Fish numbers decline: Climate change, coral bleaching blamed
Members of the fishing industry in Samoa live to tell about the changes they have witnessed to their catch over the years.
And many of them believe that this has something to do with the deteriorating marine environment.
Silupe Vaelei Alofa from Vailima said their boats now have to go further out from shore than they used to. She believes the primary cause is climate change followed by human activity such as overfishing and the use of dynamites.
The dynamites, she said, destroy the coral, which shelters fish. Consequentially they have been forced to venture further out to where the coral hasn’t been destroyed to do their fishing.
Ms. Alofa stressed the importance of responsible fishing.
“We used to earn a lot from fishing but not anymore,” she said. “It’s everyone’s responsibility (to protect our oceans). If we take care of it now our future generations will benefit.”
Paula Poalagi, from Moamoa, who has been using a long-line fishing net for 20 years has also noticed changes. He used to catch a lot of fish but that isn’t the case anymore. They are also having to go further to get a better catch.
Mr. Poalagi believes the changes have been caused by big fishing boats and urged those in big boats to stick to the designated areas.
On the other hand Loas Fereti from Faleasiu said that in the eighteen years her husband has been fishing there hasn’t been a change in the number of fishes that he catches.
She believes that “it is everyone’s responsibility to look after the marine environment” and that “if people are responsible and don’t overuse recourses then fish won’t go extinct.”
Eneliko Sio from Vaitele is another who has not noticed any changes. He stated that he only fishes for big fish so he already fishes far out.
Other changes to the marine environment have been evident in the health of coral reefs.
While their health is certainly complex, coral bleaching is one of the most obvious signs of damage.
Samantha Kwan, the Marine Conservation officer from the Ministry of Natural Resources and Environment (M.N.R.E) said that last year was “the worst year ever experienced for bleaching in Samoa.”
“Normally bleaching occurs up to one or two meters but this year there was bleaching up to twenty, twenty five meters deep,” she said.
Even some of the less susceptible corals such as the bolder corals were “all bleached last year.”
According to M.N.R.E, while some sites such as Satuiatua sustained up to 90per cent bleaching others saw only very minor bleaching such as Fagamalo.
The primary cause of coral damage in the words of Michael Donoghue, the Threatened and Migratory Species Advisor at Secretariat of Pacific Regional Environment Program (S.P.R.E.P.) is “Climate change, climate change and climate change.”
He explained that as seawater temperature rises significantly, coral becomes heat stressed and dumps zooxanthellae, the algae which inhabits it. Since zooxanthellae give coral its color this results in a bleached white appearance.
If sea temperatures were to fall quickly the coral may be able to uptake the algae again however prolonged high temperatures will cause the coral to die.
Mr. Donoghue explained that not all coral is equally susceptible to bleaching and that more resilient coral could potentially help rehabilitate damaged areas.
“The coral larvae drift in plankton… Reefs that are especially rich or resilient or are under protection will help nearby damaged reefs to recover through recruitment of coral larvae.”
Currently there is a Marine Reserve at Palolo Deep and two Marine Protected Areas in the Aleipata and Safata districts. However parts of the Marine Protected Areas are inactive.
Ms. Kwan said that of the Societies for Marine Protection in the villages “more than fifty percent are inactive,” due to lack of funding.
Some of the No Take Zones within these areas have also not been reestablished after the tsunami and cyclones destroyed buoys and markers.
Mr. Donoghue said that rising seas levels is just one of a host of threats to coral reef health, with declining reef health being at the hand of a number of factors.
“Generally speaking the health of coral reefs in Samoa has declined in recent years, due to a combination of anthropogenic factors and natural events such as cyclones and tsunamis. Anthropogenic impacts include over-exploitation, pollution, temperature rise, invasive species and poorly-managed coastal developments.”
Another major concern is increasing numbers of Crown of Thorn starfish (COTs). These are known to eat live coral MNRE has programs in place to manage their numbers when they are not in breeding season.
The majority are known to be found “on the South-Western and Western Coast of Upolu,” according to M.N.R.E.
Mr Donoghue from S.P.R.E.P reinforced this observation and highlighted contribution factors.
“The South Coast of Upolu has been especially badly impacted by an outbreak of COTs in the last five years. Such invasions are often made considerably more serious by the removal of their natural predators such as Triton shells and hump-headed wrasse, which keep the starfish under control in a balanced coral reef ecosystem.”
When asked about what the health of coral reefs around Samoa in coming years Mr Donoghue predicted that we would see a “continuing decline in reef health and species abundance and diversity, unless strong protective measures are taken at local, regional and global levels.”
Attempts to get a comment from the Ministry of Agriculture and Fisheries were not successful.