolf (DW), the two northernmost islands within the GMR, harbor the largest shark biomass on the planet.
This high concentration of sharks is possible due to the nutrient-rich currents reaching these islands, making them highly productive areas.
Additionally, the total ban on shark fishing within the marine reserve helps in maintaining a high density of sharks in the area.
“According to a 2016 study by Pelayo Salinas of the Charles Darwin Research Station, Sala, and colleagues, fish biomass there is on average 17.5 tons per hectare. That’s about twice as high as the second highest area known to science, the nearby Cocos Island National Park, Costa Rica. “
Value of a Living Shark in the Galápagos Islands?
The economic benefits of ecotourism from sharks are far greater than shark fishing (Clua et al., 2011; Gallagher & Hammerschlag, 2011; Cisneros-Montemayor et al., 2013)
In Galapagos, the net present value of a shark to the tourism industry is an astonishing $5.4 million. The value of an individual shark to the tourism industry is ~ $360,000 per year, compared to $158 obtained from a dead shark (Lynham et al., 2015).
That makes sharks alive in Galapagos the most valuable on Earth. Despite their high economic value and iconic importance, only about 50 km2 of the waters around Darwin and Wolf (representing an insignificant 0.04% of the total [marine reserve] area) were fully protected from fishing after the creation of the Galapagos Marine Reserve in 1998. These areas were not fully protected from fishing until March 2016.
For instance, the net present value of the average hammerhead shark at Cocos Island National Park was estimated at $1.6 million, compared to the ~$200 that a fisherman obtains by selling a dead shark (Friedlander et al., 2012).
What Type of Sharks are Most Common in the Galápagos Islands?
Scalloped hammerhead (Sphyrna lewini) Whale shark (Rhincodon typus) | Tiger shark (Galeocerdo cuvier) | Galapagos shark (Carcharhinus galapagensis) | Blacktip shark (Carcharhinus limbatus) | Silky shark (Carcharhinus falciformis) | White-tip reef shark (Triaenodon obesus)
The Charles Darwin Foundation recently announced the research discovery of two species of cow sharks previously unknown to the Galapagos Islands – the broadnose sevengill shark (Notorynchus cepedianus) and the bluntnose sixgill shark (Hexanchus griseus).
This is not the first time that a species previously unknown in the Galapagos has been discovered in recent years. In 2012, the spotted catshark (Bythaelurus giddingsi) was first documented within the reserve. Like the newly discovered cow shark species, the spotted catshark is also found in deep waters.
Even in 2020, we are still learning about the wealth of marine life in the Galapagos Islands. We must protect these waters and learn more about its incredible diversity before it is erased.
Sharks and the Economy of the Galapagos
Marine-based tourism supports more than a third of all jobs (37%) in the Galápagos Islands, bringing in $178 million per year. “
“Each shark in the Galápagos is worth about $5.4 million over its lifetime, thanks to interest from the booming diving and tourism industry. A dead shark, in contrast, only fetches about $200 to the fishermen.”
Given the ecological value and the economic importance of Darwin and Wolf for the dive tourism industry, the current protection should ensure the long-term conservation of this hotspot of unique global value.
Threats to Sharks Worldwide
Overfishing has dramatically depleted sharks and other large predatory fishes worldwide except for a few remote and/or well-protected areas.
Overfishing has reduced biomass of most sharks and other large predatory fishes worldwide by over 90% (Baum et al., 2003; Myers & Worm, 2003; Ward-Paige et al., 2010), and even remote locations have been severely impacted (Dulvy et al., 2008; Sibaja-Cordero, 2008; Graham, Spalding & Sheppard, 2010; White et al., 2015).
One in four species of cartilaginous fishes is now threatened with extinction due primarily to overexploitation and habitat loss (Dulvy et al., 2014).
The systematic removal of sharks from marine ecosystems has negative effects that propagate throughout the entire food web (Bascompte, Melián & Sala, 2005; Myers et al., 2007; Heithaus, Wirsing & Dill, 2012).
It is estimated that over 100 million sharks are fished every year around the world, mostly for their fins. This overfishing is the main cause behind a decline of about 90% in shark populations globally since the start of industrial scale fishing in the 60s and 70s.
Sources:
“Habitat Use, Connectivity, Migratory Routes and Status of Shark Populations.” Charles Darwin Foundation, http://www.darwinfoundation.org/en/research/projects/sharks.
“New Galápagos Sanctuary Has World’s Highest Abundance of Sharks.” National Geographic, 21 Mar. 2016, http://www.nationalgeographic.com/news/2016/03/160321-galapagos-marine-reserve-park-ecuador-conservation/.
Salinas-de-León, Pelayo, et al. “Largest Global Shark Biomass Found in the Northern Galápagos Islands of Darwin and Wolf.” PeerJ, PeerJ Inc., 10 May 2016, peerj.com/articles/1911/.
Informing and sharing news on marine life, flora, fauna and conservation in the Galápagos Islands since 2017
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