LOCAL divers express alarm on the recent reports of coral bleaching activities along the Balayan Bay, particularly in Calatagan municipal waters and are now calling for volunteers to help monitor the said incident.
Jessie delos Reyes, a long-time diving instructor and marine environment advocate based in Calatagan town has called on his fellow divers and marine volunteers to record the said coral bleacing activities.
But what is coral bleaching, by the way? When corals are stressed by changes in conditions such as temperature, light, or nutrients, they expel the symbiotic algae living in their tissues, causing them to turn completely white.
Warmer water temperatures can result in coral bleaching. When water is too warm, corals will expel the algae (zooxanthellae) living in their tissues causing the coral to turn completely white. This is called coral bleaching. When a coral bleaches, it is not dead. Corals can survive a bleaching event, but they are under more stress and are subject to mortality.
In 2005, the U.S. lost half of its coral reefs in the Caribbean in one year due to a massive bleaching event. The warm waters centered around the northern Antilles near the Virgin Islands and Puerto Rico expanded southward. Comparison of satellite data from the previous 20 years confirmed that thermal stress from the 2005 event was greater than the previous 20 years combined.
Not all bleaching events are due to warm water. In January 2010, cold water temperatures in the Florida Keys caused a coral bleaching event that resulted in some coral death. Water temperatures dropped -6.7 degrees Celsius lower than the typical temperatures observed at this time of year. Researchers will evaluate if this cold-stress event will make corals more susceptible to disease in the same way that warmer waters impact corals.
Few years back, massive coral bleaching was also recorded in most of Batangas cloral reefs.
An important action that man can take now is intensive monitoring leading yup to, during and after bleaching events, so that it can be ascertained as to what are the causes and consequencial effects of these bleaching activities.
Corall bleaching is both destructive and beneficial, some studies revealed.
The death of coral also represents a huge loss—as much as $375 billion annually— for the local economies along the globe they support. Reefs support local tourism and the commercial fishing industry. They also protect coastlines from flooding during extreme storms.
But some researchers studying coral reefs damaged by rising sea temperatures have also discovered an unexpected “bright spot” of hope for communities who depend upon them for food security.
Coral reef ecosystems support diverse small-scale fisheries—and the fish they catch are rich in micronutrients vital to the health of millions of people in the tropics, a Lancaster University-led study two years ago reveals.
And, counter-intuitively, following bleaching events that kill off coral and can transform the composition of reef ecosystems, reef fisheries can remain rich sources of micronutrients, even increasing in nutritional value for some minerals.
The findings, published in the journal One Earth, show that the availability of micronutrients from coral reef small-scale fisheries may be more resilient to climate change than previously thought. This increased understanding is critical as continued global warming means coral bleaching events are becoming more frequent and more severe, placing greater stress on these vulnerable ecosystems.
Dr. James Robinson, who led the study, said: “Our findings underline the continuing importance of these fisheries for vulnerable coastal communities, and the need to protect against over-fishing to ensure long-term sustainability of reef fisheries.”
The researchers also caution that while these fisheries have proved more resilient to climate change disturbance than expected, continued understanding of the long-term impacts of climate change to coral reef fisheries, and more data from other regions, are urgent priorities.
More than 6 million people work in small-scale fisheries that rely on tropical coral reefs. Their catches help to feed hundreds of millions of coastal people in regions with high prevalence of malnourishment, causing stunting, wasting, and anemia. However, until now, the nutritional composition of coral reef fish catches, and how climate change might affect the nutrients available from reef fisheries, was not known.
This study, led by scientists from Lancaster University and involving an international team of researchers from the Seychelles, Australia, Canada, and Mozambique, benefited from more than 20 years of long-term monitoring data from the Seychelles, where tropical reefs were damaged by a large coral bleaching event in 1998, killing an estimated 90 percent of the corals.
Following the mass-bleaching event, around 60 percent of the coral reefs recovered to a coral-dominated system, but around 40 percent were transformed to reefs dominated by seaweeds. These differences provided a natural experiment for the scientists to compare the micronutrients available from fisheries on reefs with different climate-driven ecosystem compositions.
The scientists, who used a combination of experimental fishing, nutrient analysis, and visual surveys of fish communities in the Seychelles, calculated that reef fish are important sources of selenium and zinc, and contain levels of calcium, iron, and omega-3 fatty acids comparable to other animal-based foods, such as chicken and pork.
They also found that iron and zinc are more concentrated in fish caught on reefs that have been transformed after coral bleaching and are now dominated by macroalgae such as Sargassum seaweeds. These seaweeds have high levels of minerals, which, researchers believe, is a key reason why the algal-feeding herbivorous fishes found in greater numbers on transformed reefs contain higher levels of iron and zinc.
However, still coral bleaching activities must be monitored and properly recorded. The data that would be gathered in this monitoring will help government agencies in developing programs that would be beneficial to the fisherfolks and to the local tourism industry players who are both relying on the coral reefs as their source of fishes for their tables and as dive sites for their tourist-clients.| BNN, with report from LabManager
