Fishpens, fishkill and population

I used to read a lot of stories about "fish kill" in Laguna Lake -- the biggest lake in the Philippines -- a few years ago. Today I googled the subject, no recent news, good. The latest story is about Taal Lake in Cavite, 

Presence of fishpens to blame for massive fish kill in Taal Lake – Pamalakaya

November 12, 2018, By Ellalyn de Vera-Ruiz

https://news.mb.com.ph/2018/11/12/presence-of-fishpens-to-blame-for-massive-fish-kill-in-taal-lake-pamalakaya/.

Perhaps this means that the fish farmers in Laguna Lake have improved their system so that large-scale fish kills are now avoided, or water quality in the lake has somehow improved, or these plus other factors. Meanwhile, I posted below 7 1/2 years ago.

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June 04, 2011

These are the fishpens in Laguna Lake that I took from a plane this afternoon on my way to Bacolod City to visit my sick mother. Click on the pictures to see their larger images.

Too many fishpens in the lake, just a few dozen kilometers from Metro Manila proper. And much, much more houses and structures to accommodate Metro Manila's 12 million people, which easily rises to 13-14 million daytime population on regular days as people living in the neighboring provinces of Bulacan, Pampanga, Rizal, Laguna and Cavite would troop to the big metropolis to work or study or do business.

A few days ago, there was a huge report and fish scare as a result of the big fishkill affecting bangus (milkfish) in Taal Lake, not very far from Laguna Lake. A friend from one of my discussion yahoogroups working at the Bureau of Fisheries and Aquatic Resources (BFAR) gave this brief explanation:

... natural incidence where dissolved oxygen becomes low such as night time where there is no photosynthesis. To avoid the situation such as that, we recommend the limitation of stocking density to the extent of the "carrying capacity" of the water bodies. These are all defined in the guidebook. Thus in a 10 meter x 10 meter by 5 meter floating cage in marine areas where there is sufficient current or tidal movement,we recommend the stocking density of 10,000 pieces of 5 - 6 inch bangus fingerlings which if harvested in 3 - 4 months can yield on the average 4.7 tons of bangus.

Unfortunately, others extrapolate that by deepening the depth of the cage to 15. They claim, they can triple their income not realizing that the bottom of the cage might not have enough dissolved oxygen to support life. The deeper the water, the lesser the dissolved oxygen because sunlight does no reach those areas as much as the upper portion and that oxygen gets to be dissolved into the water from wave action. Taal lake does not have any tidal movement as it is a landlocked lake.

Aside from the above explanation, Taal Volcano, in this picture, is a very active one. It is rumbling every 5 years on average, I think.

My friend who used to have a tilapia farm in Taal Lake, Batangas side, gave up his business after several cases of fishkill in the past. There were several instances where he would be harvesting tens of thousands of tilapia tomorrow or the next day, and tonight, almost all of the fish are dead. He and other fishpen farmers in the area suspect that the volcanic gases that find their way into the lake, affect the water's chemical mixture, poisoning the fish.

Philippine population is rising fast, around 1.8 million people per year, net of death and migration. It's like we are creating an equivalent of one Singapore every 3 years. The big demand for food like fish pushes for big supply of the commodity. A normal cycle in capitalism of supply meeting demand when the price and incentives are right.

While certain government regulations may help minimize fishkill and related problems in aquaculture, it's the threat of the actual fishkill and the huge financial losses associated with the event that is the biggest regulator in the minds of the entrepreneurs in the aquaculture industry. And that creates new opportunities for scientific research, like the development of new varieties of tilapia and bangus that are more resistant to certain biochemical fluctuations in the lake or other bodies of water.

Twitter notes, June 2011 (a)

I've been tweeting more often this month. Here they are, first half of the month:

@gpph Renewable energy racket/robbery, http://bit.ly/lpGkq3 and http://bit.ly/kCJFx6. They want to steal P9 B/yr from us next 20 years

@Karen_DaviLa Govt is creating more and more prohibitions. More restrictions means more revenues for the state, more extortion opportunities

You will never do anything in this world without courage. It is the greatest quality of the mind next to honor. - Aristotle

@gpph The RE racket will steal from us energy consumers P9 bill/year for 20 yrs, http://bit.ly/lpGkq3. Warming scam, more legalized robbery

From Cicero: Laws are silent in time of war... No one has the right to be sorry for himself for a misfortune that strikes everyone.

People acting in their own enlightened & rational self-interest strikes bureaucrats, politicians and social workers as dangerous. - WG Hill

Bureaucracy defends the status quo long past the time when the quo has lost its status.- Laurence J. Peter

"A welfare state is frightened of every poor person who tries to get in and every rich person who tries to get out" -- Harry Browne

philo_quotes Philosophers quotes by Noysky
Every man has a property in his own person. This nobody has a right to, but himself. ~ John Locke

Happy bday, Adam Smith (June 5, 1723). Good article by Larry Reed in 2006 about the man, http://www.mackinac.org/article.aspx?ID=7765

@NewAsianist High and increasing RP exports of services is just one result of our high population and continued economic globalization.

