Our Fisheries And Climate Change
The Philippine fisheries industry consists of the marine fishing, inland fishing and aquaculture sub-sectors. Marine fishing is the catching or harvesting of seawater fishes, invertebrates, and plants of economic importance like the galunggong, halaan, and Sargassum. Inland fishing, on one hand, is the. exploitation of aquatic plants and animals in brackishwater and freshwater areas like rivers, lakes, and Other wetlands. Aquaculture, on the other hand, is the culture or farming of marine brackishwater and freshwater species like the milkfish, tilapia, oysters, and seaweeds.
Our fisheries provide livelihood and income directly to more than a million fisherfolk and fishfarmers, and indirectly to millions of other people. With a contribution of about 5 percent to the country’s gross domestic product, fish and other fishery products supply the bulk of the animal protein in the diet of our more than 90 million population.
The excessive accumulation of carbon dioxide and other so-called “greenhouse gases” in the atmosphere mainly from industrial and agricultural activities has markedly increased the average temperature of the earth’s surface. Such a phenomenon has resulted in global warming or climate change that has brought about extreme climatic events as prolonged droughts (El Ninos), devastating typhoons, and catastrophic floods in many regions of the world including our country.
In the El Nino episode of 1997 to 1998, the lack of rainfall caused heavy losses on our fisheries, particularly brackish-water ponds for milkfish and shrimp culture. About 20.6 percent or 41,005 hectares of the country’s total area of brackishwater fishponds was adversely affected with losses of 10 percent to 80 percent of the cultured stocks valued at P’4 billion. The stocks were lost due to drying out of ponds, poor water quality, stunted growth and mortalities.
In the recent devastation of Typhoon Pepeng, fishponds for milkfish, tilapia and shrimp, fish cages, and seaweed farms in the coastal areas of Central Luzon and the Southern Tagalog Region were damaged with a loss amounting to P211 million. Millions of pesos were also lost with the submersion of the fishpens in Laguna de Bay with the rise in water level due to torrential rains and heavy runoff.
Although not as much affected by the rise in sea level and surface sea temperature caused by global warming, fishing in our marine waters is reduced with the increased frequency and intensity of typhoons. The culture of seaweeds, a major industry providing livelihood to thousands of small fisherfolk, can be seriously affected by storm surges or big waves and the prevalence of temperature-related “ice ice” disease.
Our extensive coral reef ecosystem that supports about a fourth of our total marine fisheries is particularly vulnerable to the increase in sea surface temperature. With “coral bleaching” (whitening due to death of temperature-sensitive polyps of coral species), as much as 8,000 to 24,000 metric tons of fish per year can be lost, according to Dr. Laura David of the University of the Philippines’ Marine Science Institute.
Adaptive measures are recommended to our fishfarmers and fisherfolk in responding to climate change. Fish-farms with ponds that are flood-prone need to implement mitigating strategies such as improvement in the diking and drainage systems. Fish growers using pens in lakes can shift to the use of floating and/or submersible cages that are more flexible with water level fluctuations. For seaweed farmers, the use of floating rafts or cages that can be moved to deeper and cooler waters can be an option.
By Dr. Rafael D. Guerrero III