Malamig na klima, nakakaapekto sa pangingitlog ng isda
An official of the Bureau of Fisheries and Aquatic Resources (BFAR) has confirmed that the cold weather condition prevailing in the northern part of the country, including Pangasinan, is not only a bane to crops but also to fish.
Dr. Westly Rosario, chief of the BFAR’s National Integrated Fisheries Technology Center based in Dagupan City, said fishermen have little catch to bring to shore and because of high waves, they oftentimes refrain from going to the sea to fish.
He, however, said that in this cold season, the fish are in a better situation than vegetables, which are now affected by frost because the latter cannot choose a warmer environment, unlike the former which can go to a place with warmer temperature.
In the sea, the temperature varies — it is a little bit colder in the surface, a little bit warmer in the middle and more warm in the bottom, Rosario explained.
Rosario said since the Philippines is a tropical country, the cold temperature has a big impact on aqua-culture fish being raised in ponds, pens and cages either in brackish or fresh water.
Foremost effect, he said, is that the fish often stops laying eggs, citing bangus (milkfish) which stopped laying eggs as early as November last year and to resume sometime in March when the water gets warmer.
The other species of fish also stop laying eggs but if ever they do, the mortality of the fingerlings is high due to stress caused by the cold temperature.
At the same time, the fish are easily afflicted with diseases, including the simplest form, called fungus.
Rosario said aside from these, the development of the eggs is stunted, citing the case of the eggs of fresh water prawn which normally takes 35 days to develop into fingerlings. But because of the cold weather, it would take the eggs at least 60 days to develop into that stage.
But the longer the rearing stage is, the higher will be the mortality rate among the fingerlings. And during the growing stage of the fish, they are also prone to many kinds of diseases.
“Parang tao yan na magkaroon ng stress kung malamig. The disease is caused by opportunities organism that is already present in the environment,” Rosario added.
He advised fish farmers to observe the proper stocking density of fish to prevent these from incurring stress during their growing period and to avoid feeding the fish in the early mornings as they would not eat because of the cold weather.
He said the proper time to feed the fish is at about 10 a.m. when the water in the ponds, pens and cages is already getting warmer.
Rosario said the advent of the cold weather is normally the off-season for fish farming as the fish are not growing fast since they seldom eat and are prone to diseases.
According to Rosario, fish farmers who can manage to harvest bigger milkfish are lucky because they can sell their fish at higher prices as the product is really limited during the cold season. PNA