From Plato: The measure of a man is what he does with power... There is no harm in repeating a good thing.

@wansaiful The welfare state is a good subject to write on. Politicians are well, taxpayers pay the fare :-)

@Jimparedes Fishkill is caused by insufficient dissolved oxygen in the lake, or by volcanic gases from Taal volcano, http://bit.ly/iicopk

Democracy is a form of govt where you can vote for a living instead of working for one & say what you think even if you don't think - L Reed

@Karen_DaviLa Why does the ABS-CBN network seem to cover, or amplify, the fishkill story in Taal lake compared to other network?

WhoIsMikeGordon Mike Gordon by Noysky
People who say it cannot be done should not interrupt those who are doing it. Unknown

Fr. Aristotle: Men are swayed more by fear than by reverence... Hope is the dream of a waking man... Change in all things is sweet.

From Seneca: We become wiser by adversity... In war there is no prize for runner-up.

@taxreformer Forced removal of a company's trademark & logo will not only violate IPR laws but remove distinction bet real & fake producers.

@acopatunru @east_asia_forum Not only gender timebomb of too few women, but China's popn itself will be declining, to only 700+M by 2050

@Jimparedes Next 20 yrs, China will face declining population, India's will keep rising. So India will be biggest English speaking nation

@cesdrilon Educ & health for d poor, housing & transpo for d poor, credit, irrig. & AR for d poor, CCT for d poor, soon condoms for d poor

"The spirit is willing but the flesh is weak.' Translated to russian, back to english became, 'the wine is agreeable but the meat is stale'.

@harryinitiative Cebu Pacific is getting more expensive, more crowded, longer time to check in, more flight delays. I take zest air lately.

Fr Mymathcloud: Natural numbers are better for your health…. Geometry is the science of correct reasoning on incorrect figures- George Polya

Fr mymathcloud: Old mathematicians never die; they just pass into another field….The larger d denominator, the smaller the fraction- Tolstoy

EventsCloud My Events Cloud by Noysky
@HerreraVeronica Kindness is the language which the deaf can hear and the blind can see.

MyMathCloud My Mathematics Cloud by Noysky
God does not care about our mathematical difficulties - he integrates empirically. Albert Einstein

Fr. Montberte: Good girls are bad girls that arent caught… Never make anything simple and efficient when it can be complex and wonderful.

From Mymathcloud: Old mathematicians never die; they just tend to zero… A mathematician is a device for turning coffee into theorems.

Montberte Steve Cushing by Noysky
Planes are so fast nowadays that we can go around the world in two hours, including one hour to get to the airport.

@levenezu Yes, rule of law, not rule of men, will advance the country. The laws vs killing, stealing, rape, etc. shd be upheld, no exception

@Jimparedes Favorite Stevie W song ko ay "massacre". I just called to say I love you, I just called to say how massacre :-)

Jimparedes Jim by Noysky
If you hear a voice within you say you cannot paint, then by all means paint, and that voice will be silenced. ~ Van Gogh

@karadavid that means the drainage is fully clogged. With rainy season until October or even December, it will remain flooded then.

Define apathy? I don't know and I don't care... Work delegation is good bec when things turn sour, it allows you to blame somebody else :-)

Management is like a tree full of monkeys. Those on the top see monkeys below them, those below see a__holes above them :-)

Fr mathcloud: 3 out of every two people are bad at working with fractions… The shortest distance between two points is under construction.

MyMathCloud My Mathematics Cloud by Noysky
No amount of experimentation can ever prove me right, but a single experiment might prove me wrong. Albert Einstein

MyMathCloud My Mathematics Cloud by Noysky
Not everything that counts can be counted. Not everything that can be counted counts. Albert Einstein

MyMathCloud My Mathematics Cloud by Noysky
There are three kinds of people in the world; those who can count and those who can't.

From Plato: When the mind is thinking it is talking to itself.... If particulars are to have meaning, there must be universals.

@kikopangilinan Pwede rin "renewable marriage". Every 3, 4 or 5 yrs, a marriage is automatically annulled. Couples will renew their vows.

@HarvardResearch I saw in wiki abt 200 types of cancer. What used to be seen as non-C are now confirmed as C. Thus, d rise in C cases.

Montberte Steve Cushing by Noysky
God must like stupid people; he makes so many of them. #stevec

MyMathCloud My Mathematics Cloud by Noysky
A statistician can have his head in an oven and his feet in ice, and he will say that on the average he feels fine.
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See also Twitter Notes April-May 2011, January-March 2011.
Last year: December 2010, November 2010, and October 2010.