By Dr. Stacy Jupiter
Fish Are Friends And Food
This is the fourth of several blogs documenting an 8-day, marine expedition to Fiji.
Bruce, the bull shark from the movie Finding Nemo leads a Sharks Anonymous meeting with the mantra, “I am a nice shark, not a mindless eating machine. If I am to change this image, I must first change myself. Fish are friends, not food.”
However, in Fiji, fish are both friends and food.
Fish are friends because of the many important ecosystem functions they perform on the reef.
For example, herbivorous fish, such as many parrotfish, surgeonfish, damselfish and rabbitfish, eat algae and therefore free space for new corals to grow. This process allows reefs to quickly recover from damage following disturbance. Meanwhile, predatory fish, such as sharks, grouper, snapper and emperor, are critical for keeping populations of their prey in check, which ensures a balanced ecosystem. Fish are even vital for the process of sand formation. Species like the enormous bumphead parrotfish (Bolbometopon muricatum) are equipped with teeth like crushing machines to take bites out of the reef. The calcium carbonate grains of crunched coral skeletons that come out of their other ends forms much of the white sand along outer island beaches.
In Fiji, as a majority of the population lives along the coast, fish are also a major source of protein and provide a substantial amount of cash income to local fishers. Thus, conservation in this part of the world is not just about preserving fish species and their ecosystem functions; it is just as importantly about ensuring an abundant supply of fish to sustain livelihoods and culture for the future.
Aaron Jenkins, Senior Program Officer of Wetlands International-Oceania (WIO) and Pacific fish expert is part of our joint expedition between WIO, Wildlife Conservation Society, Pacific Blue Foundation and the Waitt Institute to Totoya’s Sacred Reef. His role is to document the fish species richness of Totoya’s reefs and test his hypothesis that the southern Lau islands may serve as a center of endemism for the entire Fiji-Tonga complex. An endemic species means it is unique to a specific geographic location on the planet.
Recent fish genetic studies by researchers at Boston University indicate that there are strong evolutionary links between fish found in the Fiji-Tonga region, which are distinct from other nearby island nations. The Fiji-Tonga complex has the fifth highest record of number of endemic reef fishes of anywhere in the world. From Fiji alone, there are 22 endemic fish species from 12 separate families, of which blennies and gobies are the most represented. There are an additional 21 fish species shared by Fiji and Tonga.
(c) Keith Ellenbogen
This high level of regional endemism is particularly notable at Totoya, where thus far Aaron has located 11 of the 43 species unique to the Fiji-Tonga complex. These include four species of damselfish, including the big blue Pomacentrus callainus, as well as Neoglyphidodon carlsoni, a cave-dwelling damsel first found in Fiji by former Peace Corps volunteer Bruce Carlson, who is now Science Officer at the Georgia Aquarium. Aaron has also seen the tiny and cryptic goby Bryaninops dianneae, as well as unusually high numbers of the endemic rabbitfish, Siganus uspi, named after the University of the South Pacific whose main campus is located in the capital of Fiji.
“Generally what I am seeing is high numerical abundance of all endemic species,” says Aaron.” This may indicate that southern Lau is a nucleus for these populations of fishes for the Fiji-Tonga region.”
Fish abundance is generally high across all fish species we have seen, as well as their size. Aaron claims that he saw the largest Spanish mackerel that he has ever seen at around five feet in length. In addition, the fish are not afraid. In areas with high fishing pressure where the Wildlife Conservation Society routinely surveys, the fish dart away into any cave or hole when they see divers approaching. But the Totoya fish are friendly and curious, coming up to divers to check out the mysterious rubber-coated creatures in bubble clouds. They even exhibit this behavior directly in front of the villages.
This bodes well for the long-term management of Totoya. Because the people have an abundance of fish stocks for food on healthy coral reefs, they are unlikely to impact the unique natural heritage of their reef system when fishing for their own subsistence. However, the communities should take precaution to avoid the temptation to trade away their resources to outsiders. There are rumors that sea cucumber traders have been coming to Lau to exchange bags of sugar for bags of shark fins. Given the great number of sharks that we have seen, Totoya has at least for the moment evaded this fate. But is it all the more urgent for the communities to work with the Fiji government and NGOs to develop an island-scale management plan to preserve their resources for generations to come.