LAHAINA — At Lahaina Civic Center on April 26, as part of the Ocean Awareness Training program, Dr. Rob Toonen described recent research on marine life.
Because the populations of so many species of fish and coral have diminished due to human activities such as over-harvesting and habitat degradation, the Oahu marine biologist and his research teams wanted to know if these populations could be replenished by migration from other locations throughout the Hawaiian archipelago.
When they used DNA sampling to track the movement — dispersal and distribution — of species, they found that 85 to 98 percent of these species’ next generations come from the same island where their parents live.
This means that to help species repopulate, each island needs its own guidelines for fishing/harvesting/management for the ocean and marine species surrounding it, and specific areas set aside to protect entire ecosystems. (When many species of algae, fishes, corals, crustaceans and other sea life all live together and depend on each other, they constitute an ecosystem.)
Ecosystem sanctuaries or preserves can act as nurseries, with concentrated populations of marine life that replenish surrounding areas.
Dr. Toonen also spoke about the reproduction of marine species. They found that the larger and older the fish (or opihi, etc.), the more eggs it produces, and the better their quality, so more of their hatchlings survive to adulthood.
In fact, a typical finding showed that a 27-inch omilu (a fish in the jack or ulua family) produces 85 times the number of eggs of a 14-inch omilu! Also, the larvae of big fish grow nearly three times faster and can survive starvation for more than twice as long. This means that larger specimens need to be protected, and released if caught, so they can most effectively repopulate the species, so we will have more fish available to catch in the future.
As Dr. Toonen pointed out, both of these major findings — the uniqueness of each island’s marine ecosystem and the life history of its species, and the importance of leaving the largest specimens alone so they can reproduce — formed the basis for traditional Hawaiian kapus (restrictions) for management of Hawaii’s marine species.
He encourages the state Department of Land & Natural Resources, and all ocean users, to assist in the restoration of threatened marine populations by adopting and enforcing the traditional native practices, as well as developing rules and regulations based on these same ecological principles that have been known to Hawaiians for generations.
Hawaiians also knew that everything we do on land affects the ocean, so we need to examine our actions mauka as well.
You can contact Dr. Toonen at the Hawaii Institute of Marine Biology at the University of Hawaii at Manoa’s School of Ocean & Earth Sciences & Technology at (808) 236-7401.
Liz Foote, a Maui marine educator and conservationist with the Coral Reef Alliance and Ocean Awareness Training instructor and coordinator of local projects on marine education, offered the opportunity for all of us to help the scientists and DLNR to understand more about the activities and abundance of marine species and the effectiveness of existing regulations.
They have set up a web site at monitoring.coral.org for us to contribute data on our observations when out in the water.
You can report sightings — or lack thereof — of large parrotfish and schools of herbivorous fish, as well as catch/sightings data on roi. Check it out